Catalytic supercritical water gasification of plastics with supported RuO2: A potential solution to hydrocarbons–water pollution problem

Abstract

ABSTRACT:Here we report on a potential catalytic process for efficient clean-up of plastic pollution in waters, such as the Great Pacific Garbage Patch (CPGP). Detailed catalytic mechanisms of RuO2 during supercritical water gasification of common polyolefin plastics including low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and polystyrene (PP), have been investigated in a batch reactor at 450 °C, 60 min. All four plastics gave very high carbon gasification efficiencies (CGE) and hydrogen gasification efficiencies (HGE). Methane as the highest gas component, with a yield of up to 37 mol kg -1 LDPE using the 20 wt% RuO2 catalyst. Evaluation of the gas yields, CGE and HGE revealed that the conversion of PS involved thermal degradation, steam reforming and methanation; whereas hydrogenolysis was a possible additional mechanism during the conversion of aliphatic plastics. The process has the benefits of producing a cleanpressurized methane-rich fuel gas as well as cleaning up hydrocarbons-polluted waters.

A review on thermal and catalytic pyrolysis of plastic solid waste (PSW)

“…Moreover, it encompasses various treatment methods that result in high end value products from PSW. Such methods include glycolysis (Simon et al, 2014;2015;Sharma and Bansal, 2016), hydrolysis (Campanelli et al, 1993;Evans and Chum, 1991;Panda et al, 2010), pyrolysis (Williams, 2013;Williams and Brindle, 2002;Danon et al 2015a;2015b), aminolysis (Goje et al 2004;Sinha et al, 2010;Sadeghi et al, 2011), gasification (Dou et al, 2016;Wang and Zhao, 2016;Onwudilia and Williams, 2016) and hydrogenation (Bockhorn et al, 1999a;Aznar et al, 2006). However, advanced thermo-chemical treatment (TCT) methods namely pyrolysis has received renewed attention recently due to the numerous operational and environmental advantages it provides given global energy demand and unstable fuel market.…”

Preparation and Properties of Sodium Carboxymethyl Cellulose/Sodium Alginate/Chitosan Composite Film

“…The use of composite films prepared from natural materials is not only safe and environmentally friendly, but also enables full utilization of the properties of the raw materials by compensating for any shortcomings of the individual components and thus increasing their value for practical applications. The use of composite films for food packaging applications helps reduce the adverse effects of using plastic bags, such as fossil fuel consumption and soil and water pollution [1,2]. Targeted selection of raw materials can allow the fabrication of composite films with special properties, such as antibacterial properties and biodegradability [3,4], making them effective for food packaging applications.…”

Utilization of Plastic Wastes for Sustainable Environmental Management: A Review

“…Gasification is one of the other best techniques for plastic waste to fuel at high temperature around 450-1300°C. [135,136] In a batch reactor at 450°C for 1 h, Onwudili and Williams [136] executed catalytic supercritical water gasification of plastics. Hydrogenolysis, methanation, steam reforming reaction and thermal degradation were all involved in plastic hydrothermal gasification.…”