From waste-to-energy to waste-to-hydrogen units: A new role of waste combustion plants

The study focused on a new Waste-to-Hydrogen (WtH2) strategy, where a waste combustion plant (WCP), originally designed and operated as a Waste-to-Energy unit, provides “renewable” electricity to an electrolyser, to obtain “green hydrogen” utilised in a regional railway line. The investigation included three systems using alternative WCPs, differing for size, energy efficiency and input waste composition. A Life Cycle Assessment, with a “separate share” approach and “product&tranportation” perspective, compares trains powered by WtH2 systems, diesel or hydrogen from steam reforming, respectively. The WtH2 systems show savings ranging from 39 to 57 t CO2,eq per tonne of produced H 2 , and are in compliance with the EU decarbonisation targets. The WtH2 system including the co-generative large-scale plant has the best performance when all categories are evaluated as a single score (with improvements up to 180%). The main relevant contributions to the results come from the thermal energy recovery and biogenic waste avoided management. • Three Waste-to-Hydrogen (WtH2) systems fuelling a railway line are assessed with LCA. • WtH2 systems use combustion plants, differing for size, energy efficiency and waste. • WtH2 systems have Climate Change saving up to 57 tCO2,eq compared to fossil alternatives. • Largest plant has the best result for all impact categories, weighted as a single score. • Results depend on thermal energy recovery, waste type and its avoided management mix.