New idea for co-generation power desalting plants due to abandoned MSF desalination process

Abstract

In Gulf countries, most power plants are co-generation power desalting plants (CPDP) producing electric power and process heat for MSF seawater desalting plants. The MSF units use extensive amounts of energy and are losing grounds to Reverse Osmosis (RO) desalting system. RO system consumes much less energy than MSF system. Sooner or later, RO system will take over either as new or substitute to the present MSf plants. When RO plants substitute MSF plants, process heat from the CPDP is banned and the plants would be single purpose power plants. This reduces the efficiency of electric power production and this is one of reasons delaying the adoption of RO system. For existing co-generation plant to work efficiently, production of electric power and process heat should continue. The process heat can be used for other purposes, other than MSF desalting. One good use of this process heat is to drive absorption water chillers for district air conditioning A/C needed in Gulf area. Water-lithium bromide chillers are driven by steam or hot water in temperature range of 100–130°C, similar to conditions required by the MSF desalting units. The use of CPDP plants to produce electric power and chilled water for summer A/C can result in better utilization of fuel energy and better usage of the available equipment. The benefits of using this approach as compared to the use of conventional motor-driven mechanical vapor refrigeration MVC machines and producing power to driven them are illustrated.