摘要
分别采用酸性水溶液和碱性水溶液作为反应溶剂,在水热反应釜中进行直接液化反应,初级液化产物在不同温度下催化裂解,通过测定液体产物的酸值、羟值、热值以及残渣的纤维素、半纤维素、木质素、挥发分含量来确定最佳实验条件。结果表明:使用15%氢氧化钠水溶液作为反应溶剂时液化效果较好,主要体现为木质素明显液化。供氢体的加入对于稻壳的液化没有大的影响,液体产物的酸性变化不大,而羟值普遍减小,分子量增大。加入供氢体后产物的热值有所增加,但是热值还是偏低,不适合作为燃料油使用。以Fe^(3+)/SO_4^(2-)/TiO_2粉体为催化裂解催化剂,裂解产物不理想,热值太低。使用HZSM-5作为裂解催化剂时,催化剂加入量为6%、温度为300℃时热值发生了极大的变化,达到了10 MJ/kg以上,已经比较接近新鲜稻壳的热值,具有了作为燃料油的潜质。
The acidic and alkaline aqueous solutions were adopted as the reaction solvent respectively to proceed direct liquefaction reaction in high pressure reaction kettle. The primary liquefaction products were catalytic cracking under different temperature to confirm the optimal experimental conditions by measuring the acid value, hydroxyl value, heating value of liquid product and cellulose, hemicellulose, lignin, volatile content of residue. The results show that the liquefaction effect of the aqueous solution of 15% sodium hydroxide was good, which mainly reflected the obvious liquefaction of lignin. The addition of hydrogen donor had no influence on the liquefaction of rice husks, the acid value of the liquid products was not significant,and the hydroxy values were generally decreased and the molecular weight were increased. The calorific value in presence of hydrogen donor was increased, but being still low, not suitable for fuel oil. The pyrolysis product was not ideal and the heat value was too low with Fe（3＋）/SO4（2-）/TiO2 powder as catalyst for catalytic cracking. With HZSM-5 as cracking catalyst, the heating value changed greatly in addition of catalyst 6% and temperature of 300 ℃, which attained 10 MJ/kg. This is already closed to calorific value of fresh rice husk, which has the potential for fuel oil.
作者
杨莉
刘毅
YANG Li;LIU Yi(College of Environment and Chemistry Engineering;College of Aeronautic and Mechanical Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2018年第9期41-47,共7页
Environmental Science & Technology
关键词
直接液化
催化裂解
燃料油
direct liquefaction
catalytic cracking
fuel oil
