Showing papers on "Sour gas published in 1986"

A continuous process for recovery of sulfur from natural gas containing low concentrations of hydrogen sulfide

Abstract: A continuous catalytic process was developed to remove hydrogen sulfide from a natural gas stream using activated carbon as catalyst. The concentration range of hydrogen sulfide in the gas stream studied was 300–3000 ppmv (0.0126–0.126 moles/m3). Virtually 100 percent conversion of hydrogen sulfide was achieved by the combination of various parameters. The “field gas” employed in this study exhibited cracking of some heavier hydrocarbons and made the product sulfur slightly brown. These hydrocarbons should therefore be separated from the gas stream prior to the oxidation reaction. No carbon monoxide or carbon dioxide was produced during the oxidation of hydrogen sulfide. It is concluded that the process described herein has the potential for the removal of hydrogen sulfide as sulfur from a sour natural gas stream on a continuous basis and could therefore eliminate an environmental problem which now exists. On a developpe un procede catalytique continu utilisant du carbone active comme catalyseur pour la separation de l'hydrogene sulfure d'une alimentation de gaz naturel. La gamme de concentration de l'hydrogene sulfure dans le debit de gaz etudie est de 300–3000 ppmv (0,0126–0,126 mole/m3). Une conversion quasiment a 100% de l'hydrogene sulfure a ete realisee grǎce a la combinaison de differentes parametres. Dans le gas brut utilise dans cette etude on a observe le craquage de certains hydrocarbures lourds, ce qui a conduit a une coloration legerement brunǎtre du soufre produit. Ces hydrocarbures devraient par consequent ětre separes du courant de gaz prealablement a la reaction d'oxydation. Aucun monooxyde de carbone ou gaz carbonique n'a ete produit au cours de l'oxydation de l'hydrogene sulfure. On a conclu que le precede decrit ici presente de bonnes possibilites pour l'elimination de l'hydrogene sulfure et la production de soufre d'un courant de gaz naturel acide de maniere continue et qu'il pourrait par consequent eliminer un probleme environnemental actuel.

Method of preventing precipitation of ferrous sulfide and sulfur during acidizing

Abstract: An improved method of acidizing sour gas wells involving the injection of an aqueous acidizing solution comprising: water, an acid, an effective amount of an iron complexing agent (e.g., EDTA) capable of stabilizing the ferrous, Fe(II), ion in solution in the presence of H 2 S and an effective amount of an iron reducing agent (e.g., erythorbic acid, ascorbic acid and mixtures thereof) capable of reducing the ferric, Fe(III), ion in solution to ferrous Fe(II), ion at a pH of about 6.0 or less. Such a process is effective in reducing and inhibiting the precipitation of Fe(OH) 3 , FeS and S in sour wells.

Design & Operation of a Selective Sweetening Plant Using MDEA

Abstract: The Signalta Resources Forestburg Gas Plant was constructed during the winter of 1983 and placed on stream in April of 1984. A design outlet gas specification of 1/4 grain H/sub 2/S/100 scf was requested to ensure meeting the contract commitment of 1 grain/100 scf. The design gas flowrate was 30 MMSCFD containing 0.5% H/sub 2/S and 3% CO/sub 2/ at 415 psia and 70/sup 0/F. The overall plant is configured as shown in Figure 1. Inlet separation facilities are followed by a feed gas heater. The gas stream then flows through a filter separator followed by the amine contactor. Another filter separator is used as a sweet gas scrubber. After sweetening, the gas is routed to a dew point control refrigeration unit. Finally, a single stage of compression is required to boost the gas to 1200 psig maximum pipeline pressure. The sweetening chemical selected for the Forestburg Plant was methyldiethanolamine (MDEA). This was chosen due to its capability to remove H/sub 2/S and leave a portion of the CO/sub 2/ in the residue gas. At the time of plant commissioning it was one of the first operating MDEA facilities in Western Canada.

Process for the removal of H2 S from fluid streams using a water soluble polymeric chelate of an oxidizing polyvalent metal

Abstract: The present invention relates to a cyclic continuous process and a composition for the removal of hydrogen sulfide from a variety of sour gas streams. The sour gas stream is contacted with an aqueous solution of a water-soluble organic polymeric chelate containing an oxidizing polyvalent metal, e.g., Fe(III). The sulfur in the hydrogen sulfide is converted to elemental sulfur and the iron in the polymeric chelate is reduced. The process includes removal of the elemental sulfur, and an inexpensive method for removing water and excess low molecular weight materials, e.g., materials having molecular weights below 500, preferably using ultrafiltration or dialysis, regeneration and recycle of the reactive polyvalent metal.

Some Observations on the Corrosion of Carbon Steel in Sour Gas Environments: Effects of H2S and H2S/CO2/CH4/C3H8 Mixtures

Abstract: Experimental results and analyses on the corrosion of carbon steel in simulated aqueous sour gas environments are reported. Tests were performed at temperatures and pressures up to 95 C (2...

