Sour-water

Fluid Coking and Cracking, Delayed Coking, Alkylation, Sulfur Plants, and Sour Water Strippers 

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Refineries Refinery bottoms Refinery molasses Refinery processes Refinery sour water Refining... 

Chevron s WWT (wastewater treatment) process treats refinery sour water for reuse, producing ammonia and hydrogen sulfide [7783-06-04] as by-products (100). Degassed sour water is fed to the first of two strippers. Here hydrogen sulfide is stripped overhead while water and ammonia flow out the column bottoms. The bottoms from the first stripper is fed to the second stripper which produces ammonia as the overhead product. The gaseous ammonia is next treated for hydrogen sulfide and water removal, compressed, and further purified. Ammonia recovery options include anhydrous Hquid ammonia, aqueous Hquid ammonia, and ammonia vapor for incineration. There are more than 20 reported units in operation, the aimual production of ammonia from this process is about 200,000 t. 

Numerous other multistaged configurations are possible. One important variation of a stripper, shown in Fig. 13-7r is a refluxed stripper, in which an overhead condenser is added. Such a configuration is sometimes used to steam-strip sour water containing NH3, H2O, phenol, and HCN. 

Steam strip spent doctor solution to hydrocarbon recovery before air regeneration replace treating unit with other, less objectionable units (Merox) Use sour water oxidizers and gas incineration ... 

The catalyst dust is then separated from the resulting carbon dioxide stream via cyclones and/or electrostatic precipitators and is sent off-site for disposal or treatment. Generated wastewater is typically sour water from the fractionator containing some oil and phenols. Wastewater containing metal impurities from the feed oil can also be generated from the steam used to purge and regenerate catalysts. 

Certain refinery wastewater streams are treated separately, prior to the wastewater treatment plant, to remove contaminants that would not easily be treated after mixing with other wastewater. One such waste stream is the sour water drained from distillation reflux drums. Sour water contains dissolved hydrogen sulfide and other organic sulfur compounds and ammonia which are stripped in a tower with gas or steam before being discharged to the wastewater treatment plant. 

Vessels Containing Light Ends - Discharges should be sent to either a water disengaging drum, a sour water disengaging drum or a spent caustic disengaging drum, and accompanied by appropriate treatment methods. 

If the drum may occasionally receive water, caustic or similar aqueous streams, which would create problems in receiving facilities if pumped out with the hydrocarbon, then means of separate drainage should be be included. This may consist of a connection to the sewer from the bottom of the boot or in the case of sour water, a connection off the pumpout pump discharge routed to sour water facilities or other suitable disposal. 

Aqueous plant effluent and drawoff streams such as steam condensate, sour water, or spent caustic soda solution may require disposal to a disengaging drum. 

Sour water is to be routed to sour water stripping facilities. 

A flare seal drum may also be used as a sour water disengaging drum, if economically advantageous. In such cases, special care should be given to ensure that the drum is adequately sized to simultaneously meet all design features required for both functions. Also a separate source of makeup water must still be provided to ensure continuity of the seal. 

If HjS is continuously present in the flare gas or if the flare seal drum also functions as a sour water disengaging drum, then the effluent seal water must be routed to a sour water stripper, desalter, or other safe means of disposal. Withdrawal from the drum is by pump in place of the normal loop seal arrangement. Two pumps are provided one motor driven for normal use, and the other having a steam turbine drive with low pressure cut-in. The seal drum level is controlled by LIC with high and low alarm lights plus an independent high level alarm. 

Sauer-wasser, n. sour water, sour (any of various dilute acid solutions iised in the arts) acidulous (sparkling) water, -wein, m. sour wine verjuice. 

Typically, sour water from the FCC contains a mixture of am nium sulfide and ammonium bisulfide with an aramonia-to-hydrc sulfide ratio between 0.5 and 1.0... 

Operating variables Reduced stripping steam or atomizing steam higher preheat or riser temperature. Restore the steam flows this is not the right place to solve a sour water problem. 

The term sour water is used for water containing carbon dioxide, hydrogen sulphide and ammonia encountered in refinery operations. 

Newman (1991) gives the equilibrium data required for the design of sour water systems, as charts. 

Chevron WWT [Waste water treatment] An integrated process for treating sour water from oil refineries, particularly for removing ammonia, hydrogen sulfide, and carbon dioxide. Only physical processes are used—volatilization and condensation under various conditions. Developed by Chevron Research Company and used in 14 plants worldwide in 1985. Martinez, D., in Chemical Waste Handling and Treatment, Muller, K. R., Ed., Springer-Verlag, Berlin, 1986, 180. 

The conference was subdivided into four sessions, and chapters within this text are arranged according to these categories. Papers included in the first section (Thermodynamics of Electrolytes for Pollution Control) provide the reader with insights into the practical aspects of pollution control, as well as an overall appreciation of applied electrolyte phase equilibria. Other chapters include detailed descriptions of thermodynamic models that recently have been developed to describe important industrial pollution control processes with emphasis on acid gas absorption/sour water stripping and flue gas desulfurization. 

As an introduction to the technical aspects of the conference, the results of some studies conducted by the writer on two relevant subjects are presented below. The first commentary is concerned with the design of sour-water strippers and the effects of thermodynamic data on these designs the second commentary is concerned with the calculation of enthalpies of steam-containing mixtures, essential to the design of coal processing and related plants. 

A number of models have been developed to describe the chemistry occurring in sour-water stripping and absorption. 

For most sour water stripper design work, a computer is used to perform the calculations. Several of the proposed sour-water modules were incorporated into a tower program and a series of designs on a typical sour-water stripper have been undertaken. 

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