Recycling and recovery routes of plastic solid waste (PSW): A review

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

The current review provides an assessment of the main waste plastics valorization routes to produce syngas and H2, thus covering different gasification strategies and other novel alternative processes, such as pyrolysis and in-line catalytic steam reforming The studies dealing with plastics gasification are in general scarce However, due to the knowledge acquired on biomass and coal gasification, the state of development of plastic gasification technologies is considerable and, in fact, several gasification studies have been performed at pilot scale units Air gasification is the most studied and developed strategy and pursues the production of a syngas for energy purposes In spite of the higher H2 content and heating value of the gas produced by steam gasification, this alternative faces significant challenges, such as the energy requirements of the process and the tar content in the syngas Moreover, the co-gasification of plastics with coal and biomass appears to be a promising valorization route due to the positive impact on process performance and greater process flexibility Other promising alternative is the pyrolysis and in-line reforming, which allows producing a syngas with high hydrogen content and totally free of tar

Recent advances in the gasification of waste plastics. A critical overview

Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC−MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household ...

Emission factors for carbonaceous particles and polycyclic aromatic hydrocarbons from residential coal combustion in China.

The valorization of plastic solid waste (PSW) by primary to quaternary routes: From re-use to energy and chemicals

Formation and fate of PAH during the pyrolysis and fuel-rich combustion of coal primary tar

High-performance liquid chromatography (HPLC) with ultraviolet−visible (UV) diode-array detection was used to analyze the condensed-phase products from the fuel-rich combustion, at 1000 °C, of bituminous coal primary tar. Experiments were performed using a quartz two-stage reactor consisting of a fluidized-bed reactor coupled to a tubular-flow reactor. Eight cyclopenta-fused polycyclic aromatic hydrocarbons (CP−PAH) were identified, four of which have never before been observed as products of a bituminous coal and have also never been observed from the fuel-rich combustion of any coal:  cyclopent[hi]acephenanthrylene, cyclopenta[cd]fluoranthene, dicyclopenta[cd,jk]pyrene, cylopenta[bc]coronene. In addition to these CP−PAH, two ethynyl-substituted PAH, 2-ethynylnaphthalene and 1-ethynylacenaphthylene, were identified for the first time as bituminous coal products. Yields of individual CP−PAH spanned a range of 4 orders of magnitude. Out of the eight CP−PAH identified, acenaphthylene was found to be the mos...

Observation of Cyclopenta-Fused and Ethynyl-Substituted PAH during the Fuel-Rich Combustion of Primary Tar from a Bituminous Coal

Using high-pressure liquid chromatography with diode-array ultraviolet-visible detection, we have identified benz[f]indene (C 13 H 10 ) among the pyrolysis products of coal and the model compound anthracene, a three-ring compound representative of the aromatic moieties in coal. The coal pyrolysis experiments are conducted at 700-1000 °C in a fluidized bed reactor; the anthracene experiments, at 900-1000 °C in a laminar flow reactor. This is the first time that benz[f]indene has been identified as a product of either fuel, coal or anthracene. Oxidative ring rupture is proposed as the mechanism responsible for the formation of benz[f]indene and other indene benzologues in these products.

Meredith A. Kalish

Papers

Formation and fate of PAH during the pyrolysis and fuel-rich combustion of coal primary tar

Observation of Cyclopenta-Fused and Ethynyl-Substituted PAH during the Fuel-Rich Combustion of Primary Tar from a Bituminous Coal

Detection of Benz[f]indene among the Pyrolysis Products of Coal and Anthracene