Preacidizing method for steam-exploded material washing liquid for biogas production by anaerobic fermentation

Abstract

The invention relates to a preacidizing method for steam-exploded material washing liquid for biogas production by anaerobic fermentation. The method adopts the steam-exploded material washing liquid such as bamboo, wood, grass and the like as material, and includes the following operation steps: (1.1) material liquid regulation: the proportion between chemical oxygen demand (CODcr), Kjeldahl nitrogen and total phosphorus in the steam-exploded material washing liquid is regulated to be 200 to 500:5:1, the pH value is 4.5 to 7.0, and thereby material liquid is obtained; (1.2) material liquid inoculation: the steam-exploded material washing liquid is naturally acidized under the temperature condition of 15 DEG C to 40 DEG C, so that liquid seed can be obtained; the liquid seed and the material liquid are mixed according to inoculation amounts, the volume ratio of which is 5 to 50 percent, and thereby mixed liquid is obtained; (1.3) material liquid acidization: under the temperature condition of 15 DEG C to 40 DEG C, the mixed liquid carries out acidizing reaction on standing or continuous acidizing reaction, and thereby acidized mixed liquid is obtained; and the acidized mixed liquid can also be used as the liquid seed in the step 1.2. The acidization degree of the steam-exploded material washing liquid is increased to more than 25 percent by the preacidizing method, the acidization time is shortened to less than or equal to 24 hours, and a great deal of steam-exploded material washing liquid can continuously enter an anaerobic reactor to stably produce biogas.

Description

technical field [0001] The invention belongs to the technical field of biogas energy preparation methods, and in particular relates to a pre-acidification method for washing liquid of steam-exploded materials used for anaerobic fermentation to produce biogas. Background technique [0002] Energy and the environment are the most important topics in the sustainable development of contemporary human society. The energy used by humans is mainly fossil fuels such as coal, oil, and natural gas. The extensive exploitation and use of fossil fuels not only makes their resources increasingly scarce but also seriously pollutes the environment. In addition, with the continuous development of agriculture and forestry, various wastes produced every year are increasing year by year. These wastes are mainly lignocellulosic materials, such as bamboo processing wastes, crop stalks, rice husks, weeds, etc. The research, development and utilization of these wastes not only protect the environm...

AI Technical Summary

Problems solved by technology

The above technologies use steam explosion to pretreat lignocellulosic materials, so that the structures and components such as cellulose, hemicellulose, and lignin in the materials are destroyed and degraded. The explosive material is directly subjected to anaerobic fermentation to prepare biogas. There are still many components that have not been fully acidified and degraded in the material. These components can only be used by methanogens after continued acidification and degradation in the anaerobic bioreactor, which prolongs the fermentation cycle and is not conducive to industrialization. Continuous production

However, many wastes, especially lignocellulosic raw materials, are not easy to meet this requirement and the pre-acidification takes a long time, which limits the development of biogas production from waste