农林生物质热解木醋液净化脱色工艺研究

Study on purification and decolorization of wood vinegar from pyrolysis of agricultural and forestry biomass

我国农林剩余物资源极其丰富,但目前还未得到充分利用,采用热解工艺制备生物气是一种极有前景的处理技术。农林生物质热解气化过程中产生约10%左右的木醋液,但是木醋液成分比较复杂,富含酚类化合物、醇类化合物和少量酯类、糖类化合物,处理难度较大,若直接排放容易对环境产生较大的危害,这一直是生物质热解气化技术发展的瓶颈。本试验对木醋液净化脱色工艺进行研究,通过物理加热和廉价药剂的投入,将木醋液处理为无色、无味的循环水资源,用于气化工艺的冷却和生物气净化。通过单因素试验以及分析检测,得出最佳工艺条件为温度60℃,药剂使用量5.50%,活性炭/白土使用量6.00%,pH=7.00,在此优化条件下木醋液的加纳德色度为0.20%。通过该研究可为农林生物质热解技术的推广提供良好的技术支撑,为新农村建设贡献科技力量。

The agricultural and forestry residue resources in China are rich,but they have not been fully utilized.The preparation of biogas by pyrolysis process is a promising treatment technology.About 10%of wood vinegar is produced during the pyrolysis and gasification of agricultural and forestry biomass,and the composition of wood vinegar is relatively complex,rich in phenolic,alcohols,and a small amount of esters and sugars compounds,which is difficult to be treated.If discharged directly,it is easy to cause dangerous harm to the environment,which has always been the bottleneck of the development of biomass pyrolysis and gasification technology.In this experiment,the purification and decolorization process of wood vinegar was studied.Through physical heating and the input of cheap chemicals,the wood vinegar was processed into colorless and tasteless circulating water resources for the cooling of gasification process and biogas purification.Single factor tests and analysis indicated that the optimal process conditions were temperature 60℃,reagent dosage 5.50%,activated carbon/clay dosage 6.00%,pH 7.00.Under these optimized conditions,the Gardner Color of wood vinegar was 0.20%.This research can provide the technical support for the promotion of agricultural and forestry biomass pyrolysis technology,and contribute scientific and technological strength to the construction of new countryside.