Energy analysis and life cycle assessment of a thermal energy storage unit involving conventional or recycled storage materials and devoted to industrial waste heat valorisation

Any system intending to improve the environmental performances of a process should be assessed by Life Cycle Assessment. This work draws up profile heat provided storage recovering industrial waste at high temperature (500 °C) through 5 selected indicators: Cumulative Energy Demand, Global Warming Potential, abiotic depletion potential, particle matter and freshwater eutrophication. The calculated indicators were compared those fossil fuel substituted recovered heat, that is say natural gas, proved reduced. Then, payback times calculated; an energetic profitability evaluation Returned on Investment expanded profile. Besides, influence operating conditions variations was investigated parametric study. An optimal number cycles provide same amount energy may defined, as compromise between resource potential reduction with smaller tanks performing more returned investment deteriorated operational consumption increased due higher pressure drop tank diameter. most rewarding concerned Potential about 1.2 kgCO2-eq 65 MJ-eq per kWh (payback time lower than 3 months), doubled e.g. reached value 55. positive effect using recycled materials indicator enlightened, notably when strayed from reference case.