Gasification, wood

The second group are gas phase reaetions. The hydrocarbons formed during devolatilization break down to form hydrogen and earbon monoxide  

Tar cracking reactions to produce simpler gases also occur, as long as the residenee time in the reactor is sufficient. Gaseous eomponents can rearrange via the water gas shift or methane formation reactions  

The overall result is a fuel gas mixture of earbon oxides, hydrogen, methane, water and any remaining tar and heavier hydroearbons that escape the gasifier. Some of 

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Interfuel substitution via direct burning of wood is presently economical in certain cases, and wood gasification may be attractive in site-specific applications. Wood liquefaction, however, is not at present attractive. 

The wood for the above mentioned Brazilian plant can be grown on a regenerable basis from about 90 square miles of forest (57,600 acres). Figure 7 is a block flow diagram showing the many process steps involved in Davy s wood gasification process. 

Figure 7. Synthesis gas production for methanol via wood gasification...

Reimert, R., and Mehrling, P. Wood Gasification in Lurgi Circulating Fluidized Bed Boiler Combustor, Huagong Xuebao Vol. 38, No. 4, p. 478 (1987). 

Reimert, Rainer, and Mehrling, Peter. Wood gasification in Lurgi circulating fluidized bed, Symp. For. Prod. Res. Int. Achiev. Future, vol. 5, CSIR, Pretoria, S. Afr., pp. 1-18 (1985). 

Wood Gasification in a Pressurized, Air-Blown, Bubbling Fluid-Bed Gasifier... 

In the mid- to late 1980s, a 258-GJ/h, fluid-bed wood gasification plant was built in Florida by Alternate Gas, Inc., for Southern Electric International (Miller, 1987 Makansi, 1987 Bulpitt and Rittenhouse, 1989). Each twin gasifier was 2.44 m in diameter and converted wood chips at the rate of... 

Wood Gasification in an Air-Blown, Crossdraft Gasifier-Combustor... 

This wood gasification plant is located at the relatively new coal fired heat unit of EPZ, Amer 9 at Geertruidenberg in The Netherlands, The aim of the project is to achieve savings of 70,000 tons of coal (33,700 TOE) based on 150,000 tons of wood waste (construction demolition waste) corresponding to 170,000 CO2 t/y reduction in emissions. The equivalent electricity capacity is 29 MWe. The gasification plant has been supplied by LURGI. 

Pyrolysis experiments owed that in the CASST process the charcoal will contain 30-S0 wt.% volatiles. Gasification of this charcoal gives a gas with tar concentrations that are 10-SO times lower than for wood gasification. Furthermore, the tars produced by charcoal gasification have a lower molecular weight than the tars produced by biomass gasification. 

Results of the gasification experiments ae summarised in figure 3. The BTX as well as the ta ooncentraions in foe fuel gas decrease with decreasing volatile matta content of the gasificatiai feedstock. For a gasification feedstock with 30-50 wt.% volatiles the BTX-concentration is 4-12 times Iowa compared to wood gasification, and foe ta concentration 10-50 times lower. 

Rensfell E. Everard D. (1998) Update on Project ARBRE Wood Gasification Plant Utilising Short Rotation Coppice and Forestry Residues. Seminar on Power Production from Biomass III. Espoo, Finland. 14-15 September. 

Ohlemiller T. J., Kashiwagi T. and Wcmer K. (1987) Wood gasification at fire level heat fluxes. Combustion and Flame, 69,155-70... 

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