WO2016032313A1

WO2016032313A1 - A water extraction and energy production system and a method of using thereof

Info

Publication number: WO2016032313A1
Application number: PCT/MY2014/000223
Authority: WO
Inventors: Rosalam SARBATLY; Chel-Ken CHIAM
Original assignee: UNIVERSITI MALAYSIA SABAH
Current assignee: UNIVERSITI MALAYSIA SABAH
Priority date: 2014-08-25
Filing date: 2014-08-25
Publication date: 2016-03-03
Anticipated expiration: 2017-02-25
Also published as: MY197372A

Abstract

The present invention relates to a water extraction and energy production system(100), characterized by a screen filter(130); a first heating means(170); a membrane distillation module(HO); a second heating means(171); an osmotic membrane distillation module(120); and a mechanical system for generating mechanical energy. The present invention also relates to a method for treating water to a potable level and generating energy using the water extraction and energy production system(100).

Description

A WATER EXTRACTION AND ENERGY PRODUCTION SYSTEM AND A

METHOD OF USING THEREOF

Background of the Invention Field of the Invention

This invention relates to a liquid-treatment system and a method of use, and more particularly to a water extraction and energy production system and a method for treating liquid to a potable level and generating energy based on the water extraction and energy production system.

Description of Related Arts

Clean water and power supplies are two major concerns of life and are fundamental to economic, social, and political development as well as in sustaining human life and improving human welfare. Especially in the developing countries, many people living in the remote areas do not have access to reliable power. Diesel generator is a primary unit to produce electricity in the isolated regions. However, the power generator uses diesel fuel and emits significant quantities of greenhouse gases and other pollutants. Additionally, the diesel generators typically supply energy for a maximum of five hours per day.

With increasing global population, the gap between the supply and demand for water is widening and is reaching such alarming levels that in some part of the world, it is passing a threat to human existence. Industry has long sought processes for the desalination of salt water, such as seawater or brackish water. Seawater desalination has become a common practice to supply the growing demand for water in areas having access to the sea. Shortage of potable (drinking) water in inland areas pose much more complicated challenges to water authorities, governments, and other stakeholders. Inland regions are typically restricted to the use of already overly allocated surface water and groundwater. For example, International Publication No. 2012/1 18369 A2 disclosed a method of converting thermal energy into mechanical energy using a direct contact membrane distillation method. A working fluid is preferably obtained from membrane distillation of seawater. A stream of the working fluid is a stream of pressurised distillate produced by evaporation and condensation using a direct contact membrane distillation unit. Said stream pressurised distillate having a pressure of at least one bar. A converter is used for generating mechanical energy from said stream of said pressurised distillate, and a generator is connected to the converter for generating electricity. However, the drawback of this cited art includes several steps for producing the stream of pressurised distillate which make the process more cumbersome.

U. S. Patent No. 8,029,671 B2 disclosed systems and methods for purifying a liquid, such as an impaired water. A membrane distillation unit and forward osmosis unit are integrated into a system for purifying seawater or brackish water, such as to a potable level. However, it remains challenging to seek for an alternative source for energy production.

U. S Patent Application Publication No. 2005/0269266 disclosed an osmotic membrane distillation and its application on recovery and concentration of heavy chemical liquors. The apparatus and method are of particular value in electrolytic haloalkali production plants in offering reduced capital and operating re-concentration and dilution costs. However, this cited art enhances the concentration of the inorganic compound in an aqueous solution but it does not produce mechanical energy which may in turn converted into electricity. In addition, this cited art was not designed for potable water production which thus may lack sufficient access to safe drinking water supplies.

Accordingly, it can be seen in the prior arts that there exists a need to provide an apparatus and a method for treating water to a potable level. An attempt to reuse brine solution rather than discharging to environment is a concern. In addition, it would be an advance in the art to provide an alternative method for energy production.

Summary of Invention

It is an objective of the present invention to provide a water extraction system and a method for producing fresh water, for example clean and potable water.

It is also an objective of the present invention to provide an energy production system and a method for producing mechanical energy.

