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Wed 14 Apr, 2004 07:42 pm
According to BBC a USA company is about to build a scrubber to remove 0.04% carbon dioxide from the wind. A 10 square meter frame will collect the carbon dioxide. Some experts predict poor performance.
All the greenhouse warming solutions are incredibly costly (to someone) and most methods get costlier above a million tons per year world wide, so we should do this scrubber prototype along with 100 other pilot programs.
Strong lye = sodium hydroxide solution is exposed to air to become sodium carbonate by removing carbon dioxide from the air. The sodium carbonate can be sold for about half the cost of the sodium hydroxide if we don't flood the world market, by trying to remove a million tons of carbon dioxide from the air each year by this method. Several other metal oxides and dioxides will do the job, but typically are more costly and the market for the carbonate is smaller than for sodium carbonate.
Other costs are separating the sodium carbonate from the unreacted sodium hydroxide, which probably is mostly the cost of pumping the solutions. Shipping costs for the water solutions will be higher than for powder, so there will likely be costs of adding and removing water some weeks. Some of the reactions produce some heat, but it is unlikely that use can be made of this low grade heat except in winter time.
In theory solar energy could be used to separate the carbon dioxide from the sodium carbonate, but very high temperatures are required, and the hot carbon dioxide is worse than useless except in winter. Heat exchangers can recover some of the heat from the hot carbon dioxide with small usefulness, while the sun is behind a cloud.
There are research and development costs. Even fully developed and automated, at least one skilled person will likely be needed 24/7 for each location.
The other problem is more than a ton of carbon dioxide is released into our atmosphere for each ton of sodium hydroxide manufactured. About a ton of sodium hydroxide is needed to remove a ton of carbon dioxide from the atmosphere. Typical electric power plants have several tons of 4% sodium hydroxide that they put in a perk pond about once per week. After some initial cost this is probably free, if you also take away about the same amount of 4% sulphuric acid. Both are slightly contaminated, but that likely does not matter for the carbon dioxide scrubbing. Any ideas to use the 4% sulphuric acid? It can be used to release the carbon dioxide from the sodium carbonate, but the resulting sodium sulphate is close to valueless in large quantities.
Like many chemical processes, venting part of the carbon dioxide into the atmosphere can be avoided at less cost than from power plant flue gases when sodium hydroxide is manufactured. The big chemical companies that control most of the supply and most of the patens are unlikely to be co-operative, even though they pretend to be looking for solutions. Please comment, embellish or refute. Neil
Its a matter of location. ALl the CO2 reduction involves some kind of sequestration by converting it to something else. In the case of power plants, I like this idea more than pumping CO2 into the ground.
, (this is all speculation , no research to back up any of my opinions, especially regarding costs)
If power plants were located near coastal waters , then the production of NaOH would be a snap. Some of the power could be diverted into an electrolysis setup to run a chloralkali plant. a chloralkali process breaks seawater down into Hydrogen,HCl,Sodium Hypochlorite, and NaOH. two collect on the anode and two on the cathode. The NAOH is concentrated by hehating the water and driving it out of the NaOH solution. I dont know whether there can be a balance achieved to run the plant (oil, gas, or coal fired) the NOx and H2SO4 can be neutralized in ponds and the nAOH used for neutralizing and sequestering CO2. SOunds like its worth researching. The research, IMO should focus on a bench scale and pilot plant op to see what the economics dictate.
NOW the biggst problem, like all neutralization and reaction schemes is SLUDGE.
some of the Na2CO3 can be used for glass making so locating a glass plant nearby would be desirable.
you realize though, that , with all the deferrals on power plants , its going to take an entire change of mind to make this desirable. SOmething like incentives for colocation and environmental sustainability.
Just a thought.
Just reading, but one little question: sodium carbonate, or sodium BIcarbonate?
its sodium carbonate, youd be left with Na2CO3/water, its a stable compound.
The other neat thing is, if you locate the power, chloralkali, glass and a Titanium dioxide plant in a complex you could use NJ or E coast beach sand. Youd suck out the Ti sands , which would foul up a pure glass plant by making the glass deeply colored. So you use the H2SO4 to make the Ti/Fe (copperas) and then , by a further acid then water wash youd purify the Ti, and then convert to TiO2 . All the other chemicals created could be used even the HCl and Clorox.in the chloralkali plant.
I dont know whether NJ would even notice
Huh, thanks. Bookmarking.
Maybe we should just plant more trees.
