Influence of Animal/Plant Activated Biochar Properties on Methane Production from Corn Stalk by Anaerobic Fermentation

Abstract

Activated biochar (ABC) was prepared from typical plant/animal biochar (pig bone biochar/corn stalk biochar) by optimizing the gas production characteristics of anaerobic fermentation. The effects of the physical and chemical properties (specific surface area, surface functional group and conductivity) of ABC on the gas production characteristics of anaerobic fermentation were investigated. The results showed that the effect of pig-bone activated biochar (PABC) on anaerobic fermentation gas production characteristics was better than that of corn-stalk activated biochar (CABC). The peak period of gas production or methane production was up to 4 days earlier than that of the control group, and the cumulative methane production was up to 68% higher; this can shorten the fermentation period for up to 7 days, and the effect of stabilizing pH is better. In addition, the surface functional groups are not the dominant factors affecting the gas production characteristics, but the effects of conductivity and specific surface area cannot be neglected. For most experimental groups, when the specific surface area of PABC is more than 90 m2/g and the specific surface area of CABC is more than 100 m2/g. Methane production increases with the specific surface area increases and the controllable range of CBAC is relatively wider than that of PBAC. When the conductivity of CABC is more than 650 μS/cm and the conductivity of PABC is more than 1000 μS/cm, the conductivity has a positive correlation with methane production.