Renewable Methanol

Contents

Abstract

List of abbreviations, units and chemical formulas

List of figures, tables and images

1 - Introduction: the challenge of reducing oil dependence in an increasingly mobile global society
1.1 - Alternative mobility concepts, EU transport sector greenhouse gas emissions and petroleum import dependency
1.2 - 1G and 2G biofuels, renewable methanol and the need for EU-specific research on its potentials and viability
1.3 - Research questions, analytical approach and description of study structure

2 - Analytical framework and methodology
2.1 - Analysis system boundaries within sustainable energy planning and conceptualisation of the research context
2.2 – Technology and choice awareness in the societal context
2.3 - The Well-to-Wheels (WTW) analysis method

3 - Technical overview of methanol and its production methods
3.1 - Basic chemical properties and current uses of methanol
3.2 - A brief jaunt into the history of alcohol fuels
3.4 - Production methods for renewable methanol
3.4.1 - Current and near-term method for the production of bio-methanol
3.4.1.1 - Production of bio-methanol from upgraded biogas
3.4.2 - Novel mid-term method for the production of bio-methanol
3.4.3 - Long-term method for the production of renewable methanol

4 - Well-to-Wheels analysis
4.1 - Introduction to calculations
4.2 - WTW GHG emissions and efficiencies of renewable methanol pathways
4.2.1 - Current and near-term bio-methanol pathways
4.2.2 - Novel mid-term bio-methanol pathway
4.2.3 - Long-term renewable methanol pathway
4.3 – Comparison of renewable methanol- and comparative fossil- and biofuel pathways
4.3.1 - Comparison of WTW GHG emissions of renewable methanol- and comparative fossil- and biofuel pathways
4.3.2 - Comparison of WTW efficiencies of bio-methanol- and comparative biofuel pathways
4.4 - Conclusions

5 - Socio-economic implications of large-scale renewable methanol technology deployment in the EU
5.1 - Supply and demand for bioenergy resources in view of ambitious sustainability criteria
5.2 - Prospective outlook A: mitigating competing resource demands and creating large-scale employment through bio-methanol
5.3 - Prospective outlook B: Creating employment and improving the EU trade balance by substituting biofuel imports with domestic bio-methanol
5.4 - Conclusions

6 - Conclusions on the core analyses

7 - Political recommendations
7.1 - Implementing the ILUC Proposal
7.2 - Implementing a Pump Act
7.3 - Implementing an Open Fuel Standard

8 - Discussion of results and identification of further research needs
8.1 - Well-to-Wheels analysis
8.2 - Socio-economic implications of large-scale renewable methanol deployment
8.3 - Political recommendations

9 - Sources

Annex 1 - Pathway-specific data inputs for the WTW analysis

Annex 2 - Categorization of biomass potentials in the base study by Elbersen et al. [2012]

Annex 3 - Open Fuel Standard Bill

Abstract

Despite a number of successful European pilot projects and early commercial activities, there remains little eminent acknowledgement of renewable methanol as alternative transport fuel within the current political discourse on future sustainable mobility in the EU. To a large extent this is due to a lack of research findings on the specific potentials of renewable methanol as a viable fuel alternative in the European context. In order to expand the existing knowledge base in this respect, in this Master’s thesis it is assessed how renewable methanol technology can contribute to achieving the three explicit objectives of EU biofuels policy: Greenhouse Gas Savings, Security of Supply and Employment. This research objective is approached by way of quantitative and qualitative analyses which in this form have not yet been undertaken.

With regard to Greenhouse Gas Savings, the potentials of renewable methanol are assessed by way of the Well-to-Wheels (WTW) analysis method for different renewable methanol pathways, as well as comparative fossil- and biofuel pathways. The findings of this analysis demonstrate that renewable methanol technology holds high potentials and favourable prospects: while the EU regulations on minimum greenhouse gas emissions savings of biofuels will become gradually more stringent in the coming years, the investigated renewable methanol fuel pathways not only generally comply with these regulations but far surpass them. In some cases, emissions savings of more than 90% compared to both fossil fuels and first generation biofuels can be achieved.

In view of the policy objective of Security of Supply, the feedstock-flexibility of renewable methanol technology is found to be a fundamental prospect since it enables the utilisation of wastes and other feedstocks which so far have been under-utilised in the production of biofuels. An evaluation of sectorial supply and demand projections for bioenergy-resources in 2020 demonstrates that feedstock availability is not expected to present a barrier to introducing and deploying renewable methanol technology on a large scale in the EU. Moreover, EU trade balance effects are modelled which promise a high potential for monetary savings if the currently projected biofuel imports to the EU in 2020 were to be substituted with domestically produced renewable methanol.

With regard to the Employment objective, the potential job creation effects of deploying renewable methanol technology in the EU are assessed , indicating significant potentials: two prospective outlooks on employment creation are modelled, in one case suggesting that up to 150,000 new jobs could be created in 2020 if domestically produced renewable methanol were to substitute the projected biofuel imports to the EU.

Based on the findings of these core analyses, political recommendations are formulated and discussed, aiming to offer policy-makers indications on how to activate the deployment of renewable methanol technology in the EU, and thereby optimising sustainable energy planning in the European transport sector in general.

List of abbreviations, units and chemical formulas

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List of figures, tables and images

Figures

Figure 1.1 World oil consumption in 2010, by sector (Mtoe)

Figure 1.2 Global final energy consumption in the transport sector in 2010, by mode (Mtoe)

Figure 1.3 World liquid fuel consumption 2008–2035, by sector (MB/day)

Figure 1.4 World liquid fuel consumption 1990–2035, by region (MB/day)

Figure 1.5 EU GHG emissions 1990-2011, by sector (Mt CO2e/a)

Figure 1.6 Shares of GHG emissions in EU Transport sector 2009, by mode (%)

Figure 1.7 Final energy consumption in the EU 2000-2010, by sector (Mtoe/a)

Figure 1.8 Development of biofuels production in the EU 1990-2010 (ktoe/a)

Figure 1.9 Development of biofuels shares in EU transport fuel consumption 1990-2010 (%)

Figure 1.10 Illustration of study structure

Figure 2.1 Conceptualisation of the research context

Figure 2.2 Constituents of technology

Figure 2.3 System delineation between WTW-analysis and LCA

Figure 2.4 WTW-analysis steps

Figure 2.5 Estimations on ILUC-related GHG emissions by different authors

Figure 3.1 Transport fuel applications of methanol

Figure 3.2 Relation between RON, CR and SI engine efficiency

Figure 3.3 Simplified illustration of biomass-to-methanol process via gasification and subsequent synthesis

Figure 3.4 Methanol synthesis based on biogas temporarily stored in the natural gas network

Figure 3.5 Novel concept of bio-methanol production, integrating SOEC

Figure 4.1 WTW GHG emissions of current and near term bio-methanol pathways (g CO2e/MJ)

Figure 4.2 WTW efficiency ranges of current and near term bio-methanol pathways (%)

Figure 4.3 WTW GHG emissions of novel medium-term pathway vs. current and near term pathway (g CO2e/MJ)

Figure 4.4 WTW efficiency range of novel medium-term pathway vs. current and near term pathway (%)

Figure 4.5 WTW GHG emissions of long-term renewable methanol pathway vs. near- and medium-term bio-methanol pathways (g CO2e/MJ)

Figure 4.6 WTW GHG emissions of renewable methanol- and comparative fossil- and biofuel pathways (g CO2e/MJ)

Figure 4.7 WTW GHG emissions of different ethanol pathways (g CO2e/MJ)

Figure 4.8 WTW GHG emissions of renewable methanol- and comparative biofuel pathways in view of FQD emission savings requirements for biofuels (g CO2e/MJ)

Figure 4.9 WTW fossil intensity of all investigated pathways (MJ(fossil)/km)

Figure 5.1 Projections on the renewable energy supply in the EU27, based on stipulations in national renewable energy action plans of member states (EJ/a)

Figure 5.2 Projected demand for biofuels in the EU up to 2020, based on stipulations in national renewable energy action plans of member states (Mtoe)

Figure 5.3 Evolution of world prices of biodiesel and ethanol over a time period until 2021 (USD/hl)

Figure 7.1 Conceptualisation of complementary political measures to activate the deployment of renewable methanol technology in the EU

