The United States of America as Represented by the United States

The United States of America as Represented by the Administrator of the

The United States of America as Represented by the United States Energy

The Scientific Ecology Group. Inc.

Dale L Keairns

Eoin P O'Neill

Wen-Ching Yang

Edward J Vidt

Thomas Stephen Snyder

John W Craig

An electrochemical leaching system for cleaning contaminated fines. The system has a waste vessel for receiving and holding a contaminated fines and lixiviant mixture. On a side of the waste vessel is an anolyte vessel holding an anolyte fluid. An anolyte barrier separates the waste and anolyte vessels. On an opposite side of the waste vessel is a catholyte vessel holding a catholyte fluid. A catholyte barrier separates the waste and catholyte vessels. A potential between an anode in the anolyte vessel and a cathode in the catholyte vessel ionizes the fines contaminants into anionic and cationic contaminants in the lixiviant. The anolyte and catholyte barriers allow the anionic and cationic contaminants, respectively, to flow from the lixiviant and into the anolyte and catholyte fluids in their respective vessels without allowing bulk transfer therebetween. The anionic and cationic contaminants are then removed from the anolyte and catholyte fluids. A cleaner lixiviant and fines exits the system.

Electrochemical leaching of soil

The sorbent capacity of calcium oxide with respect to sulfur dioxide is increased by calcining limestone or dolomite in an atmosphere where the partial pressure of carbon dioxide is greater than 40 percent of the equilibrium partial pressure of carbon dioxide over calcium carbonate at the reaction temperature. Where dolomite is the starting material, it may be calcined in a two-step heating process in which the atmosphere during the first heating stage contains carbon dioxide and the temperature is maintained in the dissociation range of magnesium carbonate (M.sub.g CO.sub.3); the atmosphere of the second heating stage also contains carbon dioxide, but the temperature is maintained in the calcium carbonate (CaCO.sub.3) dissociation range. Calcium oxide so produced in such an atmosphere of carbon dioxide sufficient to delay calcination is found to have relatively large mouthed pores capable of sorbing increased amounts of sulfur.

Activation of calcium oxide as a sorbent

A distribution plate for a recirculating fluidized bed has a centrally disposed opening and a plurality of apertures adjacent the periphery to eliminate dead spots within the bed.

Distribution plate for recirculating fluidized bed

The disclosed process provides for the production of a desulfurized fuel gas from a sulfur-containing fuel oil by absorption, in a first reaction zone, of the sulfur contaminants with a calcium oxide-containing material, which material is then further treated to render it environmentally stable without producing a sulfur-rich gas process stream. The spent limestone from the oil gasifier is reacted with an oxygen-containing gas in a second reaction zone for conversion of the calcium sulfide to calcium sulfate and the sulfated material is then transferred to a third reaction zone wherein it is reacted with carbon dioxide for conversion of the calcium oxide to calcium carbonate.

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Pittsburgh, PA, United States of America

Dale L Keairns