August 10, 2026
Estimated reading time: 6 minutes
What is Mechanical Vapor Recompression (MVR)?
Mechanical vapor recompression is a technology that uses a compressor to upgrade low-pressure steam into high-pressure, high-temperature steam for reuse in industrial applications. Instead of venting surplus steam or firing a boiler to generate more, an MVR system captures that steam and puts the energy already inside it back to work.
The working principle is straightforward. A steam compressor, sometimes called an MVR compressor, draws in low-pressure vapor, compresses it mechanically, and reinjects it into the process at a higher pressure and temperature. Because the compression is driven by an electric motor rather than a fuel-fired boiler, the system converts electrical energy into thermal energy efficiently, similar in principle to how a heat pump works.
Mechanical vs. thermal vapor recompression (TVR)
MVR and thermal vapor recompression (TVR) both reuse low-pressure steam, but they get there in different ways. MVR uses a mechanical, electrically driven compressor to raise the pressure and temperature of the steam. TVR instead relies on steam-jet ejectors, using high-pressure motive steam to entrain and compress lower-pressure vapor.
In general, MVR offers higher efficiency than TVR because it does not consume additional motive steam, and its output can be finely controlled by adjusting compressor speed. TVR systems, on the other hand, have no moving parts, which can mean lower upfront costs and simpler maintenance for some applications.
Benefits of mechanical vapor recompression systems
Mechanical and thermal vapor recompression (TVR) both reuse low-pressure steam, but they get there in different ways. MVR uses a mechanical, electrically driven compressor to raise the pressure and temperature of the steam. TVR instead relies on steam-jet ejectors, using high-pressure motive steam to entrain and compress lower-pressure vapor.
In general, MVR offers higher efficiency than TVR because it does not consume additional motive steam, and its output can be finely controlled by adjusting compressor speed. TVR systems, on the other hand, have no moving parts, which can mean lower upfront costs and simpler maintenance for some applications.
Applications of MVR technology
Because MVR recovers steam that would otherwise go to waste, it suits any mechanical vapor recompression plant with a steady supply of low-pressure vapor and a high demand for process heat. Common applications include:
- Chemical processing
- Food and beverage production
- Pharmaceutical manufacturing
- Pulp and paper industry
In each of these settings, MVR turns steam that would otherwise be wasted into a dependable, lower-carbon energy source.
Case study: Mechanical vapor recompression for efficient steam upgrade
In an ongoing pilot project, a chemical process plant in the Netherlands uses mechanical vapor recompression to upgrade low-pressure steam and reuse it to supply energy. MVR, or in this case steam recompression, is a good example of the electrification of industrial energy demand. Central to the plant's MVR solution is a two-stage integrally-geared compressor, which compresses superheated steam from 3 barg to 12.5 barg in two steps. The result has been a reduction in natural gas usage and a net reduction in carbon dioxide (CO2) emissions.
MVR compressor upgrade at Terneuzen polyolefin plant
Feasibility study
In 2015, the plant collaborated on a feasibility study focused on using MVR to convert heat from surplus low-pressure steam to valuable medium-pressure steam. The plant then contacted several compressor manufacturers to explore the potential of supplying the requisite equipment.
Atlas Copco was chosen for its proposed solution of an integrally geared two-stage centrifugal compressor. The overhung arrangement of the machine's impellers on the pinion shaft ends means separate compressor bearings are not necessary. The bearings are identical to those of the compressor rotor, and the rotor shafts are made from a single heat-treated forged alloy steel. Shaft seals can be labyrinths, dry gas seals or floating carbon rings. Its integral setup makes it possible to have an intercooling/desuperheater after each compression stage, which results in increased efficiency.
Cross-section of an integrally geared compressor core
Compressor's coefficient of performance (COP)
Research on the compressor's coefficient of performance was very positive. In simple terms, COP shows the ratio between the recovered thermal power and the supplied electrical compressor power. Between November 2020 and November 2021, the MVR system achieved an overall COP of 7.5. This means that for 1 MW of electricity, 7.5 MW of thermal energy was produced, which represents a high performance, partly attributable to the inherent advantage of an open-heat pump directly compressing steam, compared to a standard compression heat pump with refrigerants.
Exterior of an integrally geared compressor core
Usage and savings
This highly energy-efficient process upgrades residual heat to high-quality heat. Using the untapped potential of low-pressure steam via MVR, the project shows how plant operators have successfully found a more energy-efficient supply. It also highlights that MVR can be used anywhere there is low-pressure steam or waste heat in excess of 80°C/180°F.
In addition to the good COP achievement, steam recompression underpins natural gas savings and CO2 emissions reductions. In the last 12 months, approximately 100 000 MWh (10 MMNm³) of low caloric natural gas was saved, and a CO2 reduction of 178 000 tons was achieved.
Ready to upgrade your steam system?
Consult our technical experts to explore custom integrally geared compressor solutions and discover how mechanical vapor recompression can optimize your plant's fuel usage and lower emissions.
Frequently asked questions
MVR stands for Mechanical Vapor Recompression.
An MVR system functions much like a heat pump: a compressor raises the pressure and temperature of a vapor, in this case steam, so its heat can be reused instead of lost.
MVR systems can carry higher upfront costs than conventional steam generation. They deliver the best return in applications with a large, steady volume of low-pressure steam available for reuse.
Explore more about Atlas Copco Gas and Process
Follow the below links to learn more about our technology and solutions.
