Effect of biological pretreatments in enhancing corn straw biogas production

A biological pretreatment with new complex microbial agents was used to pretreat corn straw at ambient temperature (about 20 °C) to improve its biodegradability and anaerobic biogas production. A complex microbial agent dose of 0.01% (w/w) and pretreatment time of 15 days were appropriate for biological pretreatment. These treatment conditions resulted in 33.07% more total biogas yield, 75.57% more methane yield, and 34.6% shorter technical digestion time compared with the untreated sample. Analyses of chemical compositions showed 5.81–25.10% reductions in total lignin, cellulose, and hemicellulose contents, and 27.19–80.71% increases in hot-water extractives; these changes contributed to the enhancement of biogas production. Biological pretreatment could be an effective method for improving biodegradability and enhancing the highly efficient biological conversion of corn straw into bioenergy.

► In the production of biogas from corn straw, pretreatments are a key initial step.
► Biological pretreatment improve biodegradability and anaerobic biogas production of corn straw.
► Crystalline and non-crystalline cellulose materials were exposed by the pretreatment.
► The biodegradability of corn straw was improved by complex changes in its physical structure and chemical composition.