溶剂吸收-称重法测定焦油的影响因素分析

ANALYSIS OF INFLUENCING FACTORS OF MEASURING GASIFICATION TAR BY SOLVENT ABSORPTION AND WEIGHING METHOD

在模拟焦油吸收装置和中试生物质气化炉系统考察正负压取样方式、粗燃气体积流量、焦油含量、取样时间、粗燃气中水分含量、焦油烘干时间、溶剂蒸发等因素对测定结果的影响。结果表明取样时间及溶剂蒸发是影响焦油测定结果准确性的2个主要因素,最佳的取样分析条件为:负压采样、粗燃气流量不大于2.0 Nm^3/h、焦油吸收时间10~15 min、取样前后量取吸收溶剂体积及60℃条件下焦油烘干6 h。在上述条件下,溶剂吸收-称量法定量焦油的相对误差可小于±5%。

It is important to precisely measure the tar content of syngas in evaluation of biomass gasification technology.Uncertainties of sampling and quantification of tar with solvent absorption and gravimetric measurement(SAGM) is investigated in simulated tar absorption device and syngas from a pilot fixed bed gasifier. The chief factors evolved in such uncertainty analysis include pressure of tar sampling,volumetric flow rate of syngas,mass content of tar in syngas,duration time of tar absorption,and mass content of water in syngas,volume of solvent evaporation during tar absorption process and variations of individual chemicals in tar in drying steps. The results showed that major contributions to the overall uncertainty are related to duration time of tar absorption and solvent evaporation during tar absorption steps. In order to keep the relative error of tar quantification by SAGM within ±5%,the following optimization conditions for tar sampling and measurement are advised,i.e.,tar sampling at negative pressure for 10-15 min,lower the volumetric flow rate of syngas passing the absorption bottles(≤2.0 Nm^3/h),and drying tar samples at 60℃for 6 h.