Fast Pyroylysis of Polyolefin Waste over Cracking Catalysts for Producing Hydrocarbon Fuels Using a Fluidized-bed Reactor

Abstract

A mixture of post-commercial polyolefin waste (PE/PP/PS) was pyrolyzed over various micro- and mesoporous catalysts using a fluidized-bed reactor operating isothermally at ambient pressure. The yield of volatile hydrocarbons with zeolitic nano-catalysts (n-ZSM-5 > n-MOR > n-USY) were higher than with non-zeolitic catalysts (MCM-41 > ASA). MCM-41 with large mesopores and ASA with weaker acid sites resulted in a highly olefinic product mixture with a wide carbon number distribution, whereas n-USY yielded a saturate-rich product mixture with a wide carbon number distribution and substantial coke levels. A novel developed model based on kinetic and mechanistic considerations which take into account chemical reactions and catalyst deactivation for the catalytic degradation of commingled polyolefin waste has been investigated. This model represents the benefits of product selectivity for the chemical composition such as alkanes, alkenes, aromatics and coke in relation to the performance and the particle size selection of the catalyst used as well as the effect of the fluidizing gas and reaction temperature.

Catalytic Pyrolysis of Dual Wastes into Worth

“…The systematic experiments discussed in this work indicate that catalyst deactivation is being produced by active-site coverage, and consequently decrease the activity of the catalyst, giving the reason of decreasing of reaction rate with reaction time. The systematic experiments discussed in this work and in earlier work [9][10][11] indicate that catalyst deactivation is being produced by active-site coverage, and consequently decrease the activity of the catalyst, giving the reason of decreasing of reaction rate with increasing the amounts of residues.…”