With the adoption of the Paris Agreement, 196 countries worldwide committed to the limitation of the global temperature rise. In order to achieve this goal more energy needs to be produced in a sustainable way. However, the industrial sector is still mainly fossil driven and therefore has to adapt to be able to utilize sustainable produced power, which most often is in the form of electricity. More than a quarter of the total heating demand is in the 100 ◦C to 200 ◦C range. In this temperature range heat pumps are a strong alternative to fossil fuels. Heat pumps can absorb energy from a low temperature heat source and deliver it at a higher, usable temperature. Various technologies for waste heat recovery were investigated in this thesis. It was identified that existing heat pump technologies are suitable to upgrade waste heat, but are limited to lower temperatures of around 120 ◦C. This limitation is mostly due to the high compressor discharge temperatures, which degrade the lubrication oil. Compression resorption heat pumps utilizing wet compression (CRHP’s) limit the superheating during compression and are able to operate oil free, because the working fluid acts as a lubricant. This increases the achievable compressor discharge temperature. The wet compression however is not yet a mature technique and an isentropic efficiency of 70% is required to be competitive with existing technologies. Absorption cycles show promising results for upgrading waste heat due to their non-isothermal heat source and sink, which can be matched to the waste heat temperature. At the Process and Energy lab experiments have been performed on a wet compressor using an ammonia water mixture. This thesis proposes a new method of analysing existing experimental data through a cycle energy balance model. In order to create a model of the experimental setup, four limitations of the setup were identified. First the influence of the gap seal flow, which is the flow from the high pressure to the lower pressure side of the compressor. Second, the mixture inside the compressor can not be assumed homogeneous, which means that both phases are not in equilibrium. Third, there is cooling oil flowing through the compressor housing which cools the process side, this results in a non-adiabatic compression. Finally the pressure drop on the high pressure side is not measured, resulting in an error when calculating the composition of the working fluid. In order to model these limitations a model of the experimental setup was created in Aspen Plus. This model was supplemented with Matlab code to account for the non-equilibrium compression as well as the pressure drop and gap seal flow. Empirical relations were used to determine the heat and mass transfer between the phases during compression. The isentropic efficiency of the modelled compressor was varied until the output matches the input indicating that the steady state solution has been found. The influence of the non-adiabatic compression and the gap seal flow seem to have a significant impact on compressor performance. It was found that the compressor has the highest volumetric and isentropic efficiency when the inlet vapor quality is around 0.85 and the performance decreases with higher vapor qualities. Isentropic efficiencies of up to 0.88 were calculated. The results were compared against previous analysis of the same experimental data which used different assumptions and did not consider the whole cycle. Finally, a case study was performed to analyse the applicability of heat pump technology to upgrade waste heat in a paper recycling plant. A conventional vapor compression heat pump (VCHP) and an electric boiler were compared to a CRHP. To deal with the uncertainty of wet compression performance a range of isentropic efficiencies were considered as well as different ammonia concentrations. The CRHP proved to be energetically and economically viable and outperformed both the VCHP and electric boiler in this case study.