| 摘要 |
<p>PURPOSE: An anaerobic digestion system capable of a pH control is provided to control the pH of digestive fluid in a methane fermentation step by lowering the CO_2 concentration of a digestion gas generated in a acid fermentation step. CONSTITUTION: An anaerobic digestion system capable of a pH control includes an acid fermentation bath(10), a digestive fluid discharge line(20), a methane fermentation bath(30), a digestion gas discharge pipe(40), CO_2 absorption tower(50), and a digestion gas supply pipe(60). An acid fermentation bath ferments a processed substance. A digestive fluid discharge line is connected to the lower end of the acid fermentation bath. A methane fermentation bath is connected to the other end of the digestive fluid discharge line. A digestion gas discharge pipe is connected to the top of the acid fermentation bath. A CO_2 absorption tower reduces the CO_2 concentration of a digestion gas discharged from a digestion gas discharge pipe by being connected to the digestion gas discharge pipe. A digestion gas supply pipe is equipped between a CO_2 absorption tower and a methane fermentation bath and supplies a digestion gas processed in a CO_2 absorption tower to the methane fermentation bath. A CO_2 concentration is reduced by processing a digestion gas generated in the acid fermentation bath in the CO_2 absorption tower, and the pH of a methane fermentation bath(30) is controlled by supplying a digestion gas in which a CO_2 concentration is reduced to the methane fermentation bath.</p> |
