Hydrogen fermentation of organic municipal wastes

Hydrogen gas is recognized as a promising energy resource in the future. Mi crobial hydrogen fermentation would be an attractive process for hydrogen r ecovery. In particular, hydrogen production using fermentative bacteria has some advantages such as a high rate of hydrogen production without light. in this study, the hydrogen production from organic wastes was investigated using batch experiments. Bean curd manufacturing waste, rice bran and whea t bran were used as the organic wastes. The effects of solid concentration on the hydrogen production potential and the characteristics of substrate d ecomposition were investigated. The percentages of hydrogen in the produced gas were between 54-78%, 43-68% and 42-72% for bean curd manufacturing was te, rice bran and wheat bran, respectively. The hydrogen production potenti als of bean curd manufacturing waste. rice bran and wheat bran were 14-21, 31-61 and 10-43 ml.g VS-1, respectively. The hydrogen yields from carbohydr ate degradation were 2.54, 1.29 and 1.73 mol of H-2 mol(-1) of hexose for b ean curd manufacturing waste, rice bran and wheat bran, respectively. The c arbohydrate was rapidly consumed just after inoculation. On the other hand, soluble protein was hardly degraded for each substrate, indicating that ca rbohydrate was the main source of the hydrogen production.