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Posts Tagged ‘Carbon Capture and Storage’

Is Carbon Capture and Storage a Viable Option?

Sun ,17/10/2021

The countries of the world have reached a consensus that we need to reduce our carbon emissions. One proposal to do that is to switch to a hydrogen economy. The problem is that currently about 95% of the hydrogen we use is made using fossil fuels, which is an energy-intensive process that produces more CO2. The fossil fuel companies plan to get around that is to capture the carbon produced and store it (CCS). The questions that must be answered are how to capture the carbon, where to store it, and how much it will cost.

It is possible to capture the CO2 and there are now several plants currently doing it. Much of the captured carbon is currently used to produce more fossil fuels, so there is little gain in doing it. The chart below will give you an idea of the magnitude of the problem. Currently, we are adding 35 billion tons of carbon dioxide to the atmosphere each year. The amount of carbon currently captured is 0.006% of that, an amount so small that it could not even be seen on the chart.


If carbon capture could be scaled up to capture most of the CO2 we are emitting, then where would we store it? The most obvious solution is to store it where it came from. The carbon from coal is mostly from strip mines and open mines, and it cannot be stored there. For petroleum and methane, storing it back underground is a possibility. However, burning them combines them with oxygen – and increases the mass and volume by a factor of two or three. It would be impossible to store more than a fraction of the CO2 back underground.


Assuming we could capture the carbon and find a place to store it, what would be the cost? This would involve acquiring the land, building the thousands of CCS plants required, and providing the energy necessary for the process. That cost has been estimated to be about $5 trillion a year, at current prices, for the rest of this century. There are certainly much less expensive options available.


So there you have it, the amount of CO2 we are putting into the atmosphere is far too great to capture, there is no adequate place to store captured CO2, and the cost would be astronomical. However, the fossil fuel companies are willing to try if we subsidize their costs, fund their research, and wait 80 years. It will be painfully obvious, long before then, that CCS is unworkable. The best plan is obviously to stop putting more carbon dioxide into the atmosphere, a solution the fossil fuel companies are unwilling to accept.


The Mythical Magic Hydrogen Economy

Tue ,02/03/2021

There’s a little bit of truth to every myth, and the hydrogen economy is no different. Hydrogen fuel cells would be wonderful for the environment. They combine hydrogen with oxygen from the atmosphere to produce electricity, and they emit pure water. The hydrogen can be made by electrolysis of water, and the energy for the electrolysis can be provided by renewable energy such as solar and wind. Though hydrogen must be stored at high pressures or low temperatures, it can be transported and used to replace fossil fuels in most of their applications. Then why are the fossil fuel companies so eager to transition to a hydrogen economy? They now are applying for grants from stimulus money for research on hydrogen power. There must be more to the story and that is where magic comes in.

It would take a tremendous amount of magic to make hydrogen a viable source of energy within 30 years. Currently, 95% of commercial hydrogen is made from fossil fuels, primarily methane. Producing hydrogen from methane is energy intensive. It requires that methane be reacted with steam-heated to about 1100°C. That reaction produces hydrogen and carbon monoxide – which is then treated with additional steam at 380°C to convert the carbon monoxide to carbon dioxide. Not only is carbon dioxide produced as a byproduct, but it takes a tremendous amount of fossil fuel to heat the steam hot enough to carry out the reaction. Hydrogen produced in this way is called Brown hydrogen, because of all the fossil fuels used. You’re probably beginning to see why fossil fuel companies are so eager to transition to a hydrogen economy.

But wait. All we would need to do is capture the carbon dioxide produced in making Brown hydrogen and store it underground. Hydrogen could then be produced without adding more CO2 to the atmosphere, so it is called Blue hydrogen. Fossil fuel companies are now pursuing grants and subsidies to develop Carbon Capture and Storage Systems (CSS) to do just that. But there are a few problems. Fossil fuel companies knew as far back as 1979 (see memo below) that adding more CO2 to the atmosphere would cause global warming and damage the environment. A CSS system requires little new technology, so why did they not develop CSS then – and global warming would never have become a problem. Fossil fuel companies did not do it because it would have made their products more expensive, and demand would have gone down. And they are even less serious about developing CSS systems now. With prices dropping on renewable technologies and energy storage systems, CSS would make carbon or hydrogen fuels so expensive that it would accelerate the transmission to renewable energy and battery storage.

Though there are currently large supplies of methane available from fracking operations, using fracked methane to produce hydrogen just isn’t a good idea. The main problems associated with fracking are methane leaks and earthquakes (caused by the disposal of fracking fluids). It has been estimated that about 20% of the methane produced at the wellhead is lost through transmission losses and leaks. Because so much methane is lost during production, France has recently prohibited American fracked methane from being sold there. Though the amount of methane in the atmosphere is small, methane is 72 times more potent as a greenhouse gas than carbon dioxide. As the graph below shows, the methane concentration in the atmosphere has grown exponentially – and it now accounts for about 1/4 as much global warming as carbon dioxide.

That brings us to hydrogen produced by electrolysis, called Green hydrogen. To create the infrastructure to produce enough Green hydrogen to transition to a hydrogen economy would take more than 30 years. To get there, we would have to start now. That would require Black and Brown hydrogen to be used while we develop a CSS system, and then Blue hydrogen could be used until we have a fully operational Green hydrogen infrastructure. We would be dependent on fossil fuels for at least 30 more years, and the concentration of carbon dioxide in the atmosphere would certainly go up. The best carbon capture systems are trees, oceans, and soils (through regenerative agriculture). Currently, those systems have not been able to keep up. Deforestation, commercial farming, and the acidification of the oceans are exhausting those systems’ abilities to capture CO2. The environment of the Earth cannot absorb much more carbon dioxide, and we certainly can’t wait 30 years on the chance that a commercial scale CSS system will be developed.

Hydrogen is very useful for things such as welding, food processing, ammonia production, and rocket fuel – but it will never be useful to power our economy. That is because a hydrogen economy would be terribly energy inefficient. If you were to use electricity from wind to produce hydrogen, transport the hydrogen to where it is needed, and use hydrogen fuel cells to power your car, about two-thirds of the energy would be lost in the process. The electrical energy that would take you 300 miles in a battery-powered car, would only take you 100 miles in a hydrogen-powered car. There is also no infrastructure in place to conveniently transport large volumes of hydrogen. Natural gas pipelines could not be used, as hydrogen reacts with metals and makes them brittle. I contrast, transmission lines for electricity are already in place and, if upgraded to handle the larger load, they could deliver power directly to your home and your car – and do it three times more efficiently.

Finally, hydrogen is explosive. If you have ever seen a hydrogen filled balloon exploded, you are probably aware of the tremendous power of a hydrogen explosion. Hydrogen explosions are rare, but are bound to happen if hydrogen were in wide use. A hydrogen explosion occurred in an AT&T Uninterruptible Power Source battery room in 2020. The explosion blew a 400 square foot hole in the roof and collapsed walls and ceilings throughout a large portion of the 50,000 square foot building. Fortunately, the computer/data center was vacant at the time and there were no injuries.

All things considered, unless you own a fossil fuel company or believe in magic, trying to convert to a hydrogen economy is a really bad idea. 

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