Solvent hybrid

Hybrid silk fibers, 22 634 Hybrid solvents, in hydrogen sulfide recovery, 23 600-601 Hybrid striped bass, aquaculture,... 

Hybrid solvents combine the best characteristics of both the chemical and physical solvents and are usually composed of a number of complementary solvents. Hybrid solvents have out-performed existing solvents and those developed for one application have been easily adapted for to others. However this is not always desirable and the tendency has been to develop tailor-made solvents using complementary solvents where the proportions are varied to suit the applications. Typical solvents are aMDEA, Purisol, Sulfinol and UCARSOL199. 

Hybrisol [Hybrid solvent] A process for removing hydrogen sulfide from natural gases. Based on the Elf Activated MDEA process, but using added methanol to improve the removal of mercaptans and COS. 

For removal of acid gas from coal gasification gas and natural gas, the scrubbing by using solvents, including the chemical (tertiary amine), physical, and hybrid solvents, is still the commercial mainstay as this technology is relatively mature with lower cost in comparison with others, although the raw gas stream needs to be cooled to room temperature. 

The absorption with the physical solvents and hybrid solvents improve the absorption selectivity significantly for H2S and other sulfur compounds, including COS, mercaptans, and CS2. 

The absorption with the hybrid solvents can combine some advantages of both chemical and physical solvents, which improve the selectivity and absorption rate. 

Finally, Total in collaboration with IFF has embarked upon a comprehensive program with a pooling of resources to develop new gas treatment technologies to better suit the bulk acid gas removal destined for re-injection applications. To this end, pre-treatment techniques and hybrid solvent processes are envisioned as the most cost-effective overall solutions. 

Hybrid solvent processes use a mixture of a physical solvent with a chemical solvent and combine some ofthe advantages of physical solvent processes with those of chemical solvent processes. The Sulfinol process has numerous industrial applications in sour gas de-acidification. Its energy requirement is relatively low, but hydrocarbon co-absorption is higher than that of an amine process. 

A number of solvent-based processes have been developed to remove H S from gas streams [1, 2]. Separation of H S is achieved through preferential chemical reaction (chemical solvents), differential physical solubility (physical solvents), or a combination of both mechanisms (hybrid solvents) [1,2]. Choice of process type is primarily related to the partial pressure of H S in the stream [1, 2]. Chemical solvents have very high absorption capacities for H S at low partial pressures, but become less effective as the reactive agent approaches saturation [1,2]. For physical solvents, the solubility of H S typically increases in a linear fashion with increasing H S partial pressure (i.e., Henry s Law behavior) [1, 2]. 

Hybrid Solvents Comprising Ionic Liquids and Amines... 

Hybrid solvents comprising ILs and amines (whether covalently attached or as mixtures) represent a promising approach by which the applicability of IL-based solvents may be extended to lower pressure applications and compete with established aqueous amine technologies. 

Hybrid solvents attempt to combine the high gas purity offered by chemical absorption and the flash regeneration along with lower energy requirements of physical absorption. Processes such as Sulfinol are a mixture of sulfolane, DIPA or MDEA, and water. If the requirement is the total removal of the acid gases, then DIPA is used. If only H2S is to be removed, then MDEA can be used. Another process is the Flexisorb PS which can treat gases to less than 50 ppm C02 and 4 ppm H2S. 

Sulfinol solvents are hybrid solvents, which combine the properties of physical solvents, which allow removal of contaminants based on their physical solubility, with the chemical solvents, in which the contaminants chemically react with components of the solvent formulation. 

Figures 3.15, 3.16 and 3.17 show two NR compounds, an SBR and an NBR bonded with solvent-borne Chemosils 211/220, a hybrid solvent-borne primer Chemosil 211 with waterborne top coat Chemosil XW7484 and a waterborne system of Chemosil XW1180 primer and XW7484 top coat. Boiling water tests (95 - 98 °C for 2 hours) show 100% rubber retention in all cases (see Figure 3.19).

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