Hydrogen sulfide exchange process

Derivation There are several methods of separating or concentrating DOD (1) fractional distillation, (2) Girdler-Spevack process, (3) hydrogen-sulfide exchange process, (4) electrolysis, (5) cryogenic methane distillation. 

Figure 13.24 Example of reflux by chemical conversion for water-hydrogen sulfide exchange process.

DUAL-TEMPERATURE WATER-HYDROGEN SULFIDE EXCHANGE PROCESS... 

Because this reflux ratio is much lower than the reflux ratio in the distillation of water derived in Eq. (13.11), the towers of a hydrogen sulfide exchange plant could be much smaller in diameter than the towers of a water distiliation plant. Because the separation factor for the exchange process (2.32) is much greater than for water distiliation ( 1.05), the towers could contain a much smaller number of plates. 

ZeoHte-based materials are extremely versatile uses include detergent manufacture, ion-exchange resins (ie, water softeners), catalytic appHcations in the petroleum industry, separation processes (ie, molecular sieves), and as an adsorbent for water, carbon dioxide, mercaptans, and hydrogen sulfide. 

In the dual-temperature H2O/H2S process (61,62), exchange of deuterium between H20(l) and H2S(g) is carried out at pressures of ca 2 MPa (20 atm). At elevated temperatures deuterium tends to displace hydrogen in the hydrogen sulfide and thus concentrates in the gas. At lower temperatures the driving force is reversed and the deuterium concentrates in H2S in contact with water on the tiquid phase. 

The potential production of sulfide depends on the biofilm thickness. If the flow velocity in a pressure main is over 0.8-1 ms-1, the corresponding biofilm is rather thin, typically 100-300 pm. However, high velocities also reduce the thickness of the diffusional boundary layer and the resistance against transport of substrates and products across the biofilm/water interphase. Totally, a high flow velocity will normally reduce the potential for sulfide formation. Furthermore, the flow conditions affect the air-water exchange processes, e.g., the emission of hydrogen sulfide (cf. Chapter 4). 

HSSX An ion-exchange process for removing salts from alkanolamines used in oil refineries for removing hydrogen sulfide. Developed by Conoco and commercialized by MPR Services (part of the Tessenderlo Group) from 1991. 

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