Centrifugal Compressors: The 'Business End' of Many Critical Industries

For many of us in the large rotating equipment market, gas turbines are our main area of focus, and for good reason. Gas turbines are manufactured using leading-edge metallurgy, coatings, and aero-centric geometries to efficiently deliver rotational power at very high temperatures and pressures. But many times, the receiving end of this rotational power is equally impressive compressors, deployed for a variety of critical industrial processes.

The centrifugal compressors market is served by over 20 OEMs globally, producing over 2,000 units per year. In 2022, the value of this market (not including related aftermarket repairs) was approximately US$3.4 billion.

This market overview focuses on units rated above 1 MW and does not address positive displacement, diaphragm, or axial compressors.

TYPES OF CENTRIFUGAL COMPRESSORS

There are two types of centrifugal gas compressors: in-line (also called beam-type or between-bearings type) and integrally geared. In-line compressors have one or more impellers in a single casing, generally with the impellers located between two radial bearings on a single shaft. An exception to this rule is the single-stage gas pipeline compressor with an overhung impeller (both radial bearings on the same side of the impeller) and axial inlet. All impellers within an in-line compressor casing rotate at the same speed.

Types of centrifugal compressors

In contrast, integrally geared compressors have two or more impellers, each located in its own casing with each casing mounted on a single gearbox with a single bull gear driving each impeller through a pinion gear. This arrangement allows each impeller to rotate at a different speed. The required total pressure ratio is achieved by having the gas move through two or more single-stage compressors in series.

Axial Inlet Pipeline Compressor: Incorporates a single impeller on an overhung shaft with the gas inlet oriented directly into the impeller eye, with the gas discharging radially. Due to reduced gas turning this design is more efficient than beam-style compressors and can achieve efficiencies above 90%.

Radially Split Barrel Compressor: Incorporates one or more impellers mounted on a single shaft between two bearings. The casing split is vertical, which allows for better sealing at higher pressures, up to 1,000 bar.

Beam-Style Pipeline Compressor: A type of radially split-barrel compressor with one to four impellers mounted between two bearings. Generally used for multistage pipeline boosting applications.

Integral Motor Compressor: A design featuring a high-speed variable frequency motor driving one or more compressor impellers in a hermetically sealed casing that uses magnetic bearings. Benefits include reduced weight and footprint compared to traditional designs and no possibility of oil or gas leaking into the environment.

TYPICAL APPLICATIONS FOR CENTRIFUGAL COMPRESSORS

Applications served by centrifugal compressors (as segmented in this report) fall into three oil and gas sectors and one industrial sector:

Upstream Oil and Gas: These compressor applications are seen in oil and gas production operations, both onshore and offshore. They include initial processing operations done close to the point of extraction, including the dehydration and separation of liquids. Also included in upstream activity are compressors used in LNG liquefaction plants. (Note, some view LNG liquefaction as a downstream activity, but for the sake of this article, we are including them in the upstream segment.)

Midstream Oil and Gas: There are thousands of compressors used in gas transportation via pipeline as well as compressors used in underground gas storage applications. This segment also includes fuel gas compressors for gas-fueled power plants.

Downstream Oil and Gas: Compressors may also be used in refining and petrochemical production processes. These applications also include compression needs for fertilizer production and its precursors (ammonia, urea, nitric acid, etc.).

Industrial: Compressors used in other industrial applications, including air separation, CO₂, compressed air energy storage, and plant/process air compressors over 10,000 m³/hr.

OEMS

The more than 20 OEMs that serve the centrifugal compressor market manufacture multiple configurations of these compressors including:

• multistage barrel
• multistage horizontal
• pipeline
• single-stage process
• integrally geared gas
• integrally geared air
• plant air
• subsea
• hermetically sealed

While many of the OEMs in this market primarily serve a regional customer base, for example, those in Russia, China, and India, other OEMs serve the market on a global basis. Many of the globally diverse OEMs have broad product lines, like those mentioned above, while others have a narrower focus on specific product types.

A detailed review of these OEMs, the market segments they serve, and the product types they offer are included in Dora Partners & Company's annual Compressor Market Forecast and Report. The largest OEMs serving this market include Baker Hughes, Siemens, Elliott Group, MAN Energy Solutions, Solar Turbines, Mitsubishi, Atlas Copco, and Shenyang Blower Works.

MARKET SIZING AND THE AFTERMARKET

A detailed analysis of the market suggests that the annual OEM revenue for centrifugal compressors is more than US$3.4 billion per year. In 2022, approximately 2,300 units were ordered from the OEMs included in our study.

From a unit quantity perspective, the industrial segment is the largest, but most of these units are smaller and less expensive than the compressors used in the other segments. Units used in upstream applications are generally the most expensive, followed by those used in the midstream and downstream segments. From a total revenue perspective, downstream is the largest application segment.

There are significant differences in driver types across the application segments, with gas turbines frequently being used in the midstream and upstream segments, and steam turbines often being used in the downstream segment. Electric motors are used in all segments with almost all units in the industrial segment using this driver type.

From a geographic perspective, the largest destination region is Asia-Pacific, followed by the Americas.

Unlike many pieces of rotating machinery, such as gas turbines, reciprocating engines, and reciprocating compressors, centrifugal compressors have very few, if any, parts that are life- or wear-limited and require replacement on a scheduled basis. A well-designed and maintained centrifugal compressor can run for decades with very little corrective maintenance. As a result, most aftermarket revenue associated with centrifugal compressors comes from both parts and services that are required when something fails or revamps the equipment to modernize it or change its capabilities.

MARKET OUTLOOK

Dora Partners has estimated that 2023 will result in new unit orders of more than US$3.6 billion, with a relatively consistent growth forecast over the next 10 years. Overall, the market is expected to grow most rapidly in the Asia-Pacific region and the industrial market segment.

Upcoming market trends include growth in LNG production, carbon capture and storage, subsea compression, and hydrogen/ammonia applications, as worldwide decarbonization initiatives advance across the globe.

Note: Dora Partners & Company’s detailed report provides a much deeper evaluation of each market segment, product strengths for each of the main OEMs, and a 10-year forecast segmented by upstream, midstream, downstream, and industrial sectors. The report includes regional and OEM market share information, application, and trend observations. In addition, OEM profiles are provided detailing product and market strengths for the top nine compressor OEMs.

About the Authors: Anthony Brough is the Principal Consultant at Dora Partners & Company, and Tony Ruegger is the Senior Consultant at Dora Partners & Company.