Techno-economic analysis of integrating an on-board CCS system and a PtG technology in a heavy vehicle fleet

Decarbonising the heavy-duty transport sector requires switching internal combustion engine (ICE) fuel from fossil to synthetic fuels. In this context, on-board carbon capture and storage (OCCS) in ICEs could provide the CO₂ needed by Power-to-gas (PtG) technologies to produce synthetic natural gas (SNG), which is then consumed again by the vehicle fleet, closing in this way the carbon loop. This study presents a techno-economic analysis of a heavy-duty vehicle fleet integrating an OCCS system with a PtG plant. The OCCS system operates by temperature swing adsorption where two sorbents, PPN-6-CH₂-DETA and zeolite 13X, are evaluated at carbon capture rates (CCR) of 70 % and 100 %. A fifth scenario examined the effect of varying the H₂:CO₂ ratio in the methanation plant at 100 % CCR using PPN-6-CH₂-DETA. Both systems were simulated using Aspen Plus and AVL Boost softwares. Moreover, a sensitivity analysis was conducted considering three key performance indicators: the CO₂ tax, natural gas (NG), and electricity prices. The results indicate that the carbon abatement cost reaches a break-even point at 150 €/tCO₂ for a fleet size of 400 vehicles. However, the capital expenditures do not achieve payback within 20 years due to the high operational expenditures and low incomes in the evaluated scenarios. The sensitivity analyses show that the CO₂ tax and the NG price must be higher than 400 €/tCO₂ and 160 €/MWh, respectively, to compensate for the current electricity price and allow the proposed systems to be techno-economic feasible.