Case Studies in Chemical and Environmental Engineering (Jun 2024)
Microwave-assisted coconut wood carbon-based catalyst impregnated by Ni and/or Pt for bio-jet fuel range hydrocarbons production from Calophyllum inophyllum L. oil using modified-microwave reactor
Abstract
Three types of activated carbon from coconut wood sawdust waste were prepared using microwave carbonization followed by microwave activation, which was coded CWMM, while activated carbon prepared through conventional carbonization followed by activation was coded CWCC. Activated carbon that was conventionally carbonized and subsequently activated using a microwave was coded as CWCM. The Ni metal was loaded on different supports, e.g., CWMM, CWCC, and CWCM, by the wet impregnation method, resulting in 1%Ni/CWMM, 1%Ni/CWCC, and 1%Ni/CWCM catalysts, respectively. Additionally, monometallic catalysts of Ni (5 wt%) and Pt (1 and 5 wt%) impregnated on CWMM were prepared using a similar method, resulting in 5%Ni/CWMM, 1%Pt/CWMM, and 5%Pt/CWMM, respectively. The Pt–Ni bimetallic catalysts impregnated on CWMM were prepared using co-impregnation, sequential impregnation, and reverse sequential impregnation methods, resulting in 2.5 wt%Pt-2.5 wt%Ni/CWMM-co, 2.5 wt%Pt-2.5 wt%Ni/CWMM-seq, and 2.5 wt%Pt-2.5 wt%Ni/CWMM-rev, respectively. The obtained catalysts were used for CIO hydrocracking using a microwave reactor under H2 gas flow. The catalyst reusability test was conducted by hydrocracking CIO using the best-performing catalyst for 5 runs. The liquid products were analyzed using a gas chromatography-mass spectrometer (GC-MS). The 1 % Ni/CWMM shows the highest yield of bio-jet fuel hydrocarbon of 15.85 wt% among the other supports. The Ni monometallic catalyst showed that higher metal content resulted in higher bio-jet fuel hydrocarbon yield; however, the Pt monometallic catalyst showed the opposite result. The bimetallic catalysts showed a higher bio-jet fuel hydrocarbon yield compared to the monometallic catalysts. The highest yield of bio-jet fuel hydrocarbon was achieved by 2.5 wt%Pt-2.5 wt%Ni/CWMM-co at 33.1 wt% with a selectivity of 99.99 %. This catalyst showed the highest surface area of 327.466 m2 g−1 and acidity of 1.276 mmol/g among the other bimetallic catalysts. The reusability test showed the yield of bio-jet fuel hydrocarbon decreased to 12.89 wt% after the fifth use of the catalyst.
