In-situ Upgrading of Napier Grass Pyrolysis Vapour Over Microporous and Hierarchical Mesoporous Zeolites

Abstract

This study presents in-situ upgrading of pyrolysis vapour derived from Napier grass over microporous and mesoporous ZSM-5 catalysts. It evaluates effect of process variables such catalyst-biomass ratio and catalyst type in a vertical fixed bed pyrolysis system at 600 o C, 50 o C/min under 5 L/min nitrogen flow. Increasing catalyst-biomass ratio during the catalytic process with microporous structure reduced production of organic phase bio-oil by approximately 7.0 wt%. Using mesoporous catalyst promoted nearly 4.0 wt% higher organic yield relative to microporous catalyst, which translate to only about 3.0 wt% reduction in organic phase compared to the yield of organic phase from noncatalytic process. GC-MS analysis of bio-oil organic phase revealed maximum degree of deoxygenation of about 36.9 % with microporous catalyst compared to the mesoporous catalysts, which had between 39 and 43 %. Mesoporous catalysts promoted production olefins and alkanes, normal phenol, monoaromatic hydrocarbons while microporous catalyst favoured the production of alkenes and polyaromatic hydrocarbons. There was no significant increase in the production of normal phenols over microporous catalyst due to its inability to transform the methoxyphenols and methoxy aromatics. This study demonstrated that upgrading of Napier grass pyrolysis vapour over mesoporous ZSM-5 produced bio-oil with improved physicochemical properties.

Effects of Zn Addition into ZSM-5 Zeolite on Dehydrocyclization-Cracking of Soybean Oil Using Hierarchical Zeolite-Al2O3 Composite-Supported Pt/NiMo Sulfided Catalysts

“…Among the biomass feedstocks, fats have such advantageous characteristics of liquids and structures with long alkyl chains that they can be transformed to fuels of gasoline, kerosine, and gas oil; aromatics; and hydrogen. Although transesterification with methanol provides biodiesel fuels, reactants such as glycerol, surplus methanol, and catalysts remain in the final stage of the reaction and have to be removed prior to their utilization. − Meanwhile, heterogeneous transesterification making fatty acid methyl ester (FAME), − catalytic cracking making gasoline, propylene, and aromatics for petrochemicals, − and hydrotreating of fats to biodiesel fuels with high cetane numbers and bio-jet fuels − ,− have already been reported during the last decade. Among them, the hydrotreating of fats gives not only vehicle fuels, C3 fraction, and light gas oil with the higher durability for oxidation than that of FAME but also raw materials for petrochemicals, especially aromatics. − For example, after treatment of fats by ZSM-5 with mesopore and macropore at 300 °C and pressure up to and including 4.0 MPa, hydrotreatment of the oils obtained was performed using NiMo/Al 2 O 3 at 340 °C and 4.5 MPa. , The two-step process using ZSM-5 with a 0.6 cm 3 /g pore volume at a high pressure gave 25–29 wt % n -paraffin and 8–15 wt % aromatics, whereas aromatics were not given by ZSM-5 with 0.35 cm 3 /g pore volume.…”