Poplars, hybrid gasification

Timpe, R.C. Hauserman, W.B. (1993).The catalytic gasification of hybrid poplar and common cattail plant chars. Energy from Biomass and Wastes XVI, Institute of Gas Technology, March 2-6, 1992, pp, 903-919. 

Since catalysis is of such current interest, this paper presents a review of some of the literature which deals with the catalytic gasification of biomass. It also summarizes the preliminary results of a bench-scale fluid bed gasification study which employed Canadian hybrid poplar. The effect of such catalysts as potassium carbonate and calcium oxide on wood gasification is reported. Hybrid poplar was selected due to its rapid growth and, therefore, its relevance to the concept of wood energy plantations. 

Five year old Ontario hybrid poplar was used during the experiments. It had a calorific value of 4700 cal/g and was hammermilled to a size range of 600 to 800 microns. The wood was then oven dried prior to gasification. 

Table 1 summarizes the results of noncatalyzed hybrid poplar gasification at 500 C in a fluidized bed reactor. Approximately forty five percent (45%) of the wood was gasified. Twenty five percent (25%) was converted to a liquid and thirty percent (30%) remained as a solid product. The gasification reached a steady state by at least four minutes as indicated by the chemical composition of the gas. Samples collected at 8 and 12 minutes had similar gas composition. No hydrogen was detected in the gas product. Carbon monoxide and carbon dioxide were the major components with a small amount of methane and low molecular weight hydrocarbons. 

Table II summarizes the catalyzed gasification results of the hybrid poplar in the presence of potassium carbonate and calcium oxide. Both of these catalysts increased the liquid and gas yield at the expense of the solid. Both catalysts promoted a final product which was approximately fifty percent (50%) gaseous. The remainder of the product was thirty percent (30%) liquid and twenty percent (20%) solid.

Gasification Results of Hybrid Poplar at 500°C in a Fluid Bed System... 

Results from the hybrid poplar gasification are encouraging and warrant additional research. Future catalytic work at Forintek will employ incremental temperatures ranging from 600 to 1000 C and will include a variety of catalysts and catalytic combinations. An attempt will be made to promote the production of the following gases which enjoy different end uses ... 

---