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Capturing carbon, revisited

In her column, Capturing carbon emissions, in the Parkersburg News and Sentinel, April 28, Christina Myer quotes U.S. Rep. David McKinley, R-W.Va.,

“Last week, the firing up of NET Power’s plant provides hope for those researching a way to make carbon capture technology so efficient and inexpensive that it can be produced and exported around the world.”

Capturing and storing CO2 must add cost because of the physics so this hope is suspect.

She also quotes the description of NET Power’s process that masks the truth through careful wording.

“It uses a high-pressure, highly recuperative, oxyfuel, supercritical CO2 cycle that makes emission capture a part of the core power generation process, rather than an afterthought. The result is high-efficiency power generation that inherently produces a pipeline-quality CO2 byproduct at no additional cost to the system’s performance.”

This seems to be verbal sleight-of-hand. The description of the process is hidden by many undefined technical terms. If the technical terms are removed, the statement reads:

“It … makes…emission capture …part of the …process, rather than an afterthought.”

I can only see one way for the conclusion, emission capture adds no additional cost to the systems performance, to be true. The additional cost must be part of the process, rather than an afterthought. Being part of the process, there is no additional cost to the system. Verbal magic.

According to Christina Myer, “NET Power also says its plant does not produce nitrous oxide, and therefore requires no equipment for handling it.”

For this to be true, the term oxyfuel must mean burning carbon with pure oxygen rather than air. Air is 80 percent nitrogen. Burning in the presence of nitrogen produces nitrogen oxides. Again, verbal magic excludes the cost of separating oxygen from air because it is already in the process, not an afterthought.

What about making carbon capture so efficient that it can be used around the world as Rep. David McKinley hopes? See (https://cleantechnica.com/2016/11/21/real-net-powers-zero-carbon-gas-generation-tech/) for a more detailed discussion of NET Power’s technology.

Many different processes have been proposed for capturing carbon emissions. All claim to add little or no cost penalty and all need just a little more research. Indeed, the column again quotes Rep. McKinley about NET Power,

“Why don’t we finish the research? We know we have to start lowering our emissions.”

Let’s look at sources of the added cost that are common to all fossil fuel processes.

Burning carbon in the air combines two oxygen atoms with each carbon atom to make CO2. Since each oxygen atom weighs more than each carbon atom, burning one ton of fossil carbon produces more than three tons of carbon dioxide. It makes no difference if the carbon is from coal, oil, or natural gas. Each ton of fossil carbon produces more than 3 tons of CO2.

Over billions of years nature converted CO2 gas into fossil fuels, rich in carbon and stored in the ground. To use a computer analogy, this is like compressing data files to one third of their size or weight. When we burn the fossil fuel, it is like decompressing the computer files and scattering the data all over the cloud. It takes a lot of effort to search the cloud and retrieve the data.

I learned physics and chemistry from three Nobel Laureates. They all taught me that the laws of thermodynamics prevent a perpetual motion machine. My parents used different words, but taught the same message: “There is no such thing as a free lunch.” or “If it sounds too good to be true, it probably is.” If CO2 could be captured, at no cost, it would violate the laws of thermodynamics and give us a free lunch.

Separating and isolating CO2 must add cost, by what ever process.

Even after the CO2 is isolated, still more cost must be added for transportation and sequestration (safe and permanent storage).

CO2 captured, by any process, will require a lot of infrastructure to transport three times more CO2 than burned carbon. Think at least the size of our current natural gas infrastructure, lots of pipes and compressors. A huge new cost.

Selling the CO2, even for enhanced oil recovery or fracking, will not work. These use less than a few percent of the CO2 produced from fossil fuels. Captured CO2 will glut the market.

The selling price for recovered CO2 including transportation must be less that 1/3 the price of the lowest cost fossil carbon fuel. At any higher price it would be cheaper to simply burn the carbon on site to produce CO2 directly. (Remember one ton of carbon makes more than 3 tons of CO2).

If the CO2 can’t be sold, pumping it into deep wells is proposed. This only adds more cost: drilling wells, compressors, monitoring to make sure it doesn’t leak back to the surface, and research to demonstrate feasibility. Michael Barnar in, “Carbon Capture is Expensive Because of Physics,” says, “it’s hard to imagine anyone with a good STEM background directly involved with it taking it seriously as a solution.”

Why then would anyone invest in the NET Power plant or any other demonstration project? The short answer is that no one, not even the fossil fuel companies, can afford to pay for large scale carbon capture. Carbon capture only adds cost.

The fossil fuel industry, like the cigarette industry before it, is trying to delay the obsolescence of its huge capital investment and maintain its profits. Investing, what sounds like a large dollar amount, in a demonstration plant is a sound idea for them. Each day of delay gives them more profits. Building a small research facility is a wonderful distraction. The investment is minuscule compared to the profits. And the fossil fuel industry has lots of profits and government subsidies to invest in delaying tactics and political lobbying.

Capturing carbon can only add cost to carbon fuel processes. No amount of research can make the added cost go away.

The cost of new electric power from renewable sources has declined. Today it actually costs less than new electric power from fossil fuel. Research and development of renewable power sources will continue to lower the cost of energy. Research on a smart power grid can lower electricity costs for all methods of generation.

However, implementing any form of carbon capture can only add cost.

Renewables or fossil fuel? The choice is ours.

***

Warren Peascoe, of Vienna, has a Ph.D. in chemistry, and 30 years experience working in the industry.

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