小球藻热解特性及其液化制油实验分析

以小球藻为研究对象,通过热重分析,研究不同钠盐催化剂及其用量对微分热重曲线的影响,确定小球藻热解最佳催化剂种类及用量.利用自行设计的直接热化学藻类油化实验装置,通过改变最佳催化剂用量,调查其对小球藻油化产物分布以及油产率的影响,并利用GC/MS分析得到油产品成分的含量,同时对油化过程进行了能量衡算.结果表明:3种钠盐催化剂均使小球藻热解反应向低温区移动,钠化合物的催化作用依次为Na2CO3Na2SO4NaCl,其中碳酸钠催化作用最显著;从微分热重曲线分析可知,催化剂中钠离子质量为小球藻样品质量5%时为理想用量,在直接热化学液化法小球藻油化实验中,碳酸钠的钠离子质量为小球藻质量的5%时,可获得较大的油产率62.58%,与热重分析结果相吻合.通过GC/MS分析得到产品油化学成分与重油相近.产品油的热值很高,为32.4,MJ/kg.能量回收率为78.2%.

Experimental Analysis of the Pyrolytic Characteristics of Chlorella and Oil Derived from its Liquefaction

In order to determine the optimal type and dosage of the catalyst of chlorella pyrolysis, differential thermogra- vimetric （DTG）curves of the chlorella with various sodium salt catalysts were investigated through thermogravimetric analysis. The effect of catalysts on the distribution of the product and oil yield was studied by changing the dosage of the catalyst in an experimental installation designed by ourselves for direct thermochemical liquefaction of chlorella. The com- position of the oil products was determined by GC/MS analysis, and the energy balance for the oil production process was also calculated. The results showed that all the three sodium salt catalysts could induce chlorella pyrolysis reaction at a lower temperature. The catalytic effect of the sodium compounds was in the following order：Na2CO3〉Na2SO4〉NaCl, and the highest conversion of chlorella pyrolysis could be obtained by using Na2CO3. DTG curves showed that the optimal amount of sodium ion dosage in the catalyst was 5% of the chlorella weight. The maximum oil yield, 62.58%,was achieved when Na＋ （Na2CO3） was 5% of chlorella weight, which was in consistent with the TG analysis result. In addition, GC/MS analysis showed fhat the calorific value of the product oil was high and energy recovery was considerable, which are 32.4 MJ/kg and 78.2% respectively.