Chin.J.Chem.Eng. ›› 2014, Vol. 22 ›› Issue (5): 576-582.doi: 10.1016/S1004-9541(14)60075-6

Previous Articles     Next Articles

Enhancing Biogas Production from Anaerobically Digested Wheat Straw Through Ammonia Pretreatment

YANG Dongyan1,2, PANG Yunzhi1, YUAN Hairong1, CHEN Shulin3, MA Jingwei3, YU Liang3, LI Xiujin1   

  1. 1 Center for Resources and Environmental Research, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Beijing Municipal Environmental Monitoring Center, Beijing 100044, China;
    3 Department of Biological Systems Engineering, Washington State University at Pullman, WA 99164-6120, USA
  • Received:2012-08-23 Revised:2012-09-24 Online:2014-05-28 Published:2014-05-06
  • Supported by:

    Supported by the National High Technology Research and Development Program of China (2008AA062401) and the China-US International Cooperation Project (2011DFA90800), the Ministry of Science and Technology, China.

Abstract: Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia (2%, 4%, and 6%, dry matter) and three moisture contents (30%, 60%, and 80%, dry matter) were applied to pretreat wheat straw for 7 days. The pretreated wheat straws were anaerobically digested at three loading rates (50, 65, and 80 g·L-1) to produce biogas. The results indicated that the wheat straw pretreated with 80% moisture content and 4% ammonia achieved the highest methane yield of 199.7 ml·g-1 (based on per unit volatile solids loaded), with shorter digestion time (T80) of 25 days at the loading rate of 65 g·L-1 compared to untreated one. The main chemical compositions of wheat straw were also analyzed. The cellulose and hemicellulose contents were decomposed by 2%-20% and 26%-42%, respectively, while the lignin content was hardly removed, cold-water and hot-water extracts were increased by 4%-44%, and 12%-52%, respectively, for the ammonia-pretreated wheat straws at different moisture contents. The appropriate C/N ratio and decomposition of original chemical compositions into relatively readily biodegradable substances will improve the biodegradability and biogas yield.

Key words: wheat straw, anaerobic digestion, biogas, ammonia pretreatment, moisture content