Catalytic Transformation of Waste Polymers to Fuel Oil

Abstract

Waste not, want not: The increase in waste polymer generation, which continues to exceed recycle, represents a critical environmental burden. However, plastic waste may be viewed as a potential resource and, with the correct treatment, can serve as hydrocarbon raw material or as fuel oil, as described in this Minireview.Effective waste management must address waste reduction, reuse, recovery, and recycle. The consumption of plastics continues to grow, and, while plastic recycle has seen a significant increase since the early 1990s, consumption still far exceeds recycle. However, waste plastic can be viewed as a potential resource and can serve, with the correct treatment, as hydrocarbon raw material or as fuel oil. This Minireview considers the role of catalysis in waste polymer reprocessing and provides a critical overview of the existing waste plastic treatment technologies. Thermal pyrolysis results in a random scissioning of the polymer chains, generating products with varying molecular weights. Catalytic degradation provides control over the product composition/distribution and serves to lower significantly the degradation temperature. Incineration of waste PVC is very energy demanding and can result in the formation of toxic chloro emissions. The efficacy of a catalytic transformation of PVC is also discussed.

Investigation into the Catalytic Activity of Microporous and Mesoporous Catalysts in the Pyrolysis of Waste Polyethylene and Polypropylene Mixture

“…Plastic materials have been extensively consumed by various industry sectors including packaging, household, construction, automobile, aerospace, and electronic [1] owing to their advantageous properties, such as light weight, good strength and durability, resistance to corrosion, excellent thermal and electrical insulation, versatility and low production costs. Nevertheless, the growing consumption of plastics has resulted in an increasing amount of municipal and industrial plastic wastes generated over the decades.…”

“…Nevertheless, the growing consumption of plastics has resulted in an increasing amount of municipal and industrial plastic wastes generated over the decades. Non-sustainable end-of-pipe treatments such as landfill and incineration remains the most common approaches for plastic wastes management [1,2]. Landfilling non-biodegradable plastic waste occupies precious land space [3,4].…”

Selective production of valuable hydrocarbons from waste motorbike engine oils via catalytic fast pyrolysis using zeolites

“…At high temperatures of 600-800 o C, the yields of cycloalkanes and cycloalkenes increased, while that of benzene derivatives decreased significantly. Kim and Kim [20] proposed a lumped mechanism of automobile engine oil degradation that involves the production of C 5-11 and C 12-25 fractions via parallel reactions from engine oil, and C 5-11 production from C [12][13][14][15][16][17][18][19][20][21][22][23][24][25] . Whilst it is difficult to trace the individual reactions involved in the evolution of various species owing to the complex composition of waste oils and the complexity associated with the transformations, the various interconversions occurring during non-catalytic fast pyrolysis of waste engine oil, based on the above results, can be summarized as follows.…”

“…Fast pyrolysis at low temperatures is characterized by C 31-55 heavy fractions and significant amount of oxygenated aromatic compounds. However, liquid transportation fuels like gasoline and kerosene contain significant amount of paraffins in a restricted carbon number range of C [5][6][7][8][9][10][11][12][13][14][15] . In order to enhance the quality of the fast pyrolysis products in terms of improving the yield of saturated hydrocarbons whilst restricting the carbon number range and also reducing the pyrolysis temperature, catalytic fast pyrolysis of waste engine oils was performed using six different zeolites at various operating conditions.…”

“…Therefore, from environmental, energy and economic viewpoints, it is necessary to develop innovative strategies to solve the issue of disposal of waste engine oils along with the generation of value added intermediates/fuels. Pyrolysis is one of the well known thermochemical processing techniques to recover valuable intermediates and chemicals from a variety of renewable and non-renewable feedstocks like waste plastics [12,13], end-of-life tyres [14,15], lignocellulosic biomass [16], coal, petroleum residues [17] and oil shales [18]. A few reports are available on conventional pyrolysis of waste engine oils [1,2,11,[19][20][21][22][23][24].…”