S -process

There can be an element of maintenance costs that is fixed and an element which is variable. Fixed maintenance costs cover routine maintenance such as regular maintenance on safety valves which must be carried out irrespective of the rate of production. There also can be an element of maintenance costs which is variable. This arises from the fact that certain items of equipment can need more maintenance as the production rate increases. Also, royalties which cover the cost of purchasing another company s process technology may have different bases. Royalties may be a variable cost, since they can sometimes be paid in proportion to the rate of production. Alternatively, the royalty might be a single-sum payment at the beginning of the project. In this case, the single-sum payment will become part of the project s capital investment. As such, it will be included in the annual capital repayment, and this becomes part of the fixed cost. 

Siemens s process A method of steel manufacture by addition of scrap metal, iron oxides and ferromanganese to molten pig (cast) iron. 

Signal processing in mechanical impedance analysis (MIA) pulse flaw detectors by means of cross correlation function (CCF) is described. Calculations are carried out for two types of signals, used in operation with single contact and twin contact probes. It is shown that thi.s processing can increase the sensitivity and signal to noise ratio. 

A manufacturer s process for analyzing aspirin tablets has a known variance of 25. A sample of ten aspirin tablets is selected and analyzed for the amount of aspirin, yielding the following results... 

Table 5. Estimated U.S. Processing Costs of Waste Disposal Method ...

Minimum Number of Exchangers. The fewest number of matches or exchangers that are requited in a network can be developed as a limit. The number needed, is generally one less than the total number of streams, S (process and utiUty), involved in the network ... 

Propylene Oxide, Report 2b, private report from SRI International s Process Economics Program, Menlo Park, Calif., Feb., 1971. 

LPG recovered from natural gas is essentially free of unsaturated hydrocarbons, such as propylene and butylenes (qv). Varying quantities of these olefins may be found in refinery production, and the concentrations are a function of the refinery s process design and operation. Much of the propylene and butylene are removed in the refinery to provide raw materials for plastic and mbber production and to produce high octane gasoline components. 

J. S. Spevack, The Concentration of Deuterium by the S-Process, ReportM-393, Columbia University, War Research Department, New York, Dec. 3,1942. 

Kocb s process also permits recovery of prebnitene, isodurene, and pentametbylbenzene by fractionation. In tbe case of isodurene, only 85% purity is acbieved wben tbe filtrate from tbe durene crystallization unit is redistilled durene is tbe principal impurity. Altbougb bexametbylbenzene can be synthesized via the trimethylation of the readily available pseudocumene, its high melting point (105.5°C) presents more of a processing challenge. 

The ammonolysis of phenol (61—65) is a commercial process in Japan. Aristech Chemical Corporation (formerly USS Chemical Division of USX Corporation) currently operates a plant at Ha verb ill, Ohio to convert phenol to aniline. The plant s design is based on Halcon s process (66). In this process, phenol is vapori2ed, mixed with fresh and recycled ammonia, and fed to a reactor that contains a proprietary Lewis acid catalyst. The gas leaving the reactor is fed to a distillation column to recover ammonia overhead for recycle. Aniline, water, phenol, and a small quantity of by-product dipbenylamines are recovered from the bottom of the column and sent to the drying column, where water is removed. 

Foi glycine (211), two production methods have been employed Stieckei s process and amination of monochloroacetic acid. 

In some cases, Bucherer s process is employed also, but strict control of reaction conditions is needed because the reactivity of formaldehyde is different from other aldehydes. DL-Alanine (212) is produced by either Strecker s or Bucherer s process from acetaldehyde. 

The dynamics of the secondary control loop should be approximately two to four times as fast as the dynamics of the primary control loop in order to achieve stable control. The secondary controller is actually part of the primary controller s process system. Hence, changes in the secondary controller tuning constants change the process system of the primary controller. Therefore, cascade control loops should always be tuned by first tuning the secondary controller and then the primary controller. If the secondary controller tuning is changed for any reason, the primary controller may need to be retuned also. 

Accidental Release Provisions. The 1990 CAAA includes provisions similar to OSHA s process safety management standard for minimi2ing the accidental release of air toxics. Based on types and quantities of ha2ardous chemicals on-site, a faciUty is required to develop and implement... 

Fig. 8. Mobil s process for aromatics from ethane (38). Ref. = refrigeration CW = cooling water Stm. = steam.

Product warehouse(s) Process pipe hues—steam, condensate, water, gas, fuel oil, air, fire, instru-... 

Is any part of the facility covered under OSHA s Process Safety Management rule ... 

Radial inflow turboexpanders are the best equipment for this application because they handle condensing streams, provide a high expansion ratio in a single stage, and are custom-built to accommodate the plant s process conditions. 

Aliphatic Polyolefins other than Polyethylene, and Diene Rubbers ll.l.S Processing Characteristics... 

Octyne and 2-octyne also give >95% anti addition vinder these conditions. The reactions are formulated as concerted Ad S processes. 

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