Method for preparing biochar and hydrogen by utilizing anaerobic fermentation byproducts

Abstract

The invention relates to a method for preparing biochar and hydrogen by utilizing anaerobic fermentation byproducts, and biochar prepared from biogas residues. The method comprises: mixing straw I, inoculated mud and distilled water, and then carrying out anaerobic fermentation to obtain a fermented mixed product; separating the fermented straw from the mixed product to obtain straw II; separatingand recovering biogas slurry from the mixed product; carbonizing the obtained straw II to obtain the biochar; and carrying out a pressurizing catalytic reaction on the obtained biogas slurry, and then collecting gas to obtain the hydrogen. According to the invention, the method is easy to operate, low in cost and environmentally friendly, provides the new path for resource recycling and disposalof anaerobic fermentation by-products, and provides the technical referencefor preparation of high-specific-surface-area biochar from biomass and preparation of hydrogen from biogas slurry; and the prepared biochar can be used in the fields of soil fertility improvement, carbon pool confluence increase and emission reduction, environmental pollution remediation and the like, the potential is huge,and the prepared hydrogen can be locally used for heat supply or power generation.

Description

technical field [0001] The present invention relates to the field of by-product recycling, energy utilization and environment in the energy conversion process, and more specifically, relates to a method for preparing biochar and hydrogen by using anaerobic fermentation by-products. Background technique [0002] The by-products of anaerobic fermentation are rich in nutrient nitrogen, and are currently used as bio-organic fertilizers to replace some chemical fertilizers, but there is a risk of soil nitrogen exceeding the standard. In addition, the use of anaerobic fermentation by-product fertilizers also has risks such as pathogenic bacteria and heavy metal pollution, odor pollution, dioxin and polychlorinated biphenyl pollution. The anaerobic fermentation project using straw as the substrate only converts part of the cellulose and most of the hemicellulose, leaving a large amount of biogas residue. Biogas slurry is the residual liquid after anaerobic fermentation, and is cur...

AI Technical Summary

Problems solved by technology

However, the steam reforming hydrogen production technology in this method first vaporizes the biogas slurry at high temperature and normal pressure (500-700°C) and then reforms it to produce hydrogen, and it is accompanied by side reactions that are prone to occur at high temperatures

This method requires high process conditions, and the operation is relatively complicated. The reaction product contains a small amount of harmful gas, and the production cost is high, so it is difficult to apply in industrial production.

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