My yard is about capacity with trees as is about 1/2 of Florida. If most of us eat less beef and mutton, some of the cattle grazing land could be planted in trees. Swampy places can't grow much but cyprus trees which are better than grass. We probably should not drain 1% of the remaining swamp per year. If we grow biomass for methane, ethanol or other energy, we will be removing trees. That seems counter-productive, but it would give potential for doubling food production (by abandoning the biomass) Think of it as a soil bank which could save billions of lives if the average food yield is reduced by any of many catastrophes, so we should do pilot programs in several kinds of biomass.
integrating an electric power plant, electrolysis of salt water (evaporative concentrating ponds?) glass plant and titanium facility with the sodium hydroxide removing the carbon dioxide from air, would surely reduce the cost (with good engineering) Has such complex symbiotic engineering often worked well? I had forgotten that sodium hydroxide can be made by electrolysis. Is several percent of the world's sodium hydroxide presently made by electrolysis? Perhaps bleach = clorox could capture the carbon dioxide. Would large amounts of hydrogen chloride and chlorine gas pollute the air? Will sodium hypochlorite react with carbon dioxide to make sodium carbonate? Would 1% sodium hypochlorite damage the glass? i'm thinking costs are lower if we can avoid separating. Perhaps glass is better made with sodium hydroxide/ then we would not need to deal with hot carbon dioxide or vent it into the atmosphere? Would a vast array of other sulphates (from the slightly contaminated sulphuric acid) complicate the production of titanium oxide? Is 4% acid strong enough to treat the sand economically? If all else fails we can make hydrogen out of 4% sulphuric acid and scrap metal. Neil
I missed the acid strength for the H2SO 4 , The TiO2 process needs fuming (concentrated ) sulfuric. The reason I chose a beach was to supply the sand for the glass . The Ti was a byproduct cleaned from the sand.
As far as the NaOH, I believe that much, if not most of the NAOH is made by the chloralkali process. Its energy intensive but in the US much of it is made by hydropower in and around Niagara Falls. What to do with the hypochlorite, hmmmm. Its a chlorine source for chloranilines and other chlororganics (also needs power).
This is getting energy intensive, sort of like the Aswaan high dam. It was first created to supply power to a rural power grid. Now, and shortly after the dam was built, much of the power is diverted to make fertilizers to amend the soils around the Nile below the dam because the
Aswan has cut off the annual floods of silt which originally was natures fertilizer. The silt now piles up behind the dam and causes great stresses on the dam walls whhich will have to be mucked out to prevent a major failure. However, all these "feel good"ublic works projects that governments undertake get to be circular and counter productive after a while.
There are a number of symbiont plant complexes all over the world. Most famous are oil refineries , petrochem and fertilizer plants which are co located. My experience , in dealing with Ti, is the Ti plant is usually co located with a sulfuric acid plant and a sulfur dome from a desulfuring operation in petroleum. Many of these are in the south. The off products of many industries are the feedstocks of an
other.
How is sulphur removed from petroleum? Will hydrogen sulfide or carbon disulfide react with carbon dioxide? Neil
sulfur is usually in an H2S form it gives the crude names like "sour" where,. "Sweet" crude contains less H2S AS far as H2S removal Im only familiar with the Clause process to remove H2S by oxidizing it in the presence of a catalyst (sorry dont remember the catalyst) Then the first oxidation product is SO2. The SO2 is trhen re-reacted with H2S using a copperas catalyst (Fe Ti O3). this converts the SO2 to elemental sulfur and is just piled up in HUUUge yellow mountains.
Theres another process which uses the Na2CO3 and a catalyst to form an HS- and this is oxidized to elemental sulfur. Im not familiar with the alkaline process. There are newer technologies like microfiltration of H2S where the H2S is reacted to form a thiol colloid, and these are micro filtered. I know nothing of this trick , or whether its in production use. Theres also some bio processes where H2S is reacted in bio filters, again , I have no familiarity with this. They usually get us geologists out of the way before any money comes out of the ground
. JIM is a petroleum engineer and probably knows this stuff best.
As far as CS2 and H2S as reactants . I think these arent considered for sequestering because of dangers in their use
H2S is very dangerous as a toxic gas and I dont think itd be advisable to use an exposed screen like with the NaOH reactions
Also CS2 , in air, is quite explosive, so , it too, I think would be rather dangerous to just expose in an air mix. It is usually reacted in retorts with wood pulp and H2SO4 and Zinc catalyst to make Rayon.
Besides, CO2 is an effective fire surpressant with carbon disulfide, so it impedes reaction(which is necessary in sequestering the CO2)
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