State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Sci Total Environ. 2022 Sep 10;838(Pt 2):155412. doi: 10.1016/j.scitotenv.2022.155412. Epub 2022 May 13.
This study investigated the effect of temperature on pyrolysis of soapstock in a fluidized bed reactor, and the characterization of soapstock chars (SCs) and pyrolysis oils (POs) were analyzed. TGA, TG-FTIR, TG-MS, and Py-GCMS were employed to investigate characteristics of SS pyrolysis. Experimental results indicated that the yield of SC decreased with increasing temperature. Pyrolysis oil (PO) yield reached the maximum of 21.05 wt% at 600 °C and the yield of non-condensable gas varied with temperatures. The content of carbon, hydrogen and nitrogen distributed in the SC decreased with the increasing temperature, and sulfur tended to be retained in SC during pyrolysis with the distribution ratio of 0.55-0.62. Ketones, alcohols and hydrocarbons were the dominate substances in PO, and higher temperature promoted the production of short-chain alkanes and the conversion of alkenes to benzene derivatives. SS pyrolysis can be divided into three stages. Stage I was mainly the evaporation of free water and light organics in the raw material. Decomposition and conversion of organics mainly occurred at stage II. Stage III was the decomposition of CaCO and secondary cracking of residual organics. Ca delayed the pyrolysis reaction of fatty acids and promoted decarboxylation which was the main deoxygenation pathway, and alkene production. This study provided a theoretical basis for the application of soapstock thermochemical treatment. It is of great significance for the quality improvement of PO and pollution control for pyrolysis processes.
本研究考察了温度对皂脚在流化床反应器中热解的影响，并对皂脚焦（SCs）和热解油（POs）的特性进行了分析。采用 TGA、TG-FTIR、TG-MS 和 Py-GCMS 研究 SS 热解特性。实验结果表明，SC 的产率随温度升高而降低。在 600°C 时，PO 的产率达到最大值 21.05wt%，不凝气的产率随温度变化。SC 中碳、氢和氮的含量随温度升高而降低，而硫在热解过程中趋于保留在 SC 中，分布比为 0.55-0.62。PO 中的主要物质为酮、醇和烃，较高的温度促进了短链烷烃的生成和烯烃向苯衍生物的转化。SS 热解可分为三个阶段。第一阶段主要是原料中游离水和轻有机物的蒸发。第二阶段主要发生有机物的分解和转化。第三阶段是 CaCO 的分解和残余有机物的二次裂解。Ca 延迟了脂肪酸的热解反应，促进了脱羧反应，这是主要的脱氧途径，以及烯烃的生成。本研究为皂脚热化学处理的应用提供了理论基础，对提高 PO 的质量和控制热解过程的污染具有重要意义。
