Simultaneous production of electrical power and potable water

Abstract

Biomass or refuse-derived fuels ( 10 ) and seawater or other non-potable water are used as an input to a combustor/evaporator ( 15, 20 ). The resulting steam heats a working fluid in an Organic Rankine Cycle ( 30, 50, 60, 75 ) process which drives a turbine (50) to produce mechanical rotation. This rotation can be used to directly drive a process or to generate electricity. The heating of the working fluid cools the steam to produce purified water. The evaporator provides a water purification process for both the separation of dissolved components as well as providing for thermal pasteurization/sterilization. Suitable water inputs are seawater, brackish water and water with those waterborne diseases and pathogens which can be killed through pasteurization/sterilization.

1 . A power generation and water purification apparatus, comprising:
 a combustion chamber to burn a fuel to provide combustion products, and having a fuel input port to receive said fuel;   a boiling tank having a water input port to receive water and a steam output port to discharge steam;   a plurality of heat exchange tubes, connected in parallel, and functionally connected to said combustion chamber to receive said combustion products, said tubes being at least partially inside said boiling tank and to transfer heat from said combustion products to said water in said boiling tank to produce said steam;   an exhaust conduit, functionally connected to the plurality of heat exchange tubes, to receive and discharge combustion products which have flowed through the plurality of heat exchange tubes;   an evaporator to transfer heat from said steam to an Organic Rankine Cycle (ORC) working fluid to evaporate said ORC working fluid to produce a high pressure ORC vapor and to condense said steam to provide purified water, said evaporator having a steam input port functionally connected to said steam output port of said boiling tank to receive said steam, a condensate port for discharging said purified water, a working fluid input port to receive said working fluid, and a vapor output port for discharging said high pressure ORC vapor;   a turbine to produce mechanical power from said high pressure ORC vapor, said turbine having a high pressure vapor input port functionally connected to said evaporator to receive said high pressure ORC vapor, and a low pressure vapor output port to discharge a low pressure ORC vapor;   a condenser to transfer heat from said low pressure ORC vapor to a cooling fluid to condense said low pressure ORC vapor to produce an ORC working fluid, said condenser having a low pressure vapor input port functionally connected to said low pressure vapor output port of said turbine for receiving said low pressure ORC vapor, an ORC working fluid condensate output port for discharging said ORC working fluid, a cooling fluid input port to receive said cooling fluid, and a cooling fluid output port to discharge said cooling fluid; and   a pump to provide said ORC working fluid to said evaporator, said pump having an ORC working fluid input port functionally connected to said ORC working fluid condensate output port, and an ORC working fluid output port functionally connected to said working fluid input port of said evaporator.   
     
     
         2 . The apparatus of  claim 1  wherein said ORC working fluid has a boiling point below the boiling point of water. 
     
     
         3 . The apparatus of  claim 1  wherein said ORC working fluid is either heptane or pentane. 
     
     
         4 . The apparatus of  claim 1  and further comprising an electrical generator, functionally connected to said turbine, to generate electricity. 
     
     
         5 . The apparatus of  claim 1  and further comprising a collection tank to collect said purified water. 
     
     
         6 . A power generation and water purification apparatus, comprising:
 a combustion chamber to burn a fuel to provide combustion products, and having a fuel input port to receive said fuel;   a boiling tank, heated by said combustion products, and having a water input port to receive water and a steam output port to discharge steam;   an evaporator to transfer heat from said steam to an Organic Rankine Cycle (ORC) working fluid to evaporate said ORC working fluid to produce a high pressure ORC vapor and to condense said steam to provide purified water, said evaporator having a steam input port functionally connected to said steam output port of said boiling tank to receive said steam, a condensate port for discharging said purified water, a working fluid input port to receive said working fluid, and a vapor output port for discharging said high pressure ORC vapor;   a turbine to produce mechanical power from said high pressure ORC vapor, said turbine having a high pressure vapor input port functionally connected to said evaporator to receive said high pressure ORC vapor, and a low pressure vapor output port to discharge a low pressure ORC vapor;   a condenser to transfer heat from said low pressure ORC vapor to a cooling fluid to condense said low pressure ORC vapor to produce an ORC working fluid, said condenser having a low pressure vapor input port functionally connected to said low pressure vapor output port of said turbine for receiving said low pressure ORC vapor, an ORC working fluid condensate output port for discharging said ORC working fluid, a cooling fluid input port to receive said cooling fluid, and a cooling fluid output port to discharge said cooling fluid; and   a pump to provide said ORC working fluid to said evaporator, said pump having an ORC working fluid input port functionally connected to said ORC working fluid condensate output port, and an ORC working fluid output port functionally connected to said working fluid input port of said evaporator.   
     
     
         7 . The apparatus of  claim 6  wherein said ORC working fluid has a boiling point below the boiling point of water. 
     
     
         8 . The apparatus of  claim 6  wherein said ORC working fluid is either heptane or pentane. 
     
     
         9 . The apparatus of  claim 6  and further comprising an electrical generator, functionally connected to said turbine, to generate electricity. 
     
     
         10 . The apparatus of  claim 6  and further comprising a collection tank to collect said purified water. 
     
     
         11 . A method to generate power and purify water, comprising:
 (a) burning a fuel to provide a hot gas;   (b) transferring heat from said hot gas to convert water into steam;   (c) transferring heat from said steam to convert an Organic Rankine Cycle (ORC) working fluid into a high pressure ORC vapor and to provide condensate from said steam as purified water;   (d) providing said high pressure ORC vapor to a turbine to generate power and to provide a low pressure ORC vapor;   (e) cooling said low pressure ORC vapor to provide an ORC working fluid condensate; and   (f) pumping said ORC working fluid condensate to be used as said ORC working fluid in (c).   
     
     
         12 . The method of  claim 11  wherein said ORC working fluid has a boiling point below the boiling point of water. 
     
     
         13 . The method of  claim 11  wherein said ORC working fluid is either heptane or pentane. 
     
     
         14 . The method of  claim 11  and further comprising automatically providing said water to be converted into steam. 
     
     
         15 . The method of  claim 11  wherein a cooling fluid is used to cool said low pressure ORC vapor. 
     
     
         16 . The method of  claim 11  wherein water is used to cool said low pressure ORC vapor. 
     
     
         17 . The method of  claim 11  and further comprising collecting said purified water. 
     
     
         18 . The method of  claim 11  wherein waste biomass is burned as said fuel to provide said hot gas. 
     
     
         19 . The method of  claim 11  wherein said power is used to generate electricity.