Rice straw pretreatment method for anaerobic fermentation

Abstract

The invention relates to a rice straw pretreatment method for anaerobic fermentation. The method comprises the following steps: (1) cutting straw into preset length; (2) bundling the cut straw; (3) conveying the bundled straw to a unbundling machine for unbundling; (4) conveying the unbundled straw into a grinder for grinding treatment and screening the ground straw; and (5) conveying the straw subjected to grinding and screening in the step (4) by a cyclone separator, collecting dust generated in the conveying process, so that a large amount of dust is prevented from diffusing into the environment, and after collecting the dust, conveying the straw into a mixing unit through the cyclone separator to be mixed with livestock manure and reflux biogas slurry for anaerobic fermentation. The pretreatment method provided by the invention is beneficial to improving the biogas conversion rate in the subsequent anaerobic fermentation process, shortening the anaerobic fermentation time, effectively reducing the environmental pollution, reducing the anaerobic fermentation cost and saving the labor cost.

Description

technical field [0001] The invention relates to a rice straw pretreatment method for anaerobic fermentation. Background technique [0002] Straws such as corn stalks and rice stalks are the main raw materials for preparing biogas. The pretreatment of these straws is one of the most important units of the biogas plant, which directly affects the volume and methane production of the subsequent anaerobic fermentation tanks. [0003] The traditional rice straw pretreatment method usually includes the following steps: 1) cutting the straw into a length of about 10cm to 20cm and tying it into a square or round bundle, stacking it for yellow storage; 2) unbundling the straw after yellow storage Go to the pulverizer for crushing. The size of the crushed straw is different, and the maximum length usually reaches about 100mm. 3) Transport the crushed straw to the hydrolysis tank for preliminary hydrolysis, and stay for 2-3 days. 4) Put the preliminary hydrolyzed straw Transport to a...

AI Technical Summary

Problems solved by technology

[0004] In the above-mentioned traditional rice straw pretreatment method, the size of the straw crushed by the pulverizer is not controlled by size screening, so that the size of the straw varies greatly, and it is easy to cause the feed inlet to be blocked during the subsequent feeding process of preliminary hydrolysis. and, in the process of anaerobic fermentation, enough cellulose and hemicellulose need to be released from the lignin, if the degree of crushing of the straw in the pulverization process is not enough, it will be difficult for the cellulose and hemicellulose to be released from the lignin Released, resulting in low conversion rate of biogas

In addition, insufficient pretreatment of straw can easily cause crusting in the fermentation tube

Moreover, in the traditional straw pretreatment method, a large amount of dust generated during the crushing process is not collected after crushing. These large amounts of dust will not only pollute the environment, but also easily cause explosion risks. This requires further improvement of the pretreatment plant. High fire rating, which greatly improves the production cost

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