Науково-технологічні рішення щодо скорочення баластних солей при очищенні коксового газу.

The coke plant at the Sparrows Point Plant consist of three coke oven batteries and two coal chemical plants. The by-product coke oven gas (COG) consists primarily of hydrogen, methane, carbon monoxide, nitrogen and contaminants consisting of tars, light oils (benzene, toluene, and xylene) hydrogen sulfide, ammonia, water vapor and other hydrocarbons. This raw coke oven gas needs to be cleaned of most of its contaminants before it can be used as a fuel at other operations at the Sparrows Point Plant. In response to environmental concerns, BSC decided to replace much of the existing coke oven gas treatment facilities in the two coal chemical Plants (A and B) with a group of technologies consisting of: Secondary Cooling of the Coke oven Gas; Hydrogen Sulfide Removal; Ammonia Removal; Deacification of Acid Gases Removed; Ammonia Distillation and Destruction; and, Sulfur Recovery. This combination of technologies will replace the existing ammonia removal system, the final coolers, hydrogen sulfide removal system and the sulfur recovery system. The existing wastewater treatment, tar recovery and one of the three light oil recovery systems will continue to be used to support the new innovative combination of COG treatment technologies.

In the production of coke, substantial volumes of effluent are generated from a liquid redox desulfurization plant of coke oven gas. The effluent typically contains NH4SCN and (NH4) 2S2O3 in high concentrations, and has generally been converted into H2SO4, (NH4) 2SO4 or CaSO4·2H2O by means of burning or wet oxygen oxidation under severe conditions.A method was developed for production of NH4SO3NH2 from the effluent.1. The effluent is treated with wet oxygen oxidation under mild neutral conditions where (NH4) 2S2O3 is selectively oxidized to NH4SO3NH2 and (NH4) 2SO4. The ratio of NH4SO3NH2 to (NH4) 2SO4 is changed with the concentration of NH3 and S2O32-.2. The resulting solution is oxidized again under more intensive conditions to transform NH4SCN into (NH4) 2SO4.3. After the oxidation of effluent, the solution is concentrated to saturation point of NH4SO3NH2 under reduced pressure at 70-80t in order to crystallize (NH4) 2SO4. The crystallized (NH4) 2SO4 is filtered and washed with water at the same temperature.4. The filtrate is cooled to crystallize NH4SO3NH2, which is separated by filtration.5. The purity of NH4SO3NH2 obtained is about 97%, and the recovery is about 98%. This process affords a commercial procedure for the preparation of NH4SO3NH2 from the desulfurization effluent.

Coke oven gas is one of by-products generated in the process of dry distillation of coal to form coke. The coke oven gas is of high value in used as not only energy but also chemical material, but it contains hydrogen sulfide（H2S）gas which limits its application. Thus, it is necessary to remove H2S from the coke oven gas in order to use it as energy or chemical material. The thermodynamic analysis is helpful to explain the adsorption of H2S on modified activated carbon. So this study examined the thermodynamic properties of adsorption of H2S on the activated carbon impregnated with 7% NaCO3, which was determined by the early experimental results of modification of activated carbon. The thermodynamic properties including H2S adsorption isotherms and adsorption heat of H2S on modified activated carbon were separately ascertained at 20～95°C through measuring the adsorption capability of H2S on the modified activated carbon. The results showed the adsorption data were correlated with the Freundlich-type isotherm equation. Thermodynamic calculation and analysis also showed that the adsorption of H2S on the modified activated carbon was physical adsorption at 20～70°C and chemical adsorption at 70～95°C. In addition, with the improvement of reaction temperature, the adsorption capacity of modified activated carbon was decreasing initially then increasing, because of the transition from physical adsorption to chemical adsorption.

There are two dominant and contrasting classes of origin of life scenarios: those predicting that life emerged in submarine hydrothermal systems, where chemical disequilibrium can provide an energy source for nascent life; and those predicting that life emerged within subaerial environments, where UV catalysis of reactions may occur to form the building blocks of life. Here, we describe a prebiotically plausible environment that draws on the strengths of both scenarios: surface hydrothermal vents. We show how key feedstock molecules for prebiotic chemistry can be produced in abundance in shallow and surficial hydrothermal systems. We calculate the chemistry of volcanic gases feeding these vents over a range of pressures and basalt C/N/O contents. If ultra-reducing carbon-rich nitrogen-rich gases interact with subsurface water at a volcanic vent they result in – concentrations of diacetylene (C4H2), acetylene (C2H2), cyanoacetylene (HC3N), hydrogen cyanide (HCN), bisulfite (likely in the form of salts containing HSO3−), hydrogen sulfide (HS−) and soluble iron in vent water. One key feedstock molecule, cyanamide (CH2N2), is not formed in significant quantities within this scenario, suggesting that it may need to be delivered exogenously, or formed from hydrogen cyanide either via organometallic compounds, or by some as yet-unknown chemical synthesis. Given the likely ubiquity of surface hydrothermal vents on young, hot, terrestrial planets, these results identify a prebiotically plausible local geochemical environment, which is also amenable to future lab-based simulation.

