Processing facilities compressors

Gas turbine driven centrifugal compressors are very efficient under the right operating conditions but require careful selection and demand higher levels of maintenance than reciprocating compressors. Compression facilities are generally the most expensive item in an upstream gas process facility. 

The first part of the Information Manual provides an overview description of the process facility, what its primary functions and products are, and what those products are used for. The process overview can include information to do with the facility s location, its impact on the environment, and general public relations issues to do with the local community. An overview of meteorology data can be included in this section also. The overview will also provide a summary of the major equipment items such as distillation columns, fired heaters, compressors, pumps, and heat exchangers. A layout sketch for each level of the facility (or each deck of a platform) should be provided. 

Compressor machines are used to increase the pressure of a gas by mechanically reducing its volume within its case. Air is most frequently compressed, but natural gas, oxygen, and nitrogen are also compressed Positive-displacement, centrifugal, and axial compressors are the three most common types used in process facilities and pipeline stations. They can handle large volumes of gas in relatively small equipment and may have a variety of drives (e.g., elearic motors and steam or gas turbines). 

Units with a power rating of less than 3 MW that are used exclusively to power natural gas field compressors upstream of natural gas processing facilities are exempt from the SO2 limits. 

The BSD can either shut down the entire facility, or it can be designed for two levels of shutdown. The first level shuts down equipment such as compressors, lean oil pumps, and direct fired heaters, and either shuts in the process or diverts flow around the process by closing inlet/outlet block valves and opening bypass valves. The second level shuts down the remaining utilities and support facilities, including generators and electrical feeds. 

All hydrocarbon process areas containing materials with gaseous materials that are not adequately ventilated (i.e., would not achieve a minimum of six air changes per hour or would allow the build up of flammable gas due to noncirculating air space). Typically applications include compressor enclosures, process modules in offshore platforms and enclosed arctic facilities. 

The diaphragm compressor (Fig. 4.1.35), one of the oldest leak-free process machines, is limited to lower power (< 100 kW) because sensitive metal diaphragms must be used due to the high compression temperatures and pressures. Its applications include laboratories, pilot installations, and special production facilities. An attractive feature is their very high pressure-ratio (up to 20) produced by a single stage as a result of the small dead-space and good cool-... 

In chemical plants, in steam and gas turbine powered compressor and power stations and pressure control facilities for natural gas, combustible fluids and gases need to be preheated in order to comply with the process parameters,... 

The sequence of engineering was adapted to the special requirements of the project. Initially, process design was completed for the three process units and the process instrument diagrams were developed. The support facilities were scoped in sufficient detail to develop the overall site plan and to determine the real estate required for site selection and the preparation of the EIR. After the EIR was submitted, detailed design started with the preparation of equipment material requisitions for fabrication and delivery of long delivery items such as compressors, large vessels, etc. 

Commercial examples The capacities for two plants were 398,000 metric tpy and 1.007 million metric tpy, respectively. After using the HAT catalysts and operation conditions of the S-TDT process, outputs for both benzene and mixed xylenes increased by 40% without any changes to the reactor, compressor and catalyst inventory for both facilities. 

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