Removal of hydrogen sulfide

Activated carbon based odor control systems 

Caustic activated carbons as hydrogen sulfide odor removal media 

The catalytic action of NaOH impregnated carbon can be summarized by the following reactions [57]  

Carbon surface as a catalyst of hydrogen sulfide oxidation 

Although direct relationship between the porosity of carbons and their hydrogen sulfide adsorption capacity was not established, the pore sizes should play a role in energetics of physical 

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Purification. The LPG generally requires treatment for removal of hydrogen sulfide [7783-06-4] H2S, organic sulfur compounds, and water in... 

A.lkali Carbonates. The hot carbonate process was originally developed by the U.S. Bureau of Miaes, usiag aqueous 25—30 wt % solutions of potassium carbonate for the removal of hydrogen sulfide and carbon dioxide. 

Hot potassium carbonate processes are intended for the removal of carbon dioxide, or the co-removal of hydrogen sulfide and carbon dioxide. As a result of the regeneration chemistry, these hot-pot processes are not suitable for the removal of hydrogen sulfide without significant carbon dioxide also in the untreated gas stream. 

Industrial gas streams, removal of hydrogen sulfide from, 23 597... 

Prussian blue (inorgchem) Fe4 Fe(CN)6 3 Ferric ferrocyanide, used as a blue pigment and in the removal of hydrogen sulfide from gases. prash an blu j prussic acid See hydrocyanic acid. pras ik as ad ... 

Thioformaldehyde is unknown in the free state, but polymers of it have been obtained by ring opening of trithiane, by removal of hydrogen sulfide from methanedithiol, by reaction of formaldehyde and hydrogen sulfide or sodium sulfide, and by reaction of sodium hydrosulfide with methylene chloride. The... 

Authentic poly(thioformaldehyde) was prepared much later by Harmon (5) by removal of hydrogen sulfide from methanedithiol and from bis(mercapto-methyl)sulfide. 

H.W. Danser E.P. Neumann, IEC 41, 2439(1949) (Industrial sonic agglomeration and collection systems) 5) R.M. Reed N.C. Updegroff, IEC 42, 2269 (1950)(Removal of hydrogen sulfide from industrial gases)... 

Alkanolamines. Gas sweetening, ie, removal of hydrogen sulfide and carbon dioxide, using alkanolamines was patented in 1930. Several amine solvents are available as of the mid-1990s. The most widely used are monoethanolamine [141-43-5], diethanolamine [111-42-2], diglycolamine [929-06-6], and methyldiethanolamine [105-59-9]. Amine processes are generally applicable when hydrogen sulfide concentration in the feed gas is relatively low (eg,... 

Many processes have been developed for the removal of hydrogen sulfide from gas streams. They can be classified as liquid absorption, liquid oxidation, dry oxidation, and adsorption. One of these processes is usually included in a coal gasification or liquefaction flowsheet since the coal sulfur is converted to H2S and finally elemental sulfur. The Stretford and Townsend direct HpS to S processes and the Recti sol process followed by a Claus plant are frequently included on coal conversion flowsheets (1 ). Kohl and Riesenfeld (2) present pertinent details for many commercial processes. 

Although the purpose of this investigation was to study the initial transient behavior of heatless adsorption, the best removal of hydrogen sulfide occurred in the run with 3.01% H S and a y = 2.88, cycle time of 12 minutes and feed rate of 190 sCCM. Removal was down to 99.55% in three hours. For the 6.32% feed the best removal for the same time period was 98.49%. 

Crude oils contain a certain amount of combined nitrogen which sometimes breaks down in thermal crackers to form these harmful nitrogen compounds. California, West Texas, and Venezuelan crudes seem to break down this way much more readily than other crudes. Catalytic-cracking units convert the nitrogen compounds in their feed to these polymerization catalyst poisons almost without exception. Other basic materials which have poisoned polymerization catalyst at times are sodium hydroxide and diethanolamine. Both of these materials are used extensively for the removal of hydrogen sulfide from the feed to polymerization units. Catalyst poisons of a basic nature can be removed from the... 

If the natural gas stream contains unacceptable quantities of hydrogen sulfide and/or carbon dioxide, they must be removed in order to make the gas suitable for transmission and sale. The details of removal of H2S and C02 from natural gas streams are beyond the scope of this chapter, but excellent discussions are available.10,12 There are many different processes available, depending upon the contaminants to be removed and their concentration in both the sour gas available and the sweetened gas to be produced. The dominant treating process is still the use of an alka-nolamine. A typical flow diagram for an amine sweetening installation for removal of hydrogen sulfide and carbon dioxide from a natural gas stream is shown in Fig. 20.10.12... 

N.C. Updegroff, IEC 42, 2269(1950)(Removal of hydrogen sulfide from industrial gases)... 

Certain catalytic systems based on the use of cobalt and molybdenum offer good resistance to sulfur. On the other hand, they cannot guarantee advanced conversioa of carbon monoxide, of which a few per cent remain in the effluent obtained. Their value resides in the simplification of the purification schemes for effluents produced by the partial oxidation of sulfiir-containing feeds. This is because they do not require prior removal of hydrogen sulfide, which can be removed subsequently in a angle add gas separation. 

Methanation as final purification for the raw gas from partial oxidation was proposed by Topsoe [739]. In this case the shift conversion is carried out in two stages with a special sulfur-tolerant shift catalyst followed by removal of hydrogen sulfide and carbon dioxide in an acid gas removal unit. Because of the potential danger of a sulfur break-through causing poisoning, the normal copper - zinc - alumina catalyst is usually not applied, which is surprising as the same risk exists in partial oxidation based methanol plants for the similarly composed methanol catalyst. 

Weaver and Winnick [111] studied the performance of a nickel/nickel sulfide cathode for the electrochemical removal of hydrogen sulfide gas from a gas stream. At 650 °C, the porous nickel cathode was converted in situ to Ni3+ S2 by the H2S in the feed gas stream. The exact composition of the nickel sulfide was found to be a function of the H2S/H2 ratio in the gas stream. A current density of 150 mA/cm was attained at an iR free cathodic overpotential of 300 mV. A maximum H2S removal of 40% was reported. The low removal percentage was due to mass transport limitations of the reactant gas to the electrode. 

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