Cellulose carbon conversion efficiency

Figure 1. Cellulose carbon conversion efficiency rjC as a function of gas-phase residence time for various gas-phase temperatures...

Figure 1 illustrates the critical role played by step 2 in cellulose gasification. By increasing the temperature achieved by the gas phase volatile matter from 500°C to 750°C, the carbon conversion efficiency nc is increased from qc = 0.1 to nc = 0.76. 

Oxide catalysts are known to be effective for oxidation reactions. In this study, we wanted to produce carbon monoxide through partial oxidation of the biomass, as this could be expected to lead to a conversion of carbon monoxide into hydrogen via the water-gas shift reaction. An oxidization of the tarry product is also expected. By these two effects, improvement of the efficiency of the gasification is expected. Oxide catalyst is expected to enhance the oxidation reaction needed for this scenario. Since oxide catalyst is considerably cheaper than nickel catalyst, its use would make the whole gasification process more economical. Hence, we decided to examine the effect of oxide catalysts on gasification with partial oxidation using cellulose as a model compound. 

Cellulose wastes can be regarded as including about 50 % carbon and 50 % water. Carbon oxydizing conversion means, as a general rule that with a mean gasification efficiency of 75 %,... 

Vast amounts of renewable biomass are available for conversion to liquid fuel, ethanol. In order to convert biomass to ethanol, the efficient utilization of both cellulose-derived and hemicellulose-derived carbohydrates is essential. Six-carbon sugars are readily utilized for this purpose. Pentoses, on the other hand, are more difficult to convert. Several metabolic factors limit the efficient utilization of pentoses (xylose and arabinose). Recent developments in the improvement of microbial cultures provide the versatility of conversion of both hexoses and pentoses to ethanol more efficiently. In addition, novel bioprocess technologies offer a promising prospective for the efficient conversion of biomass and recovery of ethanol. 

Geboers J, Van de Vyver S, Carpentier K, de Blochouse K, Jacobs P, Sels B (2010) Efficient catalytic conversion of concentrated cellulose feeds to hexitols with heteropoly acids and Ru on carbon. Chem Common 46(20) 3577—3579... 

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