酸洗预处理对稻壳生物油品质的影响

Effect of Acid-washing Pretreatment on the Bio-oil Quality's of Rice Husk

稻壳通过热解能将其中的有机质转为生物油,但是稻壳中含有的金属会降低生物油的产率,且会影响生物油的品质。通过酸洗预处理,能有效脱除金属,抑制金属对稻壳热解的不良影响。利用不同种类无机酸和有机酸对稻壳进行酸洗预处理,并在550℃下进行热解获得生物油,探究酸洗预处理对稻壳热解的影响。结果表明,酸洗预处理能有效脱除稻壳中的金属含量,减少灰分。经过各种酸溶液酸洗后的稻壳热解所得的生物油产率均有提高,并且盐酸预处理获得最高的生物油产率31.18%。此外,酸洗预处理后生物油中糖类含量明显增加,并且无机酸的效果比有机酸更为明显,其中盐酸和硫酸酸洗后糖类含量由2.8%分别增加到48.29%和51.52%。除此之外,酚类物质也明显减少,酸、酮、醛等化合物则轻微减少。酸洗预处理能有效提高生物油产率,且能提高生物油中的糖含量,从而使得生物油品质得以提升。

Rice husk can convert organic matter into bio-oil through pyrolysis energy,but the AAAEMs contained in rice husk will reduce the yield of bio-oil and affect the quality of bio-oil. Through acid-washing pretreatment,metals can be effectively removed and the adverse effects of metals on the pyrolysis of rice husks can be inhibited. In this study,different inorganic and organic acids were used for acid-washing pretreatment of rice husk( RH),and bio-oil was obtained by pyrolysis at 550℃,to explore the effect of pickling pretreatment on rice husk pyrolysis. The results showed that the pretreatment effectively removed content of alkali and alkaline earth metals( AAEMs) in the RH and reduced the ash content. The yield of bio-oil obtained from pyrolysis of all the acid-washed rice husks was increased,and the highest yield of bio-oil was 31. 18% by hydrochloric pretreatment. In addition,after acid-washing pretreatment,the contents of sugar in the bio-oil significantly increased,and the effect of inorganic acids is better than that of organic acids. The sugar contents after hydrochloric acid and sulfuric acid pretreatment increased from 2. 8% to 48. 29% and 51. 52%,respectively. In addition,phenolic substances significantly reduced. The compounds such as acids,ketones,and aldehydes were slightly reduced. Acid-washing pretreatment can effectively increase the yield and sugar content of bio-oil,so that the quality of the bio-oil can be improved.