Petrochemical plants

The illustrated pictures shows a normal and an infrared view of isolated piping in a petrochemical plant. 

In petrochemical plants, fans are most commonly used ia air-cooled heat exchangers that can be described as overgrown automobile radiators (see HeaT-EXCHANGEtechnology). Process fluid ia the finned tubes is cooled usually by two fans, either forced draft (fans below the bundle) or iaduced draft (fans above the bundles). Normally, one fan is a fixed pitch and one is variable pitch to control the process outlet temperature within a closely controlled set poiat. A temperature iadicating controller (TIC) measures the outlet fluid temperature and controls the variable pitch fan to maintain the set poiat temperature to within a few degrees. 

The dominant role of petroleum in the chemical industry worldwide is reflected in the landscapes of, for example, the Ruhr Valley in Germany and the U.S. Texas/Louisiana Gulf Coast, where petrochemical plants coimected by extensive and complex pipeline systems dot the countryside. Any movement to a different feedstock would require replacement not only of the chemical plants themselves, but of the expensive infrastmcture which has been built over the last half of the twentieth century. Moreover, because petroleum is a Hquid which can easily be pumped, change to any of the soHd potential feedstocks (like coal and biomass) would require drastic changes in feedstock handling systems. 

Design and Construction ofiEP-Gas Installations at Marine Terminals, Natural Gas Processing Plants, Refineries, Petrochemical Plants, and Tank Farms, API Standard 2510, 4th ed., American Petroleum Institute, Washington, D.C., Dec. 1978. 

Ca.pita.1 Investment ndReturns. Capital needs for commodity chemicals are usuaHy very high, hundreds of millions of doHars being needed for many petrochemical plants of economic size. Return on investment (ROI) and return on sales (ROS) vary widely. Capital needs of specialty products are usuaHy quite low, often about 50 to 600 per doHar of sales. ROI and ROS vary widely but are usuaHy higher than those for commodities. 

E. E. Ludwig, Applied Process Design for Chemical and Petrochemical Plants Gulf Publishing, Houston, Tex., 1979. 

The first industrial quantities of isopropyl alcohol were produced in 1920 in the world s first petrochemical plant, owned by Standard Oil (Exxon)... 

Ambient-cure systems are often based on lower molecular-weight soHd epoxy resins cured with aUphatic polyamines or polyamides. Curing normally occurs at ambient temperatures with a working life (pot life) of 8—24 h, depending on the formulation. Epoxy—poly amine systems are typically used for maintenance coatings in oil refineries, petrochemical plants, and in many marine appHcations. Such coverings are appHed by spray or bmsh. These are used widely where water immersion is encountered, particularly in marine appHcations (see COATINGS, MARINE). 

The current widespread interest in MFC techniques was initiated by pioneering research performed by two industrial groups in the 1970s. Shell Oil (Houston, TX) reported their Dynamic Matrix Control (DMC) approach in 1979, while a similar technique, marketed as IDCOM, was published by a small French company, ADERSA, in 1978. Since then, there have been over one thousand applications of these and related MFC techniques in oil refineries and petrochemical plants around the world. Thus, MFC has had a substantial impact and is currently the method of choice for difficult multivariable control problems in these industries. However, relatively few applications have been reported in other process industries, even though MFC is a veiy general approach that is not limited to a particular industiy. 

The combination of MPC and frequent on-line optimization has been successfully applied in oil refineries and petrochemical plants around the world. 

Tbe vertical iu-liue pumps, although relatively new additions, are finding considerable use iu chemical aucl petrochemical plants iu tbe United States, Au inspection of tbe two designs will make clear tbe relative advantages iiud disadvantages of each,... 

Scraped-surface exchangers are particularly suitable for heat transfer with crystalhzation, heat transfer with severe folding of surfaces, heat transfer with solvent extraction, and heat transfer of high-viscosity fluids. They are extensively used in paraffin-wax plants and in petrochemical plants for ciystallization. 

Carbon steel and alloy combinations appear in Table 11-12 Alloys in chemical- and petrochemical-plant sei vice in approximate order of use are stainless-steel series 300, nickel. Monel, copper alloy, aluminum, Inconel, stainless-steel series 400, and other alloys. In petroleum-refinery sei vice the frequency order shifts, with copper alloy (for water-cooled units) in first place and low-alloy steel in second place. In some segments of the petroleum industiy copper alloy, stainless series 400, low-alloy steel, and aluminum are becoming the most commonly used alloys. 