It is yet another objective of the present invention to provide a method to reuse brine solution rather than direct discharging to environment, so as to reduce disturbance on the ecology system. Accordingly, these objectives may be achieved by following the teachings of the present invention. The present invention relates to a water extraction and energy production system (100), characterised by a screen filter (130) for screening and removing water impurities from source water (220); a first heating means (170) for heating the filtered water; a membrane distillation module (1 10) having a first membrane (1 13) separating a first chamber (1 1 1 ) and a second chamber (1 12), wherein the first chamber (1 1 1 ) receives filtered water heated by the first heating means (170) and distilled fresh water is collected in the second chamber (1 12); a second heating means (171 ) for heating the fresh water resulting from treatment in the membrane distillation module (1 10); an osmotic membrane distillation module (120) connected to the membrane distillation module (1 0), having a second membrane (123) separating a first compartment (121 ) and a second compartment (122), wherein the first compartment (121 ) receives concentrated water from the membrane distillation module (1 10) and the second compartment (122) receives fresh water heated by the second heating means (171 ); a mechanical system connected to the first compartment (121 ) for generating mechanical energy from treated water from the first compartment ( 21 ). The present invention also relates to a method for treating water to a potable level and generating energy using the water extraction and energy production system (100).

Brief Description of the Drawings

The features of the invention will be more readily understood and appreciated from the following detailed description when read in conjunction with the accompanying drawings of the preferred embodiment of the present invention, in which:

Figure 1 is a diagram showing a water extraction and energy production system and method of using thereof.

Detailed Description of the Invention

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for claims. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include," "including," and "includes" mean including, but not limited to. Further, the words "a" or "an" mean "at least one" and the word "plurality" means one or more, unless otherwise mentioned. Where the abbreviations or technical terms are used, these indicate the commonly accepted meanings as known in the technical field. For ease of reference, common reference numerals will be used throughout the figures when referring to the same or similar features common to the figures. The present invention will now be described with reference to Figure 1. The present invention relates to a water extraction and energy production system (100), characterised by;

a screen filter (130) for screening and removing water impurities from source water (220);

a first heating means (170) for heating the filtered water;

a membrane distillation module (1 10) having a first membrane (1 13) separating a first chamber (1 1 1 ) and a second chamber (1 12), wherein the first chamber (1 1 1 ) receives filtered water heated by the first heating means (170) and distilled fresh water is collected in the second chamber (1 12);

a second heating means (171 ) for heating the fresh water resulting from treatment in the membrane distillation module (1 10);

an osmotic membrane distillation module (120) connected to the membrane distillation module (1 10), having a second membrane (123) separating a first compartment (121 ) and a second compartment (122), wherein the first compartment (121 ) receives concentrated water from the membrane distillation module (1 10) and the second compartment (122) receives fresh water heated by the second heating means (171 );

a mechanical system connected to the first compartment (121 ) for generating mechanical energy from treated water from the first compartment (121 ).

In a preferred embodiment of the water extraction and energy production system (100), the first heating means (170) and the second heating means (171 ) each independently comprises a heat exchanger.

In a preferred embodiment of the water extraction and energy production system (100), the first membrane (1 13) and second membrane (123) are hydrophobic and semi-permeable nanofibre membranes.

In a preferred embodiment of the water extraction and energy production system (100), the first membrane (1 13) and second membrane (123) are each independently made of polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, or any combination thereof.

In a preferred embodiment of the water extraction and energy production system (100), the osmotic membrane distillation module (120) further comprises a valve (190) connected to an outlet of the first compartment (121 ) for directing the treated water to the mechanical system.

In a preferred embodiment of the water extraction and energy production system (100), the valve (190) is a check valve.

In a preferred embodiment of the water extraction and energy production system (100), the mechanical system comprises a turbine (200). In a preferred embodiment of the water extraction and energy production system (100), the mechanical system comprises a turbine (200) and a generator (210) for converting mechanical energy to electrical energy.

The present invention also provides a method for treating water to a potable level and generating energy using the water extraction and energy production system (100), characterised by the steps of:

screening the source water (220) for removing water impurities prior to entering a water tank (140);

heating the filtered water and feeding the heated filtered water into the first chamber (1 1 1 ) of the membrane distillation module (1 10);

distilling the heated filtered water across the first membrane (113) into the second chamber (112) to form fresh water, whereby the remaining filtered water in the first chamber (11 1) is concentrated and directed to the first compartment (121) of the osmotic membrane distillation module (120);

channelling a portion of the fresh water from the second chamber (112) for use as potable water and channelling another portion of the fresh water into the second compartment (122) of the osmotic membrane distillation module (120); wherein the fresh water is heated prior to feeding into the second compartment (122);

distilling the heated fresh water across the second membrane (123) into the first compartment (121) to dilute the concentrated filtered water;

directing the diluted filtered water through the mechanical system for generating mechanical energy.

In a preferred embodiment of the method for treating water to a potable level and generating energy, the filtered water and the fresh water are each independently heated to a temperature in a range of 40 °C to 70 °C.

In a preferred embodiment of the method for treating water to a potable level and generating energy, the mechanical energy is converted into electrical energy using a generator (210).

