High-pressure process control systems

Advances in multiphase reactors for fuel industry are discussed in this work. Downer reactors have some advantages over riser reactors, but suffer from some serious shortcomings. The coupled reactors can fully utilize the advantages of the riser and the downer. For fuel industry that involves gas-liquid-solid system, slurry bed reactors especially airlift reactors are preferred due to their performance of excellent heat control and ease of seale up. For high-pressure processes, the spherical reactor is promising due to its special characteristics. 

Description The Vinnolit PVC process uses a new high-performance reactor (1), which is available in sizes up to 150 m3. A closed and clean reactor technology is applied thus, opening of the reactors is not necessary, except for occasional inspections. Equally important, high-pressure water cleaning is not necessary. All process operations of this unit are controlled by a distributed process control system (DCS). 

A major area of potential applications of inorganic membranes is high-tempcrature and/or high-pressure contaminant removal systems to protect process components and to control emissions from advanced coal-based power generation systems. The high temperature and pressure refer to 538 C (lOOO F) and above 5-35 bars, respectively. The potential applications include both bulk separation of gases and the removal of trace... 

Design of Process Control Systems for High-pressure Plants ... 

T vo carbon-capture processes have been studied in this chapter. Both use a two-column absorber/stripper flowsheet. The low-pressure amine system presents more problems in dynamic simulation than does the high-pressure physical absorption system. The plantwide control structures that are effective for the two systems are quite sunilar. 

The high-pressure process relied on large and complex plants that required careful process control. Therefore, the discovery in 1953 of the appropriate catalysts that allowed the process to be carried under low pressure ( 500 psi) was welcomed by the industry [7]. Three types of catalysts were developed about that time the Ziegler-type catalysts typically obtained by reacting alkyl aluminum compounds with titanium chloride metal oxide catalyst systems, developed by Phillips Petroleum in the United States, typically made of chromium oxide supported on a silicaceous carrier [8]) and a different type of oxide catalyst developed by Standard Oil Company. The first plants based on the Ziegler catalyst went on line in Germany by 1955 and a plant based on the Phillips catalyst in Texas opened in 1957. The third catalyst system developed much slower and was picked up by the Japanese plastics industry in a plant opened in 1961. 

A SFE system basically consists of a high-pressure pump to deliver the fluid solvent at high pressure, an extraction ceU provided with temperature controllers, and valves at both ends to maintain the high temperature and high pressure. Process scale extraction systems (Fig. 65.4) are provided with separators to separate the extracts and waste present in the solvent (unwanted compounds present in solvent other than extracts) from the solvent fluid which is generally CO2 and condensers to condense CO2 and reuse it in subsequent extraction processes. In case of SFE, sometimes the commercially manufactured extraction systems are used [59], and in certain cases, SFE extractor units are assembled in their respective laboratory units [60]. 

Figure 18 Diagram of an on-line IR process control system for polymer production. Reproduced with permission of the Society of Photo-Optical Instrumentation Engineers from Stengler RK and Weis G (1992) Infrared process control on molten polymers using a high pressure, high temperature flow cell. Proceedings of the SPIE - Society of Photo-Optical Instrumentation Engineers 68 33-38.

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