Showing papers on "Sour gas published in 1978"

Representation of NH3-H2S-H2O, NH3-CO2-H2O, and NH3-SO2-H2O Vapor-Liquid Equilibria

Abstract: A new method of calculation of vapor-liquid equilibria for ammonia/hydrogen sulfide/water and ammonia/carbon dioxide/water at 0/sup 0/-100/sup 0/C at the concentrations encountered in refinery sour water strippers and for ammonia/sulfur dioxide/water as found in gas cleaning systems was developed. The model was based on the Edwards et al. thermodynamic approach.

Removal of ammonium sulfide from wastewater by liquid membrane process

Abstract: A novel separation, which is a combination of liquid membrane permeation and conventional steam stripping (called ''extripping'') was developed to remove ammonium sulfide from sour water. A water-in-oil emulsion system is dispersed in the wastewater, and the oil film serves as the liquid membrane through which permeation can occur from the wastewater into the small aqueous droplets within the emulsion drops. H/sub 2/SO/sub 4/ is used inside the emulsion droplets to neutralize and ionize every ammonia molecule permeating across. H/sub 2/S remains in the wastewater and can be removed by steam stripping. Laboratory experiments were conducted with aqueous solutions containing 1500-2000 ppm by wt each of NH/sub 3/ and H/sub 2/S. When extripping was used, only 7.5Vertical Bar3< of the NH/sub 3/ and 5Vertical Bar3< of the H/sub 2/S remained after 10 min. The removal of NH/sub 3/ and H/sub 2/S by permeation or steam stripping alone was much slower. In principle, this process is applicable to removal of any salt of a weak acid and a weak base from its aqueous solution.

Sulfur extraction method

Abstract: Circulating oil used for removal of sulfur in sour gas wells is contacted with an aqueous solution of a lower polysulfide of an alkali metal or ammonia to form a higher polysulfide of the alkali metal or ammonia, and the oil is separated from the higher polysulfide. The higher polysulfide is converted to lower polysulfide by precipitating part of the sulfur contained therein, and the lower polysulfide is recycled for oil desulfurization.

Process corrosion control: corrosion in amine/sour gas treating contactors

Abstract: Years of experience with Sulfinol units in sour-gas service and the results of numerous laboratory tests clearly indicate that rich Sulfinol is inherently not corrosive to carbon steel because of the formation of protective films on the metal surface after contact with the solution, reports Shell Development Co. Nevertheless, under conditions of flashing or boiling, significant corrosion can occur in Sulfinol contactors. Patterns recognized from a survey of corroded units relate the occurrence of corrosion to (1) a low carbon dioxide/hydrogen sulfide ratio in the rich Sulfinol leaving the contactor and (2) a concentration of carbon dioxide in the rich Sulfinol exiting the contactor in excess of that required for equilibrium with the feed gas. Processors can prevent corrosion either by modifying the process conditions to prevent the flashing or by installing Type 304 stainless steel cladding in the critical lower part of the contactor.

Steel of excellent sulfide resistance and excellent corrosion crack resistance

Abstract: PURPOSE: To raise the sulfide resistance, setree and corrosion crack resistance, and hydrogen embrittlement resistance of steel by adding alloying elements, e.g., Mn, Cu, Ni, and Cr in a proper combination to a low-alloy steel to be used in apparatus for sour gas or sour oil. CONSTITUTION: The low-alloy steel contains 0.03 to 0.18% C, 0.10 to 0.50% Si, 0.50 to 1.50% Mn, < 0.025% P, < 0.008% S, 0.20 to 1.00% Cu, 0.10 to 0.80% Ni, 0.20 to 1.00% Cr, and 0.01 to 0.10% sol. Al, and is used for the manufacture of apparatus for sour gas and sour oil. The inclusion of Mn, Cu, Ni, and Cr in the aforesaid amounts reduces the corrosion rate and hydrogen embrittlement of steel and also raises yield strength to 25 to 70 kg/mm 2 . COPYRIGHT: (C)1979,JPO&Japio

Exclusion area for safety from high-pressure sour gas leaks.

Abstract: A discussion of considerations necessary to the preparation of a safety program which can save lives when hydrogen sulfide leaks occur during the transportation of sour oil and gas covers hydrogen sulfide toxicity; conditions such as pressure and exit velocity of gas containing hydrogen sulfide and leaking from a split in a pipe or connection; calculation of the maximum dilution factor for the case in which the leak permits free expansion; calculation of the adiabatic cooling of the expanding gas stream; hazard increase through formation of a fog, which forms if the temperature of the leaked gas mixture falls below the dew-point temperature; density; calculation of maximum concentration downwind of a ground-level source; calculation of a safety exclusion radius for any desired hazard level; calculation of the area with a time-concentration exposure greater than that specified for safety; determination of the probability that any point within the exposure distance of a leak will receive the maximum calculated exposure value; other considerations such as terrain and weather; and other related work, including rule 36 of the Texas Railroad Commission regulations on sour gas.

GPA (Gas Processors Association) H/sub 2/S removal panel. 3. GPA panelist outlines Claus process improvements in sulfur recovery

Abstract: A discussion by L.V. Kunkel at the 57th Gas Processors Association Annual Convention (New Orleans 1978) covers factors which have resulted in improving the sulfur recovery to 98-99% in Claus units used for processing sour natural gas, particularly the need to meet EPA sulfur dioxide emission standards; variations in the Claus sulfur-recovery process with emphasis on the straight-through process and its advantages over the splt-flow process; variables affecting Claus losses (e.g., equilibrium at Claus catalyst output temperatures), the amount of catalyst, bypassing of catalysts, the ratio of hydrogen sulfide to sulfur dioxide, deficiencies and excesses of air; continuous monitoring to control the hydrocarbon and water content of acid-gases; the use of surveillance to keep sulfur recovery continuously high (e.g., by maintaining low, uniform acid-gas temperatures, by minimizing hydrocarbon content, and by using dual-range acid-gas and air-control meters); and means of determining per cent recovery. Tables and graphs.

Inhibition of steel corrosion in sour gas well environments containing sulfur and ethylamine

Abstract: In producing German sour-gas wells, it was discovered that the ethylamine solution used to remove solid sulfur from plugged tubing was causing severe corrosion in lower portions of the tubing and casing. Studies identified sulfur as a dominant factor in the corrosion reaction. In low sulfur concentrations, catastrophic corrosion rates of steel occur and hydrogen is produced; higher sulfur concentrations inhibit corrosion by causing the formation of a protective FeS/sub 2/ film with no hydrogen production. The addition of an amine-phosphate inhibitor effectively prevents pitting in areas where the protective film is mechanically damaged. Simulated tubing tests have shown that sulfur addition to ethylamine solutions will extend casing and tubing lifetimes well beyond previous failure times.