Tables

Table 1.1 Development of EU import dependency on petroleum fuels 2000-2010 (%)

Table 3.1 Properties of methanol

Table 3.2 Near-term method vs. novel concept of bio-methanol production: energy efficiency and output balance

Table 4.1 WTW GHG emissions of current and near term bio-methanol pathways (g CO2e/MJ)

Table 4.2 WTW efficiencies of current and near term bio-methanol pathways (%)

Table 4.3 WTW GHG emissions of novel medium-term pathway vs. current and near term pathway (g CO2e/MJ)

Table 4.4 WTW efficiency range of novel medium-term pathway vs. current and near term pathway (%)

Table 4.5 WTW GHG emissions of long-term renewable methanol pathway vs. near- & medium-term bio-methanol pathways (g CO2e/MJ)

Table 4.6 Pathway-specific GHG reductions of renewable methanol as against comparative fuel pathways (%)

Table 4.7 WTW EROEI performance of bio-methanol pathways vs. comparative biofuel pathways (%)

Table 5.1 EU biomass potentials for energy per aggregated group and scenario in 2020 and 2030 (Mtoe)

Table 5.2 Available biomass potential per price class and per sustainability requirements in 2020 and 2030 (Mtoe)

Table 5.3 Estimated job creation per exemplary bio-methanol plant

Table 5.4 Prospective outlook A: job creation by supplying 100% of EU biofuels demand in 2020 through domestic bio-methanol: key assumptions and results

Table 5.5 Prospective outlook B: job creation by substituting the projected imports of biofuels to the EU in 2020 through domestic bio-methanol: key assumptions and results

Table 5.6 Prospective outlook B: EU trade balance effect in 2020 by substituting all biofuel imports with domestic bio-methanol

Table 7.1 Possible time plan for the gradual implementation of a Pump Act in the EU

Table 7.2 Possible time plan for the implementation of an Open Fuel Standard in the EU

Table Annex 1 Input values for the calculation of GHG emissions and efficiencies in the near-term bio-methanol pathway based on crude glycerine

Table Annex 2 Input values for the calculation of GHG emissions and efficiencies in the near-term bio-methanol pathway based on waste wood via black liquor

Table Annex 3 Input values for the calculation of GHG emissions and efficiencies in the near-term bio-methanol pathway based on farmed wood

Table Annex 4 Input values for the calculation of GHG emissions and efficiencies in the near-term bio-methanol pathway based on waste wood

Table Annex 5 Input values for the calculation of GHG emissions and efficiencies in the near-term bio-methanol pathway based on biogas

Table Annex 6 Input values for the calculation of GHG emissions and efficiencies in the medium-term bio-methanol pathway based on farmed wood

Table Annex 7 Input values for the calculation of GHG emissions and efficiencies in the long-term renewable methanol pathway based carbon emissions recycling

Table Annex 8 Input values for the calculation of transport emissions and efficiencies for the inner-EU distribution of methanol fuel

Table Annex 9 Input values for the calculation of GHG emissions and efficiencies in the comparative fossil methanol pathway

Table Annex 10 Input values for the calculation of GHG emissions and efficiencies in the comparative gasoline pathway

Table Annex 11 Input values for the calculation of GHG emissions and efficiencies in the comparative diesel pathway

Table Annex 12 Input values for the calculation of GHG emissions and efficiencies in the comparative ethanol pathway

Table Annex 13 Input values for the calculation of GHG emissions and efficiencies in the comparative biodiesel pathway

Table Annex 14 Categorization of biomass potentials in the base study by Elbersen et al. [2012]

Images

Image 3.1 Henry Ford and Thomas Edison driving in an ethanol-fuelled Ford Model T in 1917

Image 3.2 Mercedes-Benz T80 in 1940, fuelled by high-methanol blend

1 - Introduction: the challenge of reducing oil dependence in an increasingly mobile global society

The global depletion of natural resources, ecological degradation, and the threatening implications of climate change are critical pressures which have led to comprehensive national and international efforts to begin the transformation towards energy systems based on renewable resources. This implies all-encompassing structural reforms and poses particularly formidable challenges in the transport sector, which accounts for more than half of global oil consumption today and relies almost completely on fossil fuels (see Figures 1.1 and 1.2) [IEA 2012b; WEC 2011].

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Figure 1.1 - Sectorial shares in world oil consumption in 2010 (%) [own illustration, based on IEA 2012b]

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Figure 1.2 - Modal shares of world energy consumption for transport in 2010 (%) [own illustration, based on WEC 2011]

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Figure 1.3 – World liquid fuel consumption (MB/day) 2008–2035, by sector [own illustration, based on EIA 2013]

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Figure 1.4 – World liquid fuel consumption (MB/day) 1990–2035, by region [own illustration, based on EIA 2013]

In what follows, the background and further context of this research are described. Section 1.1 introduces the reader to alternative and established mobility concepts, limits the research focus to the European Union (EU) transport sector and demonstrates its increasing greenhouse gas (GHG) emissions as well as its large dependency on petroleum imports. Section 1.2 describes the present development of biofuels in the EU and points towards advanced biofuels as integral components of a sustainable mobility future. Moreover, it puts focus on renewable methanol as the core topic of investigation and describes the need for specific research concerned with its potentials and prospects in a European context. In section 1.3, the concrete research questions of this study are particularised, and the analytical structure of the study is described and illustrated.

1.1 - Alternative mobility concepts, EU transport sector greenhouse gas emissions and petroleum import dependency

Over the years, numerous scientific and non-scientific publications have emphasised different technological concepts in their outlooks, roadmaps and recommendations for future transportation. In equal measure, the medial discourse has produced different technologies as being feasible mobility concepts of the future. This multitude of highlighted technological approaches clearly shows that there is no single and outstanding road towards sustainable transportation, but that future mobility will depend on a mix of technological concepts and strategies which are currently being pursued.

Two predominant future mobility concepts which have been undergoing immense research and development activities in the past few years are hydrogen-mobility and electric mobility concepts. Advocated by different groups of politicians, scientists, and industry stakeholders, it is likely that these concepts will play increasingly important roles in the future. However, a global transport sector fully based on hydrogen or renewable electricity in fact remains a distant future scenario. Technological immaturity and often poor economic feasibility remain strong barriers to be overcome. Although for road transportation, battery-electric vehicles (BEV) have recently shown promising progress in this regard and are increasingly deployed, hydrogen-based fuel cell vehicles (FCV), which for years had been deemed by many as the sustainable transport technology per se, continue to struggle with their need for impractical technical infrastructure and, in the foreseeable future, cannot be offered at reasonable cost [Winterkorn 2013; Olah et al. 2009].

Against this backdrop it remains most likely that for decades to come, the majority of land-, sea-, and air-based vehicles will continue to rely on internal combustion engines (ICE) which today are used in more than 99% of all transport applications, thereby relying on relatively cheap and abundant materials such as iron. Importantly, besides being a well-established propulsion technology, the ICE can rely on a long-existent sophisticated transport and distribution infrastructure for liquid fuels which are stored and handled relatively easily.

Consequently, even as BEV, FCV or miscellaneous hybrid systems increasingly penetrate the land-based transportation sector, maximum efficiency gains and the use of alternative fuels in ICE technology pose the largest realistic potential for the transport sector to achieve global-scale environmental improvements and increased independence from oil in in the medium-term.

Due to the global political and societal goal of reducing GHG emissions [UN 1992], legislation is accordingly being constantly put into place in many countries across all continents. More or less ambitious GHG emission reduction targets go hand in hand with new transport sector-specific regulations such as vehicle emissions-limits or alternative fuel blending requirements.

The study at hand focusses on the situation in the EU where, while GHG emissions in other sectors have generally been falling, transport-related GHG emissions have increased by more than 30% since 1990 [EC 2013c]. This trend is illustrated in Figure 1.5. Figure 1.6 shows that road-based transport accounts for by far the largest share of all GHG emissions from the transport sector.

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Figure 1.6 – Shares of GHG emissions in EU Transport sector 2009 (%), by mode [adapted from EEA 2012]

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Figure 1.5 – EU GHG emissions 1990-2011 (Mt CO2e/a), by sector [adapted from EEA 2012]

Against this backdrop, the EU member states are obligated through the Renewable Energy Directive (RED) [EU 2009a] to assure that by the year 2020 at least 10% of their respective transport energy consumption is covered by renewables. Achieving this objective corresponds to replacing an estimated 50 billion litres of fossil transportation fuels in 2020 [Bentsen and Felby 2012].

