Carbon is an essential element for living animals and plants, but atmospheric carbon dioxide levels need to be controlled. The greenhouse effect is explained here.
One option is to use carbon dioxide as a raw material. Omnagen’s recent innovation combines carbon dioxide with methane and air to form useful chemicals. Crucially, it is self-powered, it doesn’t need any external energy, and it produces no waste gases, just useful syngas. The energy comes from the chemical energy in the methane. Patents have been applied for.
It works by combining a fuel cell which produces syngas, a mixture of carbon monoxide and hydrogen, plus electricity, and an electrolyser which consumes electricity and produces more syngas. The syngas can be further converted to liquid and solid chemicals by conventional chemical processing techniques.
There are 3 reactions:-
Fuel cell:- CH4 + ½O2 = CO + 2H2 + electricity + some heat
Electrolyser:- electricity + heat + CH4 + CO2 = 2CO + 2H2
Direct:- 2CH4 + O2 = 2CO + 4H2 + heat
Overall:- 2CH4 + CO2 + ½O2 = 3CO + 4H2
The controlled direct reaction provides heat to counter the endothermic reactions, and also helps to prevent carbon deposition at the electrodes.
This converter uses solid oxide cells, and the real innovation is how to combine these two components into a simple self-powered unit. The solution is to provide one gas flow which is a mixture of gases, and another which provides oxygen or air. The electrical connections are direct, and this also allows heat from exothermic anode reactions to transfer to cathodes on adjacent cells where the reactions are endothermic. The overall reaction rate is controlled by the oxygen supply.
As the invention involves the manipulation of gas flows, it should be very scalable. At the large scale it could be used to provide raw material for bulk chemicals and polymers. At the small scale it could be used in conjunction with small scale FT plants to produce eFuels for local consumption.
The electrolyser component may be used separately to convert a flow of carbon dioxide and methane, providing there is also a supply of electricity and air or oxygen. Conventional electrolysis of carbon dioxide and steam requires a great deal of energy, but the reaction of carbon dioxide and methane is more thermodynamically favoured, so it requires much less energy.
GB and PCT patent applications have been filed. The GB application numbers are as follows:-
Please contact Ken Omersa if you'd like more information; phone and email details are provided here.