Metrics process time

Table 35.2 shows aggregate metrics for time spent per stage, although in reality most firms have expected completion dates specific to individual NCEs. Table 35.3 shows an example of how NCEs in the Phase Iff process might be categorized in terms of their expected completion dates. 

By implementing the new route early in the development of sitagliptin, the environmental benefits will be realized over the entire lifetime of the product. The total amount of waste which will be eliminated by the new route may well exceed 150000 metric tons over the lifetime of this important new treatment for type II diabetes, including nearly 50000 metric tons of aqueous waste which will never be produced. Since the amount of raw materials and waste as well as processing time and energy has been reduced in the new route, it is a more cost-effective option for the manufacture of sitagliptin. 

The success of MPC is based on a number of factors. First, the technique requires neither state space models (and Riccati equations) nor transfer matrix models (and spectral factorization techniques) but utilizes the step or impulse response as a simple and intuitive process description. This nonpara-metric process description allows time delays and complex dynamics to be represented with equal ease. No advanced knowledge of modeling and identification techniques is necessary. Instead of the observer or state estimator of classic optimal control theory, a model of the process is employed directly in the algorithm to predict the future process outputs. 

Until World War 1 acetone was manufactured commercially by the dry distillation of calcium acetate from lime and pyroligneous acid (wood distillate) (9). During the war processes for acetic acid from acetylene and by fermentation supplanted the pyroligneous acid (10). In turn these methods were displaced by the process developed for the bacterial fermentation of carbohydrates (cornstarch and molasses) to acetone and alcohols (11). At one time Pubhcker Industries, Commercial Solvents, and National Distillers had combined biofermentation capacity of 22,700 metric tons of acetone per year. Biofermentation became noncompetitive around 1960 because of the economics of scale of the isopropyl alcohol dehydrogenation and cumene hydroperoxide processes. 

Olefin Feedstock Selection. The selection of feedstock and severity of the cracking process are economic choices, given that the specific plant has flexibiUty to accommodate alternative feedstocks. The feedstock prices are driven primarily by energy markets and secondarily by supply and demand conditions ia the olefins feedstock markets. The prices of iadividual feedstocks vary widely from time to time as shown ia Figure 2, which presents quarterly prices of the various feedstocks ia the United States from 1978 through 1991 ia dollars per metric ton (1000 kg) (4). 

The unit Kureha operated at Nakoso to process 120,000 metric tons per year of naphtha produces a mix of acetylene and ethylene at a 1 1 ratio. Kureha s development work was directed toward producing ethylene from cmde oil. Their work showed that at extreme operating conditions, 2000°C and short residence time, appreciable acetylene production was possible. In the process, cmde oil or naphtha is sprayed with superheated steam into the specially designed reactor. The steam is superheated to 2000°C in refractory lined, pebble bed regenerative-type heaters. A pair of the heaters are used with countercurrent flows of combustion gas and steam to alternately heat the refractory and produce the superheated steam. In addition to the acetylene and ethylene products, the process produces a variety of by-products including pitch, tars, and oils rich in naphthalene. One of the important attributes of this type of reactor is its abiUty to produce variable quantities of ethylene as a coproduct by dropping the reaction temperature (20—22). 

Measuring employee understanding of appropriate quality objectives is again a subjective process. Through the data analysis carried out to meet the requirements of clause 4.1.5 and 4.2.8 you will have produced metrics that indicate whether your quality objectives are being achieved. If they are being achieved you could either assume your employees understand the quality objectives or you could conclude that it doesn t matter. However, it does matter as the standard requires a measurement. Results alone are insufficient evidence. The results may have been achieved by pure chance and in six months time your performance may have declined significantly. The only way to test... 

Whilst LCA is a powerful tool, which will become increasingly useful, as it is refined and becomes more objective, its complexity and cost, and the length of time taken to carry out a full analysis make it an impractical tool to use on a day-to-day basis for research and development chemists and chemical engineers. What is really required for most practising technologists is a simple set of metrics to aid the decision-making process involved in choosing one synthetic route or product over another. 

Any one individual is unlikely to possess sufficient knowledge in all areas of interest to identify key metrics so it should be common practice for green metrics to be developed drawing on the resources of cross-disciplinary teams. In addition, to truly drive the right direction towards the design of greener, safer processes, there is the need to resist the temptation of addressing metrics in a compartmentalized manner, as many of these metrics are interrelated. Finally, one should apply the 80/20 rule liberally that is do not strive for the perfect set of metrics that covers all situations if a few metrics meet your needs most of the time. 

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