Sakowin (€9M for microwave plasma pyrolysis of natural gas)

Sakowin is a French company that manufactures energy equipment to produce hydrogen and solid carbon with zero CO2 emission from natural gas. The company offers compact, modular, and scalable systems for industrial firms, hydrogen chemical firms, IT centers, and clean transport firms. Sakowin is a member of the World Alliance for Efficient Solutions.

Challenges: hydrogen fuel

The majority of the world’s hydrogen (over 60 million tons) is currently produced via steam methane reforming (SMR) process, which requires a significant amount of energy input and emits a substantial amount of CO₂. The SMR process emits between 5 and 9 tonnes of CO₂ per tonne of hydrogen (H₂) produced.

In addition, hydrogen produced in centralized industrial plants must travel a great distance to reach its users. Hydrogen transportation involves either pressurizing the hydrogen gas above 300 pounds per square inch gage (psig) or cryogenically cooling the hydrogen gas to -253 ºC to create liquid hydrogen. The International Energy Agency estimates that the costs of hydrogen transportation could be three times that of its production.

On-site production of hydrogen can be realized by the electrolysis of water, which produces hydrogen without emitting CO₂. However, electrolysis requires 50 kWh of energy to produce 1 kg of H₂ which only gives 33 kWh of energy. 35% of the original input power is wasted. Additionally, the cost of electrolysis-produced hydrogen is higher than that of SMR-produced hydrogen.

Sakowin Technology

Sakowin develops an on-site hydrogen gas production system based on the microwave plasma technology that converts methane into cost-competitive hydrogen gas and solid carbon without emitting CO₂. The system produces hydrogen while consuming five times less electricity than an electrolyzer. The hydrogen produced on-site can be supplied directly to fuel cell vehicles, combustion engines, and energy conversion devices.

The diagram below depicts the system of microwave plasma pyrolysis of methane. The system consists primarily of natural gas (methane) feedstock, a reactor, a separation and filtration device, a compressor, a hydrogen storage tank, and a control module. The reactor consists of multiple generators that provide microwave radiation to the microwave antennas via microwave guide, a funnel-shaped reaction chamber containing feedstock gas nozzles and multiple microwave antennas, and a pipe coupled to the reaction chamber in order to cool the reaction products (hydrogen gas and carbon).

Sakowin's system of microwave plasma pyrolysis of methane — Sakowin’s system of microwave plasma pyrolysis of methane (ref. WO2022200694A1).

The multiple microwave generators generate microwaves to create plasma at each microwave antenna. The microwaves can have a power between 1 kW and 500 kW and a frequency between 400 MHz and 6 GHz (such as 2.45 GHz). To reduce electromagnetic interference between two adjacent microwave antennas, the microwave antennas are arranged as shown below.

The arrangement of microwave antennas in the reaction chamber of Sakowin's reactor — The arrangement of microwave antennas in the reaction chamber of Sakowin’s reactor (ref. WO2022200694A1).

By using multiple microwave antennas, the reactor has expanded plasma area compared to the conventional reactor using a resonant microwave cavity. Consequently, the reactor can produce more hydrogen gas.

The natural gas feedstock enters the funnel-shaped reaction chamber via high pressure nozzles. The arrangement of the nozzles creates a vortex of natural gas flow that flows around the microwave antennas. The plasmas are ignited by the ignition device once the required microwave power is attained. After the plasma’s priming phase, the natural gas flow in the vortex coupled with the microwave radiation emitted by the antennas produces stable plasmas around the antennas. The natural gas undergoes pyrolysis reaction:

CH₄(gas) → C(solid) + 2H₂(gas)

The products exit through the funnel-shaped reaction chamber’s nozzle and enter a pipe that extends from the upper part of the reaction chamber and completely surrounds the reaction chamber’s nozzle. The pipe has a cooling chamber that cools the products to enhance the carbon’s solidification.

The internal surface of the cooling chamber is covered with a multitude of fins to improve heat transfer with the reaction products that come into contact with the fins. In addition, the outer wall of the cooling chamber has a fluid circulation device, which further improves the heat transfer.

The cooled products enter a separation and filtration device that has at least one vortex separator. The cooled solid carbon thus deposited on the separator’s inner surface is collected. The separation and filtration device’s filtration system purifies the separated hydrogen. The purified hydrogen can be used in a fuel cell, combustion engine, heating system, or gas turbine.

The production of hydrogen gas can be regulated by a control module. When the filling level of the hydrogen storage tank exceeds a threshold level, the control module sends a control instruction to the ignition device, to the microwave generators, and the valve to stop or slow down the production of hydrogen. When the filling level of the hydrogen storage tank falls below a threshold level, the control module sends a control instruction to these devices to increase the production of hydrogen.

Sakowin Patent

WO2022200694A1 Decarbonised dihydrogen production unit
WO2022096817A1 Carbon-free dihydrogen production and delivery unit; method for operating said unit
WO2022129736A1 Energy production device comprising a dihydrogen production unit; method using this device

Sakowin Products

Sakowin aims for an industrial pilot of microwave plasma pyrolysis of natural gas by 2024 and commercialization of the technology by 2025. Sakowin develops a 6-kW prototype.