污泥及秸秆生物质固体燃料制备中试工艺及燃烧特性

为实现污泥的无害化和资源化处置,该文利用处理量为24t/d的中试试验台,进行了化学调理剂添加比例、脱水时间、秸秆尺寸等工艺参数对污泥制备固体燃料性能影响的研究。结果表明:以Fe3+和Ca2+为调理剂,污泥及秸秆等生物质制备固体燃料最佳的铁钙比及燃料压滤最优时间分别为1∶4～1∶2和6h;化学调质法制备的污泥固体燃料存在一个脱水极限,在脱水压力为1.2MPa、秸秆或木屑添加质量比为10%时,污泥固体燃料的质量含水率最低为40%～50%;同等条件下,秸秆越长,燃料脱水性能越好;燃料着火点低,约500K,完全燃烧温度范围窄,燃烧性能好,可做替代燃料使用。该文研究成果对降低污泥处理成本、实现污泥的无害化、资源化处置具有重要的理论意义和实用价值。

Pilot process and combustion characteristics of sludge-straw derived solid biofuel

To realize the harmless treatment and recycling of sludge, the influences of operation conditions (the ratio of Fe3+ to Ca2+, dewatering time and size of straws) on physical properties of sludge-straw derived solid biofuel were experimentally studied on a pilot experimental device with a capacity of 24 t/d. The results showed that the optimal ratio of Fe3+ to Ca2+ and dewatering time were 1:4~1:2 and 6 h respectively, and there was a dewatering limit for chemical conditioning to produce sludge-straw derived fuel. The values of moisture content was about 40%~50% under the condition that the dewatering pressure and ratio of sludge to straw were 1.2 MPa and 10:1 respectively. The biofuel produced with longer straw had lower moisture content. Thermogravimetric analysis showed that the biofuel had good combustion performance with low ignition point (about 500 K), narrow range of combustion temperature, and could be used as substituted fuel. This study can provide theoretical and practical references for realizing the recycling and innocuous treatment of sewage sludge cost-effectively.