Commercial-scale operation

Commercial-scale operations are conducted in batch, fed-batch, or continuous culture systems. Fermentation vessels include the conventional baffled aerated tank, with or without impeller agitation, and the ak-lift tower fermentors in which ak is sparged into an annular space between the... 

New furnace concepts in evolutionary stages include fluidized-bed furnaces (25), coal gasification furnaces (26), and MHD furnaces (27,28). Of these technologies, fluidized-bed combustion has reached commercial-scale operations (Fig. 11). 

A third factor affecting the quantity to be processed is the scale of the processing operation. A laboratory-scale operation will typically require less sample than a pilot-scale operation and much less than a commercial scale operation. Throughout the process, each unit operation must be supplied sufficient material to operate the process adequately while providing representative samples from the process. 

When studying a new separation, the separation factors applicable to the considered medium are first determined in our laboratories. Then the various parameters are fed into a computer which uses a program similar to the one used in fractional distillation. The data obtained are usually in excellent agreement with the results of commercial scale operations. 

These two successful commercial applications of rotating packed beds prove that scale-up from pilot-scale equipment can achieve the desired process performance in commercial-scale operations. In addition, the mechanical reliability of the rotating equipment is in line with the experience with other rotating... 

Germany demonstrated commercial-scale operation of DCL during World War II, employing the Bergius process, which they had developed. After World War II, the United States constructed a 200-300 bbl/day DCL plant at Louisiana, Missouri, based on the German technology. This plant was operated by the Bureau of Mines from 1949 to 1954. However, as the extent of petroleum deposits in the Middle East and other locations became apparent and fears of an oil shortage subsided, interest in DCL diminished. 

At this time, purified potassium carbonate was primarily of value as an ingredient in glass making. The discovery of mineral potassium chloride at Stassfurt, Germany, in 1852, rapidly provided competition to the wood ash leachate industry since this mineral could be readily converted to potassium carbonate by the Leblanc process, which was already in commercial scale oper-... 

The Purex process is the only one with commercial-scale operating history. This military technology has been modified to treat domestic spent nuclear fuel. The focus of international commercial efforts to reprocess domestic spent fuel is to recover uranium and plutonium in the spent fuel. 

Tubular reactors are commonly used in laboratory, pilot plant, and commercial-scale operations. Because of their versatility, they are used for heterogeneous reactions as well as homogeneous reactions. They can be run with cocurrent or counter-current flow patterns. They can be run in isothermal or adiabatic modes and can be used alone, in series, or in parallel. Tubular reactors can be empty, packed with inert materials for mixing, or packed with catalyst for improved reactions. It is often the process that will dictate the design of the reactor, as discussed in this entry. 

To scale up a chemical process to pilot or commercial-scale operations, a significant laboratory effort is required to define the operating ranges of the critical process parameters. A critical process parameter is any process variable that may potentially affect the product quality or yield. This information is required to prepare a Process Risk Analysis, which is an FDA prerequisite for process validation. Process parameters that are often evaluated as part of the risk analysis include reaction temperature, solvent systems, reaction time, raw material and reagent ratios, rate and orders of addition, agitation, and reaction concentration. If catalysts are employed as part of the process, additional laboratory evaluation may also be required to further define the process limits. Experimental design is often used for the evaluation of critical process parameters to minimize the total laboratory effort (4). 

Identification of Processing Equipment Requirements. When transferring processes from pilot to commercial-scale operations, a comparative analysis is usually made between the equipment used in the pilot operation with the proposed commercial facility. Process flow diagrams (PFDs) that include material balances from pilot plant experiments can facilitate this analysis. Specifications and requirements for agitation, filtration, drying, and milling devices are established based on experimental results that support these specifications and are documented. 

The validation of a new BPC entails practices that parallel those utilized for the introduction of a new pharmaceutical formulation. Thus, a large part of the initial validation effort must be linked to the developmental activities that precede commercial-scale operation. The similarity is such that aspects of reaction, and purification methodologies should be as similar as possible given of course the difference in the scale of the equipment utilized in the commercial facilities. Any differences between the BPC process utilized for the formulation batches used to establish clinical efficacy and the commercial material must be closely evaluated and their impact on the BPC products chemistry, purity profile, stability, crystal morphology, and other key attributes. 

The ammonolysis process is scheduled to reach commercial-scale operations in North America before the year 2000. Current recycling cost estimates give a material price that is 10-15 per cent higher than that of a normal PA production plant which would mean a material price of 5.5-5.75 SFr/kg. The total cost of the material will of course depend on the cost and quality of the feedstock. Large quantities of solid waste carmot be purged economically from the process. Fillers or modifiers would have to be removed from the feedstock before recycling to achieve high quality. 

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