Catalytic effect of rice straw‐derived chars on the decomposition of naphthalene: The influence of steam activation and solvent treatment during char preparation

Abstract

Rice straw char (RSC) was prepared as the catalyst for naphthalene decomposition in this work. The effects of steam activation and solvent treatment on the catalytic naphthalene decomposition during the char preparation were investigated. Four chars were prepared: RSC, steam‐activated RSC at 500°C (SRS500), steam‐activated RSC at 800°C (SRS800), and solvent‐treated RSC (ResC). The catalytic activity of each catalyst was discussed, and the catalytic mechanisms were also proposed. The results revealed that the SRS catalysts gave a higher catalytic activity than the RSC, due to the enhancement of the surface area after steam activation. The SRS800 gave the highest naphthalene conversion and net gas yield: approximately 76.9% and 45%, respectively. However, its catalytic activity was more rapidly decreased by coke deposition than the other chars. Compared with the RSC, the ResC showed a slightly lower naphthalene conversion, but the net gas yield was slightly higher, especially that of H2 and CH4, due to the existence of K in silicate form.

Recent trends and economic significance of modified/functionalized biochars for remediation of environmental pollutants

“…Biochar modification with high-temperature CO 2 -ammonia mixture application has been examined to adsorb gases (CO 2 ) obtained NH 3 and CO 2 treated-biochar under a range of creation temperatures 96 . After the manufacture of biochar from the cotton stalk, it was slowly heated up to a specific temperature (500–900 °C) in a quartz reactor with N 2 purging and then NH 3 or CO 2 was purged.…”

“…The ammonification could introduce Nitrogen-comprising groups onto biochar and enhance Nitrogen content up to about 3.90 wt% in CO 2 -ammonia treated biochar, although CO 2 application could play a substantial role in the pore formation and amend the micro-porous structure of adsorbent accelerating gas sorption capabilities of the biochar 23 . Krerkkaiwan et al 96 presented that the pore volume and surface area of the CO 2 -treated biochar were higher than the untreated biochar. CO 2 could react with the carbon of biochar to form CO, thereby forming microporous structures.…”