Abstract
Production of biodiesel utilized as a renewable energy is hampered by the problem of disposal of the strongly alkaline by-product crude glycerol. We examined simultaneous biogasification by adding crude glycerol to a methane fermentation process for food waste. We used a fermentation plant processing okar(a soy pulp).When food waste was added to this plant, the biogas production rate decreased from 2.4 ㎥/㎏-C to 1.3 ㎥/㎏-C because of the inhibition of fermentation by the food waste. However, when both food waste and crude glycerol were added to the plant, the biogas production rate recovered to 2.0 ㎥/㎏-C. Thus, simultaneous input of crude glycerol and food waste contributes to both the disposal of the strongly alkaline crude glycerol and the prevention of the fermentation inhibition by food waste. Use of biogas as an automobile fuel will reduce 0.45 tons of atmospheric CO2 per year, thereby, contributing to low carbonization.
