Method for producing biogas by virtue of large-scale anaerobic fermentation of wood fiber raw materials

Abstract

The invention discloses a method for producing biogas by virtue of large-scale anaerobic fermentation of wood fiber raw materials. The method comprises the following steps: crushing the wood fiber raw materials to be below 5.0cm and then adding an inoculum, regulating by use of water or biogas slurry and evenly mixing; adding the mixture to a continuous stirring reactor for wet anaerobic fermentation to produce biogas, wherein the stay time of the raw materials in the continuous stirring reactor is controlled to be within 15-20 days; immediately dehydrating biogas residue discharged by the continuous stirring reactor each day until the moisture content of the biogas residue is 75%-85%; directly feeding the dehydrated biogas residue into a semi-continuous feeding high-solid anaerobic reactor for further anaerobic fermentation to produce biogas. The method for producing the biogas by virtue of large-scale anaerobic fermentation of the wood fiber raw materials has the advantages that the processing capacity and the volumetric gas production rate of the anaerobic reactor are greatly improved, the volumetric gas production rate of the reactor is increased by more than 45% and more than 66% in contrast with a single CSTR process and a single high-solid anaerobic fermentation process, respectively, the unit volume capability of the reactor in processing the wood fiber raw materials is increased by more than one time, and good economic benefit can be produced.

Description

technical field [0001] The invention belongs to the field of renewable energy development and utilization and environmental protection, and specifically relates to a new high-efficiency wet-high solid coupling anaerobic fermentation process aimed at the characteristics of anaerobic fermentation of lignocellulosic raw materials for biogas production. The method aims at reducing engineering investment cost, shortening fermentation cycle and improving the treatment capacity of anaerobic reactor. Background technique [0002] Lignocellulosic raw materials refer to a large class of substances with cellulose, hemicellulose and lignin as the main components, including all trees, turf, agricultural straw, tobacco, traditional Chinese medicine residue, bagasse, etc. The output is huge and renewable. Its resource utilization is valued by countries all over the world. Anaerobic fermentation of lignocellulosic raw materials to produce biogas due to its mild operation process and low o...

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Problems solved by technology

[0005] The purpose of the present invention is to aim at the characteristics of the anaerobic bioconversion rate of lignocellulosic raw materials, which is high at the beginning and then low, and combined with the low volumetric gas production rate, low anaerobic reactor processing capacity, and high one-time investment, which are common in current lignocellulosic raw material biogas projects The problem is to make full use of the advantages of wet anaerobic fermentation and high-solid anaerobic fermentation to provide a method that is not only simple but also easy to operate, and can greatly increase the volume of the reactor to produce gas under the premise of ensuring that the anaerobic bioconversion rate of lignocellulosic raw materials remains unchanged. The method of reducing the cost of project investment by improving the efficiency and the capacity of the reactor to deal with waste

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