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Bicarb Cleans Up Stack Gas Emissions

The same baking soda (sodium bicarbonate) sold in grocery stores and used for a 101 things around the home is also one of the best solutions to scrub emissions from coal-fired power plants. Purification of flue gas emissions using sodium bicarbonate has always been recognized as a highly effective process for removing SO2, SO3, NOx and heavy metal compounds from flue gas. However, sodium bicarbonate scrubbing has 3 serious drawbacks:

1. The cost of sodium bicarbonate is excessive;
2. The resulting byproduct of the sodium bicarbonate SOx reaction (sodium sulfate) has limited economic value;
3. Sodium sulfate disposal is expensive and poses a significant environmental problem.

Despite its recognition as a superior scrubbing technology, these prohibitive operating issues have kept flue gas scrubbing with sodium bicarbonate from realizing any significant market share.

Airborne Pollution Control Inc., a Calgary based company, has developed a solution to the challenges of sodium scrubbing. The Airborne process begins with the injection of bicarbonate into the flue, where it reacts with and captures the pollutants. The key to Airborne’s patented process is its ability to regenerate the “residue” (it is converted back into sodium bicarbonate that can be reused for flue gas scrubbing), and at the same time, to make a high-grade fertilizer byproduct.

The Airborne process eliminates the disposal problem, improves the economics and most importantly it does a superior job of addressing the multiple pollutants inherent in flue gas emissions. Additionally, Airborne has a proprietary process to granulate their fertilizer. Airborne’s thin-film pan granulation technology makes the fertilizer more stable, shippable, blendable, customizable and ultimately more valuable.

Together with the Babcock & Wilcox, US Filter HPD Systems, and Icon Construction, Airborne is operating an integrated 5 MW demonstration facility to showcase the Airborne Process. The plant is located in Kentucky at LG&E Energy Corp’s Ghent generating facility.

Last year DOE received 36 proposals for projects valued at more than US$5 billion in the first round of President Bush’s Clean Coal Power Initiative. The Airborne Process was 1 of only 8 successful proposals, and was selected for US$31 million in funding for the implementation of Airborne’s multi-pollutant control process.

_______
| Clean Coal Power Initiative Round One
| http://www.netl.doe.gov/coalpower/ccpi/
| http://www.netl.doe.gov/coalpower/ccpi/pubs/news/020703.html
| “Commercial Demonstration of the Airborne Process” [PDF-495KB] __
| http://www.netl.doe.gov/publications/factsheets/project/Proj220.pdf

In short, this means that high sulfur coal can be burned in an environmentally friendly and economically efficient manner. The Airborne process removes multiple pollutants and it meets or exceeds all current and pending environmental requirements for SO2, SO3, NOx and mercury. For the first time pollution abatement becomes an economically rewarding investment for the power producer.

Over the next 5 years, Airborne has conservatively targeted the application of its technology to 10 new and existing coal-fired electrical generation plants. This conservative target represents less than 1% of the global available market and translates to a total installed capacity of approximately 7500 Megawatts (MW) out of approximately 800,000 MW of coal-fired power generated world-wide.

One concern with the production of fertilizer byproducts is maintaining a balance between the supply and demand for sulfur based fertilizers, a demand which is predicted to grow as sulfur emissions are reduced at the source. Airborne has a worldwide agreement with the Potash Corp of Saskatchewan Inc. (PCS), the world’s largest manufacturer and distributor of fertilizer products. Airborne has a worldwide marketing agreement with PCS whereby PCS will market the various fertilizer outputs, providing Airborne with access to worldwide markets and providing PCS with a unique addition to their portfolio of fertilizer products.
(http://www.airbornepollutioncontrol.com/potash.html)

Airborne has made a major investment in the development and demonstration of this patented process and is seeking equity investment partners to take it to the next level.

http://www.airbornepollutioncontrol.com/

Contact: Leonard Seidman
T: 403.253.7887 Ext: 310
E: L.Seidman@AirbornePollutionControl.com

“Multi Pollutant Control with the Airborne Process” [ 1.1 MB PDF] (… details the experimental and analytical results of a lab and pilot scale 0.3 MW coal fired combustion test facility and the progression to an integrated 5 MW facility)
http://www.airbornepollutioncontrol.com/papers/59.pdf

E-Beam Stack Gas Scrubbing

This might be titled, “Son of Ebara”, for those of you familiar with the history. It appears that dramatically better performance may be possible.

This text was provided to me by a private development group with access and connections to the new e-beam technology that is mentioned. I’ve edited the letter to remove some of the proprietary details. Even so, important ideas are disclosed. I would ask that you be especially careful not share it with anyone outside your company (as with all UFTO materials). If you’re seriously interested in pursuing this, I will put you in touch with the sources.

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Below, please, find a short overview of both old and new developments in e-beam processing of industrial exhaust gases.

E-Beam Processing of Industrial Exhaust Gases

— Background
In the past few years new methods of decomposition of VOCs as well as inorganic compounds in flue gases have been developed, primarily involving low-temperature, non-equilibrium plasmas used to selectively decompose organic molecules. The high concentration of electrons, ions, excited species and radicals make these plasmas well suited for driving decomposition reactions that otherwise could be initiated only at very high gas temperature.

Such plasma methods are of particular interest in the decomposition of dilute concentrations of halogenated organic compounds in carrier gas streams such as dry or wet (about 10% relative humidity) air. This type of gaseous waste stream is encountered for example in vapor extraction from soil, air stripping from contaminated water and air pollution control.

