藻渣热解特性及动力学分析

通过热重实验研究N₂气氛下升温速率对索氏提脂后的小球藻热解特性的影响，利用管式炉在N₂气氛下快速热解实验得出：在400℃时，小球藻热解转化率最高，生物油产率达57.6%,热解气为10%。采用等转化率方法FWO和KAS法对藻渣热解动力学进行分析和比较，结果表明：藻渣热解的主要热解阶段为25～800℃,可分为3个阶段，藻渣的DTG曲线存在两个失重峰，且随着升温速率提高，TG和DTG曲线都向高温区偏移，最大失重速率和残余固体质量都增加。N₂气氛条件下藻渣的主要热解阶段表观活化能和指前因子分别为228.46 kJ/mol和2.49×10²¹ min^-1,此阶段下FWO法和KAS法均能很好模拟藻渣热解数据，线性拟合相关系数(R²)均在0.96以上，最佳热解函数为dα/dT=2.49×10²¹/β exp(-228.46/(RT))(1-α)⁸。

Pyrolysis Characteristics and Kinetics Analysis of Algae Residue

The effect of heating rate in N₂ atmosphere on the pyrolysis characteristics of chlorella after Soxhlet fat extraction was studied by thermogravimetric experiment. The rapid pyrolysis experiment in tubular furnace under N₂ atmosphere showed that at 400℃, the pyrolysis conversion rate was the highest, where the yield of biooil and the pyrolysis gas were 57.6% and 10% respectively. The pyrolysis kinetics of algal residue was analyzed and compared by equal conversion methods of FWO and KAS. The results showed that the pyrolysis curve of algal residue could be divided into three stages, where the main pyrolysis stage was 155-800℃. There were two weight loss peaks in the DTG curve of algal residue. With the increase of heating rate, TG and DTG curves shifted to the high temperature zone, and the maximum weight loss rate and residual solid mass increased. Under N₂ atmosphere, the apparent activation energy and pre-exponential factor of the main pyrolysis stage of algal residue were 228.46 kJ/mol and 2.49×10²¹ min^-1, respectively. At this stage, the pyrolysis data of algal residue was well simulated using FWO and KAS method, and the linear fitting correlation coefficient (R²) was above 0.96. The best pyrolysis function was dα/dT=2.49×10²¹/β exp(-228.46/(RT))(1-α)⁸.