Apparatus for removing sulfur from organic polysulfides

Abstract: Sulfur-laden liquid organic phase dimethyl polysulfide (DMPS) is caused to rise from a sour gas well by reaction of the gaseous sulfur component within the well with a sulfur solvent, typically dimethyl disulfide (DMDS). The DMPS is contacted by an extraction or stripping liquid in a vertical column continuous multistage countercurrent flow extractor especially designed to promote high interfacial area contact between the liquids while flowing in opposing directions within the column.

Processes and oxidizing agents for oxidizing sulfide ion to innocuous, soluble sulfur species

Abstract: Processes and oxidizing agents for oxidizing sulfide ion found in sour water to innocuous, soluble sulfur species are provided. The processes basically comprise contacting the sour water with a nitrogen halogenated triazine or a nitrogen halogenated derivative thereof for a period of time sufficient to convert the sulfide ion to sulfate ion. The processes are particularly useful for removing sulfide ion from oil field produced waters, particularly waters associated with secondary recovery or enhanced oil recovery operations.

Catalytic process for producing sulphur from H2 S containing sour gas

Abstract: Catalytic process for producing sulphur from H2S-containing acid gas wherein the acid gas is subjected to a catalytic oxidation (1) in CLAUS stoechiometry and to a catalytic CLAUS reaction phase (2a) with deposition of sulphur on the catalyst with periodic regeneration (2b) of the sulphur-laden catalyst and cooling of the regenerated catalyst. The gas used for the regeneration and for the cooling is tapped (33) from the acid gas (7) supplied to the catalytic oxidation (1) and the gas issued from the regeneration is reintroduced (27) into said acid gas after separation (26) of the sulphur contained therein. Application for treating acid gases having a low H2S content.

Removal of hydrogen sulfide from air streams

Abstract: In a process for removing hydrogen sulfide from an oxygen-containing gas stream by passing said gas stream through activated carbon, said stream containing from about 5 ppm to about 10,000 ppm by volume, which comprises adding ammonia to said stream prior to its passage through the carbon, improvement in which the amount of added ammonia is such that its concentration will be at least equal to the concentration of the hydrogen sulfide and not greater than 10,000 ppm with the proviso that when the concentration of hydrogen sulfide exceeds 4,000 ppm by volume, the concentration of the ammonia will not be greater than 6,000 ppm by volume.

Process for removal of hydrogen sulfide from gases.

Abstract: not available for EP0199815Abstract of corresponding document: WO8602628Two stage removal of hydrogen sulfide from a gas. In the first stage solutions of hydrogen sulfide and sulfur dioxide in a solvent react to produce sulfur and water. An excess of hydrogen sulfide is maintained in the first stage resulting in a solution containing sulfur, water and the excess hydrogen sulfide, or resulting in a gas containing the excess hydrogen sulfide. The excess hydrogen sulfide in the solution or in the gas is then treated in a second stage with a solution in the same solvent of sulfur dioxide in excess of or closely equal to that required to react with the hydrogen sulfide. Excess sulfur dioxide in the vapor phase from the second stage may be absorbed in neat solvent. The solvent is selected to have a high solvating power for sulfur dioxide, a lesser but substantial solvating power for hydrogen sulfide and to promote the reaction of hydrogen sulfide with sulfur dioxide. Such gases as natural gas, synthesis gas, and the tail gas of a claus plant may be so treated. By appropriate selection of solvents and/or conditions, accompanying minor components of the gas stream being treated may be removed and recovered if of value, e.g., propane from natural gas, carbon dioxide and water from synthesis gas, etc. The process avoids the need to maintain exact stoichiometric ratios of hydrogen sulfide and sulfur dioxide, it avoids the need to use high flow rates of solvent, a liquid phase capacitance for hydrogen sulfide is provided which dampens the effect of fluctuations in hydrogen sulfide content in the gas stream, etc.

Examination of Field Data From a New Gas Sweetening Process

Abstract: A new patented sour gas sweetening process was introduced to the gas processing industry in September 1984. This process consists of bubbling sour gas through a tower filled with a proprietary formulation, an alkaline aqueous solution of an anionic oxidizing agent. The toxic hydrogen sulfide is selectively removed from the sour gas and dissolved sulfides are converted to nonhazardous sulfur by the sweetening solution in the tower. The process is generally operated at ambient temperatures. The spent slurry from this batch process has been classified as a nonhazardous waste by the U.S. Environmental Protection Agency, fourteen state agencies, and the U.K. Department of Energy. The process was initially field tested at various locations in California in cooperation with major gas producers. More than 100 units are now operating in the United States and Canada. The hydrogen sulfide concentrations of sour gases treated with this process range from as low as 10 ppm to more than 20 percent; the operating pressures range between near atmospheric to greater than 1000 psig. The largest unit processes 16 MMscf/d sour gas using one tower at 1035 psig and the smallest unit handles 8 to 10 Mscf/d gas containing greater than 20 percent hydrogen sulfide.more » This paper presents: 1. Detailed field data for over 100 operating units; 2. A description of the chemistry of the process; 3. Comparative kinetic data on several hydrogen sulfide scavengers used in other batch processes; and 4. Defines factors utilized in the design of improved towers used for this gas sweetening process based on the experience gained in the field.« less

