Clean Coal Technology from tOSU

[Mavric]

This could be interesting, and possibly revolutionary:

 

For 203 continuous hours, the Ohio State combustion unit produced heat from coal while capturing 99 percent of the carbon dioxide produced in the reaction.

 

“In the simplest sense, combustion is a chemical reaction that consumes oxygen and produces heat,” Fan said. “Unfortunately, it also produces carbon dioxide, which is difficult to capture and bad for the environment. So we found a way to release the heat without burning. We carefully control the chemical reaction so that the coal never burns—it is consumed chemically, and the carbon dioxide is entirely contained inside the reactor.”

 

Liang-Shih Fan, professor of chemical and biomolecular engineering and director of Ohio State’s Clean Coal Research Laboratory,pioneered the technology called Coal-Direct Chemical Looping (CDCL), which chemically harnesses coal’s energy and efficiently contains the carbon dioxide produced before it can be released into the atmosphere.

 

Dawei Wang, a research associate and one of the group's team leaders, described the technology’s potential benefits. "The commercial-scale CDCL plant could really promote our energy independence. Not only can we use America's natural resources such as Ohio coal, but we can keep our air clean and spur the economy with jobs," he said.

 

Full Article

[T_O_Bull]

Is there a use for carbon dioxide?

T_O_B

[Mavric]

Growing plants?

 

Per wikipedia:

 

 

Precursor to chemicals

In the chemical industry, carbon dioxide is mainly consumed as an ingredient in the production of urea and methanol. Metal carbonates andbicarbonates, as well as some carboxylic acids derivatives (e.g., sodium salicylate) are prepared from CO₂.

 

[edit]Foods

Carbon dioxide is a food additive used as a propellant and acidity regulator in the food industry. It is approved for usage in the EU^[18] (listed as E number E290), USA^[19] and Australia and New Zealand^[20] (listed by its INS number 290).

A candy called Pop Rocks is pressurized with carbon dioxide gas at about 4 x 10⁶ Pa (40 bar, 580 psi). When placed in the mouth, it dissolves (just like other hard candy) and releases the gas bubbles with an audible pop.

Leavening agents cause dough to rise by producing carbon dioxide. Baker's yeast produces carbon dioxide by fermentation of sugars within the dough, while chemical leaveners such as baking powder and baking soda release carbon dioxide when heated or if exposed to acids.

 

[edit]Beverages

Carbon dioxide is used to produce carbonated soft drinks and soda water. Traditionally, the carbonation in beer and sparkling wine came about through natural fermentation, but many manufacturers carbonate these drinks with carbon dioxide recovered from the fermentation process. In the case of bottled and kegged beer, recycled carbon dioxide carbonation is the most common method used. With the exception of British Real Ale, draught beer is usually transferred from kegs in a cold room or cellar to dispensing taps on the bar using pressurized carbon dioxide, sometimes mixed with nitrogen.

 

[edit]Wine making

Carbon dioxide in the form of dry ice is often used in the wine making process to cool down bunches of grapes quickly after picking to help prevent spontaneous fermentation by wild yeast. The main advantage of using dry ice over regular water ice is that it cools the grapes without adding any additional water that may decrease the sugar concentration in the grape must, and therefore also decrease the alcohol concentration in the finished wine.

Dry ice is also used during the cold soak phase of the wine making process to keep grapes cool. The carbon dioxide gas that results from the sublimation of the dry ice tends to settle to the bottom of tanks because it is denser than air. The settled carbon dioxide gas creates a hypoxic environment which helps to prevent bacteria from growing on the grapes until it is time to start the fermentation with the desired strain of yeast.

Carbon dioxide is also used to create a hypoxic environment for carbonic maceration, the process used to produce Beaujolais wine.

Carbon dioxide is sometimes used to top up wine bottles or other storage vessels such as barrels to prevent oxidation, though it has the problem that it can dissolve into the wine, making a previously still wine slightly fizzy. For this reason, other gases such as nitrogen or argon are preferred for this process by professional wine makers.

