Why liquefied coal (CTL) and natural gas (GTL) can’t replace oil

Preface. Here are just a few of the reasons why we aren’t likely to convert enough coal to diesel to matter as oil decines (see Chapter 11 Liquefied Coal: There Goes the Neighborhood, the Water, and the Air for more details on this in When Trucks Stop Running: Energy and the Future of Transportation)

It is not likely much coal will be converted to diesel, because if all global coal production were converted to liquid coal, perhaps 17 million barrels a day (Mb/d) could be produced. That amounts to 22 % of current world oil production. If more efficient liquefaction technologies came along, and coal now used to generate electricity and make cement, steel, aluminum, paper, and chemicals were all diverted to make liquid fuels, as much as 54 Mb/d could be made. But roughly 17 Mb/d is more likely because diverting most or all of the coal from other uses to make CTL is not realistic. After all, we do need cement and steel to build the CTL coal liquefaction plants, roads, and the trucks and pipelines to transport the CTL itself.

In the U.S. coal production could be doubled to make CTL, but that might cut reserve life in half. In the U.S., there may be 63 years of reserves at current rates of production, but only 31.5 years if we doubled coal production.

The thermal efficiency of liquefaction is roughly 50–60 %; hence, only half the coal energy used in liquefaction will come out as the energy available in the CTL fuel. And there may be other losses. An inconvenient truth about coal is that it is a dirty fuel. If carbon capture and sequestration were to be required, 40 % of the remaining energy in a liquid coal power plant would be consumed.

Liquid coal production is limited by water, which uses six to 15 tons of water per ton of CTL. In the U.S., most of the coal is in the dry states of Wyoming and Montana.

Likewise making CTL in China would be a disaster for water supplies because a great deal of water is used to produce it and a great deal of polluted water is output. If China went ahead with production in some regions of Xinjiang, Inner Mongolia, Shanxi and Liaoning it would use up 30–40% of regional water resources — a significant risks to agriculture, drinking water, and water needs (Wang 2019).

Time, and a lot of it, would be required to scale CTL production up to 17 Mb/d. It takes more than five years to construct a CTL plant, and even more time if rail, water, and pipeline infrastructure is needed (USGAO 2007; NRC 2009). The National Petroleum Council said that the U.S. could produce up to 5.5 Mb/d of CTL fuel by 2030. Sasol uses one ton of coal per 1–1.4 barrels of fuel, so a goal of 5.5 Mb/d by 2030 requires 1.6 to 2.3 billion short tons of coal. That is twice as much as the 984,842,000 tons of coal mined in the U.S. in 2013. It would be reasonable to doubt that coal production could be doubled in 15 years. Not to be forgotten: 93 % of current U.S. coal production is used to generate electricity, not for transportation fuel.

Not to mention Energy Return on Investment – does the flow chart look “simple” to you? Each step requires energy (and most are not shown), resulting in less energy in the final product.

Above all, we are out of time. Peak oil appears to have happened in 2018 (see references in Chapter 2 of Life After Fossil Fuels: A Reality Check on Alternative Energy). Peak coal has already happened, including the U.S. Powder River Basin in Montana and Wyoming, where nearly half of U.S. coal comes from, and we have the most coal reserves in the world. In 2015, the USGS said there might be 35 years left, not the 250 years we’ve assumed since the last survey in 1976.

Alice Friedemann www.energyskeptic.com Author of Life After Fossil Fuels: A Reality Check on Alternative Energy; When Trucks Stop Running: Energy and the Future of Transportation”, Barriers to Making Algal Biofuels, & “Crunch! Whole Grain Artisan Chips and Crackers”. Women in ecology Podcasts: WGBH, Planet: Critical, Crazy Town, Collapse Chronicles, Derrick Jensen, Practical Prepping, Kunstler 253 &278, Peak Prosperity, Index of best energyskeptic posts

***

Höök, M., et al. 2014. Hydrocarbon liquefaction: viability as a peak oil mitigation strategy. Philosophical Transactions. Series A: Mathematical, physical, and engineering science, 372. 34 pages

EXCERPTS:

Current world capacity of hydrocarbon liquefaction is around 400,000 barrels per day (kb/d), providing a marginal share of the global liquid fuel supply. This study performs a broad review of technical, economic, environmental, and supply chains issues related to coal-to-liquids (CTL) and gas-to-liquids (GTL). We find 3 issues predominate.

Significant amounts of coal and gas would be required to obtain anything more than a marginal production of liquids.
The economics of CTL plants are clearly prohibitive, but are better for GTL. Nevertheless, large scale GTL plants still require very high upfront costs, and for three real world GTL plants out of four, the final cost has been so far approximately 3 times that initially budgeted. Small scale GTL holds potential for associated gas.
CTL and GTL both incur significant environmental impacts, ranging from increased greenhouse gas emissions (in the case of CTL) to water contamination. Environmental concerns may significantly affect growth of these projects until adequate solutions are found.

Oil is the largest contributor to mankind’s energy needs and provides over 90% of all transportation energy (IPCC, 2007). Each year, new production must be brought on-stream to offset declining output from current production. More than two thirds of current crude oil production may need replacement by 2030 simply to meet current demand. This is likely to prove extremely challenging, and there is a significant risk of a peak of conventional oil production before 2020 (UKERC, 2009). Peaking global oil production would imply a peak in oil-sourced liquid fuels. This could potentially severely impact the world economy (Fantazzini et al., 2011), especially if alternative sources of energy and liquid fuels are unable to “fill the gap” between climbing demand and falling production on the timescale required. Coal-to-liquids (CTL) is often proposed as a possible mitigation strategy and has been an important component in several peak oil mitigation outlooks (SRES, 2000; Hirsch et al., 2005; Hirsch, 2008; IEA, 2011).

Proponents of CTL claim that it will be capable of full or partial mitigation of the expected shortfall of conventional oil due to a global oil peak. Similarly, liquefaction of natural methane gas (gas-to-liquids, or GTL) has emerged as a promising option to monetize stranded gas assets (Fleisch et al., 2002; Wood et al., 2012).

At present, world production of conventional oil stands at around 85 million barrels/day (Mb/d) and has been roughly constant since mid-2004 (Fantazzini et al., 2011). Current world CTL and GTL capacity is around 400,000 b/d (less than half a percent of oil production). Existing estimates place the global decline in existing oil production rates at between 3 and 8% annually, or in other words, new capacity of 3–7 Mb/d is required every year (Höök et al., 2009). Various observers advocate hydrocarbon liquefaction to provide everything from a minor role to production levels of several Mb/d. What expectations are reasonable? To assess this question, this paper reviews the technology, economics, environmental impact and supply chain of CTL and GTL.

Underlying chemistry

Coal is a complex compound consisting of carbon, hydrogen, oxygen, sulfur, and minor proportions of other elements. It is an aggregate of microscopically distinguishable, physically distinct and chemically different subparts baked together. CTL works by breaking up the solid hydrocarbon structures found in coal. This may be accomplished by partial breakdown directly to liquid hydrocarbons (direct coal liquefaction or DCL) or by full breakdown into hydrogen and carbon that can be reassembled into H-C-chains of a desired length (indirect coal liquefaction or ICL). The chemical reactions involved in reality are significantly more complex than the simple overview presented here.

