论文部分内容阅读
以麦秆为研究对象,通过水热炭化实验和建立反应动力学模型(考虑灰分),对麦秆水热固体产物的炭化特性和反应动力学参数进行深入研究。结果表明:在200、220和240℃反应温度下,随着停留时间的延长,生物炭质量得率逐渐减少,至停留时间为720 min时,均接近50%;生物炭H/C和O/C物质的量之比逐渐减小,并越来越接近于泥煤甚至褐煤的H/C和O/C物质的量之比。热重分析表明:生物炭展现出较好的热稳定性。以考虑灰分的半纤维素和纤维素两个平行的一级反应动力学模型描述麦秆的水热降解行为,经计算分析,半纤维素和纤维素水热反应活化能分别为54和136 k J/mol。
With straw as the research object, the carbonization characteristics and reaction kinetics parameters of the hydrothermal solid products of straw were studied deeply through the hydrothermal carbonization experiment and the establishment of reaction kinetic model (considering the ash content). The results showed that the mass yield of biochar decreased with the residence time at 200, 220 and 240 ℃, and nearly 50% when the residence time was 720 min. The biochar H / C and O / The ratio of C to C decreases gradually and becomes closer to the ratio of H / C to O / C of peat or even lignite. Thermogravimetric analysis showed that biochar exhibited better thermal stability. The two parallel first-order reaction kinetics models of hemicellulose and cellulose were used to describe the hydrothermal degradation behavior of wheat straw. The calculated hydrothermal reaction activation energies of hemicellulose and cellulose were 54 and 136 k J / mol.