 

[edit]Inert gas

It is one of the most commonly used compressed gases for pneumatic (pressurized gas) systems in portable pressure tools. Carbon dioxide also finds use as an atmosphere for welding, although in the welding arc, it reacts to oxidize most metals. Use in the automotive industry is common despite significant evidence that welds made in carbon dioxide are more brittle than those made in more inert atmospheres, and that such weld joints deteriorate over time because of the formation of carbonic acid. It is used as a welding gas primarily because it is much less expensive than more inert gases such as argon or helium. When used for MIG welding, CO₂ use is sometimes referred to as MAG welding, for Metal Active Gas, as CO₂ can react at these high temperatures. It tends to produce a hotter puddle than truly inert atmospheres, improving the flow characteristics. Although, this may be due to atmospheric reactions occurring at the puddle site. This is usually the opposite of the desired effect when welding, as it tends to embrittle the site, but may not be a problem for general mild steel welding, where ultimate ductility is not a major concern.

It is used in many consumer products that require pressurized gas because it is inexpensive and nonflammable, and because it undergoes a phase transition from gas to liquid at room temperature at an attainable pressure of approximately 60 bar (870 psi, 59 atm), allowing far more carbon dioxide to fit in a given container than otherwise would. Life jackets often contain canisters of pressured carbon dioxide for quick inflation. Aluminum capsules of CO₂ are also sold as supplies of compressed gas for airguns, paintball markers, inflating bicycle tires, and for making carbonated water. Rapid vaporization of liquid carbon dioxide is used for blasting in coal mines. High concentrations of carbon dioxide can also be used to kill pests. Liquid carbon dioxide is used in supercritical drying of some food products and technological materials, in the preparation of specimens for scanning electron microscopy and in the decaffeination of coffee beans.

 

[edit]Fire extinguisher

Carbon dioxide extinguishes flames, and some fire extinguishers, especially those designed for electrical fires, contain liquid carbon dioxide under pressure. Carbon dioxide extinguishers work well on small flammable liquid and electrical fires, but not on ordinary combustible fires, because although it excludes oxygen, it does not cool the burning substances significantly and when the carbon dioxide disperses they are free to catch fire upon exposure to atmospheric oxygen. Carbon dioxide has also been widely used as an extinguishing agent in fixed fire protection systems for local application of specific hazards and total flooding of a protected space.^[21] International Maritime Organization standards also recognize carbon dioxide systems for fire protection of ship holds and engine rooms. Carbon dioxide based fire protection systems have been linked to several deaths, because it can cause suffocation in sufficiently high concentrations. A review of CO₂systems identified 51 incidents between 1975 and the date of the report, causing 72 deaths and 145 injuries.^[22]

 

[edit]Supercritical CO₂ as solvent

See also: Supercritical carbon dioxide

Liquid carbon dioxide is a good solvent for many lipophilic organic compounds and is used to remove caffeine from coffee. Carbon dioxide has attracted attention in the pharmaceutical and other chemical processing industries as a less toxic alternative to more traditional solvents such as organochlorides. It is used by some dry cleaners for this reason (see green chemistry).

 

[edit]Agricultural and biological applications

Plants require carbon dioxide to conduct photosynthesis. Greenhouses may (if of large size, must) enrich their atmospheres with additional CO₂ to sustain and increase plant growth.^[23][24] Aphotosynthesis-related drop (by a factor less than two) in carbon dioxide concentration in a greenhouse compartment would kill green plants, or, at least, completely stop their growth. At very high concentrations (100 times atmospheric concentration, or greater), carbon dioxide can be toxic to animal life, so raising the concentration to 10,000 ppm (1%) or higher for several hours will eliminate pests such as whiteflies and spider mites in a greenhouse.^[25] Carbon dioxide is used in greenhouses as the main carbon source for Spirulina algae.

In medicine, up to 5% carbon dioxide (130 times atmospheric concentration) is added to oxygen for stimulation of breathing after apnea and to stabilize the O₂/CO₂ balance in blood.

