Process safety cost considerations

The foregoing comparison of different valve arrangements for both full main air blower trains and TPG trains emphasizes its importance. The range of desired regenerator control, expected modes of operation, and system constraints all influence the choice of valve aiTangements. The selected arrangement depends on safety consciousness, cost considerations, and desired process flexibility. 

Conceptual design—the generation of ideas for new processes (process synthesis) and their translation into an initial design. This stage includes preliminaiy cost estimates to assess the potential profitability of the process, as well as analyses of process safety and environmental considerations. 

There are two aspects of this program that will effect the research and development investment decision. First, the costs of premanufacture notification (including testing costs) will increase the investment in R D necessary to develop and market new chemicals. The health and safety properties of a chemical must now be considered an intrinsic part of the new chemical development process, right alongside consideration of the substances commercial properties. Both are equal parts of the "total product". Tb the extent that this results in increased testing for health and environmental effects, the amount of investment required to achieve a given level of output from R D will also rise. 

The general layout of an industrial process plant involves considerations of cost and safety. Some of the factors that contribute to safety and loss prevention are (i) segregation of different risks (ii) minimization of vulnerable pipework (iii) containment of accidents (iv) limitation of exposure (v) efficient and safe construction (vi) efficient... 

Safety requirements must be satisfied before a cobalt-60 source can be installed and licensed. Radiation-trained personnel must be on the staffbefore a license can be issued. At least 500,000-1,000,000 Ci (curies) of cobalt-60 are required in a production source for making wood-polymers, and at 1.00 or more per curie, a considerable investment must be made before production can begin. Besides cost considerations, the cobalt-60 radiation process does have some distinct advantages in making wood-polymer composites. Because the monomer is not catalyzed it can be stored at ambient conditions as long as the proper amount of inhibitor is maintained. The rate of free radical generation is constant for a given amount of cobalt-60 and does not increase with temperature. 

Taste research has evolved considerably over the last years what will certainly result in new compounds and lead structures. The three approaches mentioned, i.e. TDA, receptor-based assays, and molecular modelling, are complementary methods (or tools) that may reveal new taste-active and taste-modifying compounds. The TDA method may especially help discovering taste modulators, because the corresponding receptors and processes are largely unknown. However, many other parameters must be checked, apart from technical taste testing, to evaluate the commercial potential of these new molecules, i.e. stability, safety, cost, availability, range of application, etc. Therefore, just a few molecules may succeed to be widely applied to culinary products. 

At the risk evaluation step, if the risks are found to be unacceptable, then further risk control measures win he necessary. These include measures for preventing incidents and impacts (such as implementing process safety and loss management systems for minimizing chances and consequences of hazardous material releases), and measures for responding to incidents should they occur. Cost/henefit considerations will also play a role in selecting the risk control measures for implementation. Each additional risk control measure changes the risk level, and the process of improvement continues until the risks become acceptable to the stakeholders. The involvement of the stakeholders in each step in the process is indicated in Fig. 10.5 by double-headed arrows. 

Combinations of thiuram and thiazole accelerators are commonly used in sulphur cures, especially where cost is a primary consideration and heat resistance is not. Dithiocarbamates give fast cures and good ageing properties, but as they tend to be scorchy a thiazole (MBT or MBTS) is normally used with them to provide processing safety. Sulphur-donor systems based on thiuram/dithiocarbamate combinations and containing very little or no elemental sulphur provide superior ageing properties and low compression set. 

Raw materials efficiency. In choosing the reactor, the overriding consideration is usually raw materials efficiency (bearing in mind materials of construction, safety, etc.). Raw material costs are usually the most important costs in the whole process. Also, any inefficiency in raw materials use is likely to create waste streams that become an environmental problem. The reactor creates inefficiency in the use of raw materials in the following ways ... 

The choice of a suitable immobilization method for a given enzyme and appHcation is based on a number of considerations including previous experience, new experiments, enzyme cost and productivity, process demands, chemical and physical stabiHty of the support, approval and safety issues regarding support, and chemicals used. Enzyme characteristics that greatly influence the approach include intra- or extraceUular location size surface properties, eg, charge/pl, lysine content, polarity, and carbohydrate and active site, eg, amino acids or cofactors. The size, charge, and polarity of the substrate should also be considered. 

Continuous monitoring is necessary on critical machines where problems can develop rapidly and have severe financial consequences. Typical machines in this category are unspared process compressors. Remotely located machinery such as pipeline gas compressors also require continuous monitoring. Also, continuous monitoring may be dictated by safety considerations. Even though the cost of a failure is small, machines should be continuously monitored if a failure will result in hazards to personnel. Figure 8-38 depicts a typical continuous monitoring system. 

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