Below is an example of a water extraction and energy production system and a method of use from which the advantages of the present invention may be more readily understood. It is to be understood that the following example is for illustrative purpose only and should not be construed to limit the present invention in any way.

Examples

A water extraction and energy production system (100) integrates a membrane distillation module (110) and an osmotic membrane distillation module (120) for producing fresh water and energy. The osmotic membrane distillation module (120) may be any type of osmotic membrane distillation apparatus as described herein. More preferably, the osmotic membrane distillation module (120) may be according to the system disclosed in International application number PCT/MY2014/000218, which is hereby incorporated in its entirety.

Figure 1 is a diagram showing the water extraction and energy production system (100). A pump (180), preferably a feed recirculation pump, pumps source water (220) into a water tank (140). Said source water (220) preferably comprises salts. The source water (220) is screened and filtered by a screen filter (130), thereby removing water impurities from the source water (220). Said water impurities include dissolved and suspended solids. Said screen filter (130) is preferably a mesh filter.

The membrane distillation module (110) has a first membrane (1 13) separating a first chamber (1 11 ) and a second chamber (1 12). The first chamber (1 1 ) of the membrane distillation module (1 10) receives filtered water from the water tank (140) through the pump (180). And more particularly, the filtered water is heated by a first heating means (170) before being channelled into the first chamber (1 1 1 ). In a preferred embodiment, the filtered water is preferably heated to a temperature in a range of 40 °C to 70 °C. In a preferred embodiment, the filtered water is heated until the filtered water reaches a vapour and liquid state. The second chamber (1 12) is maintained at a temperature lower than the temperature of the filtered water in the first chamber (1 11). In a preferred embodiment, the second chamber is left in an ambient temperature. The filtered water vapour therefore passes across the first membrane (1 13) into the second chamber (112). The temperature difference between the first chamber (1 11 ) and the second chamber (112) across the first membrane (1 13) creates a partial pressure difference which ensures that the vapour developing at the first membrane (1 13) surface follows the pressure drop, permeating through the pores of the first membrane (1 13) and condensing on the cooler side of the second chamber (112). Therefore, distilled fresh water is collected in the second chamber (1 12), whereas the heated filtered water in the first chamber (111 ) is concentrated and directed to the osmotic membrane distillation module (120) thereafter.

The fresh water resulting from treatment in the membrane distillation module (110) is preferably distributed to two different containers. A portion of the fresh water is directed to a first container (150) for use as potable water or distributed for household use, or channelled through pipelines (230) for commercial use. Another portion of fresh water is preferably channelled into a second container (160) for storage before being directed to the osmotic membrane distillation module (120).

The osmotic membrane distillation module (120) is connected to the membrane distillation module (110), and has a second membrane (123) separating a first compartment (121 ) and a second compartment (122). In a preferred embodiment, the first compartment (121 ) receives concentrated water from the first chamber (1 1 ) of the membrane distillation module (1 0) after the membrane distillation process conducted in the membrane distillation module (1 10). The second compartment (122) receives fresh water from the second container (160) through the pump (180). In a preferred embodiment, the fresh water is heated by a second heating means (171) prior to being fed into the second compartment (122) of the osmotic membrane distillation module (120). In a preferred embodiment, the fresh water is preferably heated to a temperature in a range of 40 °C to 70 °C. The heating means (170, 171 ), and more particularly the first heating means (170) and the second heating means (171), each independently comprises a heat exchanger. Preferably, the heat exchanger operates by means of solar energy, geothermal energy or any waste heat discharged from industry. The heated fresh water in the second compartment (122) evaporates to form vapour. Due to a difference in concentration between the fresh water in the second compartment (122) and the concentrated filtered water in the first compartment (121), the fresh water vapour passes across the second membrane (123) into the first compartment (121 ). As the first compartment (121) is maintained at a lower temperature than the second compartment (122), the vapour condenses on the second membrane (123) on the side of the first compartment (121 ), thus diluting the concentrated filtered water in the first compartment (121 ). This increases the pressure in the first compartment (121 ). Said first compartment (121 ) is preferably connected to a mechanical system. In a preferred embodiment, the mechanical system comprises a turbine (200). Said first compartment (121) is connected to the turbine via a conduit for generating mechanical energy. In a preferred embodiment, the mechanical energy comprises the turbine (200) and a generator (210). The turbine (200) drives the generator (210) for generating electricity. In a preferred embodiment, the turbine (200) generates mechanical energy from the pressurised diluted filtered water received from the first compartment (121 ) of the osmotic membrane distillation module (120) and in turn the generator (210) converts the mechanical energy into electrical energy.

