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C A S E S T U DY
RO | UF | MBR |Oil and Gas
Ordos City, China

Toray MBR Reclaims Wastewater at a Coal Liquefaction Facilityin Inner Mongolia
PROJECT BACKGROUND
Coal Liquefaction, also known as a "Coal to Liquid
Fuels" (CTL) process, generates wastewater that
requires advanced treatment for reuse and tomeet strict guidelines for environmental discharge.
Ordos City, located in the Inner Mongolia regionof China, is home to some of the world's mostextensive CTL facilities. An area with a semi-aridclimate and little rainfall per year, a CTL facility in
Ordos City took initiatives to purify its wastewaterto acceptable reuse standards and help achieve
zero liquid discharge (ZLD) requirements.
CHALLENGES
The industrial effluent generated by CTL facilities
generally contains pollutants that are complex
and difficult to break down. The Ordos CTL facility
required a treatment system that could produce
high-quality filtrate while being cost-effective andmeet operational flexibility and safety. However, this site was the only
CTL plant employing direct liquefaction (DCL) in China, and the plant
could not model their wastewater treatment needs after reference
sites. With the existing conventional treatment scheme, water quality
fluctuations recurred, and the color and COD parameters remained
high. After unsuccessful trials using various biochemical treatment
options, the end-user and consultants began evaluating membrane
technologies.
PRODUCT SELECTION
The consultant examined several membrane bioreactor (MBR)
modules in both hollow-fiber and flat-sheet configurations forpiloting purposes. Test results indicated none of the hollow-fiber
modules could meet the requirements, while Toray's flat-sheet MBR
module performed most reliably. Toray MBR features highly durable
PVDF (polyvinylidene fluoride) membrane material with improved
resistance against chemicals and physical durability during airscouring. Its membrane pores are uniformly and densely distributed
along the membrane surface, increasing permeability and reducing
the build-up of foulants. Toray was selected according to these

Figure 1: MBR tank at Ordos Coal-to-Liquid Facility

Table 1 — Quick Facts
9,840 m3/day

Flow capacity
Start-up

May 2013

Plant influent

Industrial effluent from liquefaction plant

Membrane model

TMR140-200D

System configuration

7 trains with 18 units each

Membrane material

PVDF (polyvinylidene fluoride)

Nominal pore size

0.08 µm

Effluent end-use

De-mineralized process and cooling water

Figure 3:
Toray MBR
TMR140-200D

Figure 2: ZLD process using membranes

Industrial effluent

Aerobic Zone

03-CN-MB2-Ordos-202108

Advanced Oxidation

Anaerobic Zone

Membrane Bioreactor

Ultrafiltration

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Anoxic Zone

Reverse Osmosis

C A S E S T U DY
RO | UF | MBR |Toray MBR Reclaims Wastewater at a Coal Liquefaction Facility
in Inner Mongolia

product advantages, quick lead times, and reliable
technical support. Figure 2 outlines the final designof the ZLD process using the membrane bioreactor.
RESULTS
The MBR system started up in May 2013 and has
been running efficiently since Toray provided fulltechnical support and training for the installationand commissioning phases and has continued withregular visits to the site to help operators optimize
the plant's performance.
Figure 4 shows the COD (chemical oxygendemand) values of the plant's influent, permeate,and removal rate. The permeate COD (in orange)
is continuously at a low value when the influent
quality rises, indicating a high tolerance of theFigure 4: COD values

Toray MBR module even during upsets in the influent.
The raw water quality also experienced spikes in TDS, excessive
oil, and sludge concentrations. However, Toray MBR modules
continued to operate stably and avoided shutdowns through processadjustment, chemical cleaning, and other maintenance procedures.
CONCLUSION
Wastewater from CTL plants is much more challenging to treat
than other types of industrial effluent. Toray MBR technology
demonstrated the ability to deliver stable operation and longservice life under complex feed water qualities. This project hashelped cut down freshwater consumption, achieve ZLD goals with
reduced footprint, and become a key benchmark for other CTL
facilities to recycle wastewater sustainably.
Figure 5: Water quality comparison — wastewater on the left and MBR
effluent on the rightTORAY INDUSTRIES, INC.
Head Office: Nihonbashi Mitsui Tower 24th Floor, 1-1, Nihonbashi-Muromachi 2 chome, Chuo-ku,
Tokyo, 103-8666, JAPANwww.water.toray+81 3 3245-4542

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All information presented herein is believed reliable and in accordance with accepted engineering practices. Toray makes nowarranties as to the completeness of this information. Users are responsible for evaluating individual product suitability forspecific applications. Toray assumes no liability whatsoever for any special, indirect or consequential damages arising from thesale, resale or misuse of its products. © 2021 Toray Industries, Inc. Subject to change without notice.
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