Chemical Engineering March 2022 - 6

www.covestro.com) has
produced the first industrially
significant volumes of a
plant-based version of hexamethylenediamine
(HMDA).
HMDA, traditionally derived
from petroleum, is a chemical
intermediate widely used
in the manufacture of Nylon,
as well as in coatings and
adhesives. Production of
ton quantities of bio-based
HMDA from the fermentation
of sugar allows those
products to be produced
more sustainably.
Highly efficient engineered
bacteria metabolize sugar
and produce, in one step, an
aqueous solution of HMDA.
This " broth " is worked up in
a dedicated process to produce
HMDA that is suitable
for polyurethane and nylon
6,6 applications.
Genomatica is developing
the complete, integrated
process to make HMDA
from renewable feedstocks,
along with the steps
needed to build and operate
a production plant,
while
Covestro is contributing its
expertise in separating and
purifying HMDA and testing
in polyurethane applications.
Covestro has secured an
option to license Genomatica's
integrated GENO HMD
process technology for
commercial production.
PSILOCYBIN
Vocan Biotechnologies Inc.
(Victoria, B.C., Canada;
www.vocanbiotech.com)
has optimized its recombinant
production system,
successfully testing its
proof of concept for the biosynthesis
of psilocybin suitable
for use in future scaleup.
A patent application
has been filed. Psilocybin
is a psychedelic compound
that is showing enormous
promise in treating addiction
and depression.
Scientists at Vocan have
constructed optimized DNA
sequences that can produce
enzymes replicating
the biosynthetic pathway
used by Psilocybe mushrooms.
Vocan's biosynthetic
process retains the stereochemistry
of
the
natural
psilocybin
molecules found
(Continues on p. 8)
6
A new catalyst for the oxidative dehydration of
propane with CO2
C
onverting propane to propylene
by oxidative dