desalination future trends and challenges

12
SAMI REHMAN Desalination - ‘Exploring Future Trends & Challenges’

Upload: sami-rehman-meng-mres-amicheme

Post on 24-Jan-2018

380 views

Category:

Documents


3 download

TRANSCRIPT

– S A M I R E H M A N

Desalination - ‘Exploring Future Trends &

Challenges’

D E S A L I N A T I O N

• The process of removing salt from seawater

• Typical example is water and brine system

M E T H O D S U S E D F O R D E S A L I N A T I N G

W A T E R

• Sea Water Reverse Osmosis (SWRO)

• Forward Osmosis (FO)

In seawater RO systems, pressure is

applied to seawater forcing water through

a semi-permeable membrane while most

salts, colloids, bacteria and other

impurities are rejected by membrane

R O

T E C H N I C A L

A D V A N T A G E S

• Versatile - treats all types of water

brackish-seawater

• Adaptable to all sizes of installation and

energy sources eg electricity, steam

• Setting up in all geographic zones

possible

• Minimal environmental impact

• Flexibility - plant sizes;can increase

production and hence plant size to

accommodate requirement

• Operation costs proportional to flow

variations

Things to Think About

Membranes sensitive to

abuse & feed water

needs pre-treatment to

remove particulates

Operation - high quality

materials

Safe & careful disposal

of brine

Risk of

membranes to

bacterial

contamination

Process Flow Diagram - RO Plant

T Y P I C A L F E A T U R E S O N A N R O

P L A N T

• Standard features of RO systems inc. major components such

as cartridge filter, pressure vessels, membrane elements, high

pressure pumps and control instrumentation w/failsafe devices

• Energy Recovery Devices comprises pressure exchanger and

booster pump

• Cleaning In Place (CIP Unit) comprises cleaning pump,

cleaning tank, bag filter, instrument control panel

• Post-Treatment System comprises chemical dosing units

(neutralisation or chlorination)

- Membrane biofouling

- Protecting SWRO from red blossom

algae

- Need to drive down energy costs

- Treating brine reject for beneficial use

eg as salts/road salts, providing

feedstock to chemical industry

- The need for driving down capital

costs for thermal desalination units

- Environmental impact concerns for

large scale desalination

C H A N G E S O N T H E H O R I Z O N

• Use of Forward Osmosis technology - developments in

stand alone systems or combination technologies use

with RO => lower energy consumption

• Using waste heat in desalination => lower energy

costs

S U M M A R Y

• Reverse Osmosis been established

a mature and sustainable

technology for seawater treatment

• New technologies platforms such

as Forward Osmosis (FO) aim to

improve RO, and are applicable

with multiple benefits

• These process focus on reducing

energy consumption and prevent

scaling/biofouling commonly

associated with membrane

technology