微藻/核桃壳混合热解需热量及制备芳烃研究

利用热重分析仪（TG）、气相色谱-质谱联用仪（GC/MS）与固定床反应器，考察了微藻、核桃壳及混合物主要热解阶段的需热量特性，以及混合比、温度、催化剂种类对二者混合热解制备芳烃的影响规律。结果表明：在不同升温速率下，核桃壳热解在180～270℃和380～485℃处存在两个吸热峰，整体表现为吸热效应（378.56～596.45 kJ·kg^-1）；微藻热解在280～450℃处存在一个放热峰，整体表现为放热效应（-814.76～-1191.52 kJ·kg^-1）。微藻/核桃壳热解呈现较低的放热效应（-99.05～-158.04 kJ·kg^-1），表明二者混合热解可以实现一定程度的热量耦合。微藻/核桃壳热解在制备芳烃上表现出明显的协同效应，且芳烃相对含量在600℃、混合比1：1下达到最大值，为20.51%；加入Cu/HZSM-5可进一步提高混合热解的芳烃相对含量，达到35.74%。为微藻与核桃壳的高值化利用提供了新思路。

Experimental study on thermal demanding and preparation of aromatics of mixed pyrolysis of Nannochloropsis sp./walnut shell

In this study, Nannochloropsis sp. (NS) and walnut shell (WS) were used as raw materials for mixed pyrolysis, and the characteristics of thermal demanding during pyrolysis of NS, WS and NS/WS were initially investigated by a thermogravimetric analyzer and a fixed-bed reactor. Then the effects of mass ratio, reaction temperature, and catalysts on the preparation of aromatic hydrocarbons from NS/WS mixed pyrolysis were studied by a GC/MS method. Results showed that the two endothermic peaks were observed from WS pyrolysis at 180-270℃ and 380-485℃, the overall performance of WS pyrolysis took on the endothermic effect with thermal demanding values of 378.56-596.45 kJ·kg^-1 under different heating rates. An endothermic peak was obtained from NS pyrolysis at 280-450℃, the overall performance of NS pyrolysis took on exothermic effect with thermal demanding values of -814.76——1191.52 kJ·kg^-1. The pyrolysis of NS/WS presented low exothermic effect with thermal demanding values of -99.05——158.04 kJ·kg^-1, indicating that the mixed pyrolysis achieved a certain degree of thermal coupling. The mixed pyrolysis of NS/WS demonstrated a synergistic effect in the preparation of aromatic hydrocarbons. The optimum condition for aromatics preparation with a value of 20.51% was achieved at a temperature of 600℃ and a NS/WS mass ratio of 1:1. By introducing Cu/HZSM-5 catalyst, the relative content of aromatics was further improved (35.74%). This study provided a new approach for high-value utilization of NS and WS.