Methanol from biomass process costs

When methanol is made from natural gas, the gas reacts with steam to produce synthesis gas, a mixture of hydrogen and carbon monoxide. This then reacts with a catalytic substance at high temperatures and pressures to produce methanol. The process is similar when methanol is produced by the gasification of biomass. The production of methanol from biomass or coal can cost almost twice as much as production from natural gas. 

Although the great majority of methanol is currently produced using natural gas and other fossil fuels, it can also be produced from renewable biomass. HameUnck and Faaij (2002) give a very fiiU description and analysis of the cost involved in such processes. They show that in a few years such processes should yield methanol with a process efficiency of about 60% and at a cost per Joule similar to current refined diesel and gasoline prices, though at the moment these are higher by a factor of about 3. 

SAQ 4.15 Use the data in the Resource Material to answer the following question. It is 1977. The bacterial SCP from methanol plant referred to in Table 4.9 does not produce protein at a price that competes with soya protein. By how much would the cost of methanol have to fall in order that the protein from such a plant can be produced competitively with soya protein You can assume i) that the SCP processes referred to in Tables 4.7 and 4.9 to 4.15 are of 2 x 10s tons annual capacity, ii) that yield on methanol is 0.5kg biomass per kg methanol, iii) bacterial SCP contains 60% protein. 

Almost all thermochemical biomass conversion processes can be considered and thus analysed as a black box with a feedstock input and an energy output (either thermal or electrical). Useful co-products will arise in the operation of the process (eg sulphur, acetic acid, methanol even food flavouring ) from which revenue may be earned. Relatively useless by-products (eg ash, frit and other emissions to air, land and water) which arise may incur a cost in their disposal if a market for their use cannot be found. 

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