Techno-economic assessment of thermo-chemical treatment (TCT) units in the Greater London area

• We modelled the techno-economics of waste management options in Greater London.
• Pyrolysis and hydrogenation are modelled for treating the plastic fractions.
• Net present value and internal rate of return are evaluated for all scenarios.
• Waste calorific value, energy efficiencies are the most sensitive parameters.

This paper reports the results of a techno-economic performance assessment on three scenarios that reflect waste management strategies and plastics treatment in the Greater London area. The polymeric fraction treated by the three integrated scenarios was part of the municipal solid waste (MSW) produced by the residents of the boroughs of Greenwich, Lewisham, Westminster, Bromley and the City of Exeter, Devon. At present, these boroughs send their MSW to an incineration unit (IU) with combined heat and power (CHP) and a dry materials recovery facility (MRF). This conventional processing of waste treatment was considered as the baseline scenario (scenario 1), and was compared with two others set within the same system boundaries. Scenarios 2 and 3 implement a pyrolysis and a hydrocracking reactor to an extracted stream of the MRF plastics products, respectively. The MRF station incorporated is of an 87.5 ktpa capacity and the IU considered operates on a capacity of 420 ktpa. The effect of increasing the thermo-chemical treatment (TCT) units’ capacity was investigated to match the order of magnitude of both the MRF and IU capacities, ranging from 1 ktpa to 150 ktpa. Fourteen different input parameters have been chosen to perform a sensitivity analysis and the effects of ±10% changes in these variables on the net present value (NPV) and internal rate of return (IRR) have been examined. It was concluded that the hydrocracking scenario is the most favourable option for waste treatment (including the polymeric fraction) at the scale of 150 ktpa.