Chemical fixation of industrial desulfurization residues by forming an intimate admixture of the desulfurization residue, such as a flue gas desulfurization sludge, with an alkaline calcination stack dust, such as a cement kiln dust, in the presence of sufficient water to provide a mass of workable consistency, adjusting the pH of the alkaline mass with acid, such as sulfuric or phosphoric acid, to a value of below about 7, e.g. in the acid range of from below about pH 7 down to about pH 5, and drying the pH adjusted mass to constant weight, preferably after forming the pH adjusted mass into a selectively shaped article, whereby to produce an environmentally stable and leach-resistant hardened solid, cement-like fixed product.

Chemical fixation of desulfurization residues

Production of sodium bicarbonate by the Solvay-soda method, employing a volatile aliphatic amine instead of ammonia, is combined with the oxychlorination of olefins in liquid phase by using the amine hydrochloride side-product of the soda plant as chlorine source in the oxidative regeneration of the spent chlorinating liquid. The chlorinating liquid contains iodine and copper chloride or iron chloride and on regenerating the spent liquid the amine is recovered in the vapor phase and recycled to the soda plant.

Process for the combined manufacture of chlorinated hydrocarbons and sodium bicarbonate

Sodium hydroxide is formed from sodium sulphate by a three step operation comprising converting the sodium sulphate to sodium sulphide, converting the sodium sulphide to sodium bicarbonate, and converting the sodium bicarbonate to sodium hydroxide. The operations preferably are effected in conjunction with a bleached kraft pulp mill operation, so as to utilize by-product sodium sulphate from chlorine dioxide generation to produce useful sodium hydroxide as sulphur without co-producing chlorine.

Process of producing sodium hydroxide from sodium sulphate in a pulp mill

A process for producing chlorine from ammonium chloride which comprises vaporizing ammonium chloride, contacting the vapors with a metal selected from the group consisting of tin, zinc and cadmium whereby a metal chloride is formed and then electrolyzing the metal chloride in the presence of a fused salt electrolyte. The ammonium chloride is preferably obtained from the Solvay soda ash process and the process for producing chlorine is integrated with the Solvay process. The integrated process produces chlorine at a substantial energy savings and without calcium chloride being produced as a by-product.

Process for producing chlorine from ammonium chloride

The present invention consists of an absorption process with a chemical reaction to capture acid gases such as carbon dioxide, sulphur dioxide and nitrogen dioxide from the ambient air and from combustion gases from burners and internal combustion engines using fossil fuels; the aim of the invention being the acquisition of carbon credits in accordance with the "Kyoto protocol on climate change". The process is carried out in a horizontal spray absorber using an 8% solution of sodium hydroxide as absorption liquid, obtaining sodium carbonate, sodium sulphite, sodium nitrite and nitrate as byproducts. These byproducts are converted into commercial products such as calcium carbonate, barium sulphate and ammonium nitrate; for which purpose both the sodium sulphite and the sodium nitrite must previously be converted into sodium sulphate and nitrate by means of an oxidizing agent.

Process for the removal of acid gases from the air and from combustion gases from burners and internal combustion engines by means of absorption with sodium hydroxide solution and process for obtaining sodium carbonate in order to acquire carbon credits

The sodium sulfite obtained as a byproduct in the production of hydroxy aromatic compounds from aromatic hydrocarbons, sulfur trioxide and sodium hydroxide, is converted into sulfur trioxide and sodium hydroxide for recirculation of same in said production of hydroxy aromatic compounds, by a process wherein: (a) the sodium sulfite is reacted with zinc chloride to form sodium chloride and zinc sulfite; (b) the zinc sulfite is heated to form zinc oxide and sulfur dioxide and the sulfur dioxide is oxidized to sulfur trioxide; (c) the sodium chloride is reacted with ammonium bicarbonate to form ammonium chloride and sodium bicarbonate; (d) the zinc oxide is reacted with the ammonium chloride to form zinc chloride and ammonia; (e) the ammonia is reacted in the Solvay Process to form ammonium bicarbonate; and (f) the sodium bicarbonate is heated to form sodium carbonate and carbon dioxide, and the sodium carbonate is reacted with calcium oxide to form sodium hydroxide.

Matthias Thoma

Papers

Process for the conversion of sodium sulfite