Besides reducing GHG emissions, these policies are also to be seen as part of the EU strategy to reduce its heavy dependence on petroleum imports: at 32% in 2010, transportation accounted for the largest share of final energy consumption in the EU, ahead of the residential and industrial sectors (see Figure 1.7). Roughly 94% of this transport consumption was based on petroleum of which roughly 84% was imported [EUROSTAT 2012], a continuing trend over the last decade (see Table 1.1). In 2011, petroleum imports represented a daily bill of up to 1 billion € and brought about a significant EU trade balance deficit of roughly 2.5% of GDP [EC 2013a]. Furthermore, over the past four years price shocks have caused additional annual costs of 50 billion € [EC 2013a].

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Figure 1.7 - Final energy consumption (Mtoe/a) in the EU 2000-2010, by sector [EUROSTAT 2012]

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Table 1.1 – Development of EU import dependency on petroleum fuels

1.2 - 1G and 2G biofuels, renewable methanol and the need for EU-specific research on its potentials and viability

As indicated above, alternative renewable fuels, in particular liquid biofuels, have been designated to play a central role in mitigating GHG and reducing the EU’s dependency on petroleum imports. Since being promoted through various political measures such as blending requirements or according national subsidization and taxing schemes, their production has grown continuously, reaching 13 Mtoe in 2010, a share of 4.4% of total transport fuel consumption in the EU (see Figures 1.8 and 1.9^[1] ). As such, biodiesel fuels constitute roughly 75%, while other biofuels, particularly ethanol, account for the remainder [EU 2012]. Mostly, these fuels are blended with conventional fossil fuels in order to be compatible with the present vehicle and fuel infrastructure. Higher or pure blends may require minor adaptations [EC 2013a].

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Figure 1.9 – Development of biofuels production in the EU (ktoe/a) 1990-2010 [EU 2012]1

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Figure 1.8 – Development of biofuels shares (%) in EU transport fuel consumption 1990-2010 [EU 2012]1

The total generation of GHG savings through biofuels in the EU in 2010 is estimated at 25.5 Mt of CO2e [EC 2013a]. This estimation, however, does not include the effects of associated agricultural intensification and indirect land use changes (ILUC). Accurately quantifying GHG emissions of these effects is a difficult undertaking which entails a high degree of uncertainty. However, it is likely that these effects significantly reduce the estimated GHG savings proclaimed so far.

In recent years, an intensive scientific and political debate on how to deal with the implications of ILUC has taken off [Elbersen et al. 2012; EC 2012b]. Moreover, the ongoing discourse on limitations in land and resources for the production of biofuels, and on their negative impacts on biodiversity, ecosystem services and food prices [Ecofys 2012; CIFOR 2012], has led to a shift in public attitude and political perspective towards further growth of so-called first-generation (1G) biofuels which are essentially based on food crops. In order to minimize these negative impacts, advanced, so-called second-generation (2G), biofuels which are produced from wastes and residues, or from cellulosic non-food materials and lignocellulosic materials, are being increasingly promoted by EU policy makers [EC 2012b; EC 2013a]. However, mostly they stand in early stages of commercial development and are not yet produced on scales large enough to meet the EU blending quotas for renewable transport fuels [EU 2009a; EU 2009b].

In view of the apparent negative implications and according problematic outlook for 1G biofuels, research and development in the field of advanced 2G biofuels is of great importance in order to pave the road towards a sustainable mobility future. Thereby, the explicit objectives of EU biofuels policy remain [EC 2008]:

- Greenhouse Gas Savings: Whilst GHG emissions in the EU are otherwise declining, they continue to grow in the transport sector. Biofuels are a vital component to mitigating this development and to establishing sustainable mobility and a low-carbon economy in the coming decades.
- Security of Supply: The transport sector’s near-complete dependence on imported petroleum products makes the EU economy vulnerable to geopolitical instability and oil price volatility. This implies major risks for the EU economy and inner security. Biofuels are an important component to reduce this foreign dependence.
- Employment: Biofuels open up new domestic and foreign markets and create jobs along their entire value chain. This can be of significant economic benefit, particularly in rural and underdeveloped areas of the EU.

In light of these explicit objectives of EU biofuels policy and the strong need for research in the field of advanced 2G biofuels, the study at hand highlights renewable methanol, which recently has been attracting increasing scientific attention [Olah et al. 2009; Bromberg & Cheng 2010; IRENA 2013]. Existing research on renewable methanol has been undertaken selectively and at scattered geographic ends, indicating encouraging prospects in terms of achievable GHG savings and its potential for energy storage and as a compatible transport fuel alternative in future energy systems with high shares of renewable electricity [Lund et al. 2011; Mortensgaard et al. 2011].

However, despite successful European pilot projects and early commercial activities in this field, there remains little eminent acknowledgement of renewable methanol as an alternative transport fuel within the current political and public discourse on future sustainable mobility in the EU [EC 2013c; IRENA 2013; CIFOR 2012]. To a large extent this is due to a lack of research findings on the specific potentials of renewable methanol as a viable fuel alternative in the European context.

Thus, in light of the desired sustainable development in the transport sector, there exists a clear need for research which assesses the suitability and applicability of renewable methanol fuel in the concrete case of the EU. In order to expand the existing knowledge base in this respect, this study’s main aim is to assess how renewable methanol technology can contribute to achieving the three explicit objectives of EU biofuels policy: Greenhouse Gas Savings, Security of Supply and Employment. This research objective is approached by way of quantitative and qualitative analyses which in this form have not yet been undertaken.

1.3 - Research questions, analytical approach and description of study structure

The elaborations on the need for EU-specific research on renewable methanol in the above section give rise to the formulation of the following main research question (RQ) which is to be addressed in the course of the analyses of the study at hand:

- Main RQ: Which potentials does renewable methanol technology possess in regard to the EU biofuels-policy objectives of Greenhouse Gas Savings, Security of Supply and Employment?

In order to investigate these issues in a well-structured, successive, and logically sound manner, this study is divided into a number of chapters with according objectives for knowledge creation:

After describing the general analytical framework and important methodological issues in chapter 2, chapter 3 gives a comprehensive overview on various technical aspects of renewable methanol, its chemical and physical properties as transport fuel in ICE, and on different concepts for its production.

Chapter 4 assesses the potentials of renewable methanol with regard to the EU biofuels-policy objective of Greenhouse Gas Savings. Thereby, a comprehensive Well-to-Wheels (WTW) analysis of different renewable methanol pathways and comparative fossil and 1G biofuel pathways produces new results on the overall GHG emissions performance of renewable methanol fuel.

Chapter 5 investigates the potentials of renewable methanol with regard to the other two explicit EU biofuels-policy objectives Security of Supply and Employment. To do so, a fundamental analysis of the availability of bio-resources for renewable methanol production is undertaken. Based on this analysis, potential employment effects of large-scale implementation of renewable methanol technology in the EU are projected, as are the potential effects on the EU trade balance.

Within the scope of these analyses, it is also discussed how renewable methanol technology provides or contributes to two underlying qualitative biofuel-requirements which are not necessarily implied in the explicit objectives of EU biofuels policy, but which the author finds to be of imperative significance. These are, firstly, the highest possible efficiency in the utilisation of bio-resources and, secondly, the integratability in future energy systems with a high share of renewable electricity.

Generally and unless stated otherwise, the elaborations, assumptions and projections in this study are geared towards the potentials of renewable methanol technology in the EU in a temporal frame until 2020.

Chapter 6 summarizes the findings of the proceeding analyses and provides the base for the formulation of according political proposals in chapter 7. These political proposals have the aim of giving policy-makers indications and tentative recommendations for how to concretely make use of the identified potentials of renewable methanol with regard to sustainable energy planning in the EU transport sector. Thereby, the following secondary RQ is addressed:

- Secondary RQ: Which political measures could advance the implementation of renewable methanol as a sustainable energy technology in the EU?

