Techno-economic viability of upgrading thermal effluents in industries: Application in developing countries

Upgrading industrial thermal effluents using a heat pump is an effective energy conservation measure. Although it is proven and has been in use in industrialized countries, its application is grossly lacking in the developing world.Using technical and economical parameters, this paper investigates the viability of upgrading industrial thermal effluents and hence conserving energy using different types of heat pumps. Eleven different types of systems are formulated using the mathematical models developed for multi-stage vapor compression heat pumps and multi-stage vapor jet compressors and adopting the “Grossman Absorption Model” for the absorption heat transformer. A comparative analysis is performed for upgrading the low temperature industrial thermal effluents by employing various types of heat pumps with presently existing fuel and electricity prices in Thailand. It does not take into account the process details or the heat pump integration details. A case of integrating heat pumps in distillation columns in an industrial plant in Sri Lanka is also investigated. The energy saving potential clearly indicates that heat pumps are techno-economically viable in the industries of developing countries. The absorption heat transformer is very attractive since it utilizes waste heat itself to upgrade the thermal effluent temperature.