CTL processes are influenced significantly by the properties of the coal feedstock (ash content, grindability, sulfur content, plasticity, caking properties, etc.). GTL displays fewer issues in this respect since natural gas is a more homogenous feedstock. Process efficiency and yield are further influenced by the choice of catalyst. Only four group VIII-metals (Fe, Co, Ni, and Ru) have sufficiently high activities for hydrogenation of CO to merit their use as effective FT catalysts (Tavakoli et al., 2008).

The advantage of DCL is its very high liquid yield – potentially >70% of the dry weight coal (Benito et al., 1994; Couch, 2008). DCL liquids are typically of higher quality (i.e. less nitrogen, sulphur, phenols, aromatics, etc.), due to hydrogen addition, than liquids obtained from pyrolysis. The DCL liquids are effectively a synthetic crude oil (syncrude) and are directly usable in power generation or in petrochemical processes. However, they require further refining before they can be used as a transport fuel. Refining can be done directly at the CTL facility or by sending the synthetic crude oil to a conventional refinery, where it can be made into gasoline- and diesel-like fuels as well as propane, butane and many other products.

GTL technology options

There are many ways to liquefy natural gas, and several pilot plants, trial projects and research initiatives exist. However, only two companies – Sasol and Shell – have built large-scale commercial plants (>5,000 b/d capacity). The GTL industry is essentially immature and many important patents are held by relatively few companies (Wood et al., 2012). Established GTL approaches have much in common with ICL technologies, as they both work with FT synthesis and gaseous chemistry. Both high temperature and low temperature FT synthesis can be used to provide liquid fuels. There are commonly three main stages in a GTL facility: synthesis gas generation, FT reaction and product upgrading (Panahi et al., 2012). Auto-thermal reforming is the preferred technology to generate syngas since it offers better H2/CO ratio compared to all alternatives (Iandoli and Kjelstrup, 2007). The syngas generation stage is often the most capital intensive part of a GTL plant. A schematic process chain of a GTL complex can be seen in Figure 1.

Commercial GTL developments

Sasol developed the Sasol slurry phase distillate GTL process in the 1980s from their CTL technologies. Hot syngas is bubbled through a slurry of catalyst particles and liquid reaction products. Initially iron was used as a catalyst, but recent developments have used cobalt-based catalysts providing greater conversion rates. Developments by Sasol resulted in the construction of a stand-alone GTL plant with a capacity of 22,000 b/d in Mossel Bay in 1992. The project became known as Mossgas and is considered the first commercial GTL plant. A subsequent collaboration between Sasol and Qatar Petroleum used auto-thermal syngas production, slurry phase FT reactors and an isocracking product upgrading technology to develop a 32,400 b/d facility known as the Oryx plant in Qatar. The project agreement was signed in 2001 and completed in 2008 after delays and budget overruns. Sasol later engaged in a GTL feasibility study for a Nigerian plant together with Texaco in 1998. The Escravos project was agreed in 2002 and involved Sasol, Chevron Corporation and Nigerian National Petroleum Company, using the same design as the Oryx project. Delays and cost overruns caused Sasol to withdraw in 2009, although their technologies are still used under license. The capacity of the Escravos GTL plant will be 32,400 b/d when completed in 2013 – similar to Oryx in design and size. In 1993, a joint-venture consisting of Shell, Mitsubishi, Petronas and Sarawak State completed a GTL plant in Bintulu, with a final capacity of 14,700 b/d. Experience from Bintulu was used by Shell in the design of the world’s largest GTL project, the Pearl GTL plant in Ras Laffan Industrial City, Qatar. Construction started in 2007 as a joint venture between Shell and Qatar Petroleum, and production began in 2011, reaching full capacity of 140,000 b/d in 2012.

System efficiencies.

Thermal or energy efficiency is the percentage of the energy in the feed-stock that is converted into energy output as products.

Low thermal efficiencies, often in the range of 45– 55%, have been a major argument against hydrocarbon liquefaction (Liu et al., 2010). DCL is commonly seen as more efficient for producing liquid fuels than ICL because only partial breakdown of the coal is required. However, such claims can be misleading because published DCL efficiencies usually refer to the formation of an unrefined syncrude requiring additional processing into useable liquid fuels. In contrast, ICL efficiencies often refer to the final products. Caution should always be exercised when dealing with efficiencies.

The estimated overall efficiency of the DCL-process is 73% (Comolli, 1999). Other groups have estimated a thermal efficiency of 50-70%. However, Sovacool et al. (2011) criticized these estimates as misleading, because industry tends to compare the heating value of the resulting liquids with that of the inputs. Hydrogen production, product refining and other steps necessary to complete the entire product supply chain are not always included in the efficiency calculations; one needs to pay attention to how those assessments have been made. Representative efficiency for FT-synthesis used in ICL and GTL is around 50%, while the theoretical maximum has been estimated at 60–65%. Tijmensen et al., (2002) give overall energy efficiencies ranging from 33–50% for ICL co-using various biomass blends. Detailed

In essence, there is no significant efficiency advantage for either DCL or ICL, while GTL is somewhat more efficient. As a rule-of-thumb, a 50-60% thermal efficiency can be used for hydrocarbon liquefaction in general assessments. This implies that only half of the coal energy invested in liquefaction will come out as energy available as transportation fuel.

Despite differences in methodologies, all coal consumption estimates end up at approximately similar figures. As expected from the relatively low thermal efficiencies, a significant amount of coal is required to generate liquid fuels in any substantial amount. Significant CTL production is viable only in areas with abundant coal reserves. It has been estimated that large scale CTL production will be limited to about 6 countries with large coal reserves and the ability to divert significant fractions of that coal to liquefaction (Höök and Aleklett, 2010).

Obtaining reliable GTL gas consumption figures is harder. For example, the Pearl project is designed to consume 45.3 Mm3 per day to yield 120,000 b/d of condensate, propane, butane, and ethane and 140,000 b/d of GTL products (Wood et al., 2012). The National Petroleum Council (2007) gives an average conversion factor of 283 m3 natural gas per barrel GTL product. Others have estimated the carbon efficiency, i.e. the amount of carbon in the feed gas converted to saleable products, at 53-77% (Fleisch et al., 2002). Water is a vital part of the conversion processes and CTL is highly water intensive (Mielke et al., 2010). Zhang et al. (2009) state that each ton of synthetic oil output requires 8–9 tons of freshwater for DCL and 12–14 tons of fresh water in ICL. In contrast, the US Department of Energy found that water consumption is approximately equivalent for DCL and ICL at around 5–6 ton water/ton of oil (National Energy Technology Laboratory, 2006) and RAND calculated 6–12 ton water/ton of oil (RAND, 2008). 3.

Environmental impacts from CTL

When considering CTL, first we will examine impacts that apply equally to all industrial applications of coal, including landscape modification, particulate emissions and acid mine drainage. We will then examine water consumption, water contamination and greenhouse gas emissions specific to CTL.

Landscape modification

Three types of surface mining are generally used to extract shallow coal, open-pit, strip mining and mountaintop removal. In all cases the overburden is removed to expose the coal.

