Comments on: Is Capturing CO2 a Pipe Dream? New York Times blog Thu, 23 Jun 2016 20:44:05 +0000 hourly 1 NYT By: Romain L Fri, 30 May 2008 23:35:30 +0000 This only shows how much communication is needed between experts from different walks of life, and from different ‘spaces’ in the carbon world. It has been well known to engineers for years that without significant government intervention in favor of these technologies, both to decrease the impressive cost mark-up for the first plants, and to sort out the potential liabilities and property rights issues…

Shameless plug: it just turns out that we (at, a newly-launched non-profit aimed at bringing the carbon community together) are organizing a happy hour event next week in Washington DC, where we encourage everyone from the different worlds that coexist around the issue of climate change to come and meet each other in a casual atmosphere!

The event is next Tuesday 6/3 from 6 to 8pm at Marvin, 14th and U St NW in Washington, DC! Feel free to check out the website for more information:

By: G Wainright Fri, 30 May 2008 17:22:50 +0000 Purdue University report on gasification process that eliminates need for CO2 capture and sequestration

I ran across a very interesting white paper earlier this week entitled “Sustainable fuel for the transportation sector” that was published in March of 2007 by researchers at Purdue University. I believe that it has very interesting ramifications in the context of your current discussion of the feasibility of capturing and sequestering carbon for power plants because it eliminates the need to take these steps.

The paper was written by Agrawal*, Singh, Ribeiro, and Delgass of Purdue’s School of Chemical Engineering and Energy Center. It advocates synthesizing liquid hydrocarbon fuels like diesel and gasoline by employing a hybrid hydrogen-carbon (H2CAR) process that uses biomass as the carbon source and adds hydrogen gas produced from carbon-free renewable energy, such as solar or wind. Following gasification, CO, H2, CO2 and H2O pass into a reactor that produces liquid fuel. Unreacted CO2, CO and H2 are recycled back to the gasifier. The objective is to utilize every carbon atom of the feedstock to produce usable fuel. The researchers believe their process achieves this goal.

According to the paper, other existing processes are able to produce only about 30% of the total transportation fuel used in the U.S. from the available annual biomass production of 1.366 billion tons. By achieving nearly 100% efficiency in carbon utilization, the H2CAR process reduces the amount of arable land needed for sustainable fueling of the entire U.S. transportation sector to less than 40 percent of the requirements of other methods. It therefore has the potential to supply all of the fuel needed to run the entire U.S. transportation sector from the same amount of biomass.

The technique can also be used to process coal into liquids. According to the authors, the same 100% efficiency of carbon conversion applies to coal-to-liquids as to biomass-to-liquids. Consequently, no CO2 is released into the atmosphere in connection with the actual conversion process. However, using biomass to produce transportation fuels is a closed loop, in which photosynthesis converts atmospheric CO2 to O2 and biomass. The latter is converted to fuel and burned in vehicles, releasing CO2, etc. Producing liquid fuels from America’s enormous reserves of coal is not a cyclical process capable of sustainability. In the long run, using the H2CAR process in this fashion would significantly extend the life of American coal supplies. However, it probably would not reduce coal usage enough to have a sufficiently major beneficial impact on the problem of increasing levels of greenhouse gases without finding a way to permanently sequester the CO2 emissions from burning the fuel.

Inserting the process upstream of the burners in large numbers of coal-burning power plants might help to clean up particulate emissions, but the end result of burning the liquid fuel would still release massive amounts of new CO2 into the atmosphere. Consequently, it presumably would have little effect on CO2 emissions.

However, using the process in power plants that are converted to using biomass as their energy source would seem to have real potential for create a closed loop that continuously recycles atmospheric CO2 from power plants, thereby eliminating the need for mining additional fossil fuel. What that would do to the economics of producing the nations’ transportation fuels from biomass is unclear. There may simply not be enough land and water to do both. The effect on food prices of applying enormous acreages into the production of biomass for fuels is another obvious matter of deep concern.

The preferred fuels of the U.S. transportation sector are liquid hydrocarbons because of their high energy density and easy portability. Unfortunately, the cost of these fuels is projected to rise inexorably over the coming months, years and decades as the available supply fails to meet demand. While hydrogen gas shows some promise for powering our vehicles, it is hindered by the fact that it lacks the energy density of liquid hydrocarbons and, as of yet, has no infrastructure for delivery. It is often described as a means of transporting and utilizing other primary energy sources, such as sunlight, wind and electricity, rather than as an energy source in its own right.

