Carbon dioxide capture & conversion

A couple of articles regarding joint Australian and international research into successfully converting carbon dioxide into carbon.


Without looking into the details, all of the processes I’ve examined consumed so much power that you’d need to build a nuclear reactor beside your coal-fired power plant, just to power the capture and conversion. Quite apart from the costs of separating CO2 from flue gases, much of the CO2 isn’t captured at all.

In the meantime, we’re getting more efficient at pumping carbon into the atmosphere:

Something similar is happening with coal. New mines are increasingly automated. That reduces costs per tonne, so we can pollute more cheaply.


This is the RMIT media release:

and the article in Nature:

What is interesting is the scientists have done the CO2 to carbon at room temperature and that there is usable byproduct. The paper indicates that it has the potential in 'reversing the combustion of fossil fuels at minimal energy consumption.

They also have state that ‘The solid carbonaceous materials are storable, enabling a negative CO2 emission technology when driven by renewable energy sources.

It it is interesting is the end products could be used potentially as synthetic fuel byproduct/in industrial application. This may potentially have a monetary value and make the process cost neutral (?) or more cost effective. The paper states ‘In the case of a future large-scale adoption of the developed process in the form of a negative emission technology, a portion of the produced carbonaceous materials may find application as electrode materials for energy storage applications; while any produced CO may be utilised as a feedstock for further industrial processes.

If it is a scalable cost effective solution to carbon capture, it could be a solution of where to put excess energy from renewable energy generation when all sources are fully operational and exceed the demands by the consumer.

There is also likely to be a range of other technologies which are developed over time which also sequestrate carbon from the atmosphere either naturally or through clever engineering.

While these possibly won’t solve existing CO2 atmospheric levels, it may be suitable to minimise future CO2 gaseous emissions at the source of major CO2 emissions. The sooner these sort of technologies are matured, the potentially the better the long term outcomes if they are adopted.

One may never know that in the longer term, small scale devices may be installed for treating exhaust emissions from traditional ICE either running of fossil fuels or renewable energies. Maybe Dr Who was prophesying without realising it?


Most current research seems to concentrate on processing the carbon after capture. Capture is the most expensive part of the process. Flue gases are typically around 20% CO2, so the capture process needs to deal with a substantial volume, which also contains other pollutants depending on fuel quality (among other things).

Coal is already not cost-competitive. The best capture options I’ve investigated imposed an efficiency penalty of around 10% (just having the capture mechanism in place reduced power output by that amount), which would reflect in LCOE. The cost per tonne of CO2 captured was given as more than $47(US), which also impacts LCOE. I don’t remember the exact figure, but much of the CO2 wasn’t captured at all. “Less dirty coal” perhaps, but not “clean coal”.

Maybe it is becoming less competitive in Australia and other countries where there is policies favouring and subsidies supporting non-coal generation, but there are still many countries which are constructing and commissioning coal fired generation as it is there preferred cost effective solution. Gas generation, which is also principally from fossil fuels, is also preferred in many countries and why Australia’s gas exports are under high demand.

New and existing coal fired generators typically have a life of 50+ years and there is an expectation that these generators will be run to end of life. The International Energy Agency also recognises that coal will remain a dominant source of energy into the future. The sort of wording that they use is “Despite legitimate concerns about air pollution and greenhouse gas emissions, coal use will continue to be significant in the future”.

In Australia, the RMIT carbon capture technology could be used for non-coal generation sources of CO2 emissions, such as gas generation, biomass generators and in industry CO2 emissions (metal, cement, agricultural and waste sectors for example).

One should not be narrow in thought in the potential of such technologies. If the technology proves to be scalable and relatively efficient, there may be many and varied uses for the technology.

For a consumer, such technologies may change the way CO2 emissions are managed and may also impact on many products and services which are currently and will remain carbon intensive into the future.

Last time I checked, the graphs to which I linked were based on unsubsidised costs. The time of coal is past.

Such as?

politicians ? …

edit: sorry I read that as ‘insensitive’ :wink:


As others have said the energy required is huge.

There is another method though which requires no development cost. It’s all natural, organic, requires no synthetic energy source, no factories or equipment once established and it is cheap. Not to mention the byproducts are really useful.

Tree planting.


This is not new. Nutritional value of many crops have declined over past decades at the expense of yield, taste, storagability etc.

This historically and will continue to be overcome by cultivar selection and breeding. GM technologies should also be able to impact on future nutritional values and accelerate development of new cultivars, faster than traditional cross breeding.

Using existing cultivars for research and declaring ‘millions at risk of nutritional deficiencies’ ignores the ability of science to adapt to new environs. Science research and developments can’t be ignored as they are proven historically to overcome many challenges thrown at food production in the past.

Unfortunately and currently in Australia such research is at a near all time low as far as reseach funding goes, but this is likely to change in the future as part of adaption to climate change. Australia is well positioned to carry out such research.

