Process developments since

We started the fundamental research on the direct synthesis of DME finm synthesis gas, including catalyst preparation and reactor and process development, since 1998. In 2002, we... 

Concepts like quality, safety, and efficacy should be taken into consideration during process development, since it is not enough to inspect and test only the final product. Good Manufacturing Practice (GMP), as well as quality assurance systems are essential to guarantee safety, quality, and economic feasibility during the whole process and therefore to obtain a marketing license. 

In the traditional process, developed since the 1930s, alkylation is performed by reacting benzene and ethylene in the presence of a Friedel-Crafts catalyst (i.e., AICI3-HCI) under mild conditions. Table 2.8 shows the advantages and disadvantages of this process. Starting from the mid-1960s different zeolite-based... 

This process, developed since 1910, employs liquefied sulfur dioxide as solvent. First applied to dearomatize kerosenes and gas nils, the initial technique was modified to obtain pure aromatics. An examination of the equilibrium diagrams shows that, theoretically, it is impossible to obtain aromatics in a purity greater than 67 per cent at — 17.2 C, than 73 per cent at — 29°C, using sulfur dioxide as solvent. However, thanks to a kerosene backwash, very pure products can be obtained with good yields, up to 98 per cent for benzene and toluene, and 95 to 97 per cent for C8 aromatics. 

Given the limited data base from which solubility correlations can be drawn, it is essential to measure the solubility directly for the system of interest during process development. Since process conditions often favor operation with high concentrations of solute, such systems are often thermodynamically nonideal. It is necessary to measure the solubility in the solvent system(s) of interest in order to optimize the yield and the purity. To accomplish the latter relies upon the ability to measure the solubility of the key impurities as well as the product of interest. This requires the availability of both the key impurities and product however, the impurities often are not available as isolated solids. In that case, the solubility of impurities must be deduced from the purity profile of mother liquors taken from crystallizations of the actual process stream. It is often simplest and always fastest to measure the solubility and carry out crystallizations in a single-solvent system. However, working in multiple-solvent systems increases the likelihood of improving the yield, the separation factor, and the prospects of observing more of the possible crystal forms that may exist. 

Industrial Water Treatment Chemicals and Processes Developments since 1978, M. Collie, editor. Chemical Technology Review No. 217, Noyes Data Corp., Park Ridge, NJ, 1983, pp. 36 2. 

Polypropylene and polyamides have much more rigid particle size and shape requirements than thermosets. Specifically, the need is for a small particle size, with a low aspect ratio and minimal surface area. The particle size distribution should also allow for good packing, as indicated by a relatively low level of oil absorption in tests. Achieving such desired particle morphology has been the main aim of supplier process development since the 1980s. 

Besides Mobil, DICP, and UOP, SINOPEC has been actively involved in the MTO process development since 2000 (Liu, 2015). In 2005, a pilot-scale MTO unit capable of processing 12 t/a methanol feed was built in Shanghai. The SMTO process follows that of DICP and UOP, in which SAPO-34 catalyst is used. The SMTO process (100 t/d of methanol feed) has been demonstrated in Yanshan in Beijing in 2007. In 2011, an industrial SMTO unit with a capacity of 200 kt/a ethylene and propylene was brought on stream in Flenan, China (Jiang et al., 2014). 

TABLE 9.2. Ammonia Synthesis Gas Process Developments since 1920. 

In this section we present several numerical teclmiques that are conmronly used to solve the Sclirodinger equation for scattering processes. Because the potential energy fiinctions used in many chemical physics problems are complicated (but known to reasonable precision), new numerical methods have played an important role in extending the domain of application of scattering theory. Indeed, although much of the fomial development of the previous sections was known 30 years ago, the numerical methods (and computers) needed to put this fomialism to work have only been developed since then. 

The propylene-based process developed by Sohio was able to displace all other commercial production technologies because of its substantial advantage in overall production costs, primarily due to lower raw material costs. Raw material costs less by-product credits account for about 60% of the total acrylonitrile production cost for a world-scale plant. The process has remained economically advantaged over other process technologies since the first commercial plant in 1960 because of the higher acrylonitrile yields resulting from the introduction of improved commercial catalysts. Reported per-pass conversions of propylene to acrylonitrile have increased from about 65% to over 80% (28,68—70). 

Shale Oil. In the United States, shale oil, or oil derivable from oil shale, represents the largest potential source of Hquid hydrocarbons that can be readily processed to fuel Hquids similar to those derived from natural petroleum. Some countries produce Hquid fuels from oil shale. There is no such industry in the United States although more than 50 companies were producing oil from coal and shale in the United States in 1860 (152,153), and after the oil embargo of 1973 several companies reactivated shale-oil process development programs (154,155). Petroleum supply and price stabiHty has since severely curtailed shale oil development. In addition, complex environmental issues (156) further prohibit demonstration of commercial designs. 

By 1960, the elements of modem membrane science had been developed, but membranes were used in only a few laboratory and smaU, specialized industrial appHcations. No significant membrane industry existed, and total annual sales of membranes for aU appHcations probably did not exceed 10 million in 1990 doUars. Membranes suffered from four problems that prohibited their widespread use as a separation process they were too unreHable, too slow, too unselective, and too expensive. Partial solutions to each of these problems have been developed since the 1960s, and in the 1990s membrane-based separation processes are commonplace. 

Although not commercialized, both Elf Atochem and Rn hm GmbH have pubUshed on development of hydrogen fluoride-catalyzed processes. Norsolor, since acquired by Elf Aquitaine, had been granted an exclusive European Hcense for the propylene-hydrogen fluoride technology of Ashland Oil (99). Rn hm has patented a process for the production of isobutyric acid in 98% yield via the isomerization of isopropyl formate in the presence of carbon monoxide and hydrofluoric acid (100). 

Liquid-Ph se Processes. Prior to 1980, commercial hquid-phase processes were based primarily on an AIQ. catalyst. AIQ. systems have been developed since the 1930s by a number of companies, including Dow, BASF, Shell Chemical, Monsanto, SociStH Chimique des Charboimages, and Union Carbide—Badger. These processes generally involve ethyl chloride or occasionally hydrogen chloride as a catalyst promoter. Recycled alkylated ben2enes are combined with the AIQ. and ethyl chloride to form a separate catalyst—complex phase that is heavier than the hydrocarbon phase and can be separated and recycled. 

Decomposition Flame Arresters Above certain minimum pipe diameters, temperatures, and pressures, some gases may propagate decomposition flames in the absence of oxidant. Special in-line arresters have been developed (Fig. 26-27). Both deflagration and detonation flames of acetylene have been arrested by hydrauhc valve arresters, packed beds (which can be additionally water-wetted), and arrays of parallel sintered metal elements. Information on hydraulic and packed-bed arresters can be found in the Compressed Gas Association Pamphlet G1.3, Acetylene Transmission for Chemical Synthesis. Special arresters have also been used for ethylene in 1000- to 1500-psi transmission lines and for ethylene oxide in process units. Since ethylene is not known to detonate in the absence of oxidant, these arresters were designed for in-line deflagration application. 

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