Abstract:
Co-pyrolysis with low-sulfur biomass is expected to improve the yield and quality of bio-fuels, without the usage of calcium-based desulfurizer. Sulfur transformation during microwave fluidized-bed co-pyrolysis between terrestrial and marine biomass (Ascophyllum, AS; Rice straw, RS) was investigated. Sulfur release was promoted during biomass co-pyrolysis, but it was inhibited during pyrolysis between AS and low-sulfur char. Thermal cracking of biomass was promoted during co-pyrolysis between biomass, accelerating the combination of H atoms and -SH radicals. Introduction of low-sulfur bio-char (CA) inhibited the generation of bio-char and the release of sulfur. Released sulfur was captured by -OH/C = C functional groups on bio-char through dehydration reactions/addition reactions, forming mercaptan in bio-char. Furthermore, introduction of microwave and bio-char promoted the cyclization and aromatization reaction, converting mercaptan to thiophene and improving the thermal stability of solid sulfur, and thus increasing in-situ sulfur fixation rate.
摘要:
低硫生物质的共热解有望提高生物燃料的产量和质量,无需使用钙基脱硫剂。陆地和海洋生物质之间的微波流化床共热解过程中的硫转化(Ascophyllum,AS;稻草,RS)进行了调查。生物质共热解过程中促进了硫的释放,但在AS和低硫炭的热解过程中受到抑制。生物质共热解过程中促进了生物质的热裂解,加速H原子和-SH自由基的结合。低硫生物炭(CA)的引入抑制了生物炭的生成和硫的释放。释放的硫通过脱水反应/加成反应被生物炭上的-OH/C=C官能团捕获,在生物炭中形成硫醇。此外,微波和生物炭的引入促进了环化和芳构化反应,将硫醇转化为噻吩,提高固体硫的热稳定性,从而提高原位固硫率。