Process technological challenges

Staff of Panel on Plasma Processing of Materials, United States Nation Research Council, Plasma Processing of Materials Scientific Opportunities and Technological Challenges, Books on Demand, Ann Arbor, Mich., 1994. 

Building large commercial coal gasification combined cycle units could be difficult based on the history traditional power generators have had with simpler chemical processes. Sequesting the C02 can be another technological challenge. 

In the past, studies on ACC have been motivated by undesirable combustor behaviors that include combustion instabilities [1-10], poor burning efficiency [8-13], limited operational range [8-10, 14], and excessive production of pollutants ]8, 12, 13, 15-17]. These studies have contributed greatly to the present understanding of fast-response ACC, but several technological challenges still remain before the ACC technique can be implemented to practical propulsion systems. One such challenge is the use of liquid fuel for control, and maximization of control efficiency via direct injection into the combustion chamber. Such a control has been difficult to obtain and the physical processes were not well understood. 

In 1992 BHC (Boots Hoechst-Celanese) Company commercialized a new synthetic process to manufacture ibuprofen in BHC s 3500 metric-ton-per-year facility in Bishop/TX, USA, which was cited as an industry model of environmental excellence in chemical processing technology. For its innovation, BHC was the recipient of the 1997 Alternative Synthetic Pathways Award of the Presidential Green Chemistry Challenge. 

Among these polymerization processes, the gas-phase process is the most recent addition to the list. Since its emergence, the process has challenged many other existing technologies for market share. In addition to differences between the gas-phase process and the HP-free radical process shown in Table 11.1, more differences can be noted, which are shown in Table 11.2. 

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