Industrial basic operating modes

Figure 1.2 The basic operating modes of industrial-scale cultivation of suspended cells. The simplest mode is batch culture without any feed except possibly add or base for pH control. The productivity of a simple batch can be considerably increased and extended by feeding fresh, usually concentrated sterile medium until the culture vessel is completely full. The continuous...

The check list method is based on past experience. The process description, the operating mode, is screened using a list of possible failures or deviations from this particular operating mode. Thus, it is obvious that the quality and comprehensiveness of the check list directly govern its efficiency. Indeed, the experience of the authors confirms that the check list is essential. This method is well adapted to discontinuous processes as practised in the fine chemicals and pharmaceutical industries, where processes are often performed in multi-purpose plants. The basic document for the hazard identification is the process description, also called operating mode. Each step of the process is analysed with the check list. 

It is important to emphasize the general character of this definition for the volumetric productivity (Py), since it includes all phases of a production cycle in a bioreactor, allowing an evaluation of the impact of bioreactor preparation time and duration of growth and production phases on productivity. As can be observed from Equations 19 to 22, for an industrial bioreactor with a given volume and operation mode, the volumetric productivity depends basically on cell concentration in the production phase and on the specific product formation rate (qp). 

The author s group in Jerusalem is involved in both GC and GC/MS/C of fossil fuels. The availability of MS (VG ZABIIF) linked to a GC allowed various operation modes. Some of the data presented in this review have not been published previously, except in industrial reports. The main advantage in the use of GC/MS/C for saturated hydrocarbons lies in the ability to identify the branched and cyclic bio -alkanes, also called biomarkers . The basic analytical approach to the study of these compounds was discussed in Section III.A.3. However, the GC/MS/C method provides the possibility to work on the whole saturated hydrocarbon fraction, without employing extensive... 

Two operational FIA modes are used for analyzing industrial samples, particularly for continuous process monitoring and control. In the first mode, which is the basic FIA technique, the sample to be analyzed is continually drawn out from the process to be monitored and periodically injected into the carrier stream and thus into the FIA chaimel. The system is first calibrated using one or several standards of known concentration the process is then monitored via periodic sampling. The instrument may be rechecked by injecting another series of standards. In the second operational mode it is the reactant that is injected. The sample solution is pumped continuously through the FIA system and the reactant, which generates the product whose property is measured, is injected into this stream at predetermined time intervals. This technique, known as reversed FIA, has the... 

The basics of melt crystallization are provided in Chapter 15. Here, the concepts of plants and/or existing and commercially available equipment are shown. As mentioned in Chapter 15, the concepts of plants can be divided into two lines of technology solid layer crystallization and suspension crystallization. Furthermore, in industrial applications these two techniques are split into continuous and batchwise as well as into static and dynamic (stagnant or flowing melt) operating modes. A detailed overview of the different techniques and apparatuses in solid layer as well as suspension crystallization is provided in the Sections 17.1.1 and 17.1.2. 

Table 15.2 gives performance data for typical industrial type schemes using thermal power plant in a condensing steam cycle. These do not operate strictly in the simple cycle mode as varying degrees of feed heating are employed. However, overall they convey the basic cycle conditions that the industrial user would encounter and give efficiencies that can be expected. 

The remainder of this text attempts to establish a rational framework within which many of these questions can be attacked. We will see that there is often considerable freedom of choice available in terms of the type of reactor and reaction conditions that will accomplish a given task. The development of an optimum processing scheme or even of an optimum reactor configuration and mode of operation requires a number of complex calculations that often involve iterative numerical calculations. Consequently machine computation is used extensively in industrial situations to simplify the optimization task. Nonetheless, we have deliberately chosen to present the concepts used in reactor design calculations in a framework that insofar as possible permits analytical solutions in order to divorce the basic concepts from the mass of detail associated with machine computation. 

Overall, most of the requirements for a process spectrometer/analyzer are straightforward to implement, but they do require attention at the design level. Another important area, which is FTIR-specific, is the user interface and the need to provide for industry standard data communications. Standard software packages do exist for process instrumentation. For prototype development, and even for the front-end interface in a standalone mode of operation, software products, such as Microsoft s Visual Basic and National Instruments LabView, are also important instrumentation development tools. Note that National Instruments also provides important computer-based electronics and hardware that meet most of the computer interfacing, and system control and communications needs for modem instrumentation. 

When chromatographic separations (7) are operated in a batch mode, a portion of the mixture to be separated is introduced at the column inlet. A solute-free carrier fluid is then fed continually through the column, the solutes separating into bands or zones. Some industrial operations such as mixed-vapor solvent recovery and sorption of the less volatile hydrocarbons in natural gas or natural gasoline plants are being carried out on pilot plant and semiworks scales. Continuous countercurrent systems designed along the basic principles of distillation columns have been constructed. 

Ship transportation is one of the most attractive transport modes for raw chemical procurement in chemical industry. Raw materials and basic chemicals are required constantly and in huge quantities to supply continuously operating chemical production plants. The ideal transport mode is the pipeline transport. However, pipehnes dedicated for basic and raw chemicals are seldom available due to large distances to bridge, high investment costs, and the inflexibility of sourcing. In most cases, raw and basic chemicals are transported by ships if a sea or river port is available. 

In terms of the physical configurations commonly encountered in industrial practice, Aere are two basic types of reactors the tank and the tube. The ideal tank reactor is one in which stirring is so efficient that the contents are always uniform in composition and temperature throughout. The simple tank reactor may be operated in a variety of modes batch, semibatch, and continuous flow. These modes are illustrated schematically in Figure 8.1. In the simple batch reactor, the fluid elements will all have the same composition, but the composition will be time dependent. A stirred-tank reactor may also be operated in semibatch fashion. In this mode the tank is partially filled with reactant(s), and additional reactants are added progressively until the desired end composition is achieved. Alternatively, one may charge the reactants... 

One of the basic problems of crystalhzer design is the choice of method for measuring design data. The mode of operation, type of apparatus and scale of operation all have to be considered. Basically there are three choices to measure the data on the laboratory, pilot-plant or industrial-plant scale. The last of these choices is not uncommon, because many crystalhzers are designed on the basis of current experience. Generally, however, the choice hes somewhere between the laboratory unit and a pilot plant. 

HSE assessments have a long tradition within the oil-and gas industry. These assessments use a wide range of methodologies, from the strict quantitative methods such as QRA (Quantitative Risk Analysis) and FMECA (Failure Mode Effect and Criticality Analysis) to the more qualitative methods such as HAZOP (HAZard OPerability analysis). Most methods combine qualitative and quantitative data and approaches. For example, an FMECA basically uses generic failure data, expert judgments are likewise important. 

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