小麦秸秆高浓度厌氧梯度预发酵的中试研究  

Pilot Study on High-Solid Anaerobic Gradient Prefermentation of Wheat Straw

作　　者：陈若曦 何会班 赵业华 宋晓乐 刘松 袁旭峰[2] 崔宗均[2] CHEN Ruoxi;HE Huiban;ZHAO Yehua;SONG Xiaole;LIU Song;YUAN Xufeng;CUI Zongjun(Beijing University of Chemical Technology,Beijing 102200,China;China Agricultural University,Beijing 100193,China;Beijing Yingherui Environmental Technology Co Ltd,Beijing 102425,China)

机构地区：[1]北京化工大学,北京102200 [2]中国农业大学,北京100193 [3]北京盈和瑞环境科技有限公司,北京102425

出　　处：《中国沼气》2024年第5期13-22,共10页China Biogas

基　　金：北京盈和瑞环境科技有限公司内部研发课题(2023YHR001)。

摘　　要：针对现有主流秸秆沼气工程中秸秆原料疏水性强,浮渣结壳严重而运行稳定性差,产气效率低,以及传统“水解酸化”技术碳损失严重等问题,采用高浓度厌氧梯度反应器,以小麦干秸秆为原料在中试规模下(112 m^(3))探讨了短时间的厌氧预发酵对小麦干秸秆的浸水及甲烷回收发酵效果,以期获得秸秆前处理技术的突破。结果表明,随着水力停留时间从20天缩短到5天,虽然日产气量、甲烷浓度逐渐下降,有机酸有所积累,但5天停留时间下,仍能获得1.73 m^(3)·m^(-3)d^(-1)的容积产气率和39.2%的甲烷含量,有效减少了原料碳素损失;在反应器内仅需2.5 d的发酵达到了静止下96 h的吸水效果,秸秆能够完全吸水沉降。随着物料停留时间的缩短,反应器内有机酸含量增加,其浓度依次为丁酸含量(6600~18381 mg·L^(-1)),乙酸(516~4002 mg·L^(-1))、丙酸(196~1213 mg·L^(-1)),但pH值仍保持7以上。16S高通量测序结果表明,Firmicutes和Bacteroidetes是反应器内水解优势菌,Methanosarcina和Methanobacterium是两个优势甲烷菌属。随着水解加深,Methanosarcina的丰度相对下降,Methanobacterium的丰度相对上升,而总甲烷菌数量下降,导致甲烷产量略有减少。综合产酸、产气能力及秸秆沉降特性,表明本研究采用的高浓度厌氧梯度发酵秸秆吸水效果和甲烷回收效果显著,在秸秆沼气工程中具有良好应用潜力。To address the persistent challenges in conventional straw biogas projects-such as the high hydrophobicity of straw feedstock,severe scum formation,operational instability,low biogas yield,and significant carbon loss associated with traditional hydrolysis and acidification techniques-this study explored the application of a high-concentration anaerobic gradient reactor.Using dry wheat straw as feedstock,we conducted pilot-scale(112 m^(3))experiments to assess the impact of short-term anaerobic pre-fermentation on straw soaking efficiency and methane recovery.Our objective was to achieve a breakthrough in straw pretreatment technology.The findings revealed that as the hydraulic retention time(HRT)decreased from 20 days to 5 days,there was a gradual decline in daily gas production and methane concentration,alongside the accumulation of organic acids.However,even with a 5 day HRT,the reactor achieved a methane yield of 1.73 m^(3)·m^(-3)d^(-1)and a methane content of 39.2%,effectively mitigating carbon loss in the feedstock.Notably,the reactor could replicate the soaking effect of 96 hours of static soaking within just 2.5 days,enabling complete straw hydration and settling.With reduced HRT,the concentration of organic acids in the reactor increased,with butyric acid ranging from 6600 to 1838.1 mg·L^(-1),acetic acid from 516 to 4002 mg·L^(-1),and propionic acid from 196 to 1213 mg·L^(-1),while the pH remained above 7.High-throughput 16S rRNA gene sequencing identified Firmicutes and Bacteroidetes as the dominant hydrolytic bacteria,and Methanosarcina and Methanobacterium as the key methanogenic archaea.As hydrolysis progressed,the relative abundance of Methanosarcina decreased,while Methanobacterium increased,resulting in a slight reduction in total methanogen populations and a corresponding decrease in methane production.Overall,the results demonstrate that the high-solid anaerobic gradient fermentation approach significantly enhances both straw soaking efficiency and methane recovery,offering promising potentia

关 键 词：秸秆沼气 梯度厌氧发酵 秸秆吸水沉降 预发酵产气 中试研究 

分 类 号：S216.4[农业科学—农业机械化工程] X712[农业科学—农业工程]