Starfish (Asterina pectinifera) has been considered a major invasive species with no natural predators in the marine ecosystem. They can destroy the natural marine system when the population growth is too high, suggesting the development of a sustainable way to dispose of starfish. Therefore, this study offers a sustainable thermo-chemical platform for the direct conversion of starfish waste into value-added syngas (CO and H₂) and biochar. Major gaseous products from the starfish pyrolysis under both the N₂ and CO₂ conditions were H₂, CH₄ and CO. H₂ and CH₄ were likely ascribed to dehydrogenation and C–C bond scission of starfish, while CO formation was from homogeneous reaction of CO₂ with volatile organic matters from starfish pyrolysis. Under the N₂ environment, CO₂ liberated from the thermolysis of CaCO₃, a major constituent of starfish, contributed to formation of CO. Such the mechanistic effectiveness of CO₂ was confirmed by starfish pyrolysis under the CO₂ environment. However, the effectiveness of CO₂ on gas phase homogeneous reaction with volatile compounds was not fully activated during thermolysis in one-stage pyrolysis due to source depletion at high temperature. To improve the effectiveness of CO₂, additional thermal energy was applied through two-stage pyrolysis (isothermal running at 600 °C). The homogeneous reaction of CO₂ with volatile compounds liberated from starfish pyrolysis with additional thermal energy highly contributed to enhanced formation of CO. In line with the substantial generation of CO in the presence of CO₂, high concentration of CO₂ also contributed to more pore creation. These observations indicate that the construction of CO₂-looping system from starfish pyrolysis would become a sustainable way to produce syngas and porous biochar.

海星（Asterina pectinifera）被认为是海洋生态系统中没有天然天敌的主要入侵物种。当人口增长过快时，它们会破坏自然海洋系统，这表明发展了一种可持续的海星处置方式。因此，这项研究为海星废物直接转化为增值合成气（CO和H ₂）和生物炭提供了一个可持续的热化学平台。在N ₂和CO ₂条件下，海星热解的主要气体产物为H ₂，CH ₄和CO。H ₂和CH ₄可能归因于海星的脱氢和C–C键断裂，而CO的形成是由于CO ₂与海星热解过程中的挥发性有机物的均相反应。在N ₂环境下，海星的主要成分CaCO ₃的热分解释放出的CO ₂促进了CO的形成。通过在CO ₂环境下海星的热解证实了CO ₂的机理有效性。然而，由于高温下的源耗竭，在一级热解的热解过程中，CO ₂对与挥发性化合物的气相均相反应的有效性并未完全激活。提高CO的效力_{如图2所示}，通过两阶段热解（在600℃下等温运行）施加了额外的热能。CO ₂与海星热解过程中释放的挥发性化合物的均相反应以及额外的热能，极大地促进了CO的形成。与存在CO _2时产生大量CO一致，高浓度的CO ₂还有助于增加孔隙创建。这些观察结果表明，由海星热解构建的CO ₂环化系统将成为生产合成气和多孔生物炭的可持续方式。