污泥与醋糟共热解特性及碱金属迁移规律

分别采用热重分析仪、真空固定床反应器和原子吸收光谱研究了污泥与醋糟共热解过程中反应动力学、产物分布和碱金属迁移行为,探究了协同效应及碱金属迁移规律。结果表明,两者共热解过程中存在明显协同效应;与理论计算相比,混合物分解所需的活化能下降了35.38%～29.49%,脱挥发指数比计算低3.5×10-8。协同效应导致气体产率增加,生物炭、液体产率降低;醋糟的存在加速了污泥的脱挥发分析出,提高了气体产物中合成气含量,加大了生物炭中大芳香环的裂解反应,使生物油中酚类和酯类物质含量明显增加;热解终止时,碱金属元素析出量达到79.19%～86.73%。

Co-pyrolysis Characteristics of Sewage Sludge and Vinegar Residue and Migration Law of Alkali Metals

The synergetic effects during co-pyrolysis of sewage sludge and vinegar residue were investigated concerning the product distribution and reaction kinetics by thermogravimetric analysis and vacuum fixed bed reactor, and the alkali metals migration rules was analyzed by atomic absorption spectrophotometer. Results indicated that there is a significantly synergetic effect during the co-pyrolysis process. Kinetics was analyzed by Kissinger-Akahira-Sunose(KAS) method, and the activation energies needed were 35.38%~29.49% decreased for the decomposition of mixture compared with theoretical calculation and the devolatilization index were 3.5×10^-8 lower than calculation. The synergetic effect resulted in an increase in gas yields but a decrease in char yield and liquid. The presence of vinegar residue promoted the devolatilization of sewage sludge, improved the syngas (H₂+CO) content in the gaseous products, and promoted the cracking reactions of large aromatic rings in the resulted char. In addition, the co-pyrolysis process has a good effect on increasing phenols and esters of its bio-oil. At the end of pyrolysis process, the exhalation rate of alkali elements reached 79.19%~86.73%.