Low Hydrogen Sulfide Research Articles

Biological sulphate removal in an upflow packed bed reactor

Mine waters and industrial effluents with high sulphate concentrations create a disposal problem in terms of excess mineralization of surface waters. Removal of sulphate can be achieved by various processes including biological techniques, all of which involve appreciable costs. The purpose of this investigation was to improve on known biological methods for the removal of sulphate. Good sulphate removal was obtained by providing anaerobic conditions on a solid medium and maintaining a low hydrogen sulphide concentration by recirculating the water through a photosynthetic reactor for sulphur production.

Isolation and characterization of low hydrogen sulphide producing wine yeast

Variants of the wine yeast Saccharomyces cerevisiae var. montrachet no. 522 which retain more and excrete less hydrogen sulphide (H 2S) into the growth medium have been isolated and characterized. Wine produced using these low excretors has been found to contain less H 2S .

Removal of hydrogen sulfide from producer gas of shale-processing plants with the production of finished products

This article describes a method for the desulfurization of fuel gases produced in shale gasification with a low hydrogen sulfide to carbon dioxide ratio. The solution from the absorber is fed by a pump into vertical hollow regenerators with a diameter of 3m and a height of 40m for regeneration. The solution irrigates the absorber by gravity flow after passing through the regenerators upward from the bottom in cocurrent with air. The sulfur formed on regeneration of the solution is floated up by air and in the form of froth flows down into the froth collector, from which it runs into the drum vacuum filter. A part of the hydrogen sulfide trapped is oxidized to sodium thiosulfate during regeneration. The cleaned gases containing up to 600 ppm of hydrogen sulfide are used as fuels, and the removal of hydrogen sulfide from producer gas enables the tenfold reduction of sulfur dioxide emission into the atmosphere.

Thermodynamic Properties of Natural Gas, Petroleum Gas and Related Mixtures. Part I: Mixed Fluid Densities

AbstractThe present paper describes a method for very accurate correlation of mixed fluid densities of natural gas, petroleum gas and related mixtures, including low molecular weight hydrocarbons, nitrogen, carbon dioxide, carbon monoxide and hydrogen sulphide. The method is applicable for mixed fluid densities both on and off the saturation surface. The method is based on a statistical mechanical formulation of the principle of corresponding states using methane as the reference fluid. The overall agreement with known experimental densities is 0.1% for LNG and 0.2% for LPG.

Sulphur transformation and removal for Western Kentucky coals

Inhibition isotherms were measured for Western Kentucky No.9 coal. Crushed and sieved coal (−25 + 140 U.S. mesh) was fluidized in 10-g batches in a 22-mm i.d. quartz reactor up to a temperature of 870 °C. The release of hydrogen sulphide during heatup under nitrogen and at the run temperature (usually 1–2 h) under the same gas (pyrolysis), hydrogen, or hydrogen/hydrogen sulphide mixtures was followed by gas chromatography. The residue or char was analysed for pyritic, organic, sulphide, sulphate, and total sulphur. Inhibition isotherms, which are pseudo-equilibria between sulphur in the char and gaseous hydrogen sulphide, were measured at 600 and 870 °C. At the lower temperature the isotherm was found to be independent of the hydrogen sulphide concentration in the gas stream and the char sulphur content remained constant at 2.6%. At 870 °C the sulphur content of the char was greater than that of the original coal when gas mixtures of 1, 3, and 6% hydrogen sulphide in hydrogen were used, indicating the necessity of maintaining low hydrogen sulphide concentration for sulphur removal. In pure hydrogen, sulphur removal increased continuously from 47% at 600 °C to 84% at 870 °C. For pyrolysis under nitrogen, sulphur removal was 40% at 600 °C and increased to 59% at 740 °C. No further removal occurred above this temperature up to 870 °C. In addition to the inhibition isotherms, sulphur-form transformation diagrams were constructed for coal treated with nitrogen, hydrogen, and hydrogen/hydrogen sulphide mixtures. Pyritic sulphur, which comprised 40% of the sulphur in the original coal, was completely converted to ferrous sulphide at 600 °C in hydrogen and 740 °C in nitrogen. At 870 °C the sulphur content of the char produced under hydrogen was 1.1% made up of 48.4% ferrous sulphide, 43.4% organic sulphur, and 8.2% sulphate.

A fluorometric method for determining low concentrations of hydrogen sulphide in air

A fluorometric technique for the determination of low concentrations of hydrogen sulphide in air streams is described and possible limitations examined. The method is particularly suitable where accurate measurements of these low hydrogen sulphide concentrations are required in small air sample volumes. The reagent is a simple solution of fluorescein mercuric acetate (FMA—biochemical laboratory reagent grade), in dilute aqueous sodium hydroxide. Hydrogen sulphide reacts rapidly with the alkaline FMA solution, causing a quenching of fluorescence which is related in a definite way to the amount of hydrogen sulphide contained in the air stream. Reagent stability, overall precision and reproducibility of the method were found to be very satisfactory.