Influence of temperature and reaction time on the conversion of polystyrene waste to pyrolysis liquid oil. (December 2016)

• Record Type: Journal Article
• Authors: Miandad, R.; Nizami, A.S.; Rehan, M.; Barakat, M.A.; Khan, M.I.; Mustafa, A.; Ismail, I.M.I.; Murphy, J.D.
• Is Part Of: Waste management. Volume 58(2016)
• Page Start: 250
• Page End: 259
• Publication Date: 2016-12
• Subjects: CO carbon monoxide -- HDPE high density polyethylene -- HHV higher heating value -- KACARE King Abdullah City of Atomic and Renewable Energy -- KSA Kingdom of Saudi Arabia -- LDPE low density polyethylene -- MSW municipal solid waste -- NOx oxides of nitrogen -- PE polyethylene -- PP polypropylene -- PS polystyrene -- RDF refuse derived fuel -- SWM solid waste management -- TGA thermogravimetric analyzer -- TIC total ion chromatogram -- WTE waste-to-energy; Municipal plastic waste -- Pyrolysis -- Polystyrene (PS) plastic -- Liquid oil -- Batch pyrolysis reactor; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.09.023
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Polystyrene comprises 14.7% of municipal solid waste in Saudi Arabia. The optimum temperature for pyrolysis was 450 °C at 75 min retention time. At optimum conditions liquid fuel was 76% by mass of polystyrene. The liquid fuel had a high energy value of 41.2 GJ/t and density (0.92 g/cm 3 ). The liquid fuel had low pour point (−18 °C) and freezing point (−64 °C). Abstract: This paper aims to investigate the effect of temperature and reaction time on the yield and quality of liquid oil produced from a pyrolysis process. Polystyrene (PS) type plastic waste was used as a feedstock in a small pilot scale batch pyrolysis reactor. At 400 °C with a reaction time of 75 min, the gas yield was 8% by mass, the char yield was 16% by mass, while the liquid oil yield was 76% by mass. Raising the temperature to 450 °C increased the gas production to 13% by mass, reduced the char production to 6.2% and increased the liquid oil yield to 80.8% by mass. The optimum temperature and reaction time was found to be 450 °C and 75 min. The liquid oil at optimum conditions had a dynamic viscosity of 1.77 mPa s, kinematic viscosity of 1.92 cSt, a density of 0.92 g/cm 3, a pour point of −60 °C, a freezing point of −64 °C, a flash point of 30.2 °C and a high heating value (HHV) of 41.6 MJ/kg this is similar to conventional diesel. The gas chromatography with mass spectrophotometry (GC–MS) analysis showed that liquid oil contains mainly styrene (48%), toluene (26%) and ethyl-benzene (21%) compounds.