LiBr-H₂O absorption heat pumps for waste heat recovery and upgrading

LiBr-H₂O absorption heat pumps are one of the most efficient solutions for recovering and upgrading waste heat in industrial processes and commercial buildings. The LiBr-H₂O absorption cycle turns low- or medium-temperature thermal energy into higher-value useful heat, reducing primary energy consumption and CO₂ emissions.

This technology plays a strategic role in industrial decarbonisation projects, where the goal is no longer just to produce heat efficiently but to use the energy that is traditionally released through cooling towers, condensers or thermal effluents.

Depending on the application and the temperature level required, absorption heat pumps are classified as Type I and Type II (Heat Transformer), offering specific solutions for different energy recovery strategies.

LiBr-H₂O absorption heat pump technology

Absorption heat pumps use the water-lithium bromide (LiBr-H₂O) system as the refrigerant-absorbent pair to transfer thermal energy between different temperature levels through a high-efficiency thermodynamic cycle.

Unlike compression heat pumps, the process is driven mainly by thermal energy, requiring only a small amount of electricity for auxiliary pumps and control systems. This makes them a particularly attractive solution where waste heat or low-temperature heat sources are available.

Depending on the goal of the installation, the technology can be used to increase useful heat production with a driving heat source (Type I) or to directly raise the temperature of a waste heat stream (Type II), making the most of the energy in the process.

Type I absorption heat pumps

Hot water production from waste heat recovery

Type I absorption heat pumps recover low-temperature heat and, with a driving heat source, produce hot water at a higher temperature for use in industrial processes, heating or DHW production.

Depending on the operating temperatures and the unit design, they achieve thermal COPs of between 1.5 and 1.8, providing high energy efficiency and excellent use of the waste heat available. The THERMAX TCP range is the benchmark solution for these applications, combining operating reliability with a design suited to continuously running industrial processes.

Main applications

• Process hot water production.
• Food industry.
• Chemical industry.
• Pharmaceutical industry.
• DHW production.
• Industrial and commercial heating.
• Integration with cogeneration.
• District Heating networks.

Type II absorption heat pumps (Heat Transformer)

Raising the temperature of waste heat

Type II absorption heat pumps, also known as Heat Transformers, are designed to raise the temperature of a waste heat stream so that part of that energy can be reused in processes that need a higher temperature level.

In industrial applications they achieve COPs of around 0.45 to 0.50, making them a highly efficient solution for upgrading waste heat that would otherwise be released to the surroundings. The THERMAX THP range is the benchmark technology in this segment, making it possible to upgrade waste streams from demanding industrial processes such as the chemical, paper and petrochemical industries.

Main applications

• Chemical industry.
• Paper industry.
• Drying processes.
• Food industry.
• Refineries.
• Petrochemical plants.
• Heat recovery in continuous industrial processes.

LiBr-H₂O absorption heat pumps are a key technology for turning waste heat into a high-value energy resource. Both Type I solutions, aimed at efficient hot water production, and Type II Heat Transformers, designed to raise the temperature of waste streams, make the most of the energy available and move towards a more efficient, competitive and decarbonised industry.