Pyrolytic Gasification of Post-consumer Polyolefins To Allow for “Clean” Premixed Combustion

Abstract

Utilization of post-consumer waste plastics as fuels is of technological interest because their energy contents (heating values) are comparable to those of premium fuels. Pyrolytic gasification of these solid polymers yields a mixture of predominately gaseous hydrocarbons and hydrogen. This gaseous fuel mixture can then be suitably blended with air and burned in well-controlled premixed flames. Such flames are much less polluting than diffusion flames, which would have been generated had the polymers been burned in their solid state. In this work, an apparatus was designed and built to continuously process polymers, in pelletized form, and to pyrolytically gasify them at temperatures in the range of 800−900°C in N 2 -or CO 2 -containing environments. Subsequently, the gaseous pyrolyzates were mixed with air, ignited, and burned in a Bunsen-type burner in a manner similar to natural gas. Polyethylene and polypropylene pyrolyzates burned with blue-tint flames akin to those of natural gas. The flames were fairly steady and nearly stoichiometric, generating effluents with low CO/CO 2 ratios. The combustion reactions released heat in a small water boiler coupled to a miniature steam engine, which produced electricity, illustrating the feasibility of "clean" power generation from waste plastics. Because pyrolysis of polyolefins requires a nominal heat input that amounts to only a minuscule fraction of the heat released during their combustion, large-scale implementation of this technique is deemed to be technologically viable and economically favorable.

New insights into the role of lattice oxygen in the catalytic carbonization of polypropylene into high value-added carbon nanomaterials

“…The catalytic conversion of waste plastics into something useful and more valuable has aroused much interest, [1][2][3] owing to the ever-increasing generation of waste plastics (e.g., more than 25 million tons of waste plastics were generated in Europe in 2011). Chemical recycling can recover the petrochemical components of waste plastics, which could be used to produce other synthetic chemicals.…”

Influence of Stainless-Steel Catalyst Substrate Type and Pretreatment on Growing Carbon Nanotubes from Waste Postconsumer Plastics

“…Upcycling of postconsumer plastics into value-added products is important in finding solutions for the related pressing environmental pollution problems. If a sizable fraction (e.g., 13% 161 ) of the mass of discarded plastics were to be converted to CNTs, and if most of the remaining mass were to be converted to gaseous fuel, which upon premixing with air can be burned "cleanly", 42 then this technology would have a significant positive environmental impact. Accordingly, an investigation was conducted on the appropriate pretreatment of readily available austenitic stainless-steel wire-cloths (SS-304, SS-316 and SS-316lL), so that they act as effective catalysts for generation of multiwall CNTs from a variety of waste plastic feedstocks.…”

Synthesis of nano-carbons from different waste plastics and diverse catalysts

“…Also, alternative fuels can be found in municipal/industrial recycling and waste streams. Postconsumer plastics is one of those materials that has been studied extensively as an alternative fuel at Northeastern University's Combustion & Air Pollution laboratory [12][13][14][15][16][17][18][19].…”

“…Finding different applications to recycle the waste plastic is also very important. There are some researches that use the pyrolyzates as fuel [39,40]. This applications can be considered as an alternative energy resource to reduce the pressure of using fossil fuel.…”

“…This applications can be considered as an alternative energy resource to reduce the pressure of using fossil fuel. The pyrolyzates from the chemical recycling of waste plastic has also important applications, such as generating gaseous and liquid fuels [39,40] [ [41][42][43][44][45][46] and carbon nanotubes (CNTs) [12][13][14][15][16]. What are Carbon Nanotubes?…”