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Biomass Chemical Engineering ›› 2020, Vol. 54 ›› Issue (1): 1-8.doi: 10.3969/j.issn.1673-5854.2020.01.001

• Research Report •     Next Articles

Research on Capability of Semi-solid Anaerobic Digestion of Rice Straw Using Percolation Bed Reactor

Ke LIU1,3(),Jing HE2,*(),Xiuli WEI1,Tao JIANG1,3,Ning TANG1,Deyong ZHANG4   

  1. 1. Chongqing Academy of Agricultural Sciences, Chongqing 401329, China
    2. Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu 610041, China
    3. Southern Scientific Observing and Experimental Station for Development and Utilization of Rural Renewable Energy, Ministry of Agriculture, Chongqing 401329, China
    4. Key Laboratory of Agricultural Waste Recycling Technology and Equipment R & D, Chongqing 401329, China
  • Received:2019-01-14 Online:2020-01-30 Published:2020-02-11
  • Contact: Jing HE E-mail:273021978@qq.com;hejing@caas.cn
  • Supported by:
    重庆市社会民生重点项目(csts2017shms-zdyfX0052);农业部可再生能源开发利用重点实验室开放课题(2015005);农业部可再生能源开发利用重点实验室开放课题(2013005)

Abstract:

The effects on the gas production and the energy conversion rate of straw anaerobic fermentation, the performance of biogas slurry and the gas production cost after fermentation were comparative researched under four different temperatures(20, 25, 30 and 35℃) and three different pretreatment methods(NaOH, biological reagents and biogas slurry) by self-designed leach bed reactors using rice straw as raw material. The results showed that the total solid(TS) mass fraction of substrate after fermentation reached a stable level at 13% to 15%-semi-solid anaerobic fermentation; also the cumulative gas production and temperature, the changes of COD and NH3-N after fermentation were significantly correlated. It also showed that the TS biogas yield of rice straw after pre-treatment was higher than that of the untreated under the same temperature(20-30℃). The TS biogas production was 154.0 mL/g and volatile solids(VS) methane yield was 55.2 mL/g under 35℃, which increased 25.1% and 52.5% respectively comparing with those of the untreated sample. At the same time, the methane volume fraction in anaerobic fermentation gas production could be significantly improved by biogas slurry pretreatment. The methane yield of TS and VS increased, while the elevation rate of methane production gradually decreased with the increase of temperature (20-30℃). The methane production of all treatments could be increased by 90% when the fermentation temperature rose from 20 to 25℃. According to the analysis of gas production cost, the self-produced biogas slurry had better treatment effect and lower production cost. The variable cost for each 1 m3 of biogas produced was 1.62 yuan. Considering the warming of biogas fermentation tank and energy input-output balance, temperature control at 25℃ might be the optimal economic strategy mode.

Key words: rice straw, hemi-solid anaerobic digestion, percolation bed reactors, pre-treatment, biogas slurry

CLC Number: