Pyrolysis of plastic waste: opportunities and challenges

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Thermolysis of plastic waste: Reactor comparison

Plastic waste offers an attractive business opportunity if treated intelligently. Presently, owing to the lack of economically viable recycling solutions and political interest, this valuable feedstock is bound for an ill-fated destiny i.e. landfills and inefficient incineration. Landfilling plastic waste is rather a storage mechanism than a prevention mechanism. Plastics can stay in ground and in oceans for hundreds of years without decomposing, posing serious environmental hazards. Given the complexity of the plastic waste mixture and heterogeneity of waste streams, a single recycling solution is improbable; however, the current environmental situation demands an urgent need to find ways to tackle this ever-growing waste problem. Thermolysis (pyrolysis) of non-recyclable plastic waste allows the waste to be converted to a valuable hydrocarbon rich petrochemical-based feedstock. This feedstock i.e. composed of oil, wax and gas, has great potential to be used in multiple applications, one of the most attractive ones is co-feeding in a refinery. The gas and char generated in the process can be used to provide the energy needed for thermolysis. Thermolysis of plastic waste has to offer many benefits over other recycling techniques such as the recycling of feedstock contaminated with dirt and organics, recycling of problematic waste such as laminates, multilayer plastic and even hazardous plastics such as those found in electrical or demolition waste. Furthermore, it converts the solid waste that is difficult to store, transport and dispose, into liquid and wax product that is easily transportable. However, like other recycling technologies, it also suffers from some technical challenges, which should be scrutinized before choosing the recycling technology. From the practical aspects, the choice and availability of feedstock, reactor type and investments, use of a catalyst, products needed, availability of standards, REACH, and established markets etc. all these factors come into play and should be evaluated thoroughly. This presentation targets the role of thermolysis in managing global plastic waste. Technological challenges associated with reactor types used for thermolysis and the quality and upgrading of products will be discussed, i.e. comparison of the slow vs. fast thermolysis. Furthermore, the results of a national ‘Waste to Products’ project will be presented including the learnings from thermolysis experiments

Spectrum, Volume 19, Number 2

Highlights include: Flik gets a facelift --On September 13 a conference was held with a wide range of guest speakers including Dr. Cenera, Dr. Amy Van Buren, Dr. Linda Strong, Dr. Stiltner, Dr. Gary Rose and Dr. Kikoski to offer insight on 9/11 attacks --The university has had two interim librarians, the first being Mary Rogers and the current, acting librarian Susan Broadstone, since University Librarian Dorothy Kijanka retired during the 1998-1999 academic year --Welcome from Tom Pesce, student government president --Commentary from Keri Blair: Americans re-discover pride in time of tragedy --Meet your student government --SHU salutes Public Safety (photos) --“Hardball” Hits a Home Run; Entertainment World Still In Mourning --SHU Art Gallery kicks off with “Common Threads”, which brings together the work of four artists who include the use of thread, cloth, lace or images of clothing, traditional materials and skills -- --Fencer junior Sean “Ronnie” Robenson from Bethpage Long Island is athlete of the week --Sports world put on hold: University and professional athletes lend hand to rescue relief efforts

A Pyrolysis Pilot Unit Integrated to a Circulating Fluidized Bed Boiler - Experiences from a Pilot Project

A novel integrated pyrolysis pilot plant has been built in Tampere, Finland by Metso, in co-operation with UPM, Fortum and VTT. A 7 tons of bio-oil per day (2 MWfuel input) fast pyrolysis unit has been integrated with Metso’s 4 MWth CFB pilot boiler. Test runs of bio-oil production have been carried out during 2009-2010. More than 80 tons of bio-oil has been produced and utilization tests have been started in district heating burner applications

Production of pyrolytic lignin for the phenolic resin synthesis via fast pyrolysis

Recycling of waste wood into resol type phenol-formaldehyde (PF) resins via fast pyrolysis was demonstrated. Waste wood collected from the building demolition site in Finland was pyrolyzed with 20 kg/h circulating fluidized bed pyrolysis pilot unit. Pilot was operated with high organic liquid yield (60 wt% on average) and the produced fast pyrolysis bio-oil was fractionated by water addition into aqueous phase and water insoluble phase. The obtained fractions were characterized, and the water-insoluble viscous lignin fraction was used in the synthesis of PF-resins. Commercial phenol was successfully replaced by pyrolytic lignin fraction at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% producing resins of low in free formaldehyde content, but resins with high replacement ratio exhibited higher viscosities. The use of H2O/n-butanol mixture as solvent at a ratio 70:30 wt/wt% proved capable to prolong the storage time of the resin and helped to maintain the viscosity at acceptable values for at least 2 weeks before their use in the targeted application. Finally, the gluing performance of the resins was evaluated by measuring the tensile shear strength of lap joints formed by gluing 5 mm thick beech wood veneers. All the produced resins fulfilled a dry strength limit of ≥ 10 N/mm2. Wet strength limit ≥ 7 N/mm2 was fulfilled by the resins with the replacement ratio up 40 wt%, but resins with replacement ratio of 50 wt% had somewhat reduced wet strength. These results confirm a promising protentional application of pyrolysis derived lignin fraction in phenolic wood adhesives, at least in dry conditions

Valorization of Eucalyptus, Giant Reed Arundo, Fiber Sorghum, and Sugarcane Bagasse via Fast Pyrolysis and Subsequent Bio-Oil Gasification

[Image: see text] Fast pyrolysis of giant reed Arundo (Arundo donax), fiber sorghum (Sorghum bicolor L.Moench), eucalyptus (Eucalyptus spp.), and sugarcane bagasse (Saccharum officinarum) was studied in bench-scale bubbling fluidized bed reactor. Product yields were determined, and detailed physicochemical characterization for produced fast pyrolysis bio-oils (FPBOs) was carried out. The highest organic liquid yield (dry basis) was observed with sugarcane bagasse (59–62 wt %), followed by eucalyptus (49–53 wt %), giant reed Arundo (39 wt %), and fiber sorghum (34–42 wt %). After the pyrolysis experiments, produced FPBOs were gasified in an oxygen-blown autothermal catalytic reforming system for the produced synthesis gas. The gasifier consists of a partial oxidation zone where the FPBO is gasified, and the raw syngas is then reformed over a fixed bed steam-reforming catalyst in the reforming zone. The gas production (∼1.7 Nm(3)/kg FPBO) and composition (H(2) ∼ 50 vol %, CO 20–25 vol %, and CO(2) 25–30 vol %) were similar for all FPBOs tested. These results show that the combination of fast pyrolysis with subsequent gasification provides a technically feasible and feedstock flexible solution for the production of synthesis gas