Economic and environmental analysis: Straw biogas project operating at full load with dry yellow corn straw

Abstract

Due to the unique straw raw materials in China, the current straw biogas project based on the “two-stage” process of wet anaerobic digestion still has problems such as deficient technology, low production capacity, and weak profitability. In this study, we improved the original process for the biogas project, aiming at increasing biogas yield and profit. The results show that the new process (NP) can effectively recover the “carbon” by anaerobic hydrolysis, solve the problems of scum and crust, and significantly improve the biomethane yield (141.3%-321.8%), net profit ($599,667-$772,004/year), and carbon emission reduction equivalent (2.7×10⁷-4.6×10⁷ kg CO₂e/year). Based on the amount of dry yellow corn straw that can be collected annually for energy-oriented production, NP’s potential economic and environmental value is estimated to be significant. This study provides reliable technical support for efficient utilization of agricultural resources and circular economy.