The described structure of this study is illustrated in Figure 1.10:

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Figure 1.10 - Illustration of study structure

2 - Analytical framework and methodology

This chapter defines the author’s theoretical and analytical approach towards investigating the potentials of renewable methanol in view of the objectives of EU biofuels policy. Section 2.1 conceptualises and integrates the objectives of this study from a sustainable energy planning perspective. Section 2.2 defines renewable methanol as a technological concept with complex societal implications going beyond its technical dimension. Section 2.3 describes the WTW-analysis method which is applied in order to assess the potentials of renewable methanol technology with regard to GHG savings.

2.1 - Analysis system boundaries within sustainable energy planning and conceptualisation of the research context

Figure 2.1 illustrates how the research focus of this study is embedded in a larger context of interrelated sub-systems within the energy system. These interrelated sub-systems are the heat, electricity and transport sectors. Two fundamental domains underlie each of the sub-systems: the technical domain and the institutional domain. Sustainable energy planning must relate these domains in order to produce meaningful and applicable results which can optimize societal benefits by the use of environmentally and economically feasible technologies and strategic policies.

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Figure 2.1 - Conceptualisation of the research context

In spite of the explicit focus on renewable methanol in this study, the following considerations are essential from a holistic sustainable energy planning perspective.

While it is indeed possible to perform experiments or conduct specific analyses within only one of the two fundamental domains, the meaningfulness and applicability of the produced results will certainly be limited if the other domain is not taken into consideration. For example, a strictly technical optimisation of a mechanical device is of no value in itself. Only through certain mechanisms in the institutional domain can the achieved technical optimisation achieve any greater value for society.

In similar measure, experiments and analyses which take place within only one of the sub-systems must take into account the existing interrelations with other sub-systems. Only then can eventual synergies between these sub-systems be promoted and eventual conflicts be prevented or mitigated. For example, a technical innovation which is achieved in the electricity sector is likely to affect the transport and heat sectors as well. Such effects could be of a primarily technical nature, thereby affecting primarily the technical domains of both the transportation and heat sectors. However, due to the inextricable interrelation between the fundamental domains, there will certainly be secondary effects in their institutional domains as well.

Consequently, in order to produce meaningful results, the analyses in this study touch on both fundamental domains: while the WTW-analysis in chapter 4 can be seen to take place mainly within the technical domain, its results become meaningful only by further analysis of their implications for sustainable development and in light of the EU biofuels objectives. Similarly, the analysis on the availability of bio-resources in chapter 5 can in itself be ascribed primarily to the technical domain but it is also of fundamental and decisive importance to the subsequent analysis of the potentials of renewable methanol in regard to Security of Supply and Employment. Finally, only a holistic reflection on the produced results and their reciprocal implications can provide an adequate argumentative base for sound political recommendations.

2.2 – Technology and choice awareness in the societal context

In spite of the fact that it can be utilised in a multitude of technical applications, in accordance with the conceptualisation of Müller [2003], renewable methanol in itself is regarded as technology hereinafter. Thereby, technology goes beyond a purely technical dimension and is accredited with complex organisational and economic implications as well. Fittingly, Figure 2.1 illustrates technology as linking the technical and the institutional domains.

According to Müller [2003], “Technology is one of the means by which mankind reproduces and expands its living conditions. Technology embraces a combination of four constituents: Technique, Knowledge, Organisation and Product. (…) A qualitative change in any of the components will eventually result in supplementary, compensatory and/or retaliatory change in the others.”

Thereby, Technique refers to the necessary physical components of a technology, for instance energy inputs and raw materials. Knowledge refers to the theoretical and practical understanding that is essential to creating and innovating technology. Organisation refers to the managerial and coordinative dimension which is of importance when implementing the technology in society . The Product is the result if all these constituents are combined. It has a practical value and enters a consumption process. Hvelplund [2005] adds Profit as a fifth constituent, referring to the economic benefits which can be attained by utilising the technology.

Throughout the analyses in this study, each of the constituents of renewable methanol technology is addressed in some respect. For example, the Technique constituent is addressed in the assessment of different renewable methanol production pathways in the WTW-analysis as well as in the analysis on the availability of bio-resources in the EU. The Knowledge constituent is addressed in the elaborations on the innovative development of future methods for renewable methanol production in energy systems with high shares of renewables electricity. The Product and Profit constituents are mainly addressed in the socio-economic assessments of employment and trade balance effects, while the Organisation constituent is addressed in the concluding formulation of tentative political recommendations for EU policy makers.

Figure 2.2 illustrates Müller’s concept of technology [2003] and shows that all constituents interrelate and cannot be completely isolated from one another. This also refers back to the interrelatedness of the technical and institutional domains, described in section 2.1.

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This encompassing conceptualisation clearly depicts the multitude of technical, social and economic implications of technology in a societal context. In light of the general objective of this study, which is to investigate a technology that is not yet established in society, it thereby also re-emphasises the aforementioned need for specific research which assesses the suitability and applicability of renewable methanol fuel in the concrete case of the EU.

In this context it must be noted that it is in fact of fundamental importance to raise societal awareness to the choice of alternative technological options which might imply environmental, social and economic advantages [Lund 2008]. Choosing such options would often imply changes in several, or all, of the five constituents of an existing technological set-up. Following Hvelplund [2012], such profound structural changes can be described as radical technological changes and will most often challenge well-established organisations, posing a threat to their assets, profits or positions. Consequently, they will not promote these alternatives or advocate substantial changes themselves, despite their potentially advantageous social and environmental implications. In fact, such alternatives will often be actively opposed or even eliminated before having gained sufficient attention or approval in public discourse and by political decision-makers.

Thus, by producing new knowledge concerning the potentials of renewable methanol technology with regard to the EU biofuels-policy objectives of Greenhouse Gas Savings, Security of Supply and Employment, the author explicitly aims to raise choice awareness and contribute to the creation of choice at a societal level.

2.3 - The Well-to-Wheels (WTW) analysis method

The WTW analysis method is used in chapter 4 of this study to assess the GHG emissions and overall energy efficiency of different renewable methanol pathways and of a number of comparative fossil- and biofuel pathways. As such, the calculations and produced outcomes incorporate all energy inputs and emissions which take place along the pathway of a fuel.

A pathway covers the entire life chain of a fuel, beginning with the extraction of raw materials and ending with the conversion of the final fuel to kinetic energy in an ICE-based car with an emissions-standard of 95 gCO2/km, thereby complying with recent EU regulations on GHG emissions from new passenger cars in 2020 [EC 2012a]. While the method can be used to produce results on local emissions of pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), or sulfur oxides (SOx), in view of the research objectives of this study, the WTW-analysis at hand focusses on global GHG emissions as well as on the overall energy efficiency of the investigated fuel pathways.

In general terms, a WTW-analysis can be regarded as a specific life cycle assessment (LCA) of transport fuels. Consequently it is dissociated from a full LCA, or cradle-to-grave analysis, which is used to assess the environmental impact of transport vehicles themselves rather than the impact of the fuel in use [Braungart & McDonough 2002]. An LCA/cradle-to-grave analysis would therefore include additional parameters which are not included in a WTW analysis, for instance the consumption of resources and emissions of GHG in the construction and disposal of vehicles (see Figure 2.3).

Moreover, the WTW analysis at hand does not regard energy inputs and emissions outputs for the construction of required fuel infrastructure such as refineries, pipelines or ships. On the one hand, this is due to the lack and ambiguity of such data, and on the other hand, the impact of these additional inputs on the overall performance of the fuel pathways is assumed to be rather small over time [CONCAWE 2011b]. However, in view of the research objectives and system boundaries of this study, the chosen WTW-analysis method constitutes a purposeful approach.

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Methodologically, the WTW-analysis in this study is based on the methodology described in Annex V of the RED [EU 2009a], as it allocates all energy inputs and emissions outputs along a fuel pathway to one of four discrete steps. This allows for a technology-neutral comparison of very different fuel pathways and products.

The first three discrete steps, the so-called Well-to-Tank (WTT) chain, represent the combination of efforts necessary to extract a raw material, convert it into a final fuel product, and deliver it to the vehicle. The fourth and final, so-called Tank-to-Wheel (TTW) step accounts for the terminal conversion of the chemical energy bound in the fuel to kinetic energy in the ICE. Thereby, the WTW-steps consist of a complex collocation of energy inputs and GHG emissions outputs.

