Batch equipment

Auxiliaiy equipment and the special design considerations discussed for batch trays and compartments apply also to tunnel equipment. For size-estimating purposes, tray and truck tunnels and furnaces can be treated in the same manner as discussed for batch equipment. 

Process chemistry should be selected to fit existing batch equipment. 

Batch equipment located indoors. A release of flammable/toxic material tends to disperse slower than if the release is outdoors. May lead to large concentration buildup and result in operator exposure. Confined flammable releases are also more likely to result in explosion with larger overpressures. 

The goal is to maintain a history of data associated with previously executed batches, equipment operating rates, etc. and provide this information to other... 

In order to be economically viable, a continuous emulsion polymerization process must be able to produce a latex which satisfies application requirements at high rates without frequent disruptions. Since most latex products are developed in batch equipment, the problems associated with converting to continuous systems can be significant. Making such a change requires an understanding of the differences between batch and continuous reactors and how these differences influence product properties and reactor performance. 

Fig. 4.41 (n = 12 batches) and 4.42 (n = 46 batches) depict what can and what cannot be gleaned from a detailed study of such cleaned-up tables Unless a connection is fairly obvious, such as between impurities B and C in Fig. 4.42, comparisons can resemble small-talk about the weather, in that there is always a subset of data to prove a given pet notion, and another to disprove it. Why Over the course of a few months a series of insignificant changes in raw materials (a new batch), equipment (higher-capacity steam... 

The chemical route a potential decrease in manufacturing costs is roughly proportional to the reduction in number of processing steps. B2C is therefore attractive if it is an enabler for a chemistry that carmot be carried out in classic batch equipment. This is the opportunity for novel reactor technologies. The economic impact is, however, hard to define quantitatively [34, 60]. 

Safety is another reason for con.structing dedicated in.stallations, sometimes for a continuous process. The inventory of dangerous materials in continuous equipment is usually much smaller than that in batch equipment, which results in a safer process. Danger of explosions leads to performing reactions in isolated bunkers, the cost of which is comparable to that of the... 

Loonkar and Robinson (1972) extended the design problem to the optimal selection of semi-continuous equipment for pre-selected batch equipment that was fixed by the recipe. 

Optimal design. As mentioned in section 7.4.1.4, the cost of batch equipment can be used as the objective function to be minimized ... 

The relative sizes of batch equipment are specified by means of size factors Shj for a hypothetical product. The production requirements and characteristics of each product are converted to the equivalent data for the hypothetical product and the equipment sized to achieve the required production of the hypothetical product. The method proceeds in three steps (I) calculation of exact equipment sizes for a fixed number of units of the same size mj, (2) conversion of exact equipment sizes to standard sizes, and (3) choice of mj. 

The sizes of the batch equipment units are then calculated from ... 

The processing units of most large chemical plants today are not located inside buildings. This is true as far north as Michigan. The only equipment enclosed in buildings is that which must be protected from the weather, or batch equipment that requires constant attention from operators. Much of the batch equipment used today does not fit this category. It is highly automated and does not need to be enclosed. 

Most chiral chemicals are relatively small-scale products (1 to 1000 tonnes per year for pharmaceuticals, 500 to 10000 tonnes per year for agrochemicals) that are usually produced in multipurpose batch equipment This is probably the case for most catalytic reactions described in this chapter however, as a rule very little information on process technology is provided by the manufacturers. Here, we will discuss only briefly the reactor choices for hydrogenation reaction typically carried out in the liquid phase. For a successful implementation the following demands must be met ... 

Small-scale batch equipment is typically over designed for multipurpose use. 

Appropriate equipment is used for manufacturing drugs. The equipment must be maintained and calibrated at defined periods to ensure it functions as intended. After each production batch, equipment is cleaned to prevent crosscontamination from residues. Ideally, this entails that equipment should be designed without difficult-to-clean areas. A discussion of cleaning is given in Section 9.6.2. 

Energy efficiency. Temperature gradients are steady state and take place in space rather than in time, reducing the need for the expensive heating and cooling cycles common in batch equipment. 

The concept of process intensification does not need to apply to the whole of an API production process. There is merit in looking at hybrid reaction schemes, which retain the benefits of, or capital investment in, batch equipment but use continuous processes for the generation of hazardous intermediates [17] or for certain unit processes. Of these, hydrogenation [18], filtration [19], phase separation [20], crystallisation [21] and drying [22] are good examples. 

In Fig. 9.10-10 a diagram of typical batch equipment is shown, and in Fig. 9.10-11, a detail of the cell where samples can be located. 

Batch processing is used primarily when the reaction time is long or the required daily production is small. The same batch equipment often is used to make a variety of products at different times. Otherwise, it is not possible to generalize as to the economical transition point from batch to continuous operation. One or more batch reactors together with appropriate surge tanks may be used to simulate continuous operation on a daily or longer basis. 

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