The chemical reactions in the silent electric discharge were studied when hydrogen reacted on the following inorganic solid substances. (1) Potassium sulphite. Reaction products:—hydrogen sulphide potassium hydroxide. (2) Cadmium bromide. Reaction products:—metallic cadmium and hydrogen bromide. (3) Potassium perchlorate. Reaction products:—potassium chloride and water. (4) Mercuric cyanide. Reaction products:—metallic mercury and hydrogen cyanide. (5) Mercuric thiocyanate. Reaction products:—mercuric sulphide, metallic mercury, hydrogen cyanide, hydrogen sulphide, and thiocyanic acid. (6) Silver cyanide. Reaction products:—metallic silver and hydrogen cyanide. (7) Sodium thiocyanate. Reaction products:—sodium sulphide, hydrogen sulphide, and hydrogen cyanide. (8) Lead thiocyanate. Reaction products:—lead sulphide, hydrogen sulphide, and hydrogen cyanide. (9) Potassium cyanide. It was proved that potassium cyanide was hardly reduced under the conditions of this experiment. The writer wishes to express his appreciation of a grant from the Imperial Academy towards the expenses of this research.

In an occupational or military environment, a personal air-purifying respirator must be provided when breathing-air is contaminated by harmful dust, fumes, gases, aerosols, or vapors. Too often, a respirator user does not have enough information to know when to change his/her cartridge/canister and thus is potentially exposed to toxic gases. Currently, there is no definitive way to determine when respirators' carbon beds have begun to fail. When an end-of-service-life indicator (ESLI) is incorporated into the carbon bed, it informs one, in real-time, when imminent breakthrough is occurring and to replace the cartridge/canister. ESLIs are a more reliable and safer way to determine respirator end-of-service-life. To date, there are no commercially available active ESLIs for inorganic gases.;The objective of this research is to develop an inexpensive, optical sensor for the detection of hydrogen cyanide (HCN) and hydrogen sulfide (H 2S) gas, which can be used to determine the end-of-service-life of a respirator carbon bed. The sensor relies on diffuse reflectance from a paper substrate fixed with cobinamide, a Vitamin B12 derivative. Cobinamide undergoes a metal-ligand binding interaction with HCN, whereas both a binding and reduction reaction may occur with exposure to H2S. Characteristic and different spectral shifts rapidly occurred after exposure to HCN and H 2S, implying a dual ESLI could be developed to simultaneously detect both gases. Upon increasing the relative humidity from 25 to 85%, the sensitivity was found to increase 7x for cobinamide-immobilized cellulose fiber filter paper and 50x for glass fiber filter paper upon exposure to 5.0 parts-per-million (ppm) HCN---the NIOSH recommended exposure limit for HCN. The cobinamide-immobilized paper sensor successfully detected low concentrations of HCN and H2S upon imminent breakthrough of respirator canisters and cartridges (respectively). The breakthrough curves of the cobinamide paper sensor correlated well with commercial electrochemical detectors, implying that cobinamide may be used to detect both gases at a certain location in the respirator carbon bed and inform the user to replace his or her cartridge/canister.;Additionally, a low-power, inexpensive 3-color (RGB) sensor was prototyped to actively monitor the total change in color of the cobinamide complex on paper upon HCN exposure. The photodiodes detected, in real-time, a rapid change in the red, green, and blue values of the cobinamide compound upon exposure to HCN at various concentrations and relative humidity levels. Total change in color from initial cobinamide on paper increased as a function of HCN concentration, where faster reaction kinetics were observed

Optimization of hydrodynamic operating conditions of alkaline adsorbers of carbon dioxide in fine purification of coke oven gas