In the WTW-analysis at hand, the first step of a fuel pathway accounts for all efforts which are undertaken in order to extract or harvest primary energy carriers and, in some pathways, the conditioning of the primary energy carriers before they are transported to the fuel production site. Depending on the pathway, this transportation is undertaken by ships, trucks, or via pipeline.

The second step accounts for all efforts associated with the processing and transformation of the primary energy carriers, or raw materials, to produce the final fuel product. Depending on the pathway, this can include refining processes, a gasification process, or other methods.

The third step accounts for all efforts in storing, trucking and shipping the final fuel product over an assumed weighted-average distance to refueling stations within the EU.

The final step accounts for the fuel combustion in an ICE-based car with an emissions-standard of 95 gCO2/km. As such, depending on the chemical properties of the investigated fuel products, they produce varying energy efficiencies and GHG emissions.

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The input values for the undertaken calculations on GHG emissions (produced in g CO2eq/MJ^[2] ) and energy efficiency (produced in %) mainly stem from the report Well-to-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Version 3c and its appendices [CONCAWE 2011a-c], prepared and issued by the Joint Research Centre of the European Commission’s Institute for Energy and Transport in collaboration with CONCAWE, the oil companies' European association for environment, health and safety in refining and distribution. This report constitutes a body of 11 documents and 594 pages in its current third updated version and is currently the most broadly accepted scientific source of reference data for assessing energy flows and emissions of fuel pathways in the European context.

All outputs which are found in this body of documents are calculated by a software model which refers to an extensive database of energy and emissions factors for all efforts associated with WTT chains of fuels. Besides additional input from a number of scientific literature sources, a number of assumptions are also made by the author due to the lack of required data. These assumptions are based on related data in scientific literature and on personal communications with experts in the respective fields.

The investigated fuel pathways contain a high degree of complexity, depending on a wide range of inputs and competent assumptions. For example, primary inputs include the process energy required for fuel production and refining processes while secondary inputs include, for example, the energy inputs required for the production of nitrogen fertilizers which are used in the farming of biofuel feedstocks. Naturally, such complexity goes along with an irremovable degree of uncertainty in the produced results.

Adding to this uncertainty, though potential uses of by-products of fuel production processes are accounted for, the model cannot always represent the concrete energetic utilization of these by-products in the real world. For example, in the investigated 1G ethanol pathway, excess bagasse from sugarcane cultivation is accounted to provide process heat and electricity in the ethanol production step although in reality it might not actually be utilized in this way. Generally, the use of by-products for the generation of process energy can have a significant impact on the energy and GHG balances of a fuel pathway and, consequently, on the produced outputs of the WTW-model. In spite of this, in the study at hand the system boundaries can only be extended to account for the most plausible and common energetic utilization of by-products. However, although these parameters contain uncertainty and can only be partially grasped, this does not affect the essential validity and significance of the final results. This is confirmed by including a 10%-uncertainty factor in the calculation and representation of the final outputs.

Although it is certain that GHG emissions can be attributed to changes in land-use and carbon stocks, and it is highly likely that these emissions are of significance to the GHG performance particularly of 1G biofuel pathways, ILUC-related GHG emissions are excluded from the WTW-model in this study and only mentioned in passing. This is because the nature and magnitude of land-use changes are currently still subject to a scientific debate which has not yet produced widely accepted reference data [Ecofys 2010; Searchinger 2010; Malins 2012]. Similarly, GHG absorptions could be credited if previously degraded land is restored for the cultivation of bioenergy carriers. However, due to the same ambiguity of the available data base for these emissions parameters, they are also disregarded in the calculations of this analysis.

By way of illustration, this high degree of variation between scientific evaluations of ILUC-related GHG emissions is captured by Ecofys [2010] who have conducted a comparative assessment of according studies:

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Despite these issues, the WTW-analysis method allows for an encompassing analysis of the Greenhouse Gas Savings potential of renewable methanol technology in view of the research objectives of this study. Moreover, the produced results concerning the overall energy efficiency of the investigated renewable methanol and comparative biofuel pathways, gives clear indication of how efficiently they utilize biomass resources. This is of particular significance in view of the further assessment of renewable methanol technology with regard to Security of Supply.

3 - Technical overview of methanol and its production methods

This chapter briefly describes the most important chemical properties and current uses of methanol in section 3.1. Section 3.2 gives an abstract of the historical development of alcohol transport fuels in general. In section 3.3 the technical properties of methanol as transport fuel in ICE are described. Section 3.4 highlights different renewable methanol production processes, categorized with regard to their demand for biomass feedstock and their technological maturity. The elaborations in this chapter thereby provide a necessary knowledge base for the analyses in the later chapters.

3.1 - Basic chemical properties and current uses of methanol

Methanol is the most basic of all alcohols, containing only one carbon atom. Under standard conditions for temperature and pressure, it is a colourless, flammable and highly volatile liquid which mixes with many organic solvents and in any ratio with water. It burns with a faint blue, barely visible flame to produce carbon dioxide and water [METHANEX 2006]. Often it is also referred to as wood alcohol because it was first produced through the pyrolysis of wood. Moreover, it should be noted at this point that renewable methanol is chemically identical with fossil-based methanol. Table 3.1 depicts its most important basic chemical properties:

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Table 3.1: Properties of methanol [Olah et al. 2009; MI 2013a]

For many decades methanol has been an important chemical feedstock in a wide range of industrial applications. Today, the largest share of global production is used in the production of formaldehyde, acetic acid, solvents, anti-freeze, plastics and paints [MI 2013a].

In 2012, global demand stood at more than 61 Mt and it is expected to more than double to 137 Mt by 2022 [IHS 2013]. Large-scale industrial production is based almost entirely on fossil feedstock, particularly natural gas with a share of roughly 80% [MI 2013c]. However, increase in global demand is largely driven by China which possesses large coal large reserves and is rapidly expanding its production capacity. Although the methanol demand for chemical industrial applications is still increasing, the methanol demand for transport applications is currently the fastest growing market segment and has risen from 4% of global production in 2005 to 23% in 2010 [MMSA 2012]. Particularly in China, where coal-based methanol was appointed a strategic fuel in 2007, this growth has led to more than half a billion Chinese passengers being transported by vehicles running on methanol-blends today (METHANEX 2013).

3.2 - A brief jaunt into the history of alcohol fuels

In the context of this research, it should be mentioned that alcohols have been used as transport fuels since the early years of automotive development. Already in the late 19th century, ethanol-powered ICE had replaced steam engines in European farming machinery and soon after, ethanol was the preferred fuel option in early automobiles by Otto and Benz [Gustafson 2013]. It was easily distilled from fermented sugars, and European countries, with little or no oil resources, were particularly keen to produce ethanol fuel in their domestic agricultural sectors.

Some years later, when mass production of automobiles was first pioneered by Henry Ford in the United States, the engines were still designed to run on both alcohol fuels and gasoline. At the time, regular competitions between alcohol-fuelled and gasoline-fuelled vehicles were held in order to determine which proved the best performance. Soon, however, ethanol was no longer economically competitive due to the increasing availability of cheap gasoline, particularly in the United States, which possessed large petroleum resources. Moreover, the powerful Standard Oil Trust actively opposed the further development and deployment of alcohol fuels [Olah et al. 2009]. Consequently, developers started to favour and optimize engines running solely on gasoline.

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Research efforts by German company BASF in the first quarter of the twentieth century resulted in the ability to commercially produce synthetic methanol from coal. Soon after, German coal-based methanol production was strongly intensified, both in an effort to achieve energy independence and due to military considerations. While methanol fuel in fact played a major role in Europe until the end of the Second World War, subsequently the interest in alcohol fuels decreased as petroleum resources were readily and cheaply available [Olah et al. 2009].

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It was not until the oil crises in the 1970s that the interest in alcohol fuels grew again. Methanol was proposed as an alternative fuel in the United States by Reed and Lerner [1973], who described a number of technical advantages of methanol fuel and emphasised its potential to replace gasoline in the U.S. transport sector. Moreover, extensive test series carried out by Volkswagen in Germany from 1975 onwards, and by Ford and other car manufacturers in California in the 1990s, produced positive results on the engine performance, pollution reduction and fuel economy of methanol fuel [Olah et al. 2009; Ward & Teague 1996]. Although low oil prices eventually ended greater plans for large-scale methanol fuel deployment, between 1993-1998 Ford did in fact sell an M85^[3] Taurus model at the same price as its gasoline version, and at its peak more than 20,000 of these cars were driving in the U.S. [Ford 2013; P. Koustrup, personal communication].