Open-pit mining creates a large crater-like depression.
In strip-mining, as the overburden of a strip is excavated, it is placed in the excavation of the previous strip.
Mountaintop removal is applicable to horizontal coal seams in mountainous country, notably the Appalachian Mountains in the United States. At current coal prices, mountaintop removal is often the only cost-effective way to mine coal in this area. Explosives are used to remove the entire mountain top overburden and vegetation, including forests, which is placed directly in stream valleys. According to the US Environmental Protection Agency, between 1992 and 2002 surface coal mining in Appalachia damaged or destroyed more than 1900 km of streams and deforested 150,000 hectares of land, while 34,000 hectares of valleys were filled (Environmental Protection Agency, 2005).

Particulate emissions and coal processing

Particulates are emitted both when coal is mined and via wind erosion until new vegetation covers reclaimed land. Hendryx et al. (2008) found that, after accounting for other variables, lung cancer mortality was higher in Appalachian counties with extensive coal mining. Coal dust contains carcinogenic compounds and metals including zinc, cadmium, nickel and arsenic. The mining and cleaning of coal at local processing sites creates large quantities of ambient particulate matter as well as contaminated water. Water contamination and water consumption Water is used extensively throughout the coal mining and liquefaction process. Surface mines use water for dust abatement and all coal must be washed to remove soil and other contaminants before further processing. Water requirements often cause local aquifers to be depleted near coal mines. As rainwater drains through the mine it reacts with and oxidizes pyrite (FeS2) in the coal, producing sulphuric acid that may leach into local aquifers in a process called acid mine drainage (AMD). AMD often continues after the mine is no longer operational. Other contaminants that may leach into the water supply from the entire mining process include cadmium, selenium, arsenic, copper, lead, mercury, ammonia, sulphur, sulphate, nitrates, nitric acid, tars, oils, fluorides, chlorides, sodium, iron and cyanide (Spath et al., 1999; Palmer et al., 2010).

The total amount of water required for liquefaction depends on factors like plant design, location, humidity, and coal properties. CTL is classified as a water intensive process (Mielke et al., 2010), and consumption estimates range from 6–15 tons of water per ton of fuel, as noted earlier. CTL may generate or amplify water shortages in certain regions. Cooling, boiler and process water in CTL plants needs to be of reasonable quality to prevent corrosion and/or deposit formation, and treatment is typically needed. Discharged water must be treated before it can be released to the environment without causing harm (Lei and Zhang, 2009).

Rong and Victor (2011) point to water availability and water quality issues as important factors behind the recent caution toward CTL in China.

Greenhouse gas emissions

The CTL process produces significant amounts of carbon dioxide, the greenhouse gas primarily driving anthropogenic global warming. From a life-cycle perspective, it is also important to include the emission contributions from mining. Coalification, the natural process by which coal is made, traps significant amounts of methane as the coal rock is formed, called coal bed methane (CBM) that is released during the mining of coal. Methane represents approximately 14% of global GHG emissions (in CO2-equivalent) and CBM accounts for approximately 8% of total methane emissions (World Coal Association, 2012). Annual worldwide CBM release in 2000 was estimated to be 0.24 Gt CO Annual worldwide CBM release in 2000 was estimated to be 0.24 Gt CO2 equivalent. This compares with approximately 35 Gt of anthropogenic CO2 released annually (IPCC 2007). Brandt and Farrell (2007) find that even a partial transition to coal-to-liquids synfuels could raise upstream GHG emissions by several Gt of carbon per year by mid-century, approximately 7% of the current total carbon emissions, unless mitigation steps are taken. However, there are CTL plant configurations using CO2 recycling/capture/storage that may be capable of reducing emissions significantly (Williams and Larson, 2003). Mantripragada and Rubin (2009) explore some of those configurations, but also stress that handling CO2 responsibly dramatically raises CTL costs.

Our analysis highlights a strong risk for CTL plants to become financial black holes, and helps explain why China has strongly slowed down the development of its CTL program (Rong and Victor, 2011).

Unfortunately, cost escalation often occurs: apart from the Oryx plant, the final total cost has so far been approximately three times that initially budgeted. In the case of the World GTL plant in Trinidad and Tobago, the original CAPEX was expected to be 0.125 billion$, while the last estimate is roughly 0.400 billion $ (Ramdass, 2010). The unit cost is approximately $178,000 b/d, in between the Pearl and the Escravos plants — and more than 3 times the original estimate.

Supply chain issues

Supply chain risks, vulnerabilities and uncertainties (Simangunsong et al., 2012) are another important topic for energy strategies involving major hydrocarbon liquefaction undertakings. High oil prices or oil shortages that make CTL more attractive may also bring about problems for parts of the liquefaction supply chain. Business risks have been broadly reviewed by Oke and Gopalakrishnan (2009). For a CTL/GTL supply chain, we have identified three major risk categories. In a joint report, Lloyd’s of London and Chatham House have advised all businesses to begin scenario-planning exercises for the oil price spike they assert is coming in the medium term (Lloyd’s, 2010). It will prove imperative that business addresses this Schumpetarian shock in a timely fashion (Barney, 1991).

Material flow risks

Material flows involve physical movements within and between supply chain elements, such as coal transportation, movement of spare parts for CTL/GTL facilities and delivering CTL/GTL products to consumers. These concerns, and issues such as capacity change over time relate to typical supply chain design problems (Carle et al., 2012; Singh et al., 2012) complicated by many of the risks discussed above that are specific to the chemical industry (Floudas et al., 2012; Liu et al., 2011). Today, petroleum products supply 95% of all energy used in global transportation (IPCC, 2007). Oil price volatility or supply disruptions may have a major impact on transportation and this may completely change the competitiveness of CTL facilities located at a distance from coal mines. For the USA, coal accounts for 44% of the railroad tonnage (McCollum and Ogden, 2009), while the corresponding figure for China is more than 50% (Rong and Victor, 2011). Rail capacity issues and bottlenecks have been a persistent problem in several cases and future rail policies can have significant impact on CTL supply chains. The only exception is CTL facilities at mine-mouth locations. It should also be noted here that CTL/GTL may also impact existing hydrocarbon supply chains negatively and these concerns have led to the abandonment of certain projects (Rong and Victor, 2011).

Information flow risks. Supply chains are also influenced by information flows such as demand, inventory status, order fulfillments, design changes and capacity updates. Some observers even perceive information as a bonding agent between material and financial flows. Information system security and disruptions could arise from internally ill-managed systems or potentially by outside sources such as industrial espionage, hackers or similar (Faisal et al., 2007).

We also note that coal production requirement is a major factor in CTL feasibility. Significant CTL production requires equally significant coal production and resources that only a few countries or regions realistically can develop. CTL capacities in the Mb/d-range will effectively be limited to the largest coal producing countries in the world: China, USA, India, Russia, Australia and South Africa. Even if several Mb/d could be derived from CTL, this would account for only a minor share of global oil production and barely offset the decline in existing oil production (Höök and Aleklett, 2010).

We also note that almost all papers admit that financing CTL projects can be difficult unless public incentives and subsidies are provided.

