水合CaO对微拟球藻催化热解制备生物油的影响

以水合CaO为催化剂,在管式炉内研究了微拟球藻的催化热解.考察了催化剂用量对微拟球藻热解产物及油品组成的影响,并通过直接再生和强化再生研究了催化剂的再生特性.结果表明:随着水合CaO用量逐渐加大,生物油性能明显改善.在催化剂/藻质量比为1:3时催化热解得到的生物油产率为28.5%,具有含氧量低、热值高、运动黏度低、含水率低等优点.与直接热解油相比,催化热解油中羧基化合物和羟基化合物含量均有明显下降,而脂肪烃和芳香烃含量均显著增加.第1次和第2次循环再生实验中,直接再生催化剂依然具有较高的催化活性.通过在直接再生过程中引入水洗强化步骤,可对再生催化剂表面进行更新,并降低其表面的碱金属含量,明显改善再生催化剂所催化热解的油品质量,提高再生催化剂活性.

Effect of hydration CaO on production of bio-oil by catalytic pyrolysis of Nannochloropsis sp.

The catalytic pyrolysis of Nannochloropsis sp. was carried out in a bench-scale fixed bed reactor using hydration CaO catalyst. The effect of the hydration CaO dosage on pyrolysis product yield and bio-oil compositions was investigated. The regeneration characteristics of used CaO by mean of direct and intensified regeneration methods was also examined. The results showed that bio-oil quality improved significantly with increase of dosage. The bio-oil yield over the hydration CaO (mass ratio of catalyst to Nannochloropsis sp. was 1:3) was 28.5%, and it had low oxygen content, high calorific value, low kinetic viscosity, and low moisture content. Compared with direct pyrolysis oil, for the catalysis pyrolysis oil there were low contents of carboxylic compounds and hydroxyl compounds, and high content of aliphatic and aromatic hydrocarbons. The results from the regeneration experiments indicated that the catalytic activity was still higher for direct regeneration, and if water-washing intensified step was employed, leading to the significant improvement of bio-oil quality due to increase of the surface and calcium content.