It has been proposed that carbon dioxide from power generation be bubbled into ponds to grow algae that could then be converted into biodiesel fuel.^[26]

 

[edit]Oil recovery

Carbon dioxide is used in enhanced oil recovery where it is injected into or adjacent to producing oil wells, usually under supercritical conditions, when it becomes miscible with the oil. This approach can increase original oil recovery by reducing residual oil saturation by between 7 per cent to 23 per cent additional to primary extraction.^[27] It acts as both a pressurizing agent and, when dissolved into the underground crude oil, significantly reduces its viscosity, and changing surface chemistry enabling the oil to flow more rapidly through the reservoir to the removal well.^[28]In mature oil fields, extensive pipe networks are used to carry the carbon dioxide to the injection points.

 

[edit]Refrigerant

Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are employed during the transportation and storage of ice cream and other frozen foods. Solid carbon dioxide is called "dry ice" and is used for small shipments where refrigeration equipment is not practical. Solid carbon dioxide is always below −78.5 °C at regular atmospheric pressure, regardless of the air temperature.

Liquid carbon dioxide (industry nomenclature R744 or R-744) was used as a refrigerant prior to the discovery of R-12 and may enjoy a renaissance due to the fact that R134a contributes toclimate change. Its physical properties are highly favorable for cooling, refrigeration, and heating purposes, having a high volumetric cooling capacity. Due to its operation at pressures of up to 130bar (1880 psi), CO₂ systems require highly resistant components that have already been developed for mass production in many sectors. In automobile air conditioning, in more than 90% of all driving conditions for latitudes higher than 50°, R744 operates more efficiently than systems using R-134a. Its environmental advantages (GWP of 1, non-ozone depleting, non-toxic, non-flammable) could make it the future working fluid to replace current HFCs in cars, supermarkets, hot water heat pumps, among others. Coca-Cola has fielded CO₂-based beverage coolers and theU.S. Army is interested in CO₂ refrigeration and heating technology.^[29][30]

The global automobile industry is expected to decide on the next-generation refrigerant in car air conditioning. CO₂ is one discussed option.(see Sustainable automotive air conditioning)

[carlfense]

Cool stuff. Thanks Mavric.

 

I wonder how much it costs and/or how it will scale up?

[Mavric]

Cool stuff. Thanks Mavric.

 

I wonder how much it costs and/or how it will scale up?

I wonder the same. I'm sure retrofitting existing coal plants would have a huge price tag. If they get it to work large-scale, perhaps it can be included as plants are overhauled/replaced. Probably quite a ways down the road yet.

[sd'sker]

whenever i hear 'clean coal' i am highly skeptical. they have been promising clean coal for decades. i hope it is successful, because that will be great. i like to remain optimistic, but i will continue to hold my breath (get it? because smog).

[Mavric]

whenever i hear 'clean coal' i am highly skeptical. they have been promising clean coal for decades. i hope it is successful, because that will be great. i like to remain optimistic, but i will continue to hold my breath (get it? because smog).

True. But I think this is a totally different process. Previously, "clean coal" meant burning coal with fewer impurities and capturing as much as you can before it goes up the stack. They are now trying to get the energy out of the coal without burning it which apparently makes is much easier to capture the carbon dioxide and other by-products.

[sd'sker]

whenever i hear 'clean coal' i am highly skeptical. they have been promising clean coal for decades. i hope it is successful, because that will be great. i like to remain optimistic, but i will continue to hold my breath (get it? because smog).

True. But I think this is a totally different process. Previously, "clean coal" meant burning coal with fewer impurities and capturing as much as you can before it goes up the stack. They are now trying to get the energy out of the coal without burning it which apparently makes is much easier to capture the carbon dioxide and other by-products.

yeah, it is very exciting that they keep working on it. it seems like there must be a way to make coal cleaner. and you are right, this is an unique approach. it will be interesting to follow this development.