Low temperature, non-equilibrium plasmas can be generated by electron beams. They operate at atmospheric pressure in large volumes and in a highly controllable fashion making very high throughput possible. It has been also demonstrated that electron beam becomes even more efficient in decomposition of certain VOCs when combined with certain type of electrical discharge.
Advantages of e-beam induced decomposition over thermal processes become even more pronounced at dilute concentrations of VOCs in the exhaust gases. Because of the high non-equilibrium level of ionization and the selectivity of plasma-chemical decomposition processes the energy required for a given decomposition of dilute concentrations of “electron hungry” VOCs can be 10 to 100 times less than in thermal processes such as incineration, where energy is channeled to all molecules in the gaseous waste stream.

— The EBARA Experience
The Electron Beam Dry Scrubbing (EBDS) process has been first proposed as an efficient method for the simultaneous removal of SO2 and NOx from industrial flue gas in early 1970s. In this process, the e-beam energy generates high concentration of oxidants (OH, HO2, O3) converting SO2 and NOx to nitric and sulfuric acid which in turn form solid powder of ammonium nitrate and sulfate in the presence of added ammonia (NH3).

The Japan Atomic Energy Research Institute and the University of Tokyo have carried out the first research on EBDS in 1970. Follow up technical development by EBARA Corporation lead to the first 10,000 Nm3/hr pilot plant built for a sintering plant at Yahata Works Nippon Steel Corp in 1977. At this plant a flue gas at temperatures T=70-90 C containing 200 ppm of SO2 and 180 ppm of NOx has been treated by 2 x 750keV/45kW e-beam accelerators.

In the US the first and only EBARA-process demonstration unit with a maximum flow rate of 30,000 Nm3/hr has been put in operation in June 1985 at a coal fired power plant in Indianapolis, Indiana. At this plant 2 x 800 keV/80kW electron accelerators has been employed treating 1,000 ppm of SO2 and 400 ppm of NOx in a flue gas at temperatures T=66-150 C.

In December 1985 a 20,000 Nm3/hr pilot plant has been built at Badenwerk, Karlsruhe, FRG at 550 MW coal fired facility employing two 300KeV/90 kW accelerators to treat 50-500 ppm of SO2 and 300-500 ppm of NOx in 70-100 C exhaust gas. In early 1990s similar e-beam treatment pilot units have been built in China, Poland and Russia.

One of the main limitations of EBARA process has been a considerable energy requirement for oxidation of SO2/NOx in an air stream, which amounts in average to about 10 eV/molecule. For a coal fired 300 MW electrical power plant this translates to 12 MW (4% of the electrical power generated by the plant required e-beam power. Back in 1980s the most powerful accelerators were below 100 kW, so 12 MW installation would require 120 x100 kW accelerators and the total accelerator costs in the access of $180 mln. were prohibiting.

— What’s New
A new generation of powerful accelerators manufactured in Russia which can deliver 1MW of e-beam power for the cost of about $1.5 million per unit, can already reduce cost of EBARA process by order of magnitude.

Moreover, a synergetic approach combining electrical discharge and electron beam may allow another tenfold decrease in flue gas processing cost. This is done by essentially substituting much less expensive power of corona discharge for most of the expensive e-beam power. This process maintains all the advantages of e-beam processing such as stability of operation and uniform treatment of large volumes and high mass flows of flue gas — for a fraction of cost compare with e-beam treatment alone. Note that corona discharge alone, without e-beam stimulating effect, suffers from intrinsic non-uniformities and instabilities which greatly reduce its efficiency for industrial scale applications.

Experiments on SO2 oxidation in e-beam stimulated corona discharge have been conducted. We were investigating the plasma chemical processes in an electron beam driven plasma reactor for efficient decomposition of SO2 , NOx or any VOC in carrier gases at atmospheric pressures.

The reactor used an electron beam to stimulate corona discharge at sub-breakdown pulsed electric field. A combination of e-beam and superimposed electrical field in the form of stimulated corona discharge creates plasma with highly controllable electron density and temperature and therefore highly controllable chemical reaction rates.

Synergetic effect of SO2 decomposition by the combined action of e-beam and corona discharge was estimated by the coefficient K equal to the ratio of the discharge energy Wc, consumed from high-voltage source, to the energy Wb deposited by electron beam within the volume of the discharge:
K = Wc / Wb

It has been demonstrated that under certain experimental conditions the energy of discharge consumed from high-voltage source can exceed e-beam energy input by more than 300 times. In other words, a low cost high-voltage rectifier instead of a high-cost electron accelerator provided about 99.7% of the flue gas ionization energy. As a result the same SO2 decomposition effect in e-beam stimulated corona discharge can be achieved with 300 times lower e-beam power compare with irradiation by e-beam alone.

There some indications that shorter e-beam pulses and higher discharge threshold voltage Umax may also lead to the significant decrease of energy cost per oxidation of one SO2 molecule from a typical value of 10 eV/mol down to 3 or even 1eV/mol. However, even at the lower Umax values rather efficient SO2 oxidation process is taking place.

The main purpose of these initial experiments on SO2 oxidation was to demonstrate significance of synergetic effect in e-beam stimulated corona discharge. Discovered synergetic effect allows efficient SO2 decomposition under the conditions when only 0.3% of the total ionization energy is provided by an electron beam with the rest coming from a low cost electrical discharge. Further experiments are necessary to determine the optimum conditions for most efficient decomposition of SO2./NOx mixtures, as well as VOCs in industrial exhaust gases.

We are open to any form of collaboration with a US utility company or research organization, which would enable us to continue these very promising experiments.

I look forward to your comments and suggestions.