Raptor Engine Test Fire - Photo Credit - www.spacex.com
Welcome to the forty-seventh edition of my weekly blog where I take a closer look at the policies adopted by individual countries in their efforts to meet the requirements of the Paris Agreement. Particular attention is paid to the role that Carbon Capture, Utilisation, and Storage (CCUS) research and technologies are playing in the drive to meet these requirements.
This week I take a look at how advances in carbon capture and utilization technologies are being exploited to extract methane from coal beds.
Methane or CH4 (one atom of carbon and four atoms of hydrogen) is a hydrocarbon fuel in the form of dry gas that can be used to generate electricity. Methane, when released into the atmosphere, e.g. through oil and gas production can cause great damage to the environment, about 30 times the impact of CO2. Interestingly, despite the deleterious effects of methane release, using methane as a fuel is far cleaner than other fossil fuels, emitting roughly half the amount of CO2 into the atmosphere that coal does when used to generate electricity.
Methane hydrate (frozen methane or better known as ‘fire ice’) is a fossil fuel found in hydrate deposits of 300m – 6oom thick under the sea floor or under the artic. According to the British Geological Survey "estimates suggest that there is about the same amount of carbon in methane hydrates as there is in every other organic carbon store on the planet,". Simply put, more energy could be generated from methane hydrates than the world’s oil, coal, and gas reserves combined.
Enhanced Coal Bed Methane
The Pembina Institute describes the process of enhanced coal bed methane as: “CO2 is injected into partially depleted coal seams, where it's absorbed by coal, in turn displacing methane to the surface for it to be captured and consumed as fuel”.
The institute highlighted the benefits of this process as the replacement of more carbon-intensive fuels with methane and also the permanent storage of CO2 in the coal bed. It did note however that this process poses some challenges including the high cost of transporting CO2 (given that extreme care must be taken to avoid its release into the environment), the low price for methane, as well as the potential for the coal to expand following the injection of CO2 and thus block the extraction of methane.
The methane gas extracted following the injection and storage of CO2 into the coal bed can be used as fuel to power rocket engines. Elon Musk and SpaceX used liquid oxygen and methane when testing its raptor engines in September 2016. The raptor engines have three times the thrust of the merlin engines used to launch Falcon Heavy on the 6th of February 2018. The rocket used to launch Falcon Heavy had 27 merlin engines, whereas future rocket launches will be powered by 42 reusable raptor engines. Musk cited energy cost savings as a benefit of using methane with liquid oxygen instead of kerosene to fuel his future rocket engines. Musk plans to offer commercial flights to Mars by 2024 – these flights are likely to be fuelled at least in part by methane.
Storing CO2 in coal beds and enhancing the extraction of methane from the coal beds at the same time has great potential to reduce CO2 levels and for providing alternative fuel sources. Like other sources of energy generation it has its downsides such as heightened environmental risks and although methane is cleaner than coal and oil, it still is an emitter of CO2.
On the plus side, methane is a far more dynamic fuel than other fossil fuels, being truly a ‘rocket fuel’ that may power future commercial trips to space.
Next week’s blog will profile Belgium and their efforts to meet their CO2 emissions reduction targets.
If you liked this article you might enjoy reading some recent articles in the series:
Week 46 Greece: Move to Renewables is a marathon, not a sprint
Week 45 Luxembourg: Green bonds and blue electricity
Week 44 Geothermal: Supercritical CO2 brings us heat from beneath our feet
Week 43 Ireland: Dear Leo, by the time you read this letter we’ll all be gone