Compressor Technology

Compressors play an important role across the entire energy value chain, increasing the efficiency of various processes and ultimately helping to reduce emissions. 

The process is simple: 

A compressor increases the pressure of a compressible fluid – such as gas or vapour – by reducing its volume. This function allows for the efficient transport, storage, and utilisation of gases or air across various industries. 

Its main components: 

  • Inlet (Air Intake): this is where the air or gas enters the compressor. Filters here keep out dust or debris. 
  • Compression chamber: the heart of the compressor where the gas gets squeezed. The design depends on the type of compressor. 
  • Motor or Drive: powers the compression process, usually a steam or a gas turbine. 
  • Cooler: compressing gas heats it up, so coolers bring the temperature down before the gas moves on.
  • Outlet (Discharge): where the now high-pressure gas leaves the compressor for use. 

Compressors generally fall into two main categories: 

  • Turbo compressors, such as centrifugal compressors, which use rotating impellers to increase gas velocity and convert it into pressure. 
  • Piston-type compressors, such as reciprocating compressors, which compress gas by trapping and reducing its volume in a confined space. 

The various types: 

  1. Reciprocating Compressors: These compressors use pistons driven by a crankshaft to deliver high-pressure gas, making them suitable for chemical plants, refrigeration systems, and natural gas pipelines. 
  1. Centrifugal (Radial) Compressors: Employing a rotating impeller to add velocity to the gas, which is then converted to pressure, these compressors are found in heat pumps, air conditioning systems and gas turbines power plants. They also transport gases such as hydrogen over long distances. 
  1. Axial Compressors: Featuring multiple fan-like blades arranged in stages, axial compressors generate high-pressure ratios, making them essential in large gas turbines, air separation units, and blast furnace operations.  
  1. Electric Motor-Driven Compressors: Utilising electric motors, these compressors provide precise control and lower emissions, making them a preferred choice in industrial facilities with access to a reliable electrical grid.  

Compressors have different applications to support the Energy Transition:  

  • Large Heat Pumps: Compressors are central to heat pump systems, which transfer heat for industrial, commercial, and residential applications. The type of compressor used depends on factors such as required thermal power, installation parameters, and refrigerant type. 
  • CO2 storage & transport: Compressors are instrumental in carbon capture and storage (CCS) value chain. Once CO₂ is captured, compressors pressurise it for efficient transport through pipelines. Upon arrival at the storage site, the CO₂ often requires additional compression to meet the pressure needed for safe and permanent injection underground – a second, equally important role for compressors in the CCS process. 
  • Hydrogen storage & transport: Compressors are necessary for hydrogen production, storage, and transportation. Whether hydrogen is stored in salt caverns or used in industrial processes such as steel and cement production, it must be compressed to the required pressure for efficient handling and use. Compressors are also critical for transportation: along hydrogen pipelines, compressor stations maintain the necessary pressure to ensure continuous and safe delivery from production sites to end-users. 
  • Compressed-Air Energy Storage (CAES): In renewable energy systems, compressors help store excess electricity by compressing air. The stored energy can later be released to generate power when demand is higher, helping balance the energy supply.