Showing papers on "Sodium sulfide published in 1975"

Desulfurization and hydroconversion of residua with sodium hydride and hydrogen

Abstract: Sulfur-containing petroleum oil feedstocks which include heavy constituents undergo both desulfurization and hydroconversion by contacting such feedstocks with sodium hydride in the presence of hydrogen, at elevated temperatures. The mixture of reaction products resulting from the above procedure can be separated to give a petroleum oil product which has been desulfurized and demetallized and has a reduced Conradson carbon content and an increased API gravity relative to the feedstock, and a by-product of sodium sulfide salt.

Process for recovering chemicals from the waste liquors of sulfate cellulose digestion and the waste waters of bleaching

Abstract: A process for the recovery of chemicals from the waste liquors of sulfate cellulose digestion and from the waste waters of bleaching, wherein a melt from a soda-ash roaster, mainly containing sodium sulfide and sodium carbonate, but also sodium chloride, is dissolved and clarified to produce green liquor containing carbonate, sulfide and chlorides is dissolved. The carbonate is separated from the sulfide and the chlorides, at least part of the sodium chloride is separated from the sulfide in solution, at least part of the carbonate is causticized into hydroxide, and the hydroxide and sulfide in solutions is mixed together in a ratio suitable to form a digestion solution with a desired sulfide content.

Residua desulfurization with sodium oxide and hydrogen

Abstract: Heavy petroleum oils, preferably whole crude or residua, are desulfurized and upgraded by contacting the petroleum oil with sodium oxide in the presence of hydrogen at elevated temperatures. The resulting mixture comprising desulfurized petroleum oil and a dispersion of sodium salts, primarily sodium sulfide and sodium hydroxide, is separated by conventional means and sodium oxide is regenerated from the salts.

Synthesis of 2-mercaptothieno[3,2-d]- and 2-mercaptobenzo[4, 5]thieno[2,3-d]thiazoles

Abstract: 2-Mercaptothieno[3,2-d]- and 2-mercaptobenzo[4, 5]thieno[2,3-d]thiazoles were synthesized by reduction of bis(3,3′-nitro-2,2′-thienyl) and bis(2,2′-nitrobenzo[b]thien-3,3′-yl) disulfides, respectively, with sodium hydrosulfite or sodium sulfide in the presence of carbon disulfide.

Properties of sodium sulfide : sodium carbonate melts

Abstract: Modern chemical technology is an extremely efficient tool for solving problems particularly in a complicated environment such as the pulp and paper industry Here, examples are studied during which chemical technology is of fundamental importanceAt normal conditions the molten salt mixture from the kraft recovery boiler flows down into the dissolving tank without hindrance However, for certain kraft recovery boiler alternatives, knowledge of more precise data of the molten salts is required The viscosity for the case of sodium carbonate and 30 mole% sulphide has been measured and is of the magnitude 2 – 3 cP at relevant temperaturesThe main input of non-process elements (NPE) is down to the wood, and known problems include deposits in evaporators and decreasing efficiency in the causticization department Green liquor clarification is an efficient kidney for many NPE Magnesium added in the oxygen delignification does not form a closed loopIntegration of a prehydrolysis kraft pulp mill producing dissolving pulp with a plant producing viscose textile fiber could be of significant interest, as the handling of both alkali and sulphuric compounds can be integrated Problems will however arise as the capacity of the pulping line and the chemical recovery has to be adjusted