To reduce greenhouse-gas emissions, biofuels are an important first step for aviation. But using biomasses always raises the question of fuel versus food and land use conflicts. Power-to-liquid is a process to convert electricity, hydrogen and CO2 to synthetic fuels. This technology is possibly a game-changer for climate-neutral mobility but is still in its infancy. Recently, more and more industrial companies are focusing on the development of e-fuels. We talked to Dr. Ulf Neuling, a scientist at the Hamburg University of Technology (TUHH), about the potential of this technology and his plans to produce synthetical kerosene on an industrial scale.
The idea is captivating. Electricity is “liquefied” and – with the usage of CO2 – is converted to climate-neutral e-fuel. The Power-to-Liquid-process (PtL) uses renewable electricity to split water by electrolysis. The produced hydrogen is then synthesized with CO2 into liquid hydrocarbons, which can be refined e.g. to green diesel or kerosene. Global Alliance of Powerfuels, an initiative to foster this technology worldwide, declares it as the “game-changing missing link” for energy transition and climate protection. PtL-technology has many advantages:
- Climate-neutral replacement of fossil fuels for shipping, automotive industry and aviation
- Less consumption of land and water than biofuels
- Storage of “liquefied” electricity for an on-demand use in existing energy infrastructures
- Enabling of transport and trade of renewable energy from wind and sun worldwide
Synthetical Fuel for Aviation
For Dr. Ulf Neuling, expert for sustainable fuels, PtL is a big opportunity for the aviation industry. “In aviation, for many years we will be dependent on fuels. Synthetic kerosene saves 90 to 95 percent of greenhouse gases over its entire life cycle compared to fossil kerosene, and is more resource-friendly than biomass”, he points out. “Just like biofuel, e-kerosene can be used as drop-in and thus is suitable for current jet engines, refinery processes, and distribution infrastructures.” To him, e-fuel could possibly be a successor of biofuel, if it is produced in sufficient quantities. To drive development forward here, he put together a consortium of top-class partners like Dow Chemicals, Airbus, BP, German Aerospace Center, EasyJet, and Hamburg Airport. The plan is to build an industrial PtL-plant at Dow in Stade by 2022.
End to End Supply Chain to Optimise the Process
“We could use the electrolyser at Dow for hydrogen production, while emissions from the chemical processes deliver CO2”, Neuling says. The e-oil produced with Fischer-Tropsch Synthesis would be refined at BP and the green kerosene will be delivered to Hamburg Airport and the Airbus plant nearby. A perfectly seamless process, that in constant monitoring could be optimised, as currently the efficiency of the used raw materials is still low. That means, high amounts of electricity are needed to produce a small amount of e-oil.
Renewable Electricity as the Biggest Expense Factor
Low efficiency and high prices of green electricity are currently the biggest challenge. The price for e-kerosene is currently at least four times more expensive than fossil kerosene, which is approximately 550 euros per ton. But Dr. Neuling is convinced that “with larger, optimised plants and lower electricity prices, it should be possible to reduce the price to less than 1,000 euros per ton. “E-fuels require large-scale plants that need a long time to build so we should start now to be able to produce relevant quantities in around ten years.” Relevant quantities would demand about ten plants, each with an annual capacity of 1 million tons to only cover the kerosene consumption of Germany.
E-fuels require large-scale plants that need a long time to build. We should start now so that we can produce relevant quantities in around ten years.
Accelerating Development in Different Industries
The development of e-fuels is gaining momentum. In Iceland, the company Carbon Recycling International is already producing synthetic methanol on an industrial scale and provides ferries with climate-neutral fuel. A consortium around Lufthansa and the Heide refinery is planning to produce synthetic methanol and converting it into green kerosene. In the Netherlands, KLM, SkyNRG and SHV Energy and other partners are building a plant for sustainable aviation fuel, combining biomass with the PtL-process. In this case, CO2 is extracted from biomass instead of industrial processes. There are also activities in Norway. The start-up “Sunfire”, together with Nordic Blue Crude, a cleantech company, will operate in Porsgrunn an industrial scale “Blue Crude” power-to-liquid (PtL) production by 2020. The task is to produce a yearly amount of 8,000 tons of e-crude. Refineries use it as raw material to produce waxes, chewing gum and cosmetics, but also gasoline, kerosene and diesel. With the tasked amount of e-diesel for example, 13,000 cars could be supplied and 21,000 tons of fossil CO2 emissions could be avoided.
Oslo Airport as First International Hub for Sustainable Aviation Fuel
It’s only a matter of time when e-fuels will have an impact on aviation in Norway, too. In 2016, Oslo Airport became the world’s first international hub that could was able to supply sustainable aviation fuel for all aircraft. Avinor is committed to buying a certain amount of biofuel based on Norwegian biomass. A commitment to support e-fuel could be the next step for the Norwegian airport operator, that in terms of sustainability is a forerunner. The high availability of renewable electricity in Norway speaks even more for the further production and distribution of “green kerosene 2.0”.
E-fuels Provide Value for Different Markets
But also for countries that don’t have access to high amounts of renewable energy, the use of e-fuels is an option. As mentioned above, PtL offers the opportunity to store electricity. E-oil can be produced in regions with renewable energy sources and be transported to countries which do the refining process. Dr. Neuling already has a vision: “Maybe in 20 years we will have plants in Spain or in the MENA States, where e-oil is produced with ecological power from the sun, imported to European countries, where it is further refined to e-diesel or e-kerosene.” An opportunity for countries with high renewable energy potential to export while importing countries use the fuel to reach their climate-goals – given climate-neutral transportation.
The production of electricity-based fuels is a game-changer in many ways: It’s a step towards climate-friendly mobility, adds value for the economy in different countries and is an opportunity to diversify renewable energy sources.