生物质气化耦合高温热重整制合成气的反应行为分析

Kinetic analysis of biomass gasification coupled with non-catalytic reforming to syngas production

焦油污染物的洁净转化是影响生物质气化技术大规模应用的关键问题之一,粗合成气非催化重整可以将焦油组分转化为CO和H2,消除焦油的同时增加合成气的产量。本实验以热力学计算为基础,主要研究生物质气化粗合成气高温热重整的热力学、动力学行为以及反应机理。研究表明,重整反应温度、O_(2)/粗合成气比(O/G)是影响重整过程的关键因素。C_(2)H_(2)作为CH_(4)、C_(2)H_(4)、C_(6)H_(6)转化的中间产物,在反应初期逐渐累积。到反应后期,在·O、·OH、·HCO的作用下,C_(2)H_(2)逐步转化为CO和·CH_(2)、·CH_(3)、·C_(2)H_(3)。升高重整反应温度可大幅缩短焦油组分完全转化所需要的时间。重整温度1300℃、O/G比为0.16,停留时间1.5 s时,合成气的干基含量为81.07%,焦油组分转化率可达99.60%。

The clean conversion of biomass gasification tar is one of the bottlenecks affecting the large-scale application of biomass gasification.Non-catalytic reforming of raw gas can convert the tar components to CO and H2,eliminating the tar while increasing the syngas yield.This paper investigated the kinetic behavior of high-temperature non-catalytic reforming of biomass raw gas on the basis of thermodynamic calculations.The reforming temperature and O_(2)/crude syngas(O/G)ratio are the key factors affecting the reforming process.C_(2)H_(2)gradually accumulated at the beginning of the reaction as an intermediate product of the conversion of CH_(4),C_(2)H_(4)and C_(6)H_(6).Subsequently,C_(2)H_(2)converted to CO,·CH_(2),·CH_(3),and·C_(2)H_(3)under the attack of·O,·OH,and HCO·.Increasing the reforming temperature can significantly reduce the time required for complete tar conversion.At a reforming temperature of 1300℃,O/G ratio 0.16 and a residence time of 1.5 s,the dry base content of the syngas was 81.07%and the conversion of the tar reached 99.60%.