Resulf process

Several processes have been developed based on the oxidation approach, but, with some exceptions, such as the Linde Clintox process (Heisel and Marold, 1992) these have not been commercial successes because of the complexity of SO2 recovery processes and their comparatively low SO2 removal efficiencies. Hydrogen sulfide, on the other hand, can be removed at very high efficiency by a number of processes, including the selective amine processes discussed in Chapter 2. Processes that involve the conversion of Claus plant tail gas sulfur compounds to H2S and the removal of this H2S are discussed in the following sections. Processes reviewed include Parson s Beavon Sulfur Removal (BSR) process. Shell s SCOT process, FB and D Technologies Sulften process, the TPA Resulf process, and the Exxon Flexsorb SE Plus process. 

The Resulf process, which is licensed by TPA, Inc., is very similar to the BSR/MDEA, SCOT, and Sulften processes. The Claus plant tail gas is heated mixed with a reducing gas passed through a catalyst bed where sulfur vapor, SO2, COS. and CS2 ate converted to H2S cooled and passed through a selective amine absorber. Acid gas from the amine stripper is recycled to the Claus plant. It is claimed that a high efficiency version of the process, Resulf-10, produces a vent gas from the amine absorber containing a maximum of 10 ppm H2S (TPA Inc., 1994). 

Resulf A process for removing residual sulfur compounds from refinery tailgases. They are hydrogenated to hydrogen sulfide, which is absorbed in an aqueous solution of an amine such as methyl diethanolamine. Licensed by TPA. 

An alternative approach to the evaluation of fhe resulfs obfained in the previous section, and one that provides additional physical insight into the manifestation of the process, is through the coupling of induced multipole moments [51-53]. This method also enables results for energy shifts to be obtained with considerably reduced computational effort, as will be shown in what follows. 

Metabolism of the estrogens to their water-soluble glucuronide and sulfate conjugates occurs mainly in the liver. Creation of a reservoir of estrogen occurs as a result of enterohepatic recycling, a process by which estrogens undergo desulfation followed by resulfation. 

OS X but in 2007 not yet of Microsoft Vista). By enabling appropriate weighting and categorization of fhe ferms, fhe qualify of resulfing content searches (i.e. by field restriction to e.g. a named author) is improved. It is important to appreciate however that this process relates to the document as a whole any finer grained internal structure, components or relationships which the document may contain, such as reference fo discrefe molecular species, cannot be easily captured at this level. 

Figure 2.25a shows the removal rates for five dies locafed at different positions in a wafer. If represenfs fhaf fhe removal rafe of fhe confer of the wafer is relatively lower than that of fhe edge. This resulf cannof be explained simply because fhis kind of non-uniformify can be caused by a lot of factors such as machine characteristics, machine conditions, consumables, and wafer shape. The WIDNU is abouf 20% as shown in Figure 2.25b, which is inevifable because fhere are various paffern densities in a die for fhe pracfice of paffern densify effecf. Therefore, we can see thaf fhe paffern densify in a die musf be kepf uniform in real CMP process. 

---