sic membranes pre-ro treatment of scrubber effluent: case study
TRANSCRIPT
SiC Membranes forPre-RO Filtration:
Case Study
Reverse Osmosis
• Technology used to remove dissolved solids and impurities from water using semi-permeable membrane.• RO membrane requires water to
be under high pressure• Industrial RO systems can
remove up to 99.5% of dissolved salts/suspended solids from feedwater
RO can remove key contaminants
• Dissolved salts• Colloids• Organics• TSS
RO Pre-Treatment
• Performance of RO System depends highly on quality of pre-filtration
• Without proper pretreatment, fouling, scaling can occur causing membrane failure
• Increases cleaning requirements and OPEX
Why Pre-Treatment?
1. Improved pre-filtration with more efficient removal of suspended solids results in longer operating intervals of RO system before chemical cleaning.
2. Reduced chemical cleaning means prolonged lifetime for RO membranes and reduced OPEX.
3. Prior removal of TSS reduces fouling of RO membrane.
4. Quality and capacity of RO membrane is seen.
Our Solution
SiC Ceramic Membranes Ideal in scenarios with bio-fouling potential
Can be cleaned with any chemicals (pH 0-14), strong oxidziers (e.g. ozone) and have high mechanical strength enabling high pressure back flush
Ensures efficient cleaning and membrane selectivity at high temperatures
What can I remove?
• Oil • Grease• Iron• TSS• Bacteria • Algae• Organic Matter
Why SiC Membranes
• Oil repelling• Inert• Less Footprint• Longer lifetime• High Recovery• Self-cleaning
All this filtration can be accomplished in 1 single
step!
Why SiC over traditional methods
POLYMERIC MEMBRANES ARE • Not as chemically or temperature resistant as not good (ecspecially at high temperatures of oil&gas industry)
• Handle oil very poorly Polymeric membranes are
• Expensive • Low water flux
0.04 Micron 3,000 L/(m2hr)
4,000 L/(m2hr)
10,000 L/(m2hr)
>12,000 L/(m2hr)
FluxPore size
0.1 Microns
1 Microns
3 Microns
Filtration capability
How it works
Feed flow is tangential to the surface of the membrane in order to sweep rejected particles and solutes away
CROSS FLOW FILTRATION
Case Study: Filtration of
Scrubber Water
Application:• Wet scrubbers used for cleaning exhaust gases to reduce air pollution
• Harmful particles transferred from gas phase to scrubbing solution
• Liquid solution contains high amount of heavy metals -> must be removed to meet discharge limits
Challenge: • Scrubber water has fluctuating heavy metal conc.
• High T• Acidic or alkaline feedwater• High fouling potential due to scaling
Case Study: Filtration of
Scrubber Water
Test:H2O Systems to use SiC membranes to treat scrubber wastewater at Danish Biomass Fired Powerplant with 2 objectives:• Fulfill discharge requirements• Re-use scrubber wastewater as RO feedwater
Results:
Conclusion• SiC membrane installation capable of providing treated
water that meets discharge legislation requirements
• RO feed water quality is met (SDI <3)
• Improved quality of treated water (Table 1)
• Reduced footprint of filtration unit (35 m3/h system is 8 m2 with a height of 2.2 m)
• No need for chemical dosing/sludge disposal
• Chemical resistance of membrane protects against highly corrosive scrubber water
Future Outlook• SiC membranes allow for reduced installation costs with a smaller footprint and can meet future legislation requirements.
• Re-use of treated water in a closed loop reduces OPEX and environmental impact
• Polluted liquid treated by SiC membranes followed by RO membrane -> enables re-use of treated water
• 80% reduction of clean water use• Operating costs associated with waste discharge/sludge handling reduced by 90%
Next Steps• Meeting• Submit water analysis • Proposal and savings • Trial• Full systems intergration