Table 3 Bioconversion technologies for producing selected energy products from wood.
Product	Technology	Remarks
Electricity	Combustion by spreader	Developed and in use for capacities up to 55 MW equivalent
	Stokers in boiler
	Furnaces
	Fluid-bed combustion	Limited use for steam generation with wood-yard waste as fuel
	Charcoal/oil slurry firing	Under development by ERDA
Substitute natural gas	Gasification/methanation	Under intense development for coal. New development activity required for gasification of wood. Current experience at atmospheric pressure using municipal solid waste.
	Anaerobic bacterial digestion	Well-known technology for municipal sewage treatment. Lignin may inhibit bacterial activity.
Medium-Btu fuel gas	Gasification	Same as for substitute natural gas. Product can be a raw material (synthesis gas) for manufacturing methanol and ammonia.
Fuel oil	Pyrolysis	Flash-pyrolysis pilot plant using municipal solid waste to produce fuel oil now in early stages of operation. Moving-bed pyrolysis developed on significant scale by Georgia Institute of Technology. Low-grade oil may require aftertreatment.
Charcoal	Pyrolysis	Coproduct of processing or fuel-oil production. Multiple-hearth furnace process now standard practice for charcoal production
Ammonia	Gasification/hydrogen production/ammonia synthesis	Gasification same as for substitute natural gas. Carbon monoxide shift to hydrogen and ammonia synthesis widely used and well-developed technology
Methanol	Gasification /methanol synthesis	Gasification same as for substitute natural gas. Methanol synthesis widely-used, and well-developed technology
Ethanol	Cellulose hydrolysis and fermentation	Fermentation step widely used, and well-developed. Industrial experience significant for dilute sulfuric acid as the hydrolytic agent

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