GTL faces similar problems and risks. Those include high capital costs, technical efficiency and reliability issues, oil price volatility, uncertainty of petroleum product markets, project financing: in this regard, for three real GTL plants out of four, the final cost has been so far approximately three times initial budget. One additional factor is access to technology, as only a small number of companies hold many important patents (Wood et al., 2012). However, GTL faces a better situation compared to CTL, due to cheaper inputs and lower water requirements.

References

Aasberg-Petersen, K., Christiansen, T.S., Stub Nielsen, Dybkjær, I., 2003.Recent developments in auto-thermal reforming and prereforming for synthesis gas production in GTL applications. Fuel Processing Technology, 83(1–3), 253–261. DOI: http://dx.doi.org/10.1016/S0378-3820(03)00073-0

Adedeji, O. 2008. Natural Gas and the Economics of GTL with some Comparisons to LNG, The University of Texas at Austin, May 2008
Al-Shalchi, Wisam 2006. Gas to Liquids Technology (GTL), Baghdad. Available from:
http://178.89.159.60/docs/Gasifiers/Gas_To_Liquids_Technology_2006.pdf

Ang, L., Baig, Y., Kanu, E., and Pwaga, S., 2010. Natural Gas As Transportation Fuel: Conversion To Liquid Fuel And Direct Utilization, Department Of Petroleum Engineering And Applied Geophysics, Norwegian University of Science and Technology. http://iptibm1.ipt.ntnu.no/~jsg/undervisning/naturgass/oppgaver/Oppgaver2010/10Ang.pdf

Bacaud, R., Jamond, M., Diack, M., Gruber, R. 1994. Development and evaluation of iron based catalysts for the hydroliquefaction of coal.International Journal of Energy Research, 18(2):167–176. DOI: http://dx.doi.org/10.1002/er.4440180214

Bakkerud, P.K., 2005. Update on synthesis gas production for GTL. Catalysis Today, 106(1–4), 30–33. DOI: http://dx.doi.org/10.1016/j.cattod.2005.07.147

Balogun, O. and Onyekonwu M. 2009 Economic Viability of Gas-to-Liquids in Nigeria, Paper presented at the Nigeria Annual International Conference and Exhibition, 3-5 August 2009, Abuja, Nigeria. Available from
http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-128342-MS

Bao, B., El-Halwagi, M., Elbashir, N. 2010. Simulation, integration, and economic analysis of gas-to-liquid processes. Fuel Processing Technology, 91(7): 703-713. DOI: 10.1016/j.fuproc.2010.02.001

Barney, J.B. 1991. Firm resources and sustained competitive advantage. Journal of Management, 17(1):99-120.

Bartis, J., Camm, F., Ortiz, D., 2008. Producing liquid fuels from coal: prospects and policy issues. Report by RAND Corporation.MG-754-AF/NETL. Santa Monica, California. http://www.rand.org /

Bellman, D.K., et al, 2007. Coal to liquids and gas – topic paper #18.National Petroleum Council. Available from: http://www.npc.org

Benito, A., Cebolla, V., Fernandez, I.,Martinez, M.T., Miranda, J.L., Oelert, H.,Prado, I.G., 1994. Transport fuels from two-stage coal liquefaction, International Journal of Energy Research, 18(2): 257–265. DOI: http://dx.doi.org/10.1002/er.4440180225

Berg, D., Oakley, B., Parikh, S., Paterson, A., 2007.The business case for coal gasification with co-production – an analysis of the business risks, potential incentives, and financial prospects, with and without carbon sequestration. Report from Scully Capital Services. Washington, D.C. http://www.climatevision.gov/pdfs/Co-Production_Report.pdf

Black B. 2010 Monetizing Stranded Gas: Economic Valuation of GTL and LNG Projects, Master Thesis, The University of Texas at Austin, May. http://repositories.lib.utexas.edu/handle/2152/ETD-UT-2010-05-1342

BP, 2012. Statistical Review of World Energy 2012. British Petroleum. http://www.bp.com/sectionbodycopy.do?categoryId=7500&contentId=7068481

Brandt, A.R., Farrell, A.E., 2007. Scraping the bottom of the barrel: greenhouse gas emission consequences of a transition to low-quality and synthetic petroleum resources. Climatic Change, 84(3-4): 241–263. DOI: http://dx.doi.org/10.1007/s10584-007-9275-y

Bridgwater, A.V., Anders, M., 1994.Production costs of liquid fuels by indirect coal liquefaction. International Journal of Energy Research, 18(2): 97-108, DOI: http://dx.doi.org/10.1002/er.4440180207

Bunce, P., Gould, P., 1996. From lean to agile manufacturing. IEE Colloquium Digest, 1996, Issue 278.

Van der Burgt, M.J., van Leeuwen, C.J., del’Amico, J.J., Sie, S.T., 1988. The Shell Middle Distillate Synthesis process. Studies in Surface Science and Catalysis, 36,473–482. DOI: http://dx.doi.org/10.1016/S0167-2991(09)60541-3
Camm, F. Bartis, J., Bushman, C., 2008. Federal financial incentives to induce early experience producing unconventional liquid fuels.
Report by RAND Corporation. TR-586-AF. Santa Monica, California. Available from: http://www.rand.org/

Carle, M., Martel, A., Zufferey, N., 2012. The CAT metaheauristic for the solution of multi-period activity-based supply chain network design problems. International Journal of Production Economics, 139(2): 644–677. DOI: http://dx.doi.org/10.1016/j.ijpe.2012.06.016

Castelo Branco, D., Alexandre, S., and Schaeffer, R., 2010. Co2e emissions abatement costs of reducing natural gas flaring in Brazil by investing in offshore GTL plants producing premium diesel, Energy, 35(1): 158-167. DOI: http://dx.doi.org/10.1016/j.energy.2009.09.006

Chang, T., 2000. South African company commercializes new F-T process. Oil & Gas Journal, 98(2):42–45.

Chedid, R., Kobrosly, M., and Ghajar, R. 2007. The potential of gas-to-liquid technology in the energy market: The case of Qatar. Energy Policy, 35(10): 4799-4811. DOI: 10.1016/j.enpol.2007.03.017.

Chen, H., Reilly, J., Paltsev, S., 2011. The prospects for coal-to-liquid conversion: A general equilibrium analysis. Energy Policy 39(9):4713–4725. DOI: http://dx.doi.org/10.1016/j.enpol.2011.06.056

Chijemezu, M.A. 2009 Market potentials of Gas-to-Liquids technology and its comparison with Liquefied Natural Gas, Seminar paper at the Department of Petroleum and Gas Engineering University of Port Harcourt (Nigeria).

Christopher, M., Towill, D.R., 2000. Marrying the lean and agile paradigms. Proc. EUROMA Conference, Ghent, 2000, 114-121.

