The Dow Chemical Company

Structured Nano Carbon LLC

Larry H Kirby

Stephen A Bedell

Van A Kent

Thomas Frank Bailey

William R Behr

Dane Chang

Richard D Varjian

Charles A Hammond

Aubrey J Rhymes, Jr

Susan S Tsai

Danny Cross

Roberto A Abib

Charles Danny Cross

Alloys, emf attenuation materials or emf reception materials, materials for biotechnology or biomedical materials, and materials for toxin and heavy metal removal, each containing a newly discovered allotrope of carbon having a multilayered nanocarbon array, and which exhibits, among other properties, exceptional stability, electrical conductivity and electromagnetic frequency (emf) attenuation characteristics. Members of this new allotrope include nanocarbon structures possessing vast electron delocalization in multiple directions, unavailable to known fullerene-characterized materials like carbon nano-onions (CNOs), multiwalled carbon nanotubes (MWNTs), graphene, carbon nano-horns, and carbon nano-ellipsoids. Such stabilizing electron delocalization crosses or proceeds between layers, as well as along layers, in multiple directions within a continuous cyclic structure having an advanced interlayer connectivity bonding system involving the whole carbon array, apart from incidental defects.

Allotrope of carbon having increased electron delocalization

Newly discovered allotrope of carbon having a multilayered nanocarbon array exhibits among other properties exceptional stability, electrical conductivity and electromagnetic frequency (emf) attenuation characteristics. Members of this new allotrope include nanocarbon structures possessing vast electron delocalization in multiple directions unavailable to known fullerene-characterized materials like carbon nano-onions (CNOs), multiwalled carbon nano-tubes (MWNTs), graphene, carbon nano-horns, and carbon nano-ellipsoids such that stabilizing electron delocalization crosses or proceeds between layers as well as along layers in multiple directions within a continuous cyclic structure having an advanced interlayer connectivity bonding system involving the whole carbon array apart from incidental defects.

The simultaneous abatement of NO and SO.sub.2 in flue gas is provided by an absorption process and apparatus utilizing an absorbent composition comprising an aqueous solution of chelates and sulfite salt for NO abatement and amine SO.sub.2 absorbents such as piperazinones, morpholinones, piperidines, piperazines, piperazinediones, hydantoins, triazinones, pyrimidinones, oxazolidones, etc. for SO.sub.2 abatement. SO.sub.2 is thermally stripped from the spent absorbent and recovered. Metal chelates oxidized to an inactive state as a side-reaction are electrochemically reduced. An anionic exchange membrane in the electrochemical cell regenerates heat stable amine salt byproducts to be converted back to useable amine sorbent, and facilitates removal from the absorbent solution of other waste salts.

Method for simultaneous absorption of sulfur dioxide and nitric oxide

The simultaneous abatement of NO and SO.sub.2 in flue gas is provided by an absorption process and apparatus utilizing an absorbent composition comprising an aqueous solution of chelates and sulfite salts. Metal chelates oxidized to an inactive state are electrochemically reduced. In the electrochemical cell, nickel or stainless steel anode materials are stable and may be used in the place of platinum coated anode materials when the anolyte pH is maintained greater than 12. At these conditions, the anode is corrosion resistant with a long operating time between replacement. Ultrafiltration or Donnan dialysis may be used to separate the chelate sorbents from the waste salts to reduce the loss of expensive chelate sorbents. Alternatively, an anionic exchange membrane can be used to electrodialytically separate waste sulfur/nitrogen salts from the absorbent solution.

Process for absorption of sulfur dioxide and nitric oxide from flue gas

A process for abating hydrogen sulfide during geothermal steam stacking operations is disclosed. The geothermal steam to be stacked is introduced into a geothermal steam stacking line. Ferric chelating solution is injected into the stacking line in an amount effective to convert the hydrogen sulfide in the steam to sulfur. The hydrogen sulfide-abated steam and chelating solution is vented through a rock muffler and the chelating solution is optionally recovered from the muffler, regenerated and recirculated to the injection step.

H.sub.2 S abatement in geothermal steam during stacking operations

Geothermal steam is condensed with a sulfite solution to abate hydrogen sulfide. A portion of the hydrogen sulfide is converted in the condensation in the presence of soluble cationic polymeric catalysts to soluble sulfur compounds while avoiding elemental sulfur and carbonate formation. The remainder of the hydrogen sulfide is incinerated and the sulfur dioxide in the incinerator effluent is absorbed in an alkaline solution to form the sulfites for the geothermal steam condensation. By maintaining stoichiometric ratios, the hydrogen sulfide is substantially converted to soluble thiosulfate without the use of chelates, peroxides or makeup sulfites.

Removal of hydrogen sulfide with on site generated sulfite from

Gas feed streams containing sulfur dioxide such as flue gas streams are first contacted with an aqueous solution of inorganic sulfites and bisulfites having a pH range from about 2 to about 6.5 to remove a minor amount of sulfur dioxide. The same gas stream is then contact with a second aqueous solution of sulfites and bisulfites having a pH range from about 7.0 to about 12.5. Alkali metal hydroxide or ammonium hydroxide solution is added to the liquid inlet of the second contactor and the solution of the second contactor is pumped to the liquid inlet of the first contactor.

Process for selectively removing sulfur dioxide

Fluid streams containing hydrogen sulfide from a steam tubine or from a sour gas stream are contacted with an aqueous solution of a polyvalent metal chelate and a bisulfite whereby the hydrogen sulfide is converted to free sulfur and then to soluble sulfur compounds. The metal chelate is reduced to a lower oxidation state metal chelate and reduced metal chelate is subsequently oxidized with air back to the higher oxidation state and reused. The bisulfite is formed by combustion of a portion of the fluid stream and subsequent absorption of the sulfur dioxide formed thereby in a two-stage countercurrent scrubber operating at conditions favorable for high bisulfite and low sulfite formation and selective away from carbon dioxide absorption.

Removal of hydrogen sulfide from fluid streams with minimum production

Hydrogen sulfide is removed from gas streams containing it with or without carbon dioxide by contacting the gas feed stream with an aqueous liquid containing sulfide and bisulfide ions and having a pH in the range from 9 to 12 to remove a minor portion of the hydrogen sulfide and then removing the remainder with an aqueous liquid containing sulfide and bisulfide ions having a higher pH in the range from 11 to 13.5.

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Lake Jackson, TX, United States of America

Larry H Kirby