Horizontal Blowdown Drum/Catch Tank This type of drum, shown in Fig. 26-16, combines both the vapor-liquid separation and holdup functions in one vessel. Horizontal drums are commonly used where space is plentiful, such as in petroleum refineries and petrochemical plants. The two-phase mixture usually enters at one end and the vapor exits at the other end. For two-phase streams with very high vapor flow rates, inlets may be provided at each end, with the vapor outlet at the center of the drum, thus minimizing vapor velocities at the inlet and aiding vapor-hquid separation. 

Filters separate and retain the dirt from the oil. They are rated based on the size of the largest particle that can pass through, Vlost machines in petrochemical plants use lO-rnicron filters. Alarms are provided to signal when a filter becomes clogged up with dirt, A v aking system allovvvs the oil to be bypassed to an alternate filter, while the element of the first one is replaced. Filter elements can be... 

API Publ 2009, Safe Welding and Cutting Practices in Refineries, Gasoline Plants, and Petrochemical Plants, 6th ed., September 1995... 

IRI. Loss Prevention and Protection for Chemical and Petrochemical Plants. Industrial Risk Insurers, Hartford, CT. 

Any of the above reasons tnay result in noise and an increase in temperature and must be corrected. Critical installations such as a refinery, a petrochemical plant, a chemical plant or a petroleum pipeline may require special precautions and control to avert any excessive heating of the bearings, which may become fire hazards. For these installations, bearing temperature detectors with a relay and alarm facility may also be installed in the control circuit of the switching device to give warning or trip the motor if the temperature of the bearing exceeds the preset safe value. 

To have a modular construction with a wide choice of module sizes for optimum utilization of the usable area in each vertical panel, which is normally 1800 mm as illustrated in Figure 13,32, The general practice is to have the module sizes in the ratio of 1/6 (300 mm), 1/4 (450 mm), 1/3 (600 mm) and 1/2 (900 mm), etc. Some manufacturers, however, supply 1/8 (225 mm) and 1/9 (200 mm) size of modules when the sizes and number of components for a module are less and can be accommodated in such a small module size. For critical installations, however, such as for a refinery or a petrochemical plant or for the essential services of a powergenerating station or installations that are in humid conditions or are contaminated, it is advisable to have a module size no smaller than 1/6 (300 mm)... 

The leakage current at hazardous locations such as refineries, petrochemical plants and mines should not exceed 15% of the rated current of the circuit or 5 A, whichever is greater. Table 21.3 indicates the maximum permissible ground leakage currents for such areas at 15% of the rated current and the recommended maximum ground loop impedances. 

Ethane is used by petrochemical plants to make ethylene, a primary building block for many plastic products. Butane and condensate are used by refineries producing automotive fuel. For production of NGL s (natural gas liquids), die plant s recovery rate of 98% of ediane and 100% of all odier liquid products contained in natural gas, is among die best in die world. 

LNG—consisting of ethane, propane, butane, and natural gasoline (condensate)—arrives at the plant for upgrading before it is sent to petrochemical plants and refineries as feedstock. Residue gas is sold to the interstate and intrastate pipeline network. MESA, one of the world s major crude helium producers, also delivers helium to a pipeline operated by the U.S. Bureau of Mines. 

Both the Power Industry and the petrochemical industries use the aircraft-type turbine. The Power Industry uses these units in a combined cycle mode for power generation especially in remote areas where the power requirements are less than 100 MW. The petrochemical industry uses these types of turbines on offshore platforms especially for gas re-injection, and as power plants for these offshore platforms, mostly due to their compactness and the ability to be easily replaced and then sent out to be repaired. The aeroderivative gas turbine also is used widely by gas transmission companies and petrochemical plants, especially for many variable speed mechanical drives. These turbines are also used as main drives for Destroyers and Cruise Ships. The benefits of the aeroderivative gas turbines are ... 

For gas turbines, especially the more advanced high-temperature gas turbines, the oil of choice should be synthetic oil, since synthetic oils have a high flash point. Gas turbine lubrication systems should be run for about 20 minutes after shutdown since maximum temperatures are reached after 10 minutes of shutdown especially in the bearing area. Most gas turbines are also on turning gear to avoid sagging in the shaft. Mineral oils can be used for the compressor. It is not uncommon to have two types of oil in a petrochemical plant. Mineral oil costs much less than the synthetic oil. 

Ludwig, E. E., Applied Process Design For Chemical and Petrochemical Plants, Vol. 1, Gulf Publishing Co. 2nd Edition., 1977. 

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