According to the Purdue researchers, there are a number of good reasons for adding extra hydrogen to the gasification mix. In the first place, it can be produced from renewable energy sources. Second, production of hydrogen through solar generation of electricity and hydrolysis has a significantly higher annualized solar energy conversion efficiency than does producing biomass from photosynthesis. Third, adding H2 atoms to carbon atoms from coal or biomass, unlike storage of H2 in tanks, provides a method of storing massive quantities of H2 in an extremely dense and portable form. Thus, in the quest to produce large quantities of liquid hydrocarbons to use as a highly concentrated transportation fuel, hydrogen produced from wind or solar energy would seem to have a significant role to play.

Using gasification of coal or biomass to produce biofuels has its own problems, chief among which is the difficulty of “rigging” the process in order to achieve the most efficient utilization of the feedstock, the goal being to maximize the amount of fuel produced and minimize creation of undesirable byproducts. Some of these byproducts, such as CO and CO2, are poisonous and/or contribute to global warming. It may be helpful to consider briefly some of the byproducts derived from the conversion biomass into fuels.

For example, in addition to the desired fuel, when biomass is heated to greater than 400 degrees C in an oxygen-free environment, the process also yields 25 percent charcoal and large quantities of dense tars. When air is added to create “producer gas,” the output stream typically consists of CO (22%), H2 (18%), CH4 (3%) and N2 (51%). Instead of air, pure oxygen can be used to make “synthesis gas,” which is comprised of CO (40%), H2 (40%), CH4 (3%) and CO2 (17%, dry basis). Synthesis gas can be further refined with commercial catalytic methods to create methanol (CH3OH), ammonia (NH3) and diesel fuel.

Some of these byproducts create disposal problems, as in the cases of tars, CO and CO2. It will be necessary either to find uses for these byproducts, to devise practical methods of sequestering them or to discover methods of completely utilizing them in the process of making fuel. It is this latter possibility that is one of the things I find so intriguing about the proposal of the Purdue investigators.

Some experts say we cannot “farm” our way out of the twin conundra presented by Peak Oil and Global Warming. They say that the magnitude of the problem is just too great and that biofuels are not the answer. Well, I agree that some biofuels, like corn ethanol, are not the answer and that governmental incentives for their production should be repealed. However, perhaps the Purdue research offers grounds for hope that we can create an economy based on sustainable fuels.

T. Boone Pickens’ company BP Energy recently purchased some 667 wind turbines for a wind farm in Pampa, TX touted by Pickens as the largest of its kind in the world. Other large wind projects are in the construction, development or planning stages throughout the Texas-to-Montana wind corridor and offshore. This would appear to create an opportunity to combine these wind farms with on-site or nearby hydrogen electrolysis plants and H2CAR plants that would have the potential to create enormous quantities of hydrocarbon fuels.

Of course, farming sustainably on the scale envisioned to produce biofuels will create an enormous need for fertilizer. The problem becomes even more daunting if the H2CAR process is used to fuel power plants fueled by biomass. More investigation should be undertaken on the potential for using some of the wind/hydrogen energy from wind or solar farms to fuel a process for fixing large quantities of ammonia from atmospheric N2 gas to aid in the production of the required biomass from renewable sources. This could be done as a wholly separate project or possibly as part of of the H2CAR process if some quantity of air is used in producing the fuel, followed by commercial catalysis, as mentioned previously.

As previously suggested, a very large potential fly in the ointment with respect to prospects for actually “farming” our way out of the Global Warming and Peak Oil crises and eliminating our dependence on foreign oil is water availability—or lack thereof. The Ogallala Aquifer is being depleted at alarming rates by agricultural and other uses of water in large parts of the wind corridor mentioned above. Aggressive methods of reducing other water uses may have to be developed, or water may have to be imported, or electricity or hydrogen may have to be exported to other farming regions for this to work on a large scale.

