Electrochemical reactions operated with pure LOHC molecules will allow for strategic integration with thermochemical reactions for LOHC cycling. Figure shows a carbon footprint comparison of different LOHC cycling processes under different scenarios. When using renewable energy sources, the carbon footprint of hybrid LOHC cycling where TCH and ECD of pure LOare the hydrogen loading and releasing systems, respectively, is 2.2 kgCO2/kg H2 cycled. On the other hand, when hydrogen loading is via pure acetone ECH process while the hydrogen release is via IPA TCD (60% heat recovered), the carbon footprint obtained is 3.8 kgCO2/kg H2 cycled. TCD reaction requires higher energy to operate at high temperatures and can therefore be replaced by ECD reaction only when concentration greater than 4M and 9M are used for water only and 1M KOH electrolyte, respectively. Further information regarding the carbon footprint of different LOHC cycling scenarios can be obtained in supplementary information (Table ). The TCH and ECD hybrid LOHC cycling could offer a lower carbon emission system compared to the thermochemical LOHC cycling but only when pure LOHC is used in the reactions. From the simulation results, a hybrid process would only be feasible when the electrochemical processes are conducted at higher concentrations. The product from electrochemical reaction has to be separated from the electrolyte solution in order to be utilized in the thermochemical process. Pure IPA or diluted IPA b in water without separation process 0.00 0.00 a IPA ECD carbon footprint for these models is independent of the electricity source b Diluted IPA/acetone represents the range of IPA/acetone concentrations in aqueous (water only) electrolyte CONCLUSIONS Thermochemical, electrochemical and hybrid LOHC cycling processes were evaluated for their carbon footprint. The work presented here has shown that simply utilizing renewable electricity to drive a reaction does not by default result in a lower carbon footprint. The carbon footprint was found to be most influenced by the concentration of the reactant when there is need to do downstream separations before storage, transport or cycling. The distillation separation unit is the primary energy-demanding part of the electrochemical cycling process. It is necessary that LOHC couples are able to undergo ECH/ECD at high concentrations to reduce the amount of solvent used in ECH/ECD processes. Reducing solvent amount will lessen the amount of energy needed for purification or eliminating the need for separation altogether. It will also increase the hydrogen loading of the system. The carbon footprint analysis done in this work showed that electrochemical cycling of LOHC process can be more sustainable in terms of carbon emissions compared to the thermochemical and hybrid cycling of LOHC processes when distillation is not required. To achieve the lowest carbon footprint, electrochemical LOHC cycling method needs to be coupled with renewable electricity, and not require a LOHC downstream separation process.