The energy valorization of heterogeneous ligno-cellulose residues by the continuous Transpaille process

In tropical countries, agricultural development is mainly limited by drought and low soil fertility : methanisation can be a good alternative for compost, and fuel production for small pumping sets; heterogeneous lignocellulose residues constitute a large amount of available biomass in tropical agricultural systems. Transpaille equipment is based on a continuous anaerobic fermentation process, designed for continuous compost and biogas production, using any kind of agricultural residues. The complete process including fermentation and uses of biogas and compost, has been experimented in Senegal since 1983. The relationship of biogas production, load of substrat and temperature was studied to provide technical references of the fermenter in real conditions. Using 2 years of daily results, the physical functioning of the fermenter was modelised to define kinetic and retention time aspects. Then, including these results, kinetics and the performance of biodegradation were studied on the same period and data basis. A linear relationship was computed to evaluate biogas production in terms of substrate load and average fermentation temperature. Compost use was carried on through a long period multi-factor trial. The first results are very interesting in the fields of mineral fertilizer economy and soil fertility increase. Since 1985, the Transpaille fermenter is being developed in Africa for different applications : irrigated areas, electricity production, post-recolt technology