Chemical Engineering June 2016 - 7

Chementator
Commercial launch for a hybrid wastewatertreatment
process
A
hybrid process that combines
micro-flotation and
flat-sheet ceramic-membrane
filtration to remove
oil and suspended solids from
difficult-to-treat industrial wastewater
has been commercialized
by akvola Technologies (Berlin,
Germany; www.akvola.com).
The system can treat water with
high oil loads (up to 3 wt.%) with up to 99%
removal efficiency, and at a fraction of the
costs of alternative technologies, says Lucas
León, founder and CFO.
In the akvoFloat process (diagram),
wastewater is continually fed to the microflotation
zone, where the akvola MicroBubble
Generator induces fine (50-100 µm) gas
bubbles. The small bubbles have a large
surface-to-volume ratio, and agglomerate
with suspended solids, oil, grease, algae
and organic flocs to form a float layer, which
is skimmed from the tank. The water then
passes through the membrane module,
which contains dead-end-operated, flatsheet
ceramic membranes. The akvoFloat
systems are engineered to achieve stable
operation at very high fluxes - generally
five times higher than that of polymeric
membranes, says León.
Operation at higher flux enables a reducOily
wastewater
akvola
MicroBubble
Generator
Ceramic membrane
filtration
end also reduces energy costs, because the
pressure drop (transmembrane pressure of
0.2 bar) is 7-10 times lower than that used in
crossflow membrane systems, he says. Finally,
the MicroBubble Generator consumes
5-10 times less energy than conventional
dissolved air flotation (DAF) systems.
The process was first demonstrated in a
tion in the membrane area required, which
translates into lower investment costs, explains
León. Operating the membrane deadA
n
all-weather solar cell that generates
electricity by both sunlight
and rain has been developed by researchers
led by professor Qunwei
400-m3/h pilot plant that treated scrubber
water at a metallurgical-coke plant of ThyssenKrupp
in Duisburg, Germany. The company
is now focussing on treating oily industrial
wastewaters, such as that generated in
the metalworking, petroleum-refining and
steel industries. In the first quarter of 2016,
akvola Technologies has received six orders
for its akvoFloat units, the first of which (2.5
m3/h) has been operating since March at a
wastewater treatment facility in Austria. The
company is also working on the engineering
of larger scale projects (250 m3/h) with two
EPC (engineering, procurement, construction)
companies for two different applications,
says León.
Sun and rain generate electricity in this solar cell
This property inspired the researchers to
Tang from the Institute of Material Science
and Engineering at Ocean University of China
(Qingdao; http://eweb.ouc.edu.cn) and professor
Peizhi Yang from Yunnan Normal University
(Kunming, China; www.csc.edu.cn).
The researchers developed a highly efficient
dye-sensitized solar cell and coated
the cell with an extremely thin film of graphene.
Graphene conducts electricity and
has a large number of electrons that can
move freely across the entire graphene
layer (delocalized electrons). In aqueous
solution, graphene can bind positively
charged ions with its electrons, a property
used to remove lead ions and organic dyes
from solutions.
use graphene electrodes to obtain power
from the impact of raindrops. The raindrops
contain salts that dissociate into positively
and negatively charged ions. The positively
charged ions, including sodium, calcium
and ammonium ions, can bind to the graphene
surface. At the point of contact between
the raindrop and the graphene, the
water acquires additional positive ions and
the graphene acquires additional delocalized
electrons. This forms a " pseudocapacitor "
made of a double-layer of electrons
and positive ions. This produces a voltage
and current.
Tang says the all-weather solar cell will
make it possible to generate electricity also
in acid-rain-prone areas and on islands and
reefs. It can also be used in marine navigation,
he says.
Note: For more information, circle the 56-digit number on p. 74, or use the website designation.
ChemiCal engineering www.Chemengonline.Com june 2016
Oil, TSS
Cooling-tower motor
A new electric motor for drivClean
water
ing
cooling-tower fans features
a design that prevents
current from flowing through
the shaft bearings, allowing
longer lifetime and less maintenance.
The TEAO motor,
made by Marathon Motors
Corp. (Wausau, Wis.; www.
marathonelectric.com) also
has the highest ingress protection
(IP) rating for small
airborne particles of any fan
motor currently available and
can be mounted with the shaft
at any angle, the company
says. It is suitable for use in
all HVAC (heating, ventilation
and air conditioning) applications
and for cooling towers
in the power generation and
other industries, notes Chris
Voll, distribution product
manager at Marathon. The
motor is available in a range
of sizes from 3 to 250 hp.
eleCtrode slurry
A continuous process for
making electrode slurry for
lithium-ion batteries has
been developed by Bühler
AG (Uzwil, Switzerland;
www. ) and Chinese battery
producer Lishen, enabling
this critical material to be
manufactured on a larger
scale to meet the increasing
demand for electricpowered
vehicles. The new
process uses a twin-screw
extruder to make the slurry,
which formerly had to be
made batch-wise. The new
process enables a " much
more consistent quality to
be achieved, takes up 60%
less space and reduces energy
consumption by 60%, "
compared to batch production,
says Bühler.
Lishen awarded Bühler its
first large-scale order for
four production lines valued
at nearly CHF10 million
(about $10.2 million). The
investment represents a
production capacity of about
(Continues on p. 8)
7
Edited by:
Gerald Ondrey

http://www.akvola.com http://www.marathonelectric.com http://eweb.ouc.edu.cn http://www.csc.edu.cn http://www.Chemengonline.Com

Chemical Engineering June 2016

Table of Contents for the Digital Edition of Chemical Engineering June 2016