In a preferred embodiment, the osmotic membrane distillation module (120) further comprises a valve (190), preferably a check valve, connected to an outlet of the first compartment (121) for directing the diluted filtered water in a one-way direction to the mechanical system.

It is preferable to make the surface of the first membrane (1 13) and the second membrane (123) completely hydrophobic and semi-permeable nanofibre, for example permeable to water vapour and impermeable to solvent molecules and solute molecules. In an exemplary embodiment of the present invention, the first membrane (113) and second membrane (123) are each independently made of polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, or any combination thereof. In a preferred embodiment, the first membrane (1 13) has narrow pores, preferably with size of 0.1 to 1.0 micron, to allow the filtered water vapour to pass through from the first chamber (1 1 1) into the second chamber (1 12) in the membrane distillation module (110). In a preferred embodiment, the second membrane (123) has narrow pores, preferably with size of 0.1 to 1.0 micron to allow the fresh water vapour to pass through from the second compartment (122) into the first compartment (121 ) in the osmotic membrane distillation module (120). In a preferred embodiment, the first membrane (113) and second membrane (123) are each independently configured in a flat-sheet form. Although the present invention has been described with reference to specific embodiments, also shown in the appended figures, it will be apparent for those skilled in the art that many variations and modifications can be done within the scope of the invention as described in the specification and defined in the following claims.

Description of the reference numerals used in the accompanying drawings according to the present invention:

Reference

Description

Numerals

100 Water extraction and energy production system

1 10 Membrane distillation module

111 First chamber

112 Second chamber

113 First membrane

120 Osmotic membrane distillation module

121 First compartment

122 Second compartment

123 Second membrane

130 Screen filter

140 Water tank

150 First container

160 Second container

170 First heating means

171 Second heating means

180 Pump

190 Valve

200 Turbine

210 Generator

220 Source water

230 Pipeline

Claims

Claims I/We claim:

1. A water extraction and energy production system (100), characterised by:

a first heating means (170) for heating the filtered water; a membrane distillation module (1 10) having a first membrane (1 13) separating a first chamber (1 1 1 ) and a second chamber (1 12), wherein the first chamber (1 1 1 ) receives filtered water heated by the first heating means ( 70) and distilled fresh water is collected in the second chamber ( 12); a second heating means (171 ) for heating the fresh water resulting from treatment in the membrane distillation module (1 10);

2. The water extraction and energy production system (100) according to claim 1 , wherein the first heating means (170) and the second heating means (171 ) each independently comprises a heat exchanger.

3. The water extraction and energy production system (100) according to claim 1 , wherein the first membrane ( 13) and second membrane (123) are hydrophobic and semi-permeable nanofibre membranes. The water extraction and energy production system (100) according to claim 1 , wherein the first membrane (113) and second membrane (123) are each independently made of polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, or any combination thereof.

The water extraction and energy production system (100) according to claim 1 , wherein the osmotic membrane distillation module (120) further comprises a valve (190) connected to an outlet of the first compartment (121 ) for directing the treated water to the mechanical system.

The water extraction and energy production system (100) according to claim 5, wherein the valve (190) is a check valve.

The water extraction and energy production system (100) according to claim 1 , wherein the mechanical system comprises a turbine (200).

The water extraction and energy production system (100) according to claim 1 , wherein the mechanical system comprises a turbine (200) and a generator (210) for converting mechanical energy to electrical energy.

A method for treating water to a potable level and generating energy using the water extraction and energy production system (100) according to claim 1 , characterised by the steps of:

heating the filtered water and feeding the heated filtered water into the first chamber (1 11 ) of the membrane distillation module (1 10);

distilling the heated filtered water across the first membrane (113) into the second chamber (112) to form fresh water, whereby the remaining filtered water in the first chamber (1 11 ) is concentrated and directed to the first compartment (121 ) of the osmotic membrane distillation module (120); channelling a portion of the fresh water from the second chamber (1 12) for use as potable water and channelling another portion of the fresh water into the second compartment (122) of the osmotic membrane distillation module (120);

wherein the fresh water is heated prior to feeding into the second compartment (122);

distilling the heated fresh water across the second membrane (123) into the first compartment (121 ) to dilute the concentrated filtered water; directing the diluted filtered water through the mechanical system for generating mechanical energy.

The method for treating water to a potable level and generating energy according to claim 9, wherein the filtered water and the fresh water are each independently heated to a temperature in a range of 40 °C to 70 °C.

The method for treating water to a potable level and generating energy according to claim 9, wherein the mechanical energy is converted into electrical energy using a generator (210).