污泥生物-物理干化调质及微孔道气化机制研究

Bio-physical conditoning of sewage sludge has the potential to attain the moisture removal, cracking and conditioning of sewage sludge with low energy consumption and low organic consumption. The obtained bio-physical dried sludge particle with well-developed mesopores and large surface area is a kind of perfect raw material for the inner steam gasification in the microstructure of sludge particle. According to the contradiction between organic cosumption and mosture removal during the sludge biodrying process, a combined operations of short-term（2-3d）extreme thermophilic （≥70°C）spontaneous heating evaporation coupled with enhanced convective evaporation will be conducted. As for the extreme thermophilic condition with low organic cosumption of dominant themophiles, the organic cosumption of mesophilic bacteria will be restrained, the moisture and nitrogen will be removed in a short time and the sludge colloid structure is cracking and disbonding in the meantime, which will achive the granulation aroud the core; Then, the enhanced convective evaporation will be operated for enhanced moisture removal and conditioning. As for the problems of traditional pyrolysis and gasification with the non-goal product such as tar and char produced from the inhomogeneous heating way, the bio-physical conditioning process provide a kind of optimal raw material to the succedent inner pore steam gasification for the hydrogen-rich gas production. The innoer pore steam and CO2 co-gasification mechanism will be studied, as it influenced by moisture content, nitrogen composition and micropore structure which is modified with the former bio-physical conditioning process. Furthermore, the catalyzed mechanism of the inorganic metallic oxide enriched in the composite system will be studied to control the catalytic reforming process for improving the gas output and quality.

污泥生物-物理干化调质可在温和条件下低耗干化、破解、调质污泥并为后续微孔道内源蒸汽气化提供优化原料，实现污泥的清洁能源化。针对生物干化消耗有机物问题，研究基于生物自产热短期（2-3d）超高温（≥70℃）结合高强度通风的两段式生物-物理干化和调质方法。通过获得低有机物消耗的极端嗜热菌活跃的超高温条件，抑制非高温菌利用有机物，快速脱水脱氮同时脱粘破解胶体，实现污泥绕核颗粒化；高强度通风快速脱水调质。解决污泥因组分复杂，传统干化原料直接热解气化易致焦等非目标物产生问题，为蒸汽气化提供优化原料。研究通过前段的水分、氮、和微孔道结构调控影响下的内源蒸汽和二氧化碳共气化机制，考察富集无机矿物在复合体系中的催化机理。定向调控该过程中半焦和毒性产物的催化重整反应，以期显著提高目标氢气产率和品质

污泥生物物理干化可在温和条件下低耗干化、破解、调质污泥并为蒸汽气化提供优化原料。本研究基于生物自产热短期（2-3d）超高温（≥70℃）结合高强度通风的两段式生物-物理干化和调质方法，获得低有机物消耗的极端嗜热菌活跃的超高温条件，抑制非高温菌利用有机物，快速脱水同时破解胶体，实现颗粒化。高强度通风快速脱水，为热解提供优化原料。研究生物物理干化污泥(BDS)在快速热解系统中生化组分、粒度和含水率因素影响，解析BDS结构、调质效应同快速热解气化协同制富氢燃气机制，显著提高氢气产率和品质。. 最佳污泥/辅料掺比为1.5:1-2:1，短期超高温条件(>65℃，3-4d)利于水分脱除并抑制微生物代谢。高温期完成颗粒化后强化通风，4d含水率（MC）达30%以下。两阶段生物物理过程可有效实现污泥脱水、脱粘及颗粒化。干化后蛋白质、脂肪和糖类部分分解，半纤维素、纤维素和木质素富集，生物质颗粒热值(HHV)9.52MJ/kg，为优良产氢原料。BDS热解产氢主要源于成焦作用。500-900℃热解，合成气和半焦产量均高于传统热干化污泥（TDS）。>700℃时，合成气具有高浓度H2和CH4的特点。900℃H2含量最高达43.7%，产率0.0181g/g污泥；BDS中等粒径颗粒(0.27-4mm)提升合成气产量，有助于H2和CO生成。BDS中适量水分可提高合成气产量、H2产率及C转化率。MC（53.9-62.6%）合成气产量最大，其中53.9%时H2浓度最高达46.02%。连续流反应器中极端高温达70℃以上，物料停留72h颗粒化效果最佳。干化39-72h物料[MC(58.2-66.9%)]热解气H2含量最高，干化72-111h物料[MC(55-58%)]，C转化率和湿基产气量最高。. 本研究立足污泥有机物的合理分级利用，获得高效脱水和产能效果。该研究为低能耗干化污泥并进行清洁能源利用开辟新途径。