Liquid transportation fuels

South Africa has the only commercial plant producing liquid transportation fuels and other products from coal. This technology will be described later. 

Biofuels are used to create a wide variety of energy sources. Ever since the harnessing of fire, biomass has been used for heating and conking. Residential burning of biomass continues to be a primary source of fuel in less industrialized nations, but also has been used as fuel for electricity generation, and converted to liquid transportation fuels. 

SPGK [Shell PolyGasoline and Kerosene] A process for oligomerizing C2 - C5 olefins to liquid transport fuels. The reaction takes place at 200 to 280°C and is catalyzed by a zeolite. Developed by the Shell Petroleum Company, Amsterdam, in 1990. 

Gasoline and diesel fuels are used worldwide in enormous amounts and are produced by the petroleum industry by oil refining (see Chapter 2). Liquid transportation fuels are conveniently transported, distributed, and dispensed directly into our vehicles and aircraft. Increased environmental concerns did much to begin to assure cleaner burning of our fuels. In the United States, law requires significant reduction of emissions and resulted in lead-free and more recently reformulated gasoline... 

Alternatively, short-rotation hybrid poplar and selected grasses can be multicropped on an eneigy plantation in the U.S. Northwest and harvested for conversion to liquid transportation fuels and cogenerated power for on-site use in a centrally located conversion plant. The salable products are liquid biofuels and surplus steam and electric power. This type of design may be especially useful for larger land-based systems. 

P.N. Dyer, C.M. Chen, Engineering development of ceramic membrane reactor system for converting natural gas to H2 and syngas for liquid transportation fuel, Proceedings of the 2000 Hydrogen Program Review, DOE, 2000... 

Forsberg, C. (2008), Meeting US Liquid Transport Fuel Needs with a Nuclear Hydrogen Biomass System , International Journal of Hydrogen Energy (2008), doi 10.1016/j.ijhydene.2008.07.110. 

Most of the processes discussed either have been or are being used to supply synthetic fuels on a commercial basis. There is, therefore, little question as to the feasibility of these processes. In most cases, however, these ventures have proved and continue to prove economically unattractive in the face of abundant supplies of cheap natural gas and oil. When supplies dwindle and prices escalate, as is likely to happen eventually, specific processes can be expected to become marginally attractive. In the United States, probably the most competitive of the synthetic fuels are shale oil and low-CV and medium-CV gas. The more complex routes to liquid transportation fuels from coal can be expected to be more costly. In all cases a reduction in costs will occur as experience is gained from initial plants. Coal and, eventually, oil shale reserves will, however, also become depleted. Because biomass can probably make only a limited contribution to the total energy demand, other sources of energy will have to be harnessed. The development of synthetic fuels will probably be necessary to obtain the time needed for the evolution of such alternative energy sources. 

Development of Ceramic Membrane Reactor Systems for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels, Proceedings of the 2002 U.S. DOE Hydrogen Program Review, NREL/CP-610-32405, Washington, D.C., 2002. 

With world crude oil supplies shifting in quality from lighter and sweeter crudes to heavier and higher sulfur crudes, and with that trend expected to continue, most refiners are looking to residual processing to increase the amount of liquid transportation fuel which is obtained from a barrel of crude. (1 )... 

Liquid bio-oil can be easily transported and stored. Czemik and Bridgwater reviewed the research on use of bio-oils for heat and power generation, showing that it is possible and usually only requires minor modifications of existing equipment.550 Bio-oil has been successfully used as boiler fuel and also showed promise for diesel engines and gas turbines.549,565,571-584 Upgrading bio-oil to a quality for liquid transportation fuels still poses several technical challenges and is not currently economically attractive.549,564,583,585-588... 

The current study is modeled after an NRC study that resulted in the 1990 report Fuels to Drive Our Future (NRC, 1990), which analyzed the status of technologies for producing liquid transportation fuels from domestic resources, such as biomass, coal, natural gas, oil shale, and tar sands. That study evaluated the cost of producing various liquid transportation fuels from these resources on a consistent basis, estimated opportunities for reducing costs, and identified R D needs to improve technologies and reduce costs. Fuels to Drive Our Future did not include the production and use of hydrogen, which is the subject of this committee s report. The statement of task for the committee was as follows ... 

Fourth, by careful choice of the zeolite support in the preparation of a bifunctional catalyst for synthesis gas conversion, the product distribution, particularly for hydrocarbons, may be controlled. This conclusion is of importance in the design of catalysts for the production of liquid transportation fuels from synthesis gas. 

It has been estimated [3] that enough waste plant biomass is generated in the United States to produce all of the organic chemicals currently manufactured by the US chemical industry and supply a significant fraction of its liquid transportation fuel needs. For example, one ton of wheat straw affords ca. 600 kg of carbohydrates and ca. 200 kg of lignin. The former can be converted, by fermen-... 

These chemicals as well as energy vectors can be used in several applications or can be further upgraded into other useful products. They can all be produced via synthesis gas (CO + Hj) that has been the subject of extensive investigations and commercial industrial processes based on fossil based synthesis gas exist. The advantage of these vectors is that they can be either used in fuel cells for electricity or transport applications, or alternatively, they can be processed to liquid transport fuel additives such as dimethylether (DME) and dimethoxymethane (DMM). 

For example, the cost to transport one PJ of oil is approximately ten times lower than to transport the same energy content as (natural) gas. On its turn transport of gas is ten times cheaper than electricity, which on its turn is ten times cheaper to be transported than heat- For small- and medium scale B R fuelled installations the production of heat as major product is therefore the least attractive, unless they are fiilly integrated with other installations on site or deliver to a city heat grid. The economic most attractive option is to produce liquid transportation fuels. 

As other speakers at this symposium have described, the use of fuel gas produced by biomass or solid waste gasifiers can reduce the use of petroleum fuels in stationary combustion equipment (oil-fired boilers, diesel engines for electric generators or irrigation pumps). Stationary engines and furnaces, however, are not the only big users of petroleum fuels in lesser developed countries (or LDCs, the term we will employ to describe the 88 poorest nations in the world). As is the case for industrialized nations, lesser developed countries need liquid transportation fuels, and probably will for a long time. Brookhaven reports that most LDCs have increased their dependence on highway transport over the last two decades (lb). 

Potential for using alcohol fuels as a substitute or supplement for liquid transportation fuels is a topic of current interest not only in LDCs but in most areas of the world. The use of sucrose from sugar cane or by-product molasses (containing sucrose and various C sugars) has been the subject of discussions at several recent meetings of the United Nations Industrial Development Organization (UNIDO) and the Organization for Economic Cooperation and Development (OECD) (4., 5). ... 

Stiegel, G. J. PETC Review, PETC office of Fossil Energy-U.S. DOE Liquid Transportation Fuels from Coal - Part2 Indirect Liquefaction., Fall, 1991, Issue 4. 

E. Schmetz, C.L. Miller, J. Winslow, and D. Gray, Should there be a role for clean liquid transportation fuels from domestic coal in the nation s energy future . Paper presented at the Pittsburgh Coal Conference, 12-15 September, 2005, Pittsburgh, PA. www.engr.pitt.edu/pcc/... 

The U.S. currently imports about sixty (60) percent of its oil requirements (7), which is expected to increase to about 70 percent by the year 2025 (7). This reliance on foreign sources of oil has created both national and economic security issues for the U.S. It is desirable to produce liquid transportation fuels from alternative sources. The Fischer-Tropsch (F-T) process can be used to produce liquid fuels from synthesis gas (syngas), a mixture of hydrogen and carbon monoxide. Liquid fuels produced from die F-T process have very low levels of sulfur compared to petroleum products these ultra-clean fuels are environmentally friendly. However, syngas is commonly produced from natural gas, which has become significantly more expensive in recent years (2). Alternative, less expensive feedstocks for syngas production can reduce the costs of liquid fuels produced through the F-T process. 

The conversion of natural gas into liquid transportation fuel is a well-proven technology today. There are two basic technologies available the Fischer-Tropsch synthesis and the methanol route developed by Mobil Research and Development Corporation, USA. 

The methanol route is highly selective towards production of liquid transportation fuels. Only a very small amount of hydrocarbons beyond C are produced. The process uses a zeolite catalyst, developed by Mobil Research and Development Corp. (MRDC), USA. The final gasoline produced does not need further refining a nd attains the quality of unleaded premium gasoline. The world s first commercial synfuel plant for the production of gasoline from natural gas via methanol has been constructed in New Zealand and went successfully onstream in late 1985. The capacity is 570,000 tonnes of gasoline per year. The MTG reaction system is an adiabatic fixed bed version. 

The worldwide discovery of large gas fields and the declining discovery of new oil fields may lead in the direction to produce gasoline and distillate from natural gas up to the late 1990s. Oil-producing companies are also forced to search for and produce oil in more distant and remote areas which will add on cost which could not be justified by present crude oil prices. The production of liquid transport fuels from natural... 

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