Collot, A.G., 2006.Matching Gasification technologies to coal properties. International Journal of Coal Geology, 65(3-4):191–212. DOI: http://dx.doi/10.1016/j.coal.2005.05.003

Comolli, A.G., Lee, L.K., Pradhan, V.R., Stalzer, R.H., Karolkiewicz, W.F., and Pablacio, R.M., 1999. Direct liquefaction proof-of-concept program. Final report prepared by Hydrocarbon Technologies Inc. (Lawrenceville, New Jersey, USA) and Kerr-McGee Corporation (Oklahoma City, Oklahoma, USA) for the Pittsburgh Energy Technology Center, US Department of Energy, DE-92148-TOP-02. http://www.osti.gov/bridge/servlets/purl/772402-Us5qhE/webviewable/772402.pdf

CompactGTL. 2010. Compact GTL as an Associated Gas Solution, World XTL10 Summit

CompactGTL. 2011. Information center. Available at http://compactgtl.com/information-centre
Couch, G.R,, 2008. Coal to Liquids, IEA Clean Coal Centre publication CCC/132, 2008. Available
from: http://www.coalonline.info/site/coalonline/content/browser/81994/Coal-to-liquids

Day, M.E., 2003. Fischer-Tropsch Synthesis – Industrial. In: Horvath, I.T., (Ed.) Encyclopedia of catalysis. Wiley, 2003, 4775 p.

de Pater, C.J. and Baisch, S., 2011. Geomechanical Study of Bowland Shale Seismicity http://www.cuadrillaresources.com/wpcontent/
uploads/2012/02/Geomechanical-Study-of-Bowland-Shale-Seismicity_02-11-11.pdf

Deutsche Bank. 2010. Special Report: Sasol Ltd – The GTL Catalyst; Buy, Global Market Research, Deutsche Securities, November. http://www.fullermoney.com/content/2010-11-11/sasol.pdf

DOE/NETL, 2007. Baseline technical and economic assessment of a commercial scale Fischer-Tropsch liquids facility. US Department of Energy (DOE), National Energy Technology Laboratory (NETL) joint report, DOE/NETL-2007/1260, Washington, DC. http://www.netl.doe.gov/

DOE/NETL, 2009. Affordable, low-carbon diesel fuel from domestic coal and biomass. US Department of Energy (DOE), National Energy Technology Laboratory (NETL) joint report DOE/NETL-2009/1349, Washington, DC. Available from: http://www.netl.doe.gov/

Dry, M., 2002. The Fischer–Tropsch process: 1950–2000. Catalysis Today, 71(3–4):227–241. DOI: http://dx.doi.org/10.1016/S0920-5861(01)00453-9
Duvenhage, D., Coville, N.J., 2006. Deactivation of a precipitated iron Fischer–Tropsch catalyst — a pilot plant study. Applied Catalysis A: General, 298:211–216.DOI: http://dx.doi.org/10.1016/j.apcata.2005.10.009
Economides, M., 2005. The economics of gas to liquids compared to liquefied natural gas. World Energy, 8(1): 3-7, March.

EIA, 2006. Annual Energy Outlook 2006 with Projections to 2030. Energy Information Administration, February 2006. http://www.eia.doe.gov/oiaf/archive/aeo06/index.html
EIA, 2012a. Annual Energy Outlook 2012. Energy Information Administration, June 2012.
http://www.eia.gov/forecasts/aeo/
EIA, 2012b. Coalbed methane production. http://www.eia.gov/dnav/ng/ng_prod_coalbed_s1_a.htm

Eilers, J., Posthuma, S.A., Sie, S.T., 1990. The Shell middle distillate synthesis process (SMDS). Catalysis Letters, 7:253–269. DOI: http://dx.doi.org/10.1007/BF00764507

Ekinci, E. Yardim, Y., Razvigorova, M., Minkova, V., Goranova, M., Petrov, N., Budinova, T., 2002. Characterization of liquid products from pyrolysis of subbituminous coals. Fuel Processing Technology, 77–78: 309-315. DOI: http://dx.doi.org/10.1016/S0378- 3820(02)00056-5

Environmental Protection Agency, 1999. Methane emissions 1990 – 2020: inventories, projections, and opportunities for reductions. Report from US Environmental Protection Agency (EPA). EPA 430-R-99-013. September 1999. http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=600009LH.txt

Environmental Protection Agency, 2005. Final programmatic environmental impact statement on mountaintop mining/valley fills in Appalachia. Report from US Environmental Protection Agency (EPA). EPA 903-R-05002, October 2005. http://www.epa.gov/region3/mtntop/eis2005.htm

Epstein, P.R., et al., 2011. Full cost accounting for the life cycle of coal. Annals of the New York Academy of Sciences, 1219, 73–98. DOI: http://dx.doi.org/10.1111/j.1749-6632.2010.05890.x

Erturk, M., 2011. Economic analysis of unconventional liquid fuel sources. Renewable and Sustainable Energy Reviews, 15(6): 2766-2771. DOI: http://dx.doi.org/10.1016/j.rser.2011.03.028

Faisal, M.N., Banwet, D.K., Shankar, R., 2007. Information risks management in supply chains: an assessment and mitigation framework. Journal of Enterprise Information Management, 20(6):677–699. DOI: http://dx.doi.org/10.1108/17410390710830727

Fantazzini, D., Höök, M., Angelantoni, A., 2011. Global oil risks in the early 21st Century. Energy Policy, 39(12):7865–7873. DOI: http://dx.doi.org/10.1016/j.enpol.2011.09.035

Fleisch, T.H., Sills, R.A., Briscoe, M.D., 2002. 2002 – Emergence of the Gas-to-Liquids industry: a review of global GTL developments. Journal of Natural Gas Chemistry, 11(1–2), 1–14.

Fletcher, J.J., Sun, Q., Bajura, R.A., Zhang, Y., Ren, X., 2004. Coal to clean fuel – the Shenhua investment in Direct Coal Liquefaction. Presentation at the third US-China Clean Energy Conference, 18-19 October 2004, Morgantown, USA. http://www.nrcce.wvu.edu/conferences/2004/China/

Floudas, C.A., Elia, J.A., Baliban, R.C., 2012. Hybrid and single feedstock energy processes for liquid transportation fuels: a critical review. Computers and Chemical Engineering, 41: 24-51. DOI: http://dx.doi.org/10.1016/j.compchemeng.2012.02.008

Gradassi, M.J., 2001. Gas-to-liquids R&D: Setting cost reduction targets. In: Studies in Surface Science and Catalysis (ed. Iglesia, E., Spivey, J.J., Fleish, T.H.), pp. 429-434. Elsevier.

Haid, J., Koss, U., 2001. Lurgi’s Mega-Methanol technology opens the door for a new era in down-stream applications. Studies in Surface
Science and Catalysis, 136, 399–404. DOI: http://dx.doi.org/10.1016/S0167-2991(01)80336-0

Hammami, R., Frein, Y., Hadj-Alouane, A.B., 2008. Supply chain design in the delocalization context: relevant features and new
modeling tendencies. International Journal of Production Economics, 113(2): 641–656.
DOI: http://dx.doi.org/10.1016/j.ijpe.2007.10.016

Hammami, R., Frein, Y., Hadj-Alouane, A.B., 2009. A strategic-tactical model for the supply chain design in the delocalization context: Mathematical formulation and a case study. International Journal of Production Economics, 122(1): 351–365. DOI: http://dx.doi.org/10.1016/j.ijpe.2009.06.030

Hatch, 2008. Fairbanks economic development corporation coal to liquids, FEL1 Study. Report prepared by Hatch Ltd for the benefit of Fairbanks Economic Development Corporation. October 2008.

