Sammanfattning

The integration of power-to-gas (PtG) technology into existing urban anaerobic digestion (AD) plants could be an interesting concept to recycle biogenic CO₂ and increase CH₄ production as renewable fuel to further decarbonize public transport buses (PTB). However, such implementation is challenging for several reasons, including power restrictions during peak load, physical and temporal availability of CO₂ from AD plants, and the need for expensive intermediate gas storages to avoid mismatch between the constrained synthetic CH₄ production and the variable fuel demand. To investigate whether synthetic CH₄ could be a feasible alternative for buses currently powered by fossil fuels, a dynamic model was built for discrete-event simulations of PtG technology integrated into an urban AD plant designed to supply biomethane as fuel for bus fleets. Different scenarios were assessed, including variations in power availability to run a proton exchange membrane electrolyser as well as variations in the production scale of synthetic CH₄ based on ex-situ biological methanation. The results show that a constrained power utilization (maximum of 12 h per day) increased the production cost of synthetic CH₄ by 20%. In contrast, an increase in PtG production capacity from 0.75 MW_th to 2.25 MW_th decreased costs by 16%. From the PTB operators’ perspective, the total cost of ownership (TCO) increased in all analysed scenarios when replacing diesel buses by gas buses powered by synthetic CH₄. However, when using synthetic CH₄ as drop-in fuel to replace natural gas in existing gas bus fleets, the TCO could be reduced up to 4.4% depending on the PtG plant configuration and the assumed fossil fuel price. Furthermore, our results show that a carbon tax on fossil fuels has only a limited effect on promoting synthetic CH₄ as alternative fuel for PTB, and additional incentives should be put in place to prioritize a fuel switch, especially for existing gas bus fleets.

Nyckelord

Water electrolysis; Electrofuels; Carbon abatement cost; Carbon capture and utilization

Publicerad i

Energy Conversion and Management
2022, Volym: 259, artikelnummer: 115574

SLU författare

• Janke, Leandro

  • Institutionen för energi och teknik, Sveriges lantbruksuniversitet
    

• Nordberg, Åke

  • Institutionen för energi och teknik, Sveriges lantbruksuniversitet
    

Globala målen

Säkerställa tillgång till ekonomiskt överkomlig, tillförlitlig, hållbar och modern energi för alla
Göra städer och bosättningar inkluderande, säkra, motståndskraftiga och hållbara
Bygga motståndskraftig infrastruktur, verka för en inkluderande och hållbar industrialisering samt främja innovation


UKÄ forskningsämne

Nationalekonomi
Energisystem


Publikationens identifierare

DOI: https://doi.org/10.1016/j.enconman.2022.115574

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/117073