At the annual academic meeting of the Chinese Biogas Society held in October 2023, the agricultural research institute proposed to focus on the use of agricultural wastes such as straw and livestock and poultry manure for collaborative anaerobic fermentation to achieve resource recycling.
First of all, we are committed to improving the quality and gas production efficiency of biogas slurry. In addition, it is also actively exploring the high-value application of intermediate products and final products of anaerobic fermentation, such as the use of medium-chain fatty acids in aquaculture as feed additives, and the biogas slurry produced can also be fed back to the planting industry, forming a virtuous cycle of planting and breeding.
For the topic of efficient gas production from anaerobic fermentation, hydrolysis, acid production, methane production and other links were studied in depth, and a series of cutting-edge technologies were explored. In the hydrolysis process, it was found that the eutectic solvent could effectively separate the components of the material cellulose, which provided a basis for subsequent high-value utilization. In the acid production process, the focus is on the regulation and transformation of acid ammonia. In the methanogenic process, an attempt was made to improve the metabolic and conductive activity of functional microorganisms by adding different carriers.
At the same time, the team of the Academy of Agricultural Sciences is also paying attention to the early warning and monitoring technology of anaerobic fermentation engineering. With the help of advanced machine learning methods, different intermediate metabolites and process monitoring data are mined and analyzed to achieve long-term stable fermentation control and ensure efficient gas production. In this process, a number of effective monitoring and early warning indicators were screened.
In terms of improving the quality of gas production by anaerobic fermentation, the key role of conductive medium enhancement technology is emphasized. The use of iron-based materials, carbon-based materials, and other conductive mediators enhances the interaction between bacteria and methanogens, promotes electron transfer, and thus increases gas production, methane content, and gas quality.
In view of the anaerobic fermentation gas and fertilizer co-production, the research on anaerobic fermentation technology with high solid content is emphasized. By optimizing the fermentation control technology, the bottleneck of low gas yield has been broken. At present, research is underway on how to improve the efficiency of gas production through efficient carbon flow cycling and adequate degradation of lignocellulose components. At the same time, it also pays attention to the research on carbon and nitrogen balance technology of efficient fertilizer production from biogas residue to solve the problems of low compost efficiency and low product quality.
In terms of the composition adjustment of acidification products, the efficient utilization of anaerobic fermentation intermediate products is being studied, especially the efficiency improvement and component regulation of short-chain fatty acids. By adjusting the feeding frequency, pH value and other parameters, it aims to achieve differentiated acid production pathways and lay the foundation for subsequent high-value utilization.
Finally, in terms of efficient synthesis of platform compounds, the process of synthesis of medium-chain fatty acids from anaerobic fermentation intermediates was studied. Drawing on the advanced research results at home and abroad, the highly efficient microbial flora has been successfully domesticated, and the stable effect of continuous fermentation has been realized.