Chemical Engineering October 2020 - 6

vik Group (Sandviken, Sweden; www.
materials.sandvik/en) launched Sanicro
35, a unique grade that bridges
the performance gap between stainless
steels and higher-cost nickel alloys.
Sanicro 35, the latest addition to
Sandvik's growing Sanicro portfolio
of nickel alloys and austenitic stainless
steels, offers " exceptional high
performance, strength and corrosionresistance
at a wide range of temperatures, "
says the company.
" Sanicro 35 is a unique, high-performance
alternative to existing duplex
and austenitic stainless-steel grades
and more expensive nickel alloys. It
offers a cost-efficient choice for minimizing
risk and extending production
lifecycles when battling corrosion
in demanding environments, " says
business development manager
Martin Holmquist.
Designed for extremely corrosive
environments and seawater applications,
the new alloy is said to be ideal
for heat exchangers and hydraulic
and instrumentation tubing. It features
high mechanical-yield strength, superior
corrosion resistance and excellent
structural stability.
SUPERELASTIC ALLOY
Researchers from Tohoku University's
Graduate School of Engineering (Sendai,
Japan; www.eng.tohoka.ac.jp)
have discovered a novel iron-based
superelastic
alloy (SEA) capable of
withstanding extreme temperatures
- both high and low. SEAs are found
in a wide variety of commercial applications
because of their superelasticity,
which allows them to regain their original
shape. Superelasticity occurs when
the metal undergoes deformation at
the point known as critical stress.
Generally, SEAs have a positive
temperature dependence; the critical
stress increases as the temperature
rises. Conventional metal-based
SEAs, such as Ti-Ni, cannot be used
at temperatures lower than -20°C or
higher than 80°C and are costly to
make. This limits their application to
the form of thin wires or tubes.
Associate professor Toshihiro Omori
and his team developed an iron-based
SEA system, known as Fe-Mn-Al-CrNi.
This cost-effective SEA can also
operate at a much wider temperature
range of -273 to over 120°C. Another
significant advantage of the new SEA
is its controllable temperature dependence.
Increasing the amount of
chromium enables the researchers to
change the temperature dependence
from a positive to a negative. Balancing
the Cr content resulted in zero temperature
dependence with the critical
(Continues on p. 8)
6
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
OCTOBER 2020
Electric
power
Asahi
Fruit peels help recover metals from e-waste
S
cientists from Nanyang Technological
University (NTU; Singapore;
www.ntu.edu.sg), led by
professor Madhavi Srinivasan,
have developed a method of using orange
peel waste to extract precious metals
from spent lithium-ion batteries and to
make batteries from those recovered metals,
creating minimal waste in the process.
" Currently, industrial e-waste recycling
processes are energy-intensive and emit
harmful pollutants and liquid waste, pointing
to a need for eco-friendly methods as the
amount of e-waste grows, " says Srinivasan.
" Our team has demonstrated that this is
possible with biodegradable substances. "
A method that has been increasingly explored
involves hydrometallurgy, using water
as a solvent for extraction. In this process
spent batteries are shredded and crushed
to form a material called " black mass. " Metals
are then extracted from the black mass
by dissolving it in a mix of acids and other
chemicals, such as hydrogen peroxide
under heat. However, using such strong
chemicals on an industrial scale would generate
a large amount of pollutants.
The NTU team found that the combination
of orange peel that has been ovendried
and ground into powder, and citric
acid, can achieve the same goal. The team
found that its approach extracted about
90% of cobalt, lithium, nickel and manganese
from spent lithium-ion batteries - an
efficiency comparable to the method using
hydrogen peroxide.
The key lies in the cellulose in orange
peel. The cellulose is converted into sugars
under heat during the extraction process.
These sugars enhance the recovery
of metals from battery waste. Antioxidants
found in orange peel, such as flavonoids
and phenolic acids may also have contributed
to this enhancement. Solid residues
generated from this process were found
to be non-toxic.
Biogas from brewery wastewater makes
power with a fuel cell
T
his month, a demonstration project
to generate power from fuel cells
running on biogas has begun at
Asahi Breweries' Ibaraki Brewery.
Coordinated by Asahi Quality & Innovations,
Ltd., an independent research subsidiary
of Asahi Group Holdings, Ltd. (Tokyo,
Japan; www.asahigroup-holdings.com),
the project is being conducted as part of
the Japanese government's Low Carbon
Technology Research, Development and
Demonstration Program, with subsidies
from the Ministry of the Environment.
In the project (diagram), biogas is first
collected from the brewery's wastewater
treatment plant and then refined into
methane. The methane is then used as
fuel for a 200-kW Megamie solid-oxide
fuell cell (SOFC), from Mitsubishi Hitachi
Power Systems, Ltd. (MHPS; Yokohama;
www.power.mhi.com), to generate electric
power. Once in operation, the facility
will be capable of supplying around 1,600
MWh/yr of power - sufficient to power
350 ordinary households, with projected
01
Brewery
Wastewater
02
Treatment
Methane gas
(crude)
reductions in CO2 emissions of around
1,000 metric tons per year.
With the goal of reducing CO2 emissions,
Asahi Group has been working to
introduce power generation facilities utilizing
high-energy conversion efficiency fuel
cells to secure base electricity power to
operate its factories. In June 2018, the
company had developed a process to refine
the biogas generated during the treatment
of brewery wastewater to a high purity,
allowing it to be utilized as the power
source with carbon-neutral fuel cells. The
company conducted tests to generate
power with small SOFCs using this refined
biogas, and in May 2019 successfully
generated power continuously for 10,000
hours. Asahi Group has now begun the
final stage of testing for practical application
with the installation in the Ibaraki
Brewery of a MHPS Megamie SOFC system,
which was first commercialized in
2017 to run on ordinary town gas. This
project is the first application using biogas
derived from brewery wastewater as fuel.
03
Refi ne
Methane gas
(refi ned)
04
Power
generation
(SOFC)
http://www.asahigroup-holdings.com http://www.power.mhi.com http://www.eng.tohoka.ac.jp http://www.ntu.edu.sg http://WWW.CHEMENGONLINE.COM
Chemical Engineering October 2020

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