Renewable aromatics through catalytic flash pyrolysis of pineapple crown leaves using HZSM-5 synthesized with RHA and diatomite.

Abstract

The influence of reactor temperature of 300\u202f and 600\u202f°C and the acidity of the ZSM-5 and HZSM-5 catalysts on the pyrolysis product yields of the pineapple crown leaves have been investigated in a fixed bed reactor Py-GC/MS. The ZSM-5 catalyst was hydrothermally synthesized with a Si/Al ratio 50, using residual diatomite and rice husk ash as alternative sources of Al and Si for catalyst cost reduction. For the HZSM-5 synthesis, calcined ZSM-5 was activated by ion exchange between Na+ and H+. The catalysts structure was confirmed by the XRD and Rietveld treatment, SEM, FTIR, FRX, TGA and BET results. Analytical pyrolysis of the biomass was carried out at 500\u202f°C in a Py-5200 HP-R pyrolyzer connected to the GC/MS and the pyrolysis vapors were transported to a catalytic bed at 300 and 600\u202f°C. The results showed that the increase in the catalytic bed temperature promoted increased the aromatic content. The main pyrolysis products of the PCL were oxygenated compounds that were converted at 600\u202f°C using the HZSM-5 catalyst into high value renewable aromatic compounds for the chemical industry, such as benzene, toluene, xylene, etilbenzene, thereby confirming the deoxygenation activity of synthesized catalyst to produce renewable aromatics compounds which are important platform chemicals and precursors for jet fuels, gases, polymers and solvents.