Affiliation:
1. Chemical Engineering School of Engineering University of Newcastle NSW 2308 Australia
2. Centre for Advanced Materials and Industrial Chemistry RMIT University Melbourne VIC 3000 Australia
3. School of Chemical Engineering University of Queensland St Lucia QLD 4072 Australia
4. Mark Wainwright Analytical Centre University of New South Wales NSW 2052 Australia
5. Centre for Catalysis and Clean Energy Griffith University Gold Coast QLD 4222 Australia
6. Department of Chemical Engineering University of Western Australia Perth WA 6009 Australia
Abstract
AbstractCatalytic cracking of high molecular weight hydrocarbons underpins the production of fossil fuels from petroleum vapour and the recycling of polyolefin waste plastic. However, thermal cracking over conventional microporous solid acids is hindered by poor mass‐transport. Here we explore the performance of hierarchical H−Y zeolites and Al‐SBA‐15 for the catalytic cracking of 1,3,5‐triisopropylbenzene (1,3,5‐TIPB) and low‐density polyethylene (LDPE) in a continuous fixed‐bed flow reactor. Dealumination by acid washing was used to create hierarchical mesoporosity in H−Y zeolite and modify the solid acidity. Physicochemical properties were studied by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), gas adsorption, in‐situ Fourier transform infrared (FTIR), ex‐situ pyridine DRIFT, 29Si and 27Al nuclear magnetic resonance (NMR), and 1H relaxation and pulsed field gradient (PFG) NMR diffusion studies. Despite weakening acidity, the introduction of hierarchical porosity promotes deep cracking of both feedstocks; HNO3 dealuminated H−Y produces five times more cumene and benzene from 1,3‐5‐TIPB, and 33 % more benzene and xylenes from LDPE, than the parent H−Y.
Funder
Australian Research Council
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Catalysis