| Title |
Electrofuels in a circular economy: A systems approach towards net zero |
| ID_Doc |
1519 |
| Authors |
Rusmanis, D; Yang, Y; Long, AIF; Gray, N; Martins, KC; Loideain, SOO; Lin, RC; Kang, XH; Cusack, DO; Carton, JG; Monaghan, R; Murphy, JD; Wall, DM |
| Title |
Electrofuels in a circular economy: A systems approach towards net zero |
| Year |
2023 |
| Published |
|
| DOI |
10.1016/j.enconman.2023.117367 |
| Abstract |
Decarbonising the hard-to-abate sectors will be necessary in realising a future net-zero economy. Electrofuels store electricity as low carbon energy vectors such as hydrogen or methane which can be used in areas where electrification is not ideal, and as such can facilitate decarbonisation of sectors such as transport, agriculture, and wastewater treatment. In this study, the production of electrofuels was analysed at an industrial site by storing renewable electricity as green hydrogen produced using electrolysis. The analysis highlighted the need for scale in hydrogen production. The cost of hydrogen was calculated at euro8.92/kg when a 122 kW electrolyser operated solely on curtailed electricity generated from the industry site was situated at a 65,000 person equivalent municipal wastewater treatment plant. A subsequent integrated and circular approach to electrofuels production was investigated. The oxygen by-product from electrolysis could be utilised for wastewater aeration and reduce the annual electricity usage at the wastewater treatment plant by 3.6%. Furthermore, the carbon dioxide in biogas generated from sewage sludge could be converted to methane through a Sabatier reaction (4H2 + CO2 & RARR; CH4 + 2H2O) as a means of carbon capture and utilisation. The hydrogen produced from the 122 kW electrolyser could convert only 40% of the total carbon dioxide (within the biogas) in a biomethanation process, again supporting the argument for larger electrolyser systems with increased hydrogen production. Pyrolysis of digestate to produce biochar was investigated as a negative emissions technology. If pyrolysis is coupled with anaerobic digestion of feedstocks within 10 km of the industry site savings of 42.7 kt CO2/a could be achieved. In essence, a circular economy approach to electrofuel production could integrate existing electrical, gas and water infrastructure, whilst treating waste, improving the environment, decarbonising agriculture, and storing energy in the form of new low carbon energy vectors for use in heavy transport. Such an approach is vital to progressing future net-zero strategies, however future emissions accountancy processes must adapt to facilitate the benefits of a circular economy. |
| Author Keywords |
Electrofuels; Green hydrogen; Biomethanation; Circular economy; Decarbonisation |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001039995300001 |
| WoS Category |
Thermodynamics; Energy & Fuels; Mechanics |
| Research Area |
Thermodynamics; Energy & Fuels; Mechanics |
| PDF |
https://doi.org/10.1016/j.enconman.2023.117367
|