水曲柳木屑的等温热解特性研究

Investigation on Characteristics of Isothermal Pyrolysis of Fraxinusmandshurica Sawdust

本文研究了水曲柳木屑在不同工况下的等温热解特性。采用管式炉反应器,分别在400、450、500、550和600℃的N_2气氛(400mL/min)下对水曲柳木屑进行了等温热解实验,比较了生物油、炭残渣和热解气产量随等温热解时间(0~20.0 min)的变化情况。与此同时,考察了N_2流量(100~1200 mL/min)、木屑原料用量(2.0、4.0 g)对生物油、炭残渣和热解气产量的影响规律。结果表明:在较低温度400和450℃,等温热解时间对生物油和炭残渣产量影响显著,生物油产量在等温热解时间5.0 min达到最大值;在较高温度500、550和600℃,等温热解时间对生物油和炭残渣产量影响甚微;热解气产量总体上随着热解温度的升高而增大;此外,N_2流量的增大会导致生物油产量减小,而木屑原料用量也会对水曲柳木屑的热解产物分布产生微弱影响。

In this work, the characteristics of pyrolysis of Fraxinusmandshurica sawdust were investigated. Experiments were carried out in 400 mL/min N2 atmosphere at a series of fixed temperatures （400, 450, 500, 550, and 600 ℃） by tubular pyrolysis reactor, and the variation of the quantity of bio-oil, carbonaceous residue, and pyro-gas product with residence time （0-20.0 min） was compared. As such, the influence of N2 flow rate （100-1200 mL/min） and amount of feedstock （2.0 and 4.0 g） on bio-oil, carbonaceous residue, and pyro-gas product were estimated. It was shown that, at the lower temperatures （400 and 450 ℃）, the residence time ranging from 0-5.0 min significantly affected the production ofbio-oil and carbonaceous residues, and the production ofbio-oil reached its maximum at 5.0 min. However, at higher temperatures （500, 550, and 600 ℃）, there was a minor effect of residence time on the amount of products. In general, the amount of pyro-gas was increased with temperature increasing. In addition, it was found that the increase in N2 flow rate could result in the decease of bio-oil, and the distribution of pyrolysis products would slightly influenced by the amount of feedstock as well.