Materials failures in sour gas service

Abstract: Three analyses of materials failures in sour gas service are reviewed: the failures include stress corrosion cracking (SCC) of a duplex stainless steel (SS) wireline; sulfide stress cracking (SSC) of moderate hardness L-80 casing, and SSC of two forged carbon steel, gathering system fittings. The failures demonstrate the significant effects of stress level, environmental aggressiveness, and localized hard zones in promoting SCC and SSC.

High-strengh austenitic stainless steel for welding construction having superior sour resistance

Abstract: PURPOSE:To improve corrosion resistance in a weld zone as well as sour resistance by limiting the content of Ni, N, and further Nb in austenitic stainless steel to a specific range. CONSTITUTION:As material for apparatus used in the development drilling of sour oil and sour gas containing acid gas such as gaseous H2S, CO2, or the like, the chemical composition of the austenitic stainless steel containing, by weight, 0.05-0.10% C 0.10-30% Si, 2.0-4.0% Mn, 15-17% Cr, 6-11% Ni, 2-4% Mo, 0.05-0.25% V, and 0.05-0.18% N is regulated so that general expression (1) is satisfied when (Cr equivalent)=%Cr+%Mo+1.5%Si+0.5%Nb and (Ni equivalent)=%Ni=30%C+30%N+0.5%Mn. The high-strength austenitic stainless steel for welding construction combining corrosion resistance with yield strength and excelling in sour resistance can be obtained.

Zirconium-steel Bimetallic tubing for improved sour gas corrosion resistance in oil and gas wells. Discussion

Abstract: Bimetallic tubing with corrosion resistant liner material has been developed for sour gas well applications where conventional carbon steel tubes have serious corrosion problems. The present project deals with the tubing consisting of 4130 steel outer wall and zirconium liner. The manufacturing process starts with an assembled billet. To enhance the bonding between layers, either an interlayer copper or an explosive bonding technique may be used for the billet preparation. The billet is hot extruded and then tube reduced to the final size. The final tube can be heat treated and water quenched to meet the requirements of the oil field tubular products. Tests show that the bonding between layers achieved by explosive bonding and extrusion is excellent. A section of the tube with zirconium liner exposed to a brine solution saturated with hydrogen sulfide (H 2 S) under a pressure of 1.72 MPa (250 psi) and a temperature of 493 K for 1368 h showed no sign of corrosion attack by the medium. Other corrosion and stress corrosion tests for zirconium also showed excellent results.

Zirconium-Steel Bimetallic Tubing for Improved Sour Gas Corrosion Resistance in Oil and Gas Wells

Abstract: Bimetallic tubing with corrosion resistant liner material has been developed for sour gas well applications where conventional carbon steel tubes have serious corrosion problems. The present project deals with the tubing consisting of 4130 steel outer wall and zirconium liner. The manufacturing process starts with an assembled billet. To enhance the bonding between layers, either an interlayer copper or an explosive bonding technique may be used for the billet preparation. The billet is hot extruded and then tube reduced to the final size. The final tube can be heat treated and water quenched to meet the requirements of the oil field tubular products. Tests show that the bonding between layers achieved by explosive bonding and extrusion is excellent. A section of the tube with zirconium liner exposed to a brine solution saturated with hydrogen sulfide (H 2 S) under a pressure of 1.72 MPa (250 psi) and a temperature of 493 K for 1368 h showed no sign of corrosion attack by the medium. Other corrosion and stress corrosion tests for zirconium also showed excellent results.

Vent gas treatment

Abstract: PURPOSE:To make the amount of gaseous H2S to be discharged nothing in the treatment of a sour gas by circulating a vent gas stripped from a stripping column to a suction drum. CONSTITUTION:A sour gas 1 is risen in pressure with a compressor 3 via a suction drum 2 and countercurrently brought into contact with a lean glycol soln. 9 in a glycol absorption tower 7 to remove H2S and water content. A riched glycol soln. 10 drawn out from a bottom of the absorption tower 7 is supplied to a stripping column 12 and regenerated with the vapor fed from a reboiler 13. A vent gas 15 produced in this time is recirculated to the suction drum 2 with a vent gas blower 22 and the amount of H2S to be discharged is made to nothing.