Climate change is possibly one of the many future threats on food production. Other threats such as soil erosion, pests and dieases (resistance, population explosions…), fertiliser reliance/peak phosphorus, soil degradation, pollution, urbanisation of agricultural lands/land use conflicts, etc potentially have equal or bigger long term impacts on food quality and quantity.

1 Like

Perhaps, but my post belongs where it was. Moving it falsifies the record.

Seeing as the topic is getting some interest, I’ve created a dedicated thread to collect the activity :+1:


Yep, unless they changed the laws of physics, chemistry and energy the electrolysis process will consume more energy than produced oxidizing the carbon in the first place.

1 Like

Unfortunately nothing comes for free…otherwise the world’s energy generation would be running on perpetual motion.

Such technologies does have advantages to use renewable/non-renewable energy generation which exceeds the demand on the network at the time when such generation occurs. As the network is not a bank, in the past such over generation is lost (usually at the point of generation by disconnection to protect the network). Over generation occurs as the demand on the network fluctuates and there needs to be sufficient generation to cater for the changes in demand.

An example is a nuclear or coal fired energy plant, these plants can’t be shut down quickly and have significant ramp up times. Such facilities, as well as the surplus renewable generation capacity which is installed to ensure there is enough generation to meet demand when required, could be used for such purposes.

As the generation is likely to occur anyway, the excess energy could be used to back convert carbon.

I expect that specially constructing generation to cack convert carbon would not be cost effective due to the energy losses associated with the process. In such cases, minimising CO2e may be a preferable option as it would minimise the need for back conversion

I think just to tie carbon down the plantation strategy mentioned above is the leader. Even to the point of grow forest, push it over, bury it and cycle again.

In the meantime research should go into production of high value carbon from CO2, like carbon fibre, graphene or diamonds.

1 Like

Push trees over and starting again doesn’t do any good. The carbon that is buried would be all recycled back to the atmosphere in time. This is what happens in land clearing. The maximum carbon is stored when the forest is tall and strong. Having a forest stores more carbon per hectare than bare land or weeds or scrub.

You can store carbon in soil in pasture by using methods that preserve the organic content of the soil. This has other benefits such as holding more water and nutrients in the soil. Still it is a dynamic process as microbes are depleting the organic matter all the time so it must be replaced. The aim is to reach an equilibrium of maximum carbon content while still having productive land. Pasture burning as a cheap method of weed reduction is still practiced. It not only reduces soil carbon but nitrogen as well.

Old farmers tend to be very conservative socially, politically and in their land management practices. They are often climate change deniers too.


Seriously? Our current government is led by a man who brought a lump of coal into Parliament, and has proposed funding new coal-fired power plants as well as subsidising new coal mines!

In the meantime, regardless of how much it costs to capture/convert carbon dioxide it is unlikely to be commercially feasible for 20-30 years from publication of initial research (i.e. the paper mentioned at the top of this thread). Capture of CO2 would be handy to reduce what we have already put into the atmosphere, but by the time it is realistic the world should already have moved away from dinosaur batteries to renewable energy.


At various times the coal industry and Federal government in Oz have allocated substantial funds to investigate and support CC&S. I can’t get a total figure but I find references to the feds spending around $50M and the Australian Coal Association pledged a billion but only spending some $200M dollars. I am sure there was more. Overall they made quite a few TV ads, went on numerous overseas tours, contributed funding to pilots etc. We had Dr Nikki Williams telling us on TV talk shows how coal was so good and CC&S was going to make it even better.

The government pot was spent and nothing came of it. After spending some of the cash the Coal Assoc scheme was re-purposed to become a general PR slush fund to boost the industry and no more went to CC&S.

After many pilots world wide turned out to be very costly and produced nothing useful the industry has stopped spruiking CC&S. The lead article of this thread tells us the same story - it isn’t economical. Even to its strongest supporters in this country the issue is a dead duck that isn’t worth using anymore even as a delaying tactic.

Why are we still giving time and effort to this topic which has never escaped from being jammed between PR fantasy and pious hope?


No argument from me about your points but just to add to the idea about the use of the converted product I add the below comments.

Even in capture and conversion I have yet to see a perpetual energy machine that works (Wonderful to dream about but reality and physics state otherwise). To capture and then convert the carbon requires large amounts of power…so let’s say we get 1 kg of coal from the process from X amount of energy input, I am sure the X amount of energy used to produce it will be substantially more than that 1 kg will then produce in return. If the process is purely to capture the carbon in an easy storage form then using renewable energy resources (which aren’t themselves infinite) to power the process makes sense. But why oh why would you burn it again is my question of the people who want to use it again as a form of energy.


There are a couple of examples in the natural environment, which are very close to the theory of perpetual motion (but don’t quite meet the theory), and are things like moon’s/planet’s orbit and the earth’s rotation. Unfortunately these operate in a friction-less environments.Once friction is involved, this applies:

1 Like

Another article regarding research into capturing carbon dioxide.


1 Like