Effets environnementaux et production de nouvelles sources energiques de la biomasse issue du riz : cas de letuvage du riz au CePEA Sourou au Nord-Ouest du Benin

Abstract

Rice parboiling is a time and energy consuming activity, and is a source of solid and liquid wastes including husks, rice bran and wastewater. This research aims to assess the environmental effects of parboiling rice before and five years after the contractualization between rice producers and processors. The case study focused on the Center for the Promotion of Women's Agricultural Entrepreneurship (CePEA Sourou) in Natitingou in North-west Benin. The search for solutions to environmental effects, led CePEA to introduce innovations such as improved stoves, briquettes (bio-charcoal) and to apply action research through experiments aimed at optimizing processes (with 82 tests before and after contractualization). The results have shown that parboiling rice after contracting gives a better husking yield and consequently less solid waste, ie a yield of 65.34% of rice and 34.66% of solid waste after contracting, against a yield of 56.93% of rice and 43.07% of waste before contracting. As for liquid waste, the average produced after contracting is 523.59 liters, lower than that before contracting which is 545.10 liters per 100 kg of steamed paddy, an increase of 4.10%. With an annual processing capacity of 200 tonnes at CePEA, the quantity of solid waste produced is 69.3 tonnes (after contracting). The consumption of wood energy for the parboiling of 100Kg of paddy rice, is on average 18Kg, or about 36 tonnes of wood annually. By using briquettes, the cost of fuel can be reduced by 30% to 40%, saving time of 51.17 minutes for preheating and 61.93 minutes for steaming.