Sulfur recovery unit

Control Room. The control room location can be critical to the efficient operation of a faciHty. One prime concern is to locate it the maximum distance from the most ha2ardous units. These units are usually the units where LPG or other flammables, eg, hydrocarbons that are heavier than air, can be released and accumulate at grade level. Deadly explosions can occur if a pump seal on a light-ends system fails and the heavier-than-air hydrocarbons coUect and are ignited by a flammable source. Also, the sulfur recovery unit area should be kept at a healthy distance away as an upset can cause deadly fumes to accumulate. 

The Claus process is the most widely used to convert hydrogen sulfide to sulfur. The process, developed by C. F. Claus in 1883, was significantly modified in the late 1930s by I. G. Farbenindustrie AG, but did not become widely used until the 1950s. Figure 5 illustrates the basic process scheme. A Claus sulfur recovery unit consists of a combustion furnace, waste heat boiler, sulfur condenser, and a series of catalytic stages each of which employs reheat, catalyst bed, and sulfur condenser. Typically, two or three catalytic stages are employed. 

A disadvantage of the hydrocarbon—sulfur process is the formation of one mole of hydrogen sulfide by-product for every two atoms of hydrogen in the hydrocarbon. Technology for efficient recovery of sulfur values in hydrogen sulfide became commercially available at about the same time that the methane—sulfur process was developed. With an efficient Claus sulfur recovery unit, the hydrocarbon—sulfur process is economically attractive. 

Recover sulfur from tail gases in high-efficiency sulfur recovery units. 

Continuous releases of concentrated HjS streams must be segregated in a separate flare system to limit the extent of fouling and plugging problems. Releases of HjS such as diversion of sour gas product to flares during shutdown or upset of a downstream sulfur recovery unit are considered to be continuous, but safety valve releases are not included in this category. However, if a special HjS flare system is provided for continuous releases, the concentrated HjS safety valve releases should be tied into it rather than into the regular flare system. Due to the nature of HjS one should plan on frequent inspection and flushing of HjS flares to remove scale and corrosion products. 

Released acid gases in the same form as captured, i.e., H2S, COS, CO2, etc. are converted in the sulfur recovery unit to forms in which they may be exported from the industrial facility. 

Sulfur recovery is discussed later in the paper. Some liquid absorption processes produce two separate acid gas streams (selective AGR). One stream, containing the majority of sulfur compounds, is sent to the sulfur recovery unit, while the other is vented to atmosphere, environmental regulations permitting. 

Atmospheric and vacuum distillation units (Figures 4.3 and 4.4) are closed processes, and exposures are expected to be minimal. Both atmospheric distillation units and vacuum distillation units produce refinery fuel gas streams containing a mixture of light hydrocarbons, hydrogen sulfide, and ammonia. These streams are processed through gas treatment and sulfur recovery units to recover fuel gas and sulfur. Sulfur recovery creates emissions of ammonia, hydrogen sulfide, sulfur oxides, and nitrogen oxides. 

The off-gas stream from hydrotreating is usually very rich in hydrogen sulfide and light fuel gas. This gas is usually sent to a sour gas treatment and sulfur recovery unit along with other refinery sour gases. 

The H2S formed exits the FCCU in the dry gas and is removed downstream in the sulfur recovery unit. The increase in H2S production, 5-20%, can typically be managed within a refinery s operations (Figure 16.2). A different mechanism of SO uptake has been presented by Magnabosco [5],... 

The acid gas stream from the purification process is sent to a sulfur recovery unit which is usually a Stretford or a Claus unit. The product from these units is elemental sulfur. 

Because of the presence of hydrogen sulfide in Jay field crude oil, complex facilities, including oil stabilization, gas sweetening, and sulfur-recovery units, were required to produce salable oil and gas. To initiate field production and to provide extended well tests, a small 2.000-B/D facility was installed initially. As development drilling proceeded, 6.S00- and 12,000-B/D modules were built when and where needed. By using the modular-facility design concept, the field producing capacity was more than 00,000 B/D within 2V4 years of discovery. 

Claus sulfur recovery unit, 200 long tons per day (ltpd) 11... 

The H S containing stream from the acid gas removal unit is sent to the sulfur recovery unit to produce molten sulfur. Figure 6 is a typical process flow diagram of synthesis gas production for methanol via coal gasificiation by the Winkler gasifier. 

National Emission Standards for Hazardous Air Pollutants for Primary Copper Smelting National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production National Emission Standards for Hazardous Air Pollutants for Primary Lead Smelting National Emission Standards for Hazardous Air Pollutants for Petroleum Refineries Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units... 

Root, C., H. Schadler, R. Bentley and Steve Tzap. 2007. Acid-gas injection in New Mexico relieves sulfur-recovery unit duty. Oil Gas J. Sept. 17, pp. 72-82. 

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