Current Process

Rh - Te - C catalyst has been proposed as an improved oxidative acetoxylation catalyst. The advantage of this catalyst is higher l,4-diacetoxy-2-butene selectivity than the Pd-based catalyst. Although 95% selectivity can be obtained, improvement of durability is desired due to the rhodium leaching [20]. Another feature of the Rh catalyst is the formation of c/s-isomer. The three-dimensional structure of the x-allyl intermediate might be different in both catalysts. 

To increase total yield of 1,4-butanediol, isomerization of 3,4-diacetoxy-1-butene, which is a major by-product in oxidative acetoxylation, has been examined. Isomerization of 3,4-diacetoxy-l-butene to l,4-diacetoxy-2-butene requires only Iwtppm Pd-phosphite catalyst [21]. Therefore, catalyst recovery is not necessary in view of the production cost. 

Ideally, direct oxidative hydration of 1,3-butadiene is desired rather than acetoxy-lation, but the technical difficulty is very high because water is less reactive compared with acetic acid. 

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The basic Solvay process remains the dominant production route for soda ash. Its continued success is based on the raw matedals, salt and limestone, being more readily available than natural alkaU. AH soda ash processes are based on the manipulation of saline phase chemistry (6,7) an understanding of which is important both to improving current processes and to the economic development of new alkaU resources. 

Preparation of the vitamins in commercial quantities can involve isolation, chemical synthesis, fermentation, and mixed processes, including chemical and fermentation steps. The choice of process is economic, dictated by the need to obtain materials meeting specifications at the lowest cost. Current process technologies (ca 1997) employed for each vitamin are indicated in Table 9. 

Some combing plants also produce shrink-resistant treated wool-top. The current process incorporates chlorination, and the appHcation of a shrinkproofing polymer. Chlorination is likely to be replaced soon by mote environmentally friendly treatments. 

Removal of Free Fatf Fields. Alkali treatment of the oil is accompHshed by the use of caustic soda solutions to neutralize the excess free fatty acids. Because castor oil readily forms emulsions with water and/or alkaline solutions, special techniques have been developed to neutralize the acids. A continuous counter-current process was developed using a stationary contact reactor (15). Treatment in the presence of a solvent is also utilized (16). 

Problem Definition InteUigent selection of a separator requires a careful and complete statement of the nature of the separation problem. Focusing narrowly on the specific problem, however, is not sufficient, especi ly if the separation is to be one of the steps in a new process. Instead, the problem must be defined as broadly as possible, beginning with the chemical reactor or other source of material to be separated and ending with the separated materials in their desired final form. In this way the influence of preceding and subsequent process steps on the separation step will be iUuminated. Sometimes, of course, the new separator is proposed to replace an existing unit the new separator must then fit into the current process and accept feed materials of more or less fixed characteristics. At other times the separator is only one item in a train of new equipment, all parts of which must work in harmony if the separator is to be effective. 

For all risk measures it is possible to estimate the risk level of the current process as well as the risk levels from incorporation of various risk reduction alternatives. Management can then use this information as an important input in the final risk decision-making process. 

Change in service may lead to inappropriate instrumentation for the current process. 

Process equipment function changes with different steps in process sequence (e.g., same vessel used as feed tank, reactor, crystallizer pump used to pump in/out). Instrumentation and controls not kept in phase with the current process step (e.g., control set points, interlocks etc.). 

Calibration unsuitable for current process/step. Some processes require greater accuracy of measurements. 

When only common-cause variability is present, the process is performing at its best possible level under the current process design. For a process to be capable of producing components to the specification, the sum of the common-cause and assignable-cause variability must be less than the tolerance. 

The management program should include written facility operating procedures. These procedures should provide ample instruction for sound operation and be consistent with the safety and environmental information, Procedures should be reviewed and updated periodically to reflect current process operating practices. Procedures provide the means for education of new employees about the process and provide education to all employees on new equipment and practices. 

Nevertheless, current processes of raw material decomposition that are based on digestion of the material by highly concentrated hydrofluoric and sulfuric acids yield highly acidic solutions. 

Substantial quantities of aluminum, copper, and steel are reused as scrap. The challenge is to purify the scrap metal sufficiently to process it for reuse. There is opportunity for new processes that can remove unwanted elements—either alloyed or piece contaminants—more effectively and at lower cost than current processes. 

Techniques are available that enable software development teams to better understand the workflows and environments of users, and can be more generally applied to gain understanding of the current processes and functions (and thus the information needs) of different kinds of scientists working in a corporate or academic environment. 

One of the most widely established processes using SCCO2 is the decaffeination of coffee. Prior to widespread use of this process in the 1980s the preferred extraction solvent was dichloromethane. The potential adverse health effects of chlorinated materials were realized at this time and, although there was no direct evidence of any adverse health effects being caused by any chlorinated residues in decaffeinated coffee there was always the risk, highlighted in some press scare stories. Hence the current processes offer health, environmental and economic advantages. 

Evaluate current process trends and anticipate future operational states. 

Continuous ion-exchange separation technology, which adopts counter-current processing in a rotating turntable, is currently making an impact and 70% of the world s lysine manufacture units use this technology. 

Using the optimum settings, biodiesel is produced at a volumetric production rate of 61 kg biodiesel/m -min, which compares well with 42 kg/m -min reported for typical batch processes (17). In addition, the current process is much more efficient since there is no separate separation step and reactor cleaning in between batches can be omitted (18). 

Economically, the elimination of lead and nickel emissions will result in an improved product because exposure of the metal to combustion gases in the current process results in porosity and entrainment of hydrogen gas in the metal. Overall, AMPCO estimates an annual savings in operations and maintenance expenses of USD 1.2 million with the use of this technology. Assuming the same 70% industry adoption, economic savings by 2010 could reach USD 5.8 million. Without the new electric induction heating process, the capital costs required for compliance could be USD 3 million. 

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