Non-thermal Plasma-Assisted Deconstruction of High-Density Polyethylene to Hydrogen and Light Hydrocarbons over Hollow ZSM-5 Microspheres

Abstract

Non-thermal catalytic plasma has unfolded novel routes for a circular economy, providing a powerful cost-effective alternative to produce valued-added fuels from plastic waste. In this work, non-thermal plasma-assisted deconstruction of high-density polyethylene (HDPE) over a ZSM-5 catalyst with different morphologies, i.e., microspheres and nanoparticles, is reported. Deconstruction of HDPE over thermal routes is presented to benchmark the plasma pathways. Experimental data revealed that the highest yield/selectivity toward hydrogen and light hydrocarbons such as methane, ethylene, acetylene, and ethane was obtained through the plasma route over the hollow ZSM-5 microspheres. The spherical morphology helps in securing better stability compared to that of the ZSM-5 nanoparticles. We observed the demarcation of two different regimes resulting from the products formed. In the plasma regime (low plasma power), the ethylene monomer is prevalent while hydrogen is dominant when employing high plasma power (endothermic zone). These findings provide a novel insight into the chemical upcycling of HDPE to value-added products to potentially help address the current global plastic contamination in an efficient and sustainable way.

Plasma driven ammonia synthesis over silica: The role of the catalyst morphology and porous structure

“…The N 2 adsorption-desorption curve of the mesoporous silicas of both mesoporous gyroid-and spherical-shaped display type IV a rming the presence of mesoporous structure. In contrast, the N 2 adsorption-desorption curve of the macroporous silicas including spherical-and gyroid-shaped morphology displayed type VI isotherms verifying the presence of macroporous structure, but with a mixture of micro-and meso-porous pore regime [17]. Moreover, the H 2 pore shape of mesoporous silicas shows bottleneck constrictions in their structure.…”

“…Previous studies have also indicated that the combination between plasma and catalyst can deliver vibrationally excited N 2 effectively [15]. More importantly, plasma-based reaction systems offer great exibility, safety, and straightforward switch ON/OFF, and do not require complex heat/chilling systems [16,17]. Such advantages place NTP as a high-potential technology for decentralized small-scale ammonia synthesis powered by intermittent renewables, which increases the overall economic capability of the plasma process.…”

CO2 and HDPE Upcycling: A Plasma Catalysis Alternative

“…Previous works have explored the plasma catalytic decomposition of HDPE with nonthermal atmospheric DBD plasma when employing an acid catalyst HZSM-5 zeolite, which favored the formation of light or gaseous hydrocarbons. 51 This motivated us to pursue the understanding of the product formation in a more homogeneous plasma environment (radio frequency plasma) using a greenhouse gas (GHG) CO 2 , a mild oxidant, by exploring various alkaline earth metal perovskites (MgTiO 3 , CaTiO 3 , SrTiO 3 , BaTiO 3 ) as plasma enhancers. The main driving force behind using the presented materials is the absence of acid sites, which has been shown to produce high yields of liquid hydrocarbons.…”

Sustainable ammonia synthesis from seawater and nitrogen by single-step plasma catalysis: a step towards New England’s farmers nitrogen autonomy

“…25 This added to their conceptualization as modular small-scale systems for ammonia synthesis results in simple lightweight units compared to high pressure thermal reactors, which comprise added complex insulation/cooling systems. 26 Indeed, our group has studied ammonia synthesis over NTP catalytic processes over the past years. [27][28][29][30][31][32] The achieved fundamental understanding on the effects of different catalysts, plasma-catalyst synergisms, and energy efficiency on ammonia synthesis allow us to primarily estimate the great potential of ammonia synthesis from N2 and "green" H2 sources, which is an important step to achieve zero-carbon ammonia synthesis.…”