Chemical Engineering September 2022 - 6

issue of Nature, the filamentous
structure of the
enzyme, now described
at atomic level for the first
time, acts like a nanowire
and is evidently responsible
for the extremely efficient
conversion rates of
the two gases.
The structure reveals why
the hydrogen-dependent
CO2 reductase (HDCR)
enzyme is orders of magnitude
more efficient than
all chemical catalysts and
far better than all known
enzymes at producing
formic acid as a liquidorganic-hydrogen
carrier
from H2 and CO2. " The
hydrogen concentrations
in the ecosystem of these
bacteria are low, and, in
addition, the CO2 and
H2 concentrations can
switch. Formation of filaments
and bundling not
only substantially increase
the concentration of these
enzymes in the cell. The
thousands of electronconducting
iron atoms in
this 'nanowire' can also
store the electrons from
hydrogen oxidation intermediately
when even
just one hydrogen bubble
passes by the bacteria, "
explains professor Volker
Müller, head GUF's Dept.
of Molecular Microbiology
and Bioenergetics.
WASTE-TO-H2
Raven SR (Pinedale,
Wyo; www.ravensr.com)
plans to use INNIO's (Jenbach,
Austria; www.innio.
com) Jenbacher engines
[60 Hz] with a " Ready for
H2 " option to produce
renewable energy. The
energy system will power
and heat Raven SR's SSeries
H2-production facility
at a sanitary landfill
in Richmond, Calif.
At
the site, landfill gas (LFG)
will be the primary fuel
to provide power for the
non-combustion
process
that converts waste
to H2. The H2 product
will be resold to power
fuel cells in heavy-duty
trucks. The Raven SR
process will also provide
a residual fuel contain(Continues
on p. 8)
6
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
SEPTEMBER 2022
Energy costs cut by 50% for
high-strength aluminum alloys
A
luminum alloy 7075 has excellent
mechanical properties, including
high strength for lightweighting applications,
but its production process
is energy intensive, which raises costs
and limits its use. Now, scientists at Pacific
Northwest National Laboratory (PNNL;
Richland, Wash.; www.pnnl.gov) have developed
a process for making the alloy that
eliminates the major energy-consuming
step in conventional production: homogenization.
Eliminating this heat-treatment step
reduces the energy required for the overall
production by half.
In conventional production of Al 7075, homogenization
involves heating castings of the
metal to around 500°C for up to 24 hours
to dissolve intragranular secondary phases
of alloying elements (aluminum, zinc, magnesium,
copper) before extruding the metal.
The PNNL team developed
a process,
known as shear-assisted
processing and
extrusion (ShAPE),
that combines heating
and physical deformation
of the metals, so
that a separate homogenization
step is
not required.
PNNL
Extruded Direction
Extruded
tubing
Billet
container
Extruded
tubing
TC
Extrusion die
Processed zone
Transition zone II
Transition zone I
Unhomogenized
7075 base billet
Spiral
grooves
A
Heat
generation
Print the filter shape needed
n adaptable sintered filter element
that is manufactured by 3D printing
will be introduced this month at
the Powtech exhibition (September
27-29; Nuremberg, Germany; see also pp.
29-30). Developed by Herding GmbH Filtertechnik
(Amberg, Germany; www.herding.
com), Omikron is an adaptable sinter-plate
filter element that can be tailor made to the
desired size and shape (photo), in quantities
as low as a single element.
Up to now, the company's conventional
sinter-plate filters have been focused on a
linear lamella geometry. Although these elements
are available in a wide variety of dimensions,
there had been no change to the
linearity of the basic geometry determined by
the sinter shape. The new Omikron filter element
eliminates the geometric limitations of
standardized shapes, and, for the first time,
makes it possible to adapt geometries to the
intended use and structural conditions.
Smaller sizes are also possible. Before the
introduction of Omikron, Herding's smallest
filter element had a filtration area of 0.7 m²,
but thanks to the new production process,
significantly smaller filter elements can now
be manufactured, which is beneficial for biotechnology
applications.
Both the basic body and the coating of
the filter elements are produced from polyethylene
(PE), and the filter element complies
with V(EG) 1935/2004, VO(EU) 10/2011, as
well as U.S. Food and Drug Admin. (FDA) requirements
for applications in the food and
pharmaceutical sectors. Further productspecific
features are the possibilities to wash
and sterilize the filter element according to
industrial standards, the company says.
Herding
In the ShAPE machine, metal billets are
simultaneously pushed through a small
opening in a die that rotates. Together, the
rotational movement and deformation thoroughly
mixes the metal elements as they
are being extruded, PNNL says, essentially,
homogenizing the metal billet in a few seconds
immediately before it is extruded.
Using ShAPE results in energy savings of
up to 50%, PNNL scientists say, and also
improves the quality of the mixing of the individual
alloying elements, which leads to
stronger final products.
A study published in a recent issue of
Materials and Design reports electron
microscope images of the alloy's microstructure
that show the effectiveness of
the ShAPE process at mixing the alloy elements.
The technology is available for licensing
from PNNL.
Die
plunge
Extrusion
direction
Mandrel
Die rotation
Mandrel
Temperature,
strainand strain rate
increase
7075 Unhomogenized
billet
http://www.pnnl.gov http://www.ravensr.com http://www.herding.com http://www.herding.com http://www.innio.com http://www.innio.com http://WWW.CHEMENGONLINE.COM
Chemical Engineering September 2022

Table of Contents for the Digital Edition of Chemical Engineering September 2022