This paper reports a study into the influence of sodium carbonate concentration (10, 30, and 50 kg/m3) in the simultaneous presence of sodium thiosulfate (250 kg/m3) and quinhydrone (5 kg/m3) on the coefficient of the phase distribution of hydrogen sulfide in a quinhydrone absorbing solution. The research was carried out at the laboratory installation using chemical analysis methods of liquid and gas phases. It has been found that the coefficient of phase distribution increases dramatically with an increase in the degree of saturation of the quinhydrone solution with hydrogen sulfide. At the same time, in the presence of sodium thiosulfate in quinhydrone absorbing solutions, the coefficient of phase distribution increases compared to carbonate solutions of the same concentration. Thus, the partial hydrogen sulfide pressure over a quinhydrone solution at low degrees of hydrogen sulfide saturation (up to 3 %) is 5...10 times larger than that over soda solution, while at high degrees (60...80 %) it is almost the same. It can be argued that at the high concentrations of sodium carbonate and the degree of the saturation of quinhydrone solution with hydrogen sulfide the effect of sodium thiosulfate on the partial pressure of hydrogen sulfide decreases. An equation of the effect exerted by the NaНS concentration and the starting Na2CO3 concentration on the H2S partial pressure over quinhydrone solutions has been proposed. Based on the experimental studies' results, the equilibrium constant values for a hydrogen sulfide chemisorption reaction involving a quinhydrone solution have been calculated. To ensure the high absorption capacity, the process of hydrogen sulfide chemisorption should be carried out using solutions with a maximum concentration of sodium carbonate, 40...50 kg/m3. The presence of ballast components (Na2S2O3, NaHCO3) slightly reduces the sorption capacity of an absorbing solution. The results obtained could be used in engineering calculations and when developing technology for purification of fuel gases from hydrogen sulfide by a quinhydrone method.

The beneficial effect of antibiotics in pouchitis suggests that an unidentified fecal bacterial product causes this condition. A candidate compound is hydrogen sulfide, a highly toxic gas produced by certain fecal bacteria, which causes tissue injury in experimental models. We investigated hydrogen sulfide release and sulfate-reducing bacterial counts in pouch contents to determine whether hydrogen sulfide production correlates with pouchitis. During incubation at 37 degrees C, the production of hydrogen sulfide, methylmercaptan, carbon dioxide, and hydrogen were studied using fresh fecal specimens obtained from 50 patients with ileoanal pouches constructed after total proctocolectomy for ulcerative colitis (n = 45) or for familial adenomatous polyposis (n = 5). Patients with ulcerative colitis were divided into five groups: a) no history of pouchitis (pouch for at least 2 years; n = 8); b) past episode(s) of pouchitis but no active disease for the previous year (n = 9); c) pouchitis in the past year but presently inactive (n = 9); d) ongoing antibiotic treatment (metronidazole or ciprofloxacin) for pouchitis (n = 11); e) currently suffering from pouchitis (n = 8). Release of hydrogen sulfide when pouchitis was active (6.06 +/- 1.03 micromol g(-1) 4 h(-1)) or had occurred in the past year (4.71 +/- 0.41 pmol g(-1) 4 h(-1)) was significantly higher (P < 0.05) than when pouchitis had never occurred (1.71 +/- 0.43 micromol g(-1) 4 h(-1)) or had been inactive in the past year (2.62 +/- 0.49 micromol g(-1) 4 h(-1)). Antibiotic therapy was associated with very low hydrogen sulfide release (0.68 +/- 0.29 micromol g(-1) 4 h(-1)). Pouch contents from familial adenomatous polyposis patients produced significantly less hydrogen sulfide (0.75 +/- 0.09 micromol g(-1) 4 h(-1)) than did any group of nonantibiotic-treated ulcerative colitis patients. Sulfate-reducing bacterial counts in active pouchitis (9.5 +/- 0.5 log10/g) were significantly higher than in those who never experienced pouchitis (7.38 +/- 0.32 log10/g), and these counts fell dramatically with antibiotic treatment. No statistically significant differences in carbon dioxide and hydrogen were observed among the groups not receiving antibiotics. Pouch contents of patients with ongoing pouchitis or an episode within the previous year released significantly more hydrogen sulfide than did the contents of patients who never had an attack of pouchitis and those with longstanding inactive disease. The response to therapy with metronidazole or ciprofloxacin was associated with marked reductions in hydrogen sulfide release and sulfate-reducing bacteria. These results provide a rationale for additional studies to determine whether the high sulfide production is a cause or effect of pouchitis. The lower hydrogen sulfide production by pouch contents of familial adenomatous polyposis vs. patients with ulcerative colitis suggests a fundamental difference in gut sulfide metabolism that could have implications for the etiology of ulcerative colitis as well as the pouchitis of patients with ulcerative colitis.

Simultaneously remove Phosphine, hydrogen sulfide and hydrogen Cyanide: Synergistic effect of micro-electrolysis and liquid-phase catalytic electrolysis

