Abstract: A process for recovering the calcium values and sulfide values from a calcium sulfide-containing material is disclosed. The calcium sulfide-containing material dispersed in an aqueous medium is digested in the presence of hydrogen sulfide under conditions to provide a mole ratio of S.sup.-.sup.-/Ca.sup.+.sup.+ of between 1.5 and 2.0. After filtration to remove undissolved solids, the mother liquor is stripped with an inert gaseous medium, e.g. nitrogen, steam, etc., whereby hydrogen sulfide is stripped therefrom with the concomitant formation of calcium hydroxide which is subsequently separated by filtration. The gaseous overhead from the stripping operations may be fractionated to form a recycleable hydrogen sulfide-containing stream.

Abstract: A cooling tower with a plurality of radially extending circumferentially spaced tubular heat exchanger units having their heat exchanger surfaces in vertical planes, preferably upwardly and outwardly inclined vertical planes, with the radial outer end of each unit having a greater width (in the vertical direction) than the radial inner end of each unit.

Abstract: An air cooled exchanger is provided with a plurality of individual wind screens which are disposed to prevent wind from entering the exchanger, without adversely affecting normal cooling air flow. The load of the wind screens is carried by the exchanger; in particular, the tube frame.

Abstract: This disclosure teaches a direct fired heater with a double casing. The double casing includes a somewhat conventional inner casing having a burner penetrating therethrough and an outer casing spaced from the inner casing to form a passage in flow communication between the atmosphere and the burner. The outer casing surrounds the burner and is provided with an acoustic inner surface to minimize escape of noise. Design of refractory linings with respect to thickness and density allows for maintenance of skin temperature of the inner casing above the condensation ranges of SO.sub.2 and SO.sub.3.

Abstract: Acetaldehyde is produced from ethane by contacting ethane in the absence of added chlorine or hydrogen chloride with a molten mixture of the higher and lower valent form of a multivalent metal chloride and the oxychloride of the metal, such as a mixture of cuprous chloride, cupric chloride and copper oxychloride, in the presence of ethylene and ethyl chloride and optionally also vinyl chloride. Acetaldehyde is produced with no net production of ethyl chloride and ethylene, and if vinyl chloride is present, no net production of vinyl chloride.

Abstract: Process for producing vinyl chloride from ethane by contacting, in a first reactor, ethane and chlorine and/or hydrogen chloride, as fresh feed, and as recycle, hydrogen chloride, ethyl chloride, ethylene and unconverted ethane with a molten mixture, including cuprous chloride, cupric chloride and copper oxychloride, to produce a reaction effluent including vinyl chloride, dichloroethane, primarily 1,2-dichloroethane, and the aforementioned recycle components. The vinyl chloride is recovered as product, the recycle components are recovered and recycled to the first reactor, and the 1,2-dichloroethane is recovered and recycled to the first reactor or contacted in a second reactor with a molten mixture including cuprous and cupric chloride to dehydrochlorinate the 1,2-dichloroethane to vinyl chloride.

Abstract: Olefinic halides are produced by catalytic dehydrohalogenation of the corresponding saturated halide by direct contact thereof with a melt containing a multivalent metal halide in its higher and lower valence state. In particular, 1,2-dichloroethane is dehydrochlorinated to vinyl chloride by contacting thereof with a molten salt mixture of cuprous and cupric chloride at high per pass conversion and high vinyl chloride selectivity.

Abstract: Coke is desulfurized by calcining coke at a temperature of 1600.degree. - 2200.degree. F. in admixture with sodium carbonate, followed by direct contact with phosgene or a mixture of carbon monoxide and chlorine at a temperature of 1200.degree. - 1800.degree. F. to produce coke having sulfur contents of less than 0.5 percent.

Abstract: Coal is hydroliquefied with the hydrogen consumption being limited to that required for effective liquefaction and/or deashing. Ash is removed and the liquid coal product hydrotreated in a second stage to produce synthetic crude.

Abstract: Anhydrides of carboxylic acids, more particularly, of aromatic, naphthenic and saturated aliphatic acids having at least one pair of carboxyl groups attached to adjacent carbon atoms, can be prepared by thermal decomposition of amine salts of the acids, with removal of the amine. The amine salts may be produced by aqueous hydrolysis of the corresponding nitriles, imides, or amides in the presence of an amine, or by hydrolysis to the ammonium salts followed by conversion to the amine salt by stripping off ammonia in the presence of an amine.