If we fail to realize that overpopulation of this country threatens to overwhelm even the potential of the Purdue process to create sustainable grid electricity and/or transportation fuels, we may be doomed to devolve permanently to lower tech, more isolated lifestyles amid pervasive shortages of food, energy and other commodities. On the way down, we are likely to experience much human suffering, strife, violence and even massive population die-offs. This will inevitably occur not only in the rest of the world, but within the U.S. as well. It is therefore imperative that we take rising oil prices and gas shortages for what they are—a dire warming of the likely consequences of adopting the Purdue technology and then reverting to business as usual. New technologies like the H2CAR process and large-scale wind farming offer a flickering hope for the future. However, if we do not recognize the need to achieve zero population growth in the near future, it will probably all be for naught.

DISCLAIMER: I am not an expert on gasification, just an interested layman hoping to stimulate a lively discussion of the feasibility of biomass-to-fuels. I hope readers of Dot Earth who have particular expertise with regard to this subject will correct any errors contained in my comments. However, I encourage all interested denizens of this site to put in their two cents, as well.

By: Peter P Fri, 30 May 2008 17:01:33 +0000 The global warming computer models mean nothing. For example James Hansen, NASA scientist, predicted a 0.45-degree Celsius (0.81-degree Fahrenheit) rise in global temperature from 1988 to 1997. But in reality (a place environmental activists rarely visit) the increase was a mere 0.11-degree Celsius. This is very close to the natural rise in temp that was happening before the industrial revolution.

The climate alarmists are even wrong on the matter of 1998 being the warmest year on record – at least for the U.S. According to a new analysis, Aug 2007, which discovered an error in a NASA dataset, 1934 is the new warmest year on record for the U.S. In fact, four of the warmest 10 years in the U.S. date from the 1930s while only three date from the last 10 years. This is an embarrassing setback for alarmists, especially since about 80 percent of man made carbon dioxide (CO2) emissions occurred after 1940.

Climate change campaigners are frightened that, if the lid is lifted off the Pandora’s Box of modern day climate science, the vast uncertainties and contradictions in the field will become apparent and public support for multi-billion dollar climate change schemes will quickly die.


No more money should be wasted on the global warming scam.

By: Brad Arnold Fri, 30 May 2008 11:06:25 +0000 Clean coal as it is commonly understood is unfeasible:


Also, I suggest you read this GreenPeace publication “False Hope: Why carbon capture and storage won’t save the climate”

Fortunately, there is a technology coming down the pipeline that offers clean coal: biologically converting CO2 from coal plants into fuel:


Watch this 15 minute Craig Venter interview clip-I’ve watched over a hundred thousand hours of video, and this is the most amazing thing I’ve ever seen:

Using CO2 from coal-fired plants as fuel stock, making the carbon dioxide an asset! How slick is that? You can thank the genomic revolution for this gift (see my blog at for more information).

By: richard schumacher Thu, 10 Apr 2008 05:04:44 +0000 Calculating from the observed rate of increase of atmospheric CO2, we would have to capture, compress, and permanently store the equivalent of at least one thousand cubic miles (at 1 atmosphere pressure) of CO2 every year. This is impossible. We have to stop wasting time, money and political will on pointless diversions such as CCS.

By: Dan Thu, 28 Feb 2008 05:34:41 +0000 One big problem with CO2 sequestration is that for every ton of carbon we bury in the form of CO2, the atmosphere loses over two tons of oxygen. That is, we will be slowly reducing the oxygen content of the air that we breathe. At least if the CO2 is in the atmosphere, plants at least have a shot at it to recycle the oxygen.

By: jtberman Wed, 20 Feb 2008 06:52:49 +0000 I have been following James Hansen’s proposals who is vehement about weaning ourselves from coal. His proposal is to create electricty through the burning of cellulosic plants, and sequester that CO2 under the oceans where “it is inherently stable”, thereby creating power and drawing down atmospheric C – see figure 37, page 53 of this document:
He has a lot of other intriguing ideas outlined there and in other writings and publications listed here:

By: Larry Wed, 13 Feb 2008 23:34:57 +0000 This is all because of the coal lobby. It should be a billion toward a large scale demonstration of solar thermal. At that size it gets pretty damn cheap per watt. But then the coal industry doesn’t get a steady income from it, the fuel (sunlight) is free.

