Process production, operating modes

Tablet production systems can be operated manually however most of the systems nowadays operate automatically in order to produce a sufficient number of tablets. Further requirements depend on the type of machine, the production process, the operation mode of the machine, and the production rate of the machine.

The hydrocracking process is characterized by a very low gas production and a low LPG yield especially when operated for maximum distillates. Byproducts in this operating mode are ... 

The H-Coal process could operate in one of two modes, depending on the desired product slate. In the "syn-cmde" mode, a fluid-bed coking unit was employed to maximize recovery of distillate from the Hquefaction product (Fig. 7a). When operated in the fuel oil mode (Fig. 7b), no coker was used and the primary product was a coal-derived low sulfur fuel oil. Total hydrogen demand on the process was also reduced in the latter mode of operation. 

Solvent-Refined Coal (SRC) This processing concept was initiated by the Pittsburgh Midway Coal Mining Co. in the early 1960s. The SRC-I process operating mode is designed to produce a solid fuel for utility applications. Typical operating conditions and product yields for SRC-I are shown in Table 27-14. 

At the current time, there is considerable interest in the preparative applications of liquid chromatography. In order to enhance the chromatographic process, attention is now focused on the choice of the operating mode [22]. SMB offers an alternative to classical processes (batch elution chromatography) in order to minimize solvent consumption and to maximize productivity where expensive stationary phases are used. 

The alternative to batch mode operation is continuous operation. In the continuous mode there is a continuous flow of medium into the fermentor and of product stream out of the fermentor. Continuous bioprocesses often use homogenously mixed whole cell suspensions. However, immobilised cell or enzyme processes generally operate in continuous plug flow reactors, without mixing (see Figure 2.1, packed-bed reactors). 

Approximate equipment sizing. There are many combinations of equipment units that meet the requirements concerning the functions of all equipment units and the time horizons for all products. Based on the Flatz (1980) concept, a simple procedure is presented to determine feasible equipment sizes that meet all requirements for plants operated in a single-product campaign mode (no process overlapping). The procedure is illustrated in Fig. 7.4-10. 

Batchwise operating three-phase reactors are frequently used in the production of fine and specialty chemicals, such as ingredients in drags, perfumes and alimentary products. Large-scale chemical industry, on the other hand, is often used with continuous reactors. As we developed a parallel screening system for catalytic three-phase processes, the first decision concerned the operation mode batchwise or continuous. We decided for a continuous reactor system. Batchwise operated parallel sluny reactors are conunercially available, but it is in many cases difficult to reveal catalyst deactivation from batch experiments. In addition, investigation of the effect of catalyst particle size on the overall activity and product distribution is easier in a continuous device. 

Han (H3) and Han and Wilenitz (H4) have also presented steady-state models of fertilizer granulators based on population balance on the granules in the process loop operating in the snowballing mode. From the viewpoint of process control some interesting interrelationships between various recycle ratios, crusher speed, crusher product size, and the granule growth rate have been established. 

All these problems could be convincingly overcome by application of the continuous operation mode [63 d)]. Most interestingly, this unusual continuous biphasic reaction mode enabled the quantitative separation of relatively high boiling products from the ionic catalyst solution under mild temperature conditions and without use of an additional organic extraction solvent. More details of this process are included in Chapter 8, Section 8.2.2.3. 

A set of products cfr CFR to be produced at multiple refinery sites i I is given. Each refinery consists of different production units m that can operate at different operating modes p P. An optimal feedstock from different available crudes cr CR is desired. Furthermore, the process network across the multiple refineries is connected in a finite number of ways and an integration superstructure is defined. Market product prices, operating cost at each refinery, and product demands are assumed to be known. 

From the refinery side, the proposed model will provide the optimal network integration between the refineries, process expansion requirements, operating policy based on different feedstock combination alternatives, process levels and operating modes. On the petrochemical side, the model will establish the design of an optimal petrochemical process network for the production of PVC from the range of process technologies and feedstocks available to satisfy a given demand. 

Suspension systems can be operated in different modes batch, fed-batch, chemostat, and perfusion (Fig. 1). These operation modes differ basically in the way nutrient supply and metabolite removal are accomplished, which in turn determines cell concentration, product titer and volumetric productivity that can be achieved [8]. The intrinsic limitation of batch processes, where cells are exposed to a constantly changing environment, limits full expression of growth and metabolic potentials. This aspect is partially overcome in fed-batch cultures, where a special feeding strategy prolonges the culture and allows an increase in cell concentration to be achieved. In perfusion and chemostat processes nutrients are continuously fed to the bioreactor, while the same amount of spent medium is withdrawn. However, in perfusion cultures the cells are retained within the bioreactor, as opposed to continuous-flow culture (chemostat), which washes cells out with the withdrawn medium [9]. 

A comparison for the different cases of the production costs and dependence on the annual capacity is given in Fig. 8.1-4. The results are based on the cascade-operation mode, with three extractors, extraction at 280 bar and 65°C, cycle-times of 7.5 hours, and a separation pressure of 60 bar for the non-isobaric process. 

Safety and loss performance in the chemical industry is the result of the interaction of plant design, construction and maintenance with production processes, and trained people applying a well-developed operating discipline. An accident leading to personal injury, property damage, or product loss invariably is the result of the failure of one or more of these elements. Each factor involved in chemical production—equipment, process, product, and people—may be subject to a variety of failure modes which may lead to accidents. 

To design or optimize an ED process several parameters are to be taken into account, namely stack construction and spacer configuration, operation mode, membrane perm-selectivity, feed and product concentration, flow velocities, current density and voltage applied to the electrodes, recovery... 

Batch is a discontinuous operation mode, and cell growth occurs without any additional supplementation of nutrients after inoculation of cells. While substrates are metabolized, the cell population grows, forming the product and other metabolites. The volume is maintained constant throughout the whole process. 

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