Flexible processes

Feedstocks for this very flexible process are usually vacuum distillates, deasphalted oils, residues (hydrotreated or not), as well as by-products from other processes such as extracts, paraffinic slack waxes, distillates from visbreaking and coking, residues from hydrocracking, converted in mixtures with the main feedstock. 

This highly flexible process allows the best optimization of yields in desirable products and it features a high degree of selectivity. 

Cavanaugh, T.A., D.E. Blaser and R.A. Busch (1978), Fluid coking/Flexi-coking, a flexible process for upgrading heavy crudes . Japanese Petroleum Institute (JPI) Conference, Tokyo. 

Pressure Zero shift, air leaks in signal lines. Variable energy consumption under temperature control. Unpredictable transmitter output. Permanent zero shift. Excessive vibration from positive displacement equipment. Change in atmospheric pressure. Wet instrument air. Overpressure. Use independent transmitter mtg., flexible process connection lines. Use liquid filled gauge. Use absolute pressure transmitter. Mount local dryer. Use regulator with sump, slope air line away from transmitter. Install pressure snubber for spikes. 

RI and FS are interdependent processes and are generally performed concurrently rather than sequentially, although the FS uses the data provided by the RI. This approach should be viewed as a dynamic, flexible process that can and should be tailored to specific circumstances of individual sites. It is not a rigid step-by-step approach that must be conducted identically at every site. Figure 16.3 illustrates a generic timeline of the phasing of RI/PS activities. 

Another integrated carbon capture technology is called the fuel-flexible process developed by General Electric (GE). This process takes different feedstocks such as coal and biomass and produces hydrogen and electricity in adjustable ratios (Rizeq et al., 2002). The reaction scheme for this process involves two chemical loops operated using three fluidized-bed reactors as shown in Figure 17.5. 

Heat from all the hot exhaust gas streams is used for steam generation to drive the steam turbine. Thus, the final products from the GE fuel-flexible process are pure hydrogen from the first reactor, C02 from the second reactor, and heat for electricity production from the third reactor. A portion of the solids in the chemical loops needs to be purged to avoid ash accumulation and maintain solid reactivity (Rizeq et al., 2002). The overall energy conversion efficiency for the GE fuel-flexible process is estimated to be 60% (Rizeq et al., 2003). 

The advantages provided by the continuous reactor prompted us to explore CCTP in a reactor with two CSTRs connected in series [11]. This reaction scheme depicted in Scheme 6 provides a highly flexible process for production of a wide range of diblock OBC compositions. The block composition can easily be varied by changing the production rate in either reactor. The comonomer content of either block can also be independently tailored by varying the feed compositions because the process operates in two independent reactors. This CCTP scheme also produces multiple chains per catalyst, an advantage over stoichiometric living polymerization systems, but is necessarily stoichiometric in CSA. The reaction produces... 

Bok, Grossmann and Park (2000) explained a classification of chemical process networks and characterized them as either dedicated or flexible processes. Dedicated processes operate at one mode and for high volume products whereas flexible processes operate at different modes and produce different products at different times. In the formulation introduced in this chapter, we account for different... 

Bok, J.K., Grossmann, I.E., and Park, S. (2000) Supply chain optimization in continuous flexible processes. Industrial S. Engineering Chemistry Research, 39, 1279. 

The first generation NLO polymers were side chain polymers, usually made by copolymerisation of a monomer bearing the chromophore bridged by a flexible spacer group with a co-monomer, commonly methacrylates. This is a flexible process allowing a wide range of co-polymers to be made. A typical example of this type of polymer is the methyl methacrylate azo dye co-polymer (5.9). 

Many different organoboranes have been developed and are in use at present to control selectivities, which makes hydroboration a particularly valuable and flexible process. A further important advantage of this method is that a wide range of functional groups tolerate hydroboration. Catalytic hydroboration, a recent development, is a new way of asymmetric hydroborations. Detailed treatment of hydroboration can be found in monographs321 323 324 331 and review papers.320 325 332-335... 

Grossmann, I. E., and Morari, M., Operability, resiliency and flexibility—process design objectives for a changing world. Int. Conf. Found. Computer-Aided Process Design, 2nd, Snowmass, CO (1983). 

Kotjabasakis, E., and Linnhoff, B., Sensitivity tables for the design of flexible processes (1)—How much contingency in heat exchanger networks is cost effective Chem. Eng. Res. Des. 64 (1986). 

Membranes and membrane processes are best suited in this context as their basic aspects well satisfy the requirements of process intensification for a sustainable industrial production. In fact, they are precise and flexible processing techniques, able to maximize phase contact, integrate conversion and separation processes, with improved efficiency and with significantly lower energy requirements compared to conventional techniques. 

Powder pressing is a very flexible process in that materials that are difficult to melt or deform may be produced in a variety of shapes and sizes. Adding to the flexibility of the process may be the fact that the starting powder does not need to be uniform. Different size powders, or more commonly, different types of powders may be used to produce composite microstructures. These different powders may be distributed uniformly throughout the fabricated component, or isolated to form a functionally graded material. Powder pressing is commonly used to... 

Compounder Creates Flexible Process with Conveyor Line, Plastics Machinery Auxiliaries, May 2003. 

ARCO Chemical Co. Methyl tertiary butyl ether (MTBE) Mixed C4s streams and methanol Reliable, flexible process optimized by 15 years of commercial operations 31 1995... 

Hamiltilon, C. J., and Mokenzie, A. B. The Circulating Fluidize Bed An Efficient and Flexible Process for Combustion of Low-Grade Fuels, Chemeca 85 13th Aust. Chem. Eng. Conf., p. 477 (1987). 

We ve developed a process (or methodology) that is capable of guiding organic growth. Dubbed (Define-Discover-Develop-Demonstrate), this structured-yet-flexible process forms the basis and architecture of how we ve categorized and presented the 55 techniques in this book (see Exhibits 1.4 and 1.5). The purpose of is to enable end-to-end innovation that involves... 

Partial hydrogenation is a flexible process and can produce different products... 

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