Equipment batch reactors

For more complex equipment, the columns might contain measurements for internal distillatiou, batch-reactor intermediate conditions, or tubular-reactor between-bed conditions. Some of these... 

With PI, traditional proeess design criteria (particularly those focused around stirred batch reactors) are thrown out and the equipment is designed to mateh the chemistry. It is not unexpected, therefore, to find that PI has been successfully applied to reactions that are very fast and exothermic, where the process is being limited by poor design. Traditionally these proeesses have been handled either by the use of large amounts... 

Aim of this work was to optimise enzymatic depolymerization of pectins to valuable oligomers using commercial mixtures of pectolytic enzymes. Results of experiments in continuous and batch reactor configurations are presented which give some preliminary indications helpful to process optimisation. The use of continuous reactors equipped with ultrafiltration membranes, which assure removal of the reaction products, allows to identify possible operation policy for the improvement of the reaction yield. 

The fine chemicals business is characterized by a small volume of products manufactured. Therefore, batch production predominates and small-scale reactors are used. The need to implement fine chemistry processes into existing multiproduct plants often forces the choice of batch reactors. However, safety considerations may lead to the choice of continuous processing in spite of the small scale of operation. The inventory of hazardous materials must be kept low and this is achieved only in smaller continuous reactors. Thermal mnaways are less probable in continuous equipment as proven by statistics of accidents in the chemical industries. For short reaction times, continuous or semicontinuous operation is preferred. 

There are two ways of laying out a processing area. The grouped layout places all similar pieces of equipment adjacent. This provides for ease of operation and switching from one unit to another. For instance, if there are 10 batch reactors, these would all be placed in the same general area, and could be watched by a minimum of operators if they were spread out over a wide area, more operators might be needed. This type of scheme is best for large plants. 

Batch reactors are often used for liquid phase reactions, particularly when the required production is small. They are seldom employed on a commercial scale for gas-phase reactions because the quantity of product that can be produced in reasonably sized reactors is small. Batch reactors are well suited for producing small quantities of material or for producing several different products from one piece of equipment. Consequently they find extensive use in the pharmaceutical and dyestuff industries and in the production of certain specialty chemicals where such flexibility is desired. When rapid fouling is encountered or contamination of fermentation cultures is to be avoided, batch operation is preferable to continuous processing because it facilitates the necessary cleaning and sanitation procedures. 

When the specified production capacities are low, processes based on batch reactors will usually have lower capital investment requirements than processes calling for continuous operation, so batch reactors are often preferred for new and untried processes during the initial stages of development. As production requirements increase in response to market demands, it may become more economic to shift to continuous processing but, even in these cases, there are many industrial situations where batch operation is preferable. This is particularly true when the operating expenses associated with the reactor are a minor fraction of total product cost. At low production capacities, construction and instrumentation requirements for batch reactors are usually cheaper than for continuous process equipment. Moreover, it is generally easier to start up, shut down, and control a batch reactor than a comparable capacity continuous flow reactor. 

The catalytic experiments were carried out in a small four-necks glass batch reactor (50-ml), equipped with magnetic stirrer, thermometer, and condenser. In order to avoid the lost of isobutylene formed during reaction the condenser was kept at -13°C by the means of a cryostat. The temperature was maintained at 343 K and the speed of stirring was 800 rpm. Alkylation reaction was carried out at atmospheric pressure. 

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