| 摘要 |
<p>PURPOSE:To increase the amt. of the digester gas to be produced by separating night soil to solid component and liquid, treating the liquid in a direct methane formation stage, and subjecting the solid matter to a methane formation treatment in succession to an acid formation stage after hydrolyzing the same with an acid, alkali, etc. CONSTITUTION:Night soil 9 is subjected to a solid-liquid sepn. with a solid- liquid separator 1 such as a screen, a thickener or the like. The solid component is hydrolyzed by a hydrolyzer 2 where acid or alkali is added thereto under heating and high molecular org. materials are converted to lower molecular materials. The treated night soil is then put into an acid fermentation tank 3. The gas formed in the tank 3 is circulated therein to stir and mix the night soil and to bring the same into contact with facultative anaerobe, whereby the org. materials are decomposed to volatile org. acids such as acetic acid, propionic acid or the like. The liquid component of the night soil and the outflow liquid from the acid fermentation tank are conducted to a methane fermentation tank 4, where the gas generated from the tank is circulated to stir and mix the liquid and to bring the same into contact with methane forming bacteria. The volatile org. acids are thus converted to gaseous methane, carbon dioxide, etc.</p> |