An effective means of handling the accelerated production of hydrogen sulfide resulting from waterflooding the Wilmington oil field had become an absolute necessity. A feasibility study comparing possible systems showed the Stretford Process to hold great promise. The prediction has proved to be almost an understatement. proved to be almost an understatement. Introduction The Stretford Process has been increasingly accepted throughout the world during the last decade for treating coke oven gas, reformed petroleum products, and effluents arising in the manufacture of certain industrial products. As we shall explain, the process appears useful also for treating oilfield gases under certain conditions. In general, these conditions are: (1) that hydrogen sulfide is present in lower concentration, (2) that the ratio of CO2 to H2S is high, and (3) that the air content does not exceed a few percent. Where higher hydrogen sulfide concentrations and lower CO2/H2S ratios prevail, an amine process followed by a Claus system for the production of process followed by a Claus system for the production of sulfur might be more economical. Where hydrogen sulfide concentrations are extremely low, it may be more desirable to treat the gas with partly regenerable or nonregenerable chemicals, such as was done in the iron sponge purification system and the nonregenerable liquid chemical system employed in the Wilmington field before this Stretford unit was installed. One of the most important features of the Stretford Process is that it is almost entirely pollution free. Neither Process is that it is almost entirely pollution free. Neither gaseous nor liquid pollutants are discharged in the day-today operation. Sulfur produced is innocuous, and may have a market value, or it may be easily disposed of without producing surface pollution. pollution. In the Wilmington field the injection of large quantities of water from ocean-charged aquifers has been responsible for converting the normally sweet natural gas to sour gas, with hydrogen sulfide content increasing at compound growth rates in excess of 50 percent/year. As evidence of this, Fig. 1 shows the growth of hydrogen sulfide concentration in the older portion of the Wilmington field to the west. (Process Plants "A" and "B" are natural gasoline extraction plants that have processed the entire volume of Wilmington field gas. The two curves represent the intake concentrations of all gas processed, with the exception of the Long Beach Units - East Wilmington - gas.) Fig. 2 demonstrates the increased hydrogen sulfide content in the gas as the water cut increases for typical wells in the Ranger zone, Block VI, East Wilmington. The phenomenal increase in hydrogen sulfide quickly made the earlier sweetening units obsolete. It became necessary to decide on a long-term solution in the form of a process unit that could treat all of the gas of the East Wilmington field operated by the Long Beach Unit, and possibly also a large part of the gag from the older part of the Wilmington field to the west. The unit would have to have enough capacity to take care of growth for several years. Attractive features to look for were that the process be selective, that it employ a regenerable chemical, and that it produce sulfur rather than hydrogen sulfide as the effluent. produce sulfur rather than hydrogen sulfide as the effluent. The process had to be one in which risk was minimal, since the entire oil production of the Wilmington field depended on its reliability. P. 545

The universality of inhibitors is understood as their ability to inhibit several types of corrosion attack: hydrogen sulfide and carbon dioxide corrosion, hydrogen diffusion into metal, development of sulfate-reducing and other types of bacteria, negative impact on the mechanical properties of metals. Indicators of universalism of new inhibitor have been studied. Producer of the inhibiting compositions is Limited Liability Company «INCORGAZ» (S-Petersburg, Russia). The efficacy of the inhibitor in the concentration of 25 - 200 mg/L has been studied with respect to carbon steel in a highly mineralized chloride medium (pH= 6) and NACE medium (5 g/L NaCl, 0.25 g/L CH3COOH, pH =3.5) containing H2S (50-400 mg/L) and CO2 (1at) separately and together. The bactericidal properties of the inhibitor were studied with respect to sulfate-reducing bacteria in the Postgate medium. The investigations were carried out by the methods of linear polarization resistance, electrochemical impedance spectroscopy, gravimetry, potentiodynamic polarization. The protective effectiveness of the inhibitor reaches 80% in the presence of CO2 and 90% in hydrogen sulphide environments. The inhibitor repeatedly reduces the number of sulfate-reducing bacteria and the production of biogenic hydrogen sulfide and inhibits the diffusion of hydrogen into steel.

The utility of waters from the high-temperature areas in Iceland for space heating as determined by their chemical composition

This chapter investigates three ionic liquids (ILs), namely butyl pyridinium acetate ([BPy][AC]), butyl pyridinium benzoate ([BPy][BZ]), and butyl pyridinium propionate ([BPy][PR]), applied as potential absorbents for acid gases (hydrogen sulfide and carbon dioxide) in natural gas. The molecular dynamics (MD) simulation results indicate that the ILs have a relatively low dynamic and compact structure, with high viscosity in their pure state. Consistent with the findings of other researchers, the qualitative analysis of the simulation data for the mixture of an IL with acid and methane gases suggests that the dynamics of the IL enhances in the presence of these gases. The radial distribution functions reveal strong interactions and structural compatibility between the ILs and hydrogen sulfide molecules, indicating their suitability for hydrogen sulfide absorption. The amount of carbon dioxide gas absorbed by these ILs was calculated to be in the range of 0.08–0.11, while the absorption of hydrogen sulfide gas ranged from 0.12 to 0.18. [BPy][PR] IL exhibited the highest percentage of absorption for carbon dioxide (0.1083) and hydrogen sulfide (0.177). Furthermore, a comparison of the interactions between acidic gases and [BPy][PR] with the results of methyldiethanolamine (MDEA) clearly demonstrates the superior physical absorption of these gases by [BPy][PR].

Chapter 7 - Acid gas treating