As a way of improving process efficiency of pyrolysis of waste biomass, the effect of carbon dioxide (CO₂) on pyrolysis of spent coffee grounds (SCGs) was examined using a two-stage pyrolysis reactor consisting of a region with increasing temperature and an isothermal region. It was experimentally validated that CO₂ accelerates thermal cracking of organic compounds formed during the pyrolysis of SCGs. The expedited thermal cracking attributed to employing CO₂ in pyrolysis of SCGs led to changing pyrolytic products in gas, liquid, and solid phases. The production of gaseous carbon monoxide was increased when using CO₂ as the pyrolysis medium. In liquid pyrolytic products, the formation of phenolic compounds was hindered in the CO₂-assited pyrolysis. Biochar morphology (solid pyrolytic product) was also changed with different pyrolysis environments. This study shows that CO₂ can help improve applicability of pyrolysis of waste biomass by modifying three phase pyrolytic products in a two-stage pyrolyzer.

作为提高废物生物质热解过程效率的一种方法，使用了两级热解反应器，研究了二氧化碳（CO ₂）对废咖啡渣（SCG）热解的影响，该反应器由一个温度升高和等温的区域组成地区。实验证明，CO ₂促进了SCG热解过程中形成的有机化合物的热裂解。由于在SCG的热解中使用CO ₂导致的热裂解加速，导致气相，液相和固相中的热解产物发生了变化。当使用CO ₂作为热解介质时，气态一氧化碳的产生增加。在液体热解产物中，CO中阻碍了酚类化合物的形成₂辅助热解。生物炭的形态（固体热解产物）也随着不同的热解环境而改变。这项研究表明，CO ₂可以通过在两级热解器中改性三相热解产物来帮助提高废物生物质热解的适用性。