Ethanol on the other hand was strongly promoted in Brazil where a dedicated national programme ProAlcool strongly promoted the cultivation of sugarcane for ethanol fuel. This eventually resulted in millions of Brazilian vehicles fuelled by domestic ethanol [Coelho et al. 1999]. Eventually, the intermediate comeback of cheap petroleum and the discovery of domestic oil resources off the Brazilian coast stifled the ethanol market. However, while ethanol production stood below 1 billion l in 1975, it stood at 26 billion l in 2009 [Bentsen and Felby 2012] and so-called flex-fuel vehicles (FFV), which are able to run on mixtures of gasoline and alcohol, continue to dominate the Brazilian market today.

In sum, throughout the decades, the development of automotive alcohol fuels has been closely linked to the development of petroleum prices and thereby has undergone phases of growth and of stagnation. In recent years, the global demand for alcohol fuels has increased again, particularly for ethanol in the United States and Europe, and for coal-based methanol in China.

3.3 - Characteristics of methanol as transport fuel

Methanol can be used in various transport fuel applications. Currently it is most widely used for the production of methyl tertiary butyl ether (MTBE) and tert-amyl methyl ether (TAME), common oxygenating gasoline additives which are used to increase engine performance through improved fuel combustion efficiency. These so-called octane-boosters replaced other lead-based additives, which were generally phased out in the early 1990s. The fastest growing transport application however is its use as a blended component in conventional commercially available gasoline fuel. Moreover, methanol and its derivate dimethyl ether (DME) are used as a diesel substitute in compression ignition (CI) engines. In view of mobility concepts based on propulsion technologies other than the ICE, methanol furthermore holds potential as a hydrogen source for FCV.

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Figure 3.1 – Transport fuel applications of methanol

In the following, the characteristics of methanol fuel are further described. The focus lies on its use as neat fuel in gasoline spark ignition (SI) engines, since this is its application which is investigated in the latter WTW-analysis. Generally no adjustments must be made to gasoline-fuelled vehicles in order to run on methanol blends below 10% [SAE 1993]. For higher blends, some adjustments to the fuel tank as well as to the fuel distribution and injection components are usually necessary. Moreover, there is a need for a variable sensor which can determine the alcohol content in the fuel in order to optimise the combustion [Olah et al. 2009]. It should be noted however that recently it has been stated that in modern cars with electronic fuel injection, only adjustments to the engine control unit software and an exchanged fuel pump seal are required to run on neat methanol fuel [Zubrin 2013]. Furthermore, certain components used in the storage and distribution of methanol must be of different design and chemical composition than those used for gasoline to prevent corrosion and intermixture with water [Olah et al. 2009].

Methanol is a relatively simple chemical and contains roughly half the energy density of gasoline, which is a more complex mixture of different hydrocarbons and additives. However, despite its lower energy content, it has a higher research octane number (RON) of 109 (the RON of gasoline normally lies between 92-98). While a high octane rating is usually associated with properties such as high power, fast acceleration and high top-speed, the following efficiency-related advantages over gasoline are more important in the context of this research:

- The higher RON of methanol signifies that in the combustion chamber of the spark ignition engine, the fuel/air mixture can be compressed to a smaller volume before being ignited by the sparking plug. Accordingly, the so-called compression ratio of methanol is higher: while the ratio of methanol is about 27:1, that of gasoline is about 9:1. The compression ratio can be defined as the maximum volume of the combustion chamber when the piston is furthest away from the cylinder head, divided by its minimum volume when the piston is closest to the cylinder head. More simply put, the higher compression ratio of methanol signifies that a more complete combustion of the fuel/air mixture in the engine is possible [EB 2013b]. As a result, the potential occurrence of so-called engine knocking in the cylinder is strongly reduced. Engine knocking can be described as the uncontrolled combustion, or self-ignition, of the fuel/air mixture if the temperature in the combustion chamber is too high. This knocking effect leads to high mechanic and thermic stress in the engine and can cause severe damage. In using high-octane methanol fuel with a low flame temperature (methanol: 1,870°C / gasoline: 2030°C) the combustion temperature is decreased and its proclivity to detonate is reduced. Thus, a higher compression ratio is achievable, allowing for a more complete combustion, increasing efficiency and generally reducing emissions of NOx, SOx, particulate matter (PM) and volatile organic compounds (VOC) [Nowell 1994; EB 2013b; MI 2013b]. Figure 3.2 illustrates the relation between the RON, CR and the SI engine efficiency:

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- The 3.7 times higher heat of vaporization of methanol signifies a greater absorption of heat when it passes from the liquid to the gaseous state. This induces a substantial cooling effect of the fresh charge, particularly in modern direct injection (DI) engines which have gained widespread use in recent years, especially in Europe [P. Koustrup, personal communication]. This relative cooling effect is equivalent to a RON increase of 24, significantly improving the overall thermal efficiency and knock resistance of methanol combustion even further [Olah et al. 2009; Stein et al. 2012]. Naturally, this applies most strongly in engines which are specifically optimized for methanol fuel but it is also the case in conventional gasoline engines if slight modifications are undertaken [Nowell 1994]. In this context and in light of the advantages described above, additional efficiency improvements, fuel economy and environmental advantages could also follow from smaller and lighter engine blocks and reduced cooling requirements in engines optimized for methanol fuel.

In sum, the combustion properties of methanol signify a superior thermal efficiency and fuel economy over gasoline fuel and also explain why, despite being only half as energy-dense, the same power output can be achieved with less than double the amount of methanol.

Confirming these observations, comparative fuel test results by Brusstar & Bakenhus [2002] show that overall thermal efficiency levels of over 40% can be reached in SI engines by using neat alcohol fuel. This exceeds even state-of-the-art diesel engines. This knowledge is used by the author in the WTW-analysis model in chapter 4, in applying a vehicle-efficiency range (step 4) for the investigated alcohol fuels which is greater than the efficiency of gasoline.

3.4 - Production methods for renewable methanol

This section offers descriptions of different methods for the production of methanol from renewable resources. They are categorized with regard to their demand for biomass feedstock and their technological maturity: while the near-term and medium-term methods of renewable methanol production are based on gasification of biomass-feedstock (see sections 3.4.1 and 3.4.2), their final product is referred to as bio -methanol. On the other hand, the described long-term method of renewable methanol production does not depend on biomass resources but relies on the capture and chemical recycling of CO2 (see section 3.4.3). Therefore, it is not described as bio- methanol, but in what follows is referred to as renewable methanol.

3.4.1 - Current and near-term method for the production of bio-methanol

In the near-term (meaning the coming years until at least 2020), bio-methanol production will continue to be based on more or less the same technical principles as the production of almost all fossil-based methanol today: these principles are the thermochemical reforming of the feedstock through gasification, and the subsequent catalytic conversion to methanol.

As such, the technology is highly flexible with regard to possible feedstocks since any kind of biomass resource is principally suitable for the production process via gasification. This includes, for instance, products and residues from the agricultural and forestry sectors, municipal waste, animal waste, aquatic plants and algae. Enzymatically converting biomass to methanol is not further regarded here because almost all efforts in the area of enzymatic conversion of biomass to alcohol are currently focussed on ethanol.

According to Olah et al. [2009], solid biomass feedstock is usually dried and pulverized at first, reducing the moisture content to an optimal 15-20%. Then the biomass is heated at 400-600°C to obtain a pyrolysis gas consisting of carbon monoxide, hydrogen, methane, volatile tars, carbon dioxide and water. In so doing, the pyrolysis also produces a significant amount of charcoal as residue. In a second gasification step, this charcoal is reacted with oxygen at 1.300-1.500°C, producing additional carbon monoxide.

