多原料高浓度混合共发酵制气与纯化提质研究最终报告

周红军 江皓 聂红

摘 要：该研究针对目前我国规模化生物燃气工程原料单一、产气率低、装备落后等技术瓶颈，旨在开发多种原料混合共发酵制气关键技术，优化高效率、低能耗厌氧发酵工艺与装置，并对生物燃气进行纯化提质和高值利用研究，使生物燃气分别达到民用或燃气的要求。针对畜禽粪便、作物秸秆、有机垃圾和农产品废弃物等四大类20多种不同原料成分分析及产气潜力和特性研究，进行了单一物料和不同物料混合的厌氧消化实验，以此建立了沼气发酵原料特性及产气性能数据库，并研究多种原料的C/N比及营养物质的合理调配技术，提高了单一原料的产气效率。研究了畜禽粪便、有机垃圾等原料中的去除泥砂和有害杂质工艺。针对秸秆发酵，着重研发原料切碎、贮存和预接种混合技术及装置，提高秸秆产气效率。研究了高浓度发酵（TS≥10%）和干发酵（TS≥20%）过程中混合原料的搅拌方式及混合程度对厌氧共发酵工艺的影响，优化了不同混合原料的发酵工艺参数，提高原料产气率。开展了多原料高浓度混合共发酵制气基础研究。包括混合原料配比技术的研究；不同类型模型底物的厌氧水解动力学研究；不同单一原料的厌氧水解动力学研究；高浓度单相厌氧消化模型；固体床两相厌氧消化模型；沼气的生物脱硫技术基础研究。采用甲烷氧化脱氧工艺去除沼气中的氧，针对沼气脱氧剂和沼气脱氧工艺展开了研究。根据沼气中硫化物的形态分布，采用多种吸附剂有针对性地吸附不同的硫化物，主要研究了精脱硫剂及脱硫工艺。采用碳酸丙烯酯法和加压水洗法脱除沼气中的CO2，针对吸收溶剂地研制及脱除CO2工艺的开发展开了研究。该研究最终建立了不同发酵原料成分及其产气特性的数据库，两种以上混合原料厌氧共发酵，进料固形物含量大于10%，中温沼气产率大于1.2 Nm3/m3罐容天。建设了多原料共发酵的中试装置一套。完成示范工程建设，形成产业化核心技术，达到如下指标：产品CH4 97%，CO 23%，H2S 10 ppm，甲烷回收率≥99%，压力≤1.0 Mpa；纯化能耗≤0.80 kwh/m3生物天然气；精脱硫剂硫容≥10%，碚硫温度为常温；在贵金属催化剂作用下，使垃圾场沼气中的O2<0.60%达到欧洲标准；沼气中硫化氢、羰基硫、二硫化碳、硫醇、硫醚和噻吩等硫化物脱至1 ppm以下。

关键词：多原料发酵 甲烷 二氧化碳 硫化物 氧气

Abstract：In order to solve some problems of the current large-scale biogas projects in China， such as a single raw material， low rate of gas production and backward equipment， this study aims to develop some key technologies of multi-materials co-fermentation， optimize fermentation process and apparatus for high efficiency and low energy consumption， develop biogas upgrading techniques， and make the production gas meet the requirements of civil gas or vehicle gas. For manure， crop residues， organic waste and agricultural waste， 20 different raw materials were analyzed. Anaerobic digestion experiments were carried out using single and mixed materials， in order to establish biogas fermentation feedstock characteristics and gas production performance database， and to study the allocation of C/N ratio and nutrients from different feedstock. The technologies of removing sediment and harmful impurities from manure， organic waste and other raw materials were studies. For straw， the technologies and devices of chopping raw material， storage， pre-inoculation and mixing were developed to improve the efficiency of gas production. In the fermentation of a high concentration （TS≥10%） and dry fermentation （TS≥20%），the effects of mixing method and degree were figured out. The fermentation parameters were optimized to improve the gas production rate.A series basic research of multi-material fermentation was studied， including the mixing technology of raw materials，anaerobic hydrolysis kinetics of different model substrate and single feedstock， high concentration of single-phase anaerobic digestion model， solid bed two-phase anaerobic digestion model， biogas biological desulfurization. Using methane oxidation process to remove oxygen in the biogas， the desoxidant and deoxidation process were studied. For different types of sulfide in biogas， the fine desulfurization process and agent were tested. Propylene carbonate absorbing and water scrubbing were applied for CO2 removal. This study eventually established database of various materials for fermentation. Using two or more materials for mixed anaerobic fermentation， the feed solid content was greater than 10%， and the yield of biogas was over 1.2 Nm3/（m3·day）.The demonstration projects were built up. The following indicators were achieved：CH4≥97%， CO2≤3%，H2S≤10 ppm，methane recovery≥99%， pressure≤1.0 MPa； energy consumption≤0.80 kwh/m3 biogas； fine desulfurizer sulfur capacity≥10%，O2<0.60%， sulfide<1ppm.

Key Words：Multi-material fermentation；Methane；Carbon dioxide；Sulfide；Oxygen

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