Hendryx, M., O’Donnell, K., Horn, K., 2008. Lung cancer mortality is elevated in coal mining areas of Appalachia. Lung cancer mortality is elevated in coal-mining areas of Appalachia. Lung Cancer, 62(1), 1–7. DOI: http://dx.doi.org/10.1016/j.lungcan.2008.02.004

Hirsch, R.L., Bezdek, R. Wendling, R., 2005. Peaking of world oil production: impacts, mitigation, & risk management. US Department of Energy Report. http://www.netl.doe.gov/publications/others/pdf/Oil_Peaking_NETL.pdf

Hirsch, R.L., 2008. Mitigation of maximum world oil production: Shortage scenarios. Energy Policy, 36(2): 881–889. DOI: http://dx.doi.org/10.1016/j.enpol.2007.11.009

Holland, A., 2012. Examination of possibly induced seismicity from hydraulic fracturing in the Eola Field, Garvin County, Oklahoma
(Open File Report), Oklahoma Geological Survey, August 2011.

Hossain, I. and Gülen, G. 2007. Lifecycle analysis of different urban transport options for Bangladesh, Energy Policy, 35(10): 4909-4918.
DOI: 10.1016/j.enpol.2007.04.036

Huang, L., Schobert, H.H., 2005. Comparison of temperature conditions in direct liquefaction of selected low-rank coals. Energy & Fuels,
19(1):200–207, http://dx.doi.org/10.1021/ef0301710

Höök, M., Hirsch R.L., Aleklett, K., 2009. Giant oil field decline rates and their influence on world oil production. Energy Policy, 37(6):2262–2272. DOI: http://dx.doi.org/10.1016/j.enpol.2009.02.020

Höök, M., Aleklett, K., 2010. A review on coal to liquid fuels and its coal consumption. International Journal of Energy Research, 34(10):848–864. DOI: http://dx.doi.org/10.1002/er.1596

IEA, 2011. World Energy Outlook 2011. Available from: http://www.iea.org
IEA, 2012. World Energy Outlook 2012. Available from: http://www.iea.org
IEA 2012c. Golden rules for a golden age of gas. World Energy Outlook special report on natural gas, 2012.

Iandoli, C.L., Kjelstrup, S., 2007. Exergy analysis of a GTL process based on low-temperature slurry F−T reactor technology with a cobalt
catalyst. Energy & Fuels, 21(4), 2317–2324. DOI: http://dx.doi.org/10.1021/ef060646y

IPCC, 2007. IPCC Fourth Assessment Report: mitigation of climate change. Available from: http://www.ipcc.ch/pdf/assessmentreport/
ar4/wg3/ar4-wg3-chapter5.pdf

Kerr, J., 2006. Streamlining the cash flow. Supply Chain Management Review, S25–S31.

Khodakov, A.Y., Chu., W., Fongarland, P., 2007. Advances in the Development of Novel Cobalt Fischer−Tropsch Catalysts for Synthesis of Long-Chain Hydrocarbons and Clean Fuels. Chemical Reviews, 107(5), 1692–1744. DOI: http://dx.doi.org/10.1002/chin.200733255

de Klerk, A., 2009. Beyond Fischer-Tropsch: Coal-to-liquids production and refining. Elsevier, 752 p.

Kreutz, T., Larson, E., Liu, G., Williams, R., 2008. Fischer-Tropsch Fuels from Coal and Biomass, Proceedings of the 25th Annual International Pittsburgh Coal Conference, 29 September to 2 October, Pittsburgh, USA. http://web.mit.edu/mitei/docs/reports/kreutz-fischer-tropsch.pdf

Krishnamurthy, R. and Yauch, C.A. 2007. Leagile manufacturing: a proposed corporate infrastructure. International Journal of Operations & Production Management, 27(6), 588–604. DOI: http://dx.doi.org/10.1108/01443570710750277

Larson, E.D., Fiorese, G., Liu,G., Williams, R, Kreutz, T., Consonni, S., 2009. Co-production of synfuels and electricity from coal + biomass with zero net carbon emissions: an Illinois case study. Energy Procedia, 1(1): 4371-4378. DOI: http://dx.doi.org/10.1016/j.egypro.2009.02.251

Lei, S., Zhang, J., 2009. An analysis of coal-to-oil industry’s impact on environment. Shenhua Science and Technology 7(3), 84–88.

Levary, R.R., 2007. Ranking foreign suppliers based on supply risk. Supply Chain Management, 12(6):392–394. DOI: http://dx.doi.org/10.1108/13598540710826317

Li, Y.W., 2007. Synfuels China and its Development in advanced CTL Process Technologies. Presentation by Synfuels China LTD, 23 May 2007. Available from: http://live.belfercenter.org/files/06-yongwang_li.pdf
Liu, Z., Shi, S., Li, Y., 2010. Coal liquefaction technologies — development in China and challenges in chemical reaction engineering. Chemical Engineering Science, 65(1):12–17. DOI: http://dx.doi.org/10.1016/j.ces.2009.05.014

Liu, P., Whitaker, A., Pistikopoulos, E.N., Li, Z., 2011. A mixed-integer programming approach to strategic planning of chemical centres: A case study in the UK. Computers and Chemical Engineering, 35(8): 1359-1373. DOI: http://dx.doi.org/10.1016/j.compchemeng.2011.01.014

Lloyd’s, 2010. Sustainable energy security — strategic risks and opportunities for business. Lloyd’s of London white paper on sustainable energy security. http://www.lloyds.com/~/media/Lloyds/Reports/360%20Energy%20Security/7238_Lloyds_360_Energy_Pages.pdf
Longwell, J.P., Rubin, E.S., Wilson, J., 1995. Coal: Energy for the future. Progress in Energy and Combustion Science, 21(4): 269–360. DOI: http://10.1016/0360-1285(95)00007-0

Loomis, J., Quattlebaum, K.,Brown, T., Alexander, S., 2003. Expanding institutional arrangements for acquiring water for environmental purposes: transactions evidence for the Western United States. International Journal of Water Resources Development, 19(1):21–28.
DOI: http://dx.doi.org/10.1080/713672720

Malhotra, R., 2005. Direct coal liquefaction – lessons learned. Paper presented at GCEP advanced coal workshop, Brigham Young University, Provo, USA, 16 March 2005. http://gcep.stanford.edu/pdfs/RxsY3908kaqwVPacX9DLcQ/malhotra_coal_mar05.pdf

Mantripragada, H., Rubin, E., 2009. CO2–reduction potential of coal-to-liquids (CTL) plants. Energy Procedia, 1(1):4331–4338. DOI: http://dx.doi.org/10.1016/j.egypro.2009.02.246

Mantripragada, H., Rubin, E., 2011. Techno-economic evaluation of coal-to-liquids (CTL) plants with carbon capture and sequestration. Energy Policy, 39(5):2808–2816. DOI: http://dx.doi.org/10.1016/j.enpol.2011.02.053

McCollum, D.L., Ogden, J.M., 2009. Future impacts of coal distribution constraints on coal costs. Transportation Research Part E: Logistics and Transportation Review, 45(3):460–471. DOI: http://dx.doi.org/10.1016/j.tre.2008.09.011

Mielke, E., Anadon, L., Narayanamurti, V., 2010. Water Consumption of Energy Resource Extraction, Processing, and Conversion – a review of the literature for estimates of water intensity of energy-resource extraction, processing to fuels, and conversion to electricity. Discussion Paper 2010-15.BelferCenter.Available from: http://belfercenter.ksg.harvard.edu/publication/20479/

Milici, R., 2009. Coal-to-Liquids: Potential Impact on U.S. Coal Reserves. Natural Resources Research, 18(2):85–94. DOI: http://dx.doi.org/10.1007/s11053-009-9093-1

Myers, T., 2012. Potential contaminant pathways from hydraulically fractured shale to aquifers. Groundwater, 50(6), 872–882. DOI: http://dx.doi.org/10.1111/j.1745-6584.2012.00933.x

National Energy Technology Laboratory, 2006. Emerging issues for fossil energy and water. Available
from: http://www.netl.doe.gov/technologies/oil-gas/publications/AP/IssuesforFEandWater.pdf

NONOX BV, 2007. Enhancements in the well to wheel path of natural gas, Multi Disciplinair Project Group 3, Eindhoven University of Technology, Department of Chemical Engineering and Chemistry. Available from http://students.chem.tue.nl/ifp23/report.pdf

NRC, 2012. Induced Seismicity Potential in Energy Technologies (Prepublication), National Academies Press, 2012.

National Petroleum Council, 2007. Facing the Hard Truths about Energy and supplementary material: Topic Papers on GTL and CTL. http://www.npchardtruthsreport.org/

Nunez-Mata, D. 2010. Evaluation Of Alternatives For Disposal And Monetization Of Associated Natural Gas – Offshore Deepwater Brazil, Master Thesis, Mewbourne School Of Petroleum And Geological Engineering, University of Oklahoma (USA).
http://mpge.ou.edu/research/documents/2010%20thesis/DANIEL%20NUNEZ%20MATA.pdf

NY Times, 2011.Natural gas’s toxic waste, drilling down. The New York Times Series on natural-gas drilling. Accessed Aug 20, 2012

Oke, A., Gopalakrishnan M., 2009. Managing disruptions in supply chains: A case study of a retail supply chain. International Journal of Production Economics, 118(1):168–174. DOI: http://dx.doi.org/10.1016/j.ijpe.2008.08.045

Ogugbue, C., Chukwu, G. and Khataniar, S. 2007 . Economics of GTL Technology for Gas Utilization, Society of Petroleum Engineers – Hydrocarbon Economics and Evaluation Symposium, Dallas (Texas, USA), April 1-3, 107654-MS. http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-107654-MS

Oil and Gas Eurasia 2009. Flaring Up – Companies Pay High Costs To Be Green, 4, April. Available at
http://www.oilandgaseurasia.com/articles/p/97/article/883/

Osborn, S., Vengosh, A., Warner, N., Jackson R., 2011. Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing, Proceedings of the National Academy of Science, January, 2011.

Palmer, M.A., et al, 2010. Mountaintop mining consequences. Science, 327(5962), 148–149.
DOI: http://dx.doi.org/10.1126/science.1180543

Panahi, M., Rafiee, A., Skogestad, S., Hillestad, M., 2012. A natural gas to liquids process model for optimal operation. Industrial and Engineering Chemical Research, 51(1), 425–433. DOI: http://dx.doi.org/10.1021/ie2014058

Patel, B. 2005. Gas Monetisation: A techno-Economic Comparison of Gas-to-Liquid and LNG, Foster Wheeler, Presented at 7th World Congress on Chemical Engineering, Glasgow. Available from
http://www.fosterwheeler.com/publications/tech_papers/files/IChemE%20WCCE%2005%20LNG%20versus%20GTL.pdf
Purwanto, W. Mulia, Saputra, A. , Thaib, A., Hanif, A., Yagus, A. 2005. Gas-To-Liquids (GTL) as an option in monetizing stranded gas field. feasibility analyses using integrated process routes, Departemen Teknik Gas dan Petrokimia Fakultas Teknik Universitas Indonesia.
Available from http://www.docstoc.com/docs/90765442/GTL-for-Matindok-Gas-Fields-as-an-option

Rahmin I. 2008. SPECIAL REPORT: GTL, CTL finding roles in global energy supply, Oil & Gas Journal, 196(12), March 24.
Rahman, O. and Al-Maslamani, M. 2004. GTL: Is it an attractive route for monetization, Society of Petroleum Engineers – Abu Dhabi
International Conference and Exhibition, 10-13 October 2004, Abu Dhabi, United Arab Emirates, 88642-MS. Available from
http://www.onepetro.org/mslib/servlet/onepetropreview%3Fid%3D00088642%26soc%3DSPE
Rahman O. 2008. Gas to Liquid (GTL): is it an attractive route for gas monetization? GTL vs. LNG Economics, Egypt Oil and Gas Newspaper, 13:10. http://www.egyptoil-gas.com/read_article_issues.php?AID=143
Ramdass, A. 2010. NIB’s US$ 10 World GTL Investment a con job, Trinidad Express Newspapers, Trinidad Express Newspapers, September 23. Available from http://www.trinidadexpress.com/news/NIB_s_US_10m_World_GTL_investment__a_con_job_-103685499.html

RAND, 2008. Producing liquid fuels from coal – prospects and policy issues. Monograph prepared for the US Air Force and the National Energy Technology Laboratory of the US Department of Energy by RAND Corporation. Available from: http://www.rand.org

Robertson, E. 1999. Options for gas-to-liquids technology in Alaska, Idaho National Engineering and Environmental Laboratory, INEEL/EXT-99-01023, Prepared for the U.S. Department of Energy Office of Fossil Energy under DOE Idaho Operations Office Contract DE-AC07-99ID1372. Available from http://www.inl.gov/technicalpublications/Documents/3318115.pdf

Robinson, K., Tatterson, D., 2008. Economics on Fischer-Tropsch coal-to-liquids method updated. Oil& Gas Journal, 106(40):22-26.