The final product of the gasification steps, the so-called syngas, must then be modified in order to reach the optimal composition for the subsequent methanol synthesis: this includes the removal of CO2, technically problematic tars, and the generation of at least twice as many H2 molecules as CO molecules in the syngas [Hamelinck & Faaij 2001]. In the final methanol production unit the syngas is then synthesized to methanol over a heterogeneous copper-based catalyst. For this, an excess of hydrogen in the syngas is desirable for optimal methanol formation. The synthesis accords to the following equations:

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The third equation describes a reaction in which carbon monoxide is produced which then can react further with present hydrogen to produce methanol. Naturally, the progress of these reactions depends on the precise syngas composition and reaction conditions such as pressure and temperature. Therefore, controlling these conditions is of importance in order to optimize the methanol synthesis. As the resulting crude methanol is partly contaminated with by-products, it is distilled in one or more distillation columns to achieve the desired purity.

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Figure 3.3 – Simplified illustration of biomass-to-methanol process via gasification and subsequent synthesis [Adapted from Mortensgaard et al. 2011]

Usually, a part of the biomass feedstock itself is burned to generate the required process heat for gasification. This eliminates the need for an external energy source. However, if an external renewable energy source such as solar or wind power were used instead, the efficiency of biomass utilisation could be improved. For the same reasons, a renewable energy input for the drying of the biomass feedstock pre-gasification is desirable.

Naturally, the biomass-to-methanol efficiency of plants based on the technical concepts described above will vary according to their concrete biomass feedstock and technical arrangement. In the evaluation of different bio-methanol pathways in the WTW-analysis in chapter 4, efficiency values ranging from 59.2–65.8% are therefore applied (step 3), based on information acquired from different scientific sources [Mortensgaard et al. 2011; T. Ekbom, personal communication; CONCAWE 2011a].

In this context it should also be noted that various research and development (R&D) activities are currently concerned with optimising gasification processes of different biomass feedstocks and the efficiency of biomass-gasification is expected to increase between 5-10% in the coming years through technical innovation [Bromberg & Cheng 2010]. On the other hand, the improvement potential, with regard to the methanol synthesis efficiency, is rather limited since this step represents a long-established procedure, well known from conventional natural gas-based methanol production [P. Koustrup, personal communication].

Currently operating producers which use the production principles described above include Dutch company BioMCN which produce bio-methanol from crude glycerine (a residue of biodiesel production), and the Canadian company Enerkem which operates a facility converting municipal solid waste to methanol, derived ethanol and chemicals. Moreover, in Sweden Värmlandsmetanol relies on forest residues for the production of bio-methanol and the consortium BioDME uses black liquor feedstock to produce bio-DME via bio-methanol.

3.4.1.1 - Production of bio-methanol from upgraded biogas

The production of bio-methanol from upgraded anaerobically digested biogas is technically very similar to the production of methanol from natural gas, which today is the most widely used feedstock due to relatively low capital and operating costs. Upgraded biogas is also referred to as biomethane.

In order to upgrade raw biogas to biomethane quality, the raw biogas mainly requires removal of carbon dioxide, water and impurities such as hydrogen sulphide. Ideally, the high hydrogen content of biomethane then enables a straightforward production process involving the steam reforming of the biomethane in order to obtain syngas, the purification of the syngas, subsequent catalytic synthesis and final distillation.

Because the suppressing of unwanted CO2 emissions in the steam reforming of methane is technically difficult and requires a high energy input, it is disadvantageous to the process efficiency and economy. Moreover, it can be regarded as relatively inefficient because methane is first transformed to carbon monoxide in an oxidative reaction and then is reduced with hydrogen to produce methanol. Although current R&D activities are expected to yield efficiency improvements in the near future [IRENA 2013], directly transforming methane to methanol would therefore be more desirable and improve both, efficiency and economics. However, although the direct oxidation of methane to methanol is actively being researched, so far it has been difficult to establish a practical process which is competitive with syngas-based methanol production [Olah et al. 2009].

Figure 3.4 illustrates a concept where biogas is stored temporarily in the natural gas network before being processed to methanol. This concept is represented in the WTW-analysis in chapter 4. Although not yet commercialised, the storage and transportation of the biogas in the natural gas grid enables bio-methanol production in large-scale cost-effective facilities. Starting in 2014, BioMCN will take into operation such a facility in the Netherlands [BioMCN 2013c].

Figure 3.4 - Methanol synthesis based on biogas temporarily stored in the natural gas grid [Adapted from Mortensgaard et al. 2011]

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3.4.2 - Novel mid-term method for the production of bio-methanol

An advanced concept for the gasification-based production of bio-methanol is described by Mortensgaard et al. [2011]. In this novel concept, the methanol production is optimized by the addition of a regenerative solid oxide electrolyser cell (SOEC) to the process. It is expected that this concept will gain concrete significance between 2020 and 2030.

Most importantly in this novel concept, hydrogen can be derived from the SOEC-electrolysis in order to optimise the syngas composition for the subsequent methanol synthesis. In optimising the syngas composition, a much-improved exploitation of the carbon in the biomass feedstock can be achieved. Therefore, despite the higher electricity consumption of the plant through the integration of SOEC, the overall plant efficiency is greatly increased.

As such, the demand for hydrogen in the syngas is the main controlling parameter for the SOEC unit, determining its capacity and activity. Moreover, pure oxygen can be derived from the SOEC-electrolysis in order to improve the gasification efficiency and, compared to the gasification with ambient air, to gasify the biomass without producing unwanted NOx. The benefit of nitrogen-free syngas is that the gas clean-up and further process steps downstream are greatly facilitated, further improving the efficiency and economy of the entire process [Hamelinck & Faaij 2001]. Moreover, compared to the gasification with ambient air, the gasification of pure oxygen can take place at higher temperatures, thereby lowering the content of tars and unwanted components in the syngas. Excess heat from the gasification process is used to generate inlet steam for the SOEC unit, improving the overall efficiency.

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Figure 3.5 – Novel concept of bio-methanol production, integrating SOEC [Adapted from Mortensgaard et al. 2011]

It would also be possible to increase the efficiency of this concept by coupling it with a biomass-based power plant, sharing a common biomass feedstock and extracting steam from the biomass boilers for the electrolysis in the SOEC unit. Moreover, if a district heating network were connected to the plant, the overall efficiency could be increased even further. Clearly, this would have positive implications for the plant economy [IRENA 2013].

The gasification unit of the plant should be able to operate independently from the SOEC unit. In so doing, it could continue to operate at regular full load while, in accordance to the spot market electricity price, the SOEC unit may operate only in part load. This would reduce the impact of volatile electricity spot market prices on the methanol output and consequently would improve the plant economy particularly in future energy systems with higher shares of variable and uncertain renewable electricity.

To sum up, while in the near-term bio-methanol production method, described in chapter 3.4.1, large amounts of carbon dioxide must be removed to optimise the syngas composition for the subsequent methanol synthesis, this carbon can be exploited through the addition of hydrogen in the novel concept. Thereby, the so-called carbon efficiency is doubled and twice as much methanol output can be produced from the same amount of biomass input. In view of potential biomass constraints it is clear that improving the carbon efficiency of biofuel production processes is of great importance. Thus, the upgrading of biomass energy inputs via renewable electricity-based electrolysis is very likely to become more relevant in the future [Lund et al. 2011; Grandal 2012].

Table 3.2 depicts the input/output performance of the novel concept, in comparison to the current and near-term concept of bio-methanol production on wood-feedstock basis. The doubling of the methanol output in the novel concept as well as the efficiency parameters of 59.2% in the current and near-term method and 70.8% in the novel concept are applied in the respective pathways in the WTW-analysis in chapter 4 (step 3).

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3.4.3 - Long-term method for the production of renewable methanol

Despite innovations with regard to the efficiency of biofuel production, limited biomass resources cannot be expected to cover the entire demand for liquid transport fuels in the long-term [Hedegaard 2008; IEA 2012a]. Consequently, non-biomass advanced renewable fuel alternatives are being developed and will have to be deployed in order to eventually gain full independence from fossil fuels. In this broad context, an approach which has recently gained increasing attention is the on-site capture of CO2 emissions and their chemical recycling to methanol, using hydrogen obtained from renewables-based electrolysis or other methods of cleavage [AFS 2013; CRI 2013b]:

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Suitable catalysts for the synthesis are of a very similar nature to those used in the production of methanol via syngas. However, research in this field is active and improved catalysts are currently being developed. The hydrogen input can be derived from renewables-based regenerative electrolysis but other renewable hydrogen supply methods are possible as well, for instance through photocatalytic splitting of water. Capital investment for a methanol plant using this technology is comparable to the capital investment of gasification-based methanol plants [Olah et al. 2009]. Limiting factors for the scale of such plants are, rather, the price of electricity and the availability of carbon dioxide.