[This bias toward efforts that favor the politically-valued energy options (coal and farmed fuels), to the detriment of solar, was highlighted in a couple of my recent stories for the Energy Challenge series — on solar and declining research money.]

By: Paul K Sun, 10 Feb 2008 13:39:45 +0000 Oops, the last post was mine, and was made in response to Luther’s post. Sorry.

By: Luther Sat, 09 Feb 2008 23:29:51 +0000 Pressure needed for injection depends on the depth of the zone, and the pressure loss in the injection wells etc. In general, if you try and use a shallow zone, with the corresponding lower pressure, you will need a much larger volume reservoir to sequester the CO2, whereas in a deeper zone, you will be able to store a lot more CO2 per cubic meter of reservoir rock.

I used a zone about 8000-12,000 feet deep, because this is typically the depth of a lot of CO2 miscible flood EOR projects. As a general conservative rule of thumb, you will need a pressure about equal to the hydrostatic head of water to that depth, but you may be able to get away with only 70-80% of the hydrostatic head. For an 8000 feet deep reservoir, hydrostatic head is around 3400 psig, and for 12,000 feet, you would need around 5000 psig.

It is unlikely that you will be able to use a pressure of only 900 psig, unless you are planning to use a shallower salt deposit cavity, like our strategic oil storage projects. But these cost a lot of money to construct.

But i am not really an expert in the reservoir storage issues. I was mainly responding to a post that claimed that traditional amine systems or pressure swing adsorption units could be used to scrub CO2 from flue gases; and the post implied we could use these traditional CO2 scrubbing technologies on existing stack gases.

This has been looked at, and almost universally rejected for cost reasons. This is why the DOE, at the instigation of the coal industry and coal country politicians, have been looking at IGCC plants. Here is a link to a diagram of a typical IGCC plant on Wikipedia. Look how complicated it is!

There are dozens of problems with this technology, that will have to be solved, to make IGCC feasible. As just one example, look at the stream labeled “slag and water” coming out of the coal gasifier. Remember, that gasifying coal will create all kinds of carcinogenic HC compounds, like benzene, etc. Cleaning up a waste stream from a large gasifier is no simple task. This diagram doesn’t show the sour water treating system. Look at the stream labeled “COS->H2S hydrolysis”. Coal contains a lot of sulfur that will be converted to H2S and then presumably sent to a sulfur plant. This diagram doesn’t show the sulfur plant (which produces liquid molten sulfur) along the sulfur plant tail gas unit etc.

In summary, IGCC is a very complicated process plant; more similar to a refinery or a complex chemical plant, than a power plant. The cost of developing this technology, and building these plants is huge… It is easy to see why this FutureGen plant cost has gone sky high.

By: Luther Browning Thu, 07 Feb 2008 22:55:47 +0000 Paul K. you were sounding good until you started compressing the CO2. At 20 deg C CO2 is a liquid at 900 psig. If you are going to put it in the ground, say a depleted sand zone, little surface pressure will be required or needed. When the liquid CO2 is in the formation you want the pressure low enough so it stays there. If you pump it in at 4000 psi there will be a formation fracture and a leak to the atmosphere. Like you I think there are better ways of producing electricity. But it will be more expensive to the consumer. But if Greenland melts it will seem dirt cheap compared to the loss of our coastal cities or the cost of building dikes around them. None of the candidates running for president are able to comprehend the magnitude of the problem. I hope they will have a competent science advisor.

By: kim Thu, 07 Feb 2008 04:18:04 +0000 Bah, we’re cooling because of the sun. The colder weather is not our fault, but your perception of extreme weather is a religious one.

By: Paul K Wed, 06 Feb 2008 21:49:42 +0000 We have fallen off the cliff… more and more extreme weather events can be expected. Massive droughts AND horrendous flooding as global warming exacerbates extreme weather conditions.

The question is how many more people must die, before Americans target the naysayers and the vested interests that control our government. When we will hold these bureaucratic Republicans responsible for the deaths of Americans, and the destruction of our planet?

By: kim Wed, 06 Feb 2008 19:58:38 +0000 If we are headed for a Grand Minimum, and if carbon dioxide has any warming effect, then the more kids will survive the more carbon dioxide we release.

So figure it out before we all fall off a cliff.