Rong, F., Victor, D.G., 2011.Coal liquefaction policy in China: Explaining the policy reversal since 2006. Energy Policy, 39(12):8175–8184. DOI: http://dx.doi.org/10.1016/j.enpol.2011.10.017

Sasol, 2002.Mind over matter – The Sasol Story: A half-century of technological innovation. 176 p. Available from: http://www.sasol.com

Sasol, 2005.Unlocking the potential wealth of coal. Information brochure. Available from: http://www.sasol.com
Schmitt, A., Singh, M., 2012, A quantitative analysis of disruption risk in a multi-echelon supply chain. International Journal of Production Economics, 139(1):22-32. DOI: http://dx.doi.org/10.1016/j.ijpe.2012.01.004
Simangunsong, E., Hendry, L.C., Stevenson, M., 2012. Supply-chain uncertainty: a review and theoretical foundation for future research. International Journal of Production Research, 50(16): 4493–4523. DOI: http://dx.doi.org/10.1080/00207543.2011.613864
Singh, A.R., Mishra, P.K., Jain, R., 2012. Design of global supply chain network with operational risks. International Journal of Advanced Manufacturing Technologies, 60(1-4): 273–290. DOI: http://dx.doi.org/10.1007/s00170-011-3615-9
Smyth, R, Narayan, P.K., Shi, H., 2012. Inter-fuel substitution in the Chinese iron and steel sector. International Journal of Production Economics, 139(2): 525–532. DOI: http://dx.doi.org/10.1016/j.ijpe.2012.05.021

SRES, 2000. Special Report on Emissions Scenarios. Report by the Intergovernmental Panel on Climate Change (IPCC). Available from: http://www.ipcc.ch/
Sovacool, B.K., Cooper, C., Parenteau, P., 2011. From a hard place to a rock: Questioning the energy security of a coal-based economy. Energy Policy, 39(8):4664–4670. DOI: http://dx.doi.org/10.1016/j.enpol.2011.04.065
Spath, P.L., Mann, M.K., Kerr, D.R., 1999. Life cycle assessment of coal-fired power production. Report from National Renewable Energy Laboratory (NREL), NREL/TP-570-25119, June 1999. Available from:http://www.nrel.gov/docs/fy99osti/25119.pdf
SSEB, 2006. American energy security – building a bridge to energy independence and to a sustainable energy future. Report from the Southern States Energy Board (SSEB). Norcross, Georgia, July 2006. http://www.americanenergysecurity.org/studyrelease.html
Steynberg, A.P., Nel., H.G., 2004. Clean coal conversion options using Fischer–Tropsch technology. Fuel, 86(6):765–770. DOI: http://dx.doi.org/10.1016/j.fuel.2003.09.023
Talberth, J., 2009. Economic feasibility of coal to liquids development in Alaska’s interior. Report prepared for the Northern Alaska Environmental Center. Available from: http://www.sustainable-economy.org/main/send_client_files?f=CTL%2520Comments.pdf
Tavakoli, A., Sohrabi, M., Kargari, A., 2008. Application of Anderson–Schulz–Flory (ASF) equation in the product distribution of slurry phase FT synthesis with nanosized iron catalysts. Chemical Engineering Journal, 136(2–3):358–363. DOI: http://dx.doi.org/10.1016/j.cej.2007.04.017
Tijmensen, M., Faaij, A., Hamelinck, C., van Hardeveld, M., 2002. Exploration of the possibilities for production of Fischer-Tropsch liquids and power via biomass gasification. Biomass and Bioenergy, 23:129–152.DOI:http://dx.doi.org/10.1016/S0961-9534(02)00037-5
Towill, D.R., Christopher, M., 2001. The supply chain strategy conundrum ~ to be Lean or Agile or to be Lean and Agile. Proceedings of the International Logistics Symposium, Salzburg, 2001, 3–12.
UKERC, 2009. Global oil depletion: an assessment of the evidence for a near-term peak in global oil production. UK Energy Research Centre, London. Available from: http://www.ukerc.ac.uk/
US Department of Energy, 2011. Shale gas production subcommittee second ninety day report. Secretary of Energy Advisory Board, November 2011. Available from: http://energy.gov/downloads/90-day-second-report-shale-gas-production-secretary-energy-advisoryboard

US House, 2011. Chemicals used in hydraulic fracturing. United States House of Representatives Committee on Energy And Commerce, April 2011.
Vallentin, D., 2008. Policy drivers and barriers for coal-to-liquids (CtL) technologies in the United States.Energy Policy, 36(8):3198–3211. DOI: http://dx.doi.org/10.1016/j.enpol.2008.04.032
Velasco, J., Lopez, L., Velásquez, M., Boutonnet, M., Cabrera, M., Järas, 2010. Gas to liquids: A technology for natural gas industrialization in Bolivia, Journal of Natural Gas Science and Engineering, 2(5), 222-228. DOI: 10.1016/j.jngse.2010.10.001
Velocys. 2010. Microchannel GTL Technology: Demonstration through to Commercialisation, smi Gas to Liquids 2010, Hilton London Kensington 27 – 28 October 2010. Available from
http://bdd30412c4435fb83871bb42c4abc74fdcc18bff.gripelements.com/downloads/oxfordcatalysts-velocys_gtl_update_oct10.pdf
Velocys. 2011. Media and Press Overview. Available from http://velocys.com/ocgf01.php
Wang, P., Jin, L., Liu, J., Zhu, S., Hu, H., 2011. Analysis of coal tar derived from pyrolysis at different atmospheres. Fuel, article in press. DOI: http://dx.doi.org/10.1016/j.fuel.2010.06.041

Wang J et al (2019) Water Footprint Assessment for Coal-to-Gas in China. Natural Resources Research.
Wei, H., Wong, C.W.Y., Lai, K., 2012. Linking interorganisational trustwith logistics information integration and partner cooperation under environmental uncertainty. International Journal of Production Economics, 139(2): 642–653.
Williams, R., Larson, E., 2003. A comparison of direct and indirect liquefaction technologies for making fluid fuels from coal. Energy for Sustainable Development, 7:79–102.
Williams R et al (2009) Fischer–Tropsch fuels from coal and biomass: Strategic advantages of once-through (“polygeneration”) configurations. Energy Procedia, 1(1):4379-4386. DOI: http://dx.doi.org/10.1016/j.egypro.2009.02.252
Wood, D.A., Nwaoha, C., Towler, B.F., 2012. Gas-to-liquids (GTL): A review of an industry offering several routes for monetizing natural gas. Journal of Natural Gas Science and Engineering, 9, 196–208. DOI: http://dx.doi.org/10.1016/j.jngse.2012.07.001
Woods, T., Wilkinson P. and McGill, C., 2002. Meeting the Gas Supply Challenge of the Next 20 Years Non-Traditional Gas Sources, Report prepared for the National Renewable Energy Laboratory -American Gas Foundation. Available at http://www.gasfoundation.org/ResearchStudies/GasSupplyStudyNonTraditional1Final.pdf World Coal Institute, 2006. Coal: liquid fuels. Report from 2006. http://www.worldcoal.org/
World Coal Association, 2012. What is coal seam methane? Available from:http://www.worldcoal.org/coal/coal-seam-methane
Wu J et al (2011) Assessment of coal and biomass to liquid fuels in central Appalachia, USA, International Journal of Energy Research. 36(7):856–870. DOI: http://dx.doi.org/10.1002/er.1838
Yang, J., Sun, Y., Tang, Y., Liu, Y., Wang, H., Tian, L., Wang, H., Zhang, Z.,Xiang, H., Li, H., 2006. Effect of magnesium promoter on iron-based catalyst for Fischer–Tropsch synthesis. Journal of Molecular Catalysis A: Chemical, 245(1-2):26-36. DOI: http://dx.doi.org10.1016/j.molcata.2005.08.051
Yurchak, S., 1988.Development of Mobil’s fixed-bed Methanol-to-Gasoline (MTG) process. Studies in Surface Science and Catalysis, 36, 251–272.
Zhang, Y., Xiang, W., Zhou, T., Lei, J., 2009. The development of coal liquefaction: opportunities and challenges. Coal Economy Research 8:6–8 (in Chinese)