A wide range of possible sources exist for the capture and purification of carbon dioxide emissions, for example large power plants or factories producing cement, aluminium or steel. The process of recovering CO2 from these gas streams is a well-developed procedure which can be based on a number of chemical and physical processes. Furthermore, the capture of carbon dioxide emissions is technically and economically most feasible if they are relatively concentrated. For example, flue gas emissions from fossil-based power plants are highly suitable for recovery as they contain up to 15% CO2 by volume. In comparison, the average regular atmospheric CO2-concentration is only 0.0398% by volume [ESRL 2013]. The capturing of CO2 from these concentrated emissions sources requires its purification from pollutants such as hydrogen sulphide (H2S) and SOx, otherwise technical problems such as the degradation of the catalyst systems will occur [Kohl & Nielsen 1997].

It seems clear that capturing even a small fraction of the global industrial CO2 emissions represents a huge potential for the production of renewable methanol and its derivatives. Recently, American-Icelandic company CRI has started to operate a commercial-scale methanol plant in Iceland based on these principles. CRI takes advantage of the low prices for renewable electricity and the availability of concentrated CO2-emission from a local geothermal power plant [CRI 2013a]. Moreover, Blue Fuel Energy from Canada uses the principles described above to produce methanol, derived DME and gasoline [BFE 2013]. It is clearly difficult to project when this concept can and will be feasibly deployed on larger scales. However, in what follows it is not expected to play a large-scale role before 2030 [Olah et al. 2009].

Graves et al. [2010] claim an electricity-to-fuel efficiency of 70% in a state-of-the-art plant using this technology. This value is also represented in the respective pathway in the WTW analysis in chapter 4 (step 3).

4 - Well-to-Wheels analysis

This chapter assesses the potentials of renewable methanol technology primarily with regard to the EU biofuels-policy objective of Greenhouse Gas Savings. Thereby, the author makes use of the WTW analysis method, introduced in section 2.3, to assess the GHG emissions and overall energy efficiency of different renewable methanol pathways which incorporate the production methods described in section 3.4. The produced WTW efficiencies thereby indicate how efficiently given natural resources are utilized and therefore must also be viewed as important parameters in regard to the Security of Supply objective.

The WTW-analysis moreover includes different fossil- and biofuel pathways which are of relevance in the EU transport context, thereby creating a base for comparative evaluation. The range of comparative fuels is chosen according to the delimitations of this analysis, focussing on liquid fuels in ICE: gasoline, diesel, fossil methanol, ethanol and biodiesel.

The author has sought to ensure that the chosen renewable methanol pathways are of potential relevance in the European context and to identify the most thorough and up-to-date data available as input for the calculations. Thereby, no renewable methanol pathways are included which are based on municipal waste, animal waste, aquatic plants or algae. On one hand, this is due to a lack of according basic data and, on the other hand, the marginal potential relevance of these feedstocks for renewable methanol technology within the time frame of this study.

Section 4.1 describes the fundamental calculative parameters and assumptions which define the WTW model. Section 4.2 produces and describes the results on the WTW GHG emissions and efficiencies of the investigated renewable methanol pathways. Thereby, the near-term, medium-term and long-term concepts of renewable methanol production (see sections 3.4.1, 3.4.2 and 3.4.3 respectively) are incorporated. Section 4.3 evaluates the WTW GHG emissions and efficiency performance of the renewable methanol pathways in comparison to the chosen comparative fossil- and biofuel pathways, thereby producing comparative results. Section 4.4 summarizes the findings of the proceeding sections and concludes on the identified potentials of renewable methanol technology in regard to the EU biofuels policy objectives of Greenhouse Gas Savings and Security of Supply.

4.1 - Introduction to calculations

The WTW GHG emissions of the investigated fuel pathways are produced in g CO2e/MJ and are the sum of the respective emissions from all efforts and processes in each of the four discrete WTW steps:

E (WTW GHG emissions of fuel pathway) = Σ {e(c) (GHG emissions of step 1), e(p) (GHG emissions of step 2), e(td) (GHG emissions of step 3), e(u) (GHG emissions of step 4)}

Consequently, the WTW GHG emissions of the investigated fuel pathways are calculated as follows^[4]:

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In step 1, e(c) accounts the emissions from all efforts associated with the cultivation and extraction processes of raw materials. Depending on the fuel and its production pathway, this can include emissions from harvesting or collecting primary energy carriers, emissions from potential waste or leakage and from the production of necessary chemicals and support products needed for the cultivation or extraction processes.

In step 2, e(p) accounts the emissions from all efforts associated with processing the fuel. Depending on the fuel and its production pathway, this can include emissions from the processing itself but also from potential waste and leakage and from the production of necessary chemicals and support products which are used in the processing step.

In step 3, e(td) accounts the emissions from all efforts associated with transporting and distributing the fuel to fuelling stations within the EU. This can include emissions associated with storage as well as the transport and distribution in both ships and trucks.

In step 4 (TTW), e(u) accounts the emissions from the fuel combustion in the vehicle engine. A value of zero has been chosen for biofuels due to the underlying assumption of carbon-neutrality: this means that the biomass feedstock has absorbed and bound CO2 during its natural process of plant growth. During its decomposition or its combustion, this bound amount is set free, closing the carbon cycle and neutralizing the carbon balance. All associated external emissions of biofuels are accounted for in the previous steps of the WTT chain.

The WTW efficiencies of the investigated fuel pathways are produced in % as Energy Returned on Energy Invested (EROEI^[5] ). Thereby the WTW efficiency of a fuel pathway is the product of the respective efficiencies of all efforts and processes in each of the four discrete WTW steps:

H (WTW efficiency of fuel pathway) = Π {η(c) (efficiency of step 1), η(p) (efficiency of step 2), η(td) (efficiency of step 3), η(u) (efficiency of step 4)}

As the data input for the efficiency calculations of the respective fuel pathways stems from the same sources as the inputs for the calculations of their GHG emissions, the coherence of the calculations and the validity of the results are ensured. Thereby, the WTW efficiencies are calculated as follows:

H (WTW efficiency of fuel pathway) = η(c) * η(p) * η(td) * η(u)

In accordance to the above, in step 1, η(c) accounts all energy inputs associated with the cultivation and/or extraction of raw materials.

In step 2, η(p) accounts for all energy which must be invested in order to process or refine the fuel product.

In step 3, η(td) accounts all energy inputs associated with the transport and distribution of the fuel to fuelling stations within the EU.

Lastly, in step 4 (TTW), the end-use efficiency η(u) accounts for the energy loss which occurs when chemically bound energy is converted to kinetic energy in the ICE. Thereby, a vehicle-efficiency range is applied for the alcohol fuels which is 10-40% higher than the vehicle-efficiency of gasoline fuel. This is done in order to account for the superior combustion properties, thermal efficiency and fuel economy of alcohol fuels, particularly methanol, described in section 3.3.

Throughout the following sections, the respective fuel- and pathway-specific inputs and underlying assumptions for the calculations are further clarified and discussed. Furthermore, the Annex chapter of this study includes data tables which show the inputs for the calculations.

[...]

^[1] The red Biodiesel curve here accounts for biodiesel, biodimethylether, Fischer-Tropsch diesel, cold-pressed plant oil and other liquid biofuels which are added to, blended with or used straight as transport diesel. The blue Biogasoline curve represents mainly bioethanol but also accounts for biomethanol, bio-ETBE and bio-MTBE [EU 2012; EUROSTAT 2013].

^[2] According to their varying reactivity, the unit CO2e accounts the following values to different greenhouse gases: CO2: 1; CH4: 25; N2O: 298 [IPCC 2007].

^[3] M85 is a fuel blend of 85% methanol and 15% gasoline.

^[4] Although in the investigated biofuel pathways the calculations refer to renewable raw materials, fossil energy inputs are currently used in e(c), e(p) and e(td).

^[5] The EROEI can be described as the “ratio of the amount of usable energy acquired from a particular energy resource to the amount of energy expended to obtain that energy resource” [Murphy & Hall 2010]. In the study at hand the values refer to: MJ (fuel output) / MJ (energy input).