Methanol from biomass feedstocks

Considering the full production cycle, methanol from biomass emits less carbon dioxide than ethanol from biomass. This is because short rotation forestry, the feedstocks of methanol, requires the use of less fertilizer... 

Science Applications, Inc., has recently completed a comprehensive technical and economic assessment of producing methanol from biomass feedstocks employing developed gasification technology. This study includes an assessment of biomass availability and the distribution and markets for methanol fuels as well as thermochemical conversion technology. 

Producing methanol from biomass or coal costs about twice as much as producing it from natural gas. This encourages the use of nonrenewable petrochemical sources over biomass or coal. Considering the full production cycle, methanol from biomass emits less carbon dioxide than ethanol from biomass. This is because short rotation forestry, the feedstocks of methanol, requires the use of less fertilizer and diesel tractor fuel than the agricultural starch and sugar crops which are the feedstocks of ethanol. 

Among the various products that can be synthesized from biomass, methanol was selected because of its versatile applicability to the electricity, transportation, and chemical sectors. Conversion of methanol from biomass is achieved via oxygen-steam gasification followed by shift conversion and methanol synthesis. Three feedstocks were selected for conversion to methanol—wood residue, corn stover, and furfural residue. Availability of... 

Biofuels. Biofuels are Hquid fuels, primarily used ia transportation (qv), produced from biomass feedstocks. Identified Hquid fuels and blending components iaclude ethanol (qv), methanol (qv), and the ethers ethyl /-butyl ether (ETBE) and methyl /-butyl ether (MTBE), as well as synthetic gasoline, diesel, and jet fuels. 

Methanol, which is also known as wood alcohol, is a colorless and odorless liquid alcohol fuel that can be made from biomass, natural gas, or coal. It is the simplest alcohol chemically and it may be used as an automobile fuel in its pure form (Ml 00), as a gasoline blend of typically 85% methane to 15% unleaded gasoline (M85). It is also used as a feedstock for reformulated gasoline. M100 or pure methanol may be used as a substitute for diesel. In M85, the gasoline is added to color the flame of burning fuel for safety reasons and to improve starting in cold weather. 

Methanol and ethanol are alcohol fuels that can be produced from various renewable sources. Alcohol fuels are converted from biomass or other feedstocks using one or several conversion techniques. Both government and private research programs are finding more effective, less costly methods of converting biomass to alcohol fuels. Methanol was originally a by-product of charcoal production, but today it is primarily produced from natural gas and can also be made from biomass and coal. 

This paper covers the current technology of methanol production, reviews how the energy crisis and the escalation of hydrocarbon feedstocks impact that technology, and describes conventional, new, and potential uses for methanol. Methanol is a chemical intermediate and solvent produced from several feedstocks and is consumed in a variety of end uses. Prior to the development of a synthetic route to methanol, commercial quantities were obtained from the destructive distillation of wood or other biomass. Now, with interest focused on conservation and the use of renewable resources, methods have been proposed to use biomass again as a methanol feedstock. While some of these proposals hold great appeal, they are still speculative and beyond the scope of this paper. (Methanol from wood is discussed in the following chapter.)... 

When perfected, synthesis-gas-to-ethanol technology can be expected to have a large impact on fermentation ethanol markets. It is likely that thermochemical ethanol would then be manufactured at production costs in the same range as methanol from synthesis gas, which can be produced by gasification of virtually any fossil or biomass feedstock. Applying the advances that have been made for conversion of lignocellulosic feedstocks via enzymatically catalyzed options, it has been estimated that the production cost of fermentation ethanol... 

The production of multiple products is generally seen as necessary to increase the economic viability of biomass conversion. This is encapsulated in the concept of a biorefmery , which according to the National Renewable Energy Laboratory (NREL) is a facility that integrates conversion processes and equipment to produce fuels, power and chemicals from biomass [23], Examples of chemicals that can be produced from biomass include ethanol, methanol, furfural, paper, lignin, vanillin, lactic acid, dimethylsulfoxide and xylitol. In many cases, using biomass as a feedstock for chemical production requires an initial step to separate or fractionate the three main components into usable fractions [20, 22], This also maximises the usage of the different biomass components. 

Such complimentary synthesis routes or "HYBRIDS can achieve remarkable reductions in capital cost and expensive biomass carbon utilisation. The methane and wood hybrid to produce methanol from the resulting syn-gas would use 722 nr of natural gas and 0.4 tonne of biomass to produce 1 tonne of methanol at a capital cost of around 10 k /TJ/annum capacity on the 1000 tpd product scale. Though part of the feedstock is then priced at the international oil price (energy equivalent) a plant scale of 3000 tpd operating at 60 per cent efficiency will meet the economic criteria of the simple model used in this paper. 

Use of Different Fuels and Their Characteristics - The best commercial, dry, low NOx combustors today are optimized for clean-burning natural gas. However, with raised natural gas prices over the next decade, power plants may be forced to burn low-heating value fuel gas, products of gasification or low quality residual fuels. As the combustion becomes more complicated, e.g. lean-premixed combustors, to handle NOx emissions from different fuels is bound to become more complex, too. Hence, development of the catalytic combustor must also be directed towards fuels other than natural gas. These fuels could be other hydrocarbon feedstock, e.g. diesel fuels,which are more available than natural gas in some parts of the world, and kerosene,which is used for jet-turbines in aeroplanes. An increased use of renewable fuels, such as methanol, ethanol and low-heating value fuels derived from biomass or waste will also lead to a demand to put these fuels to use in gas turbines. ... 

As outlined above, biomass feedstock can also be employed for the production of syngas and, thus, methanol produced from biomass-derived syngas and fuels obtained through processing of biomass-based methanol can be considered as typical biofuels. Blends with petrol containing up to 20% of methanol can be used in combustion engines without elaborate modifications. However, the comparatively low energy density and safety concerns have limited so far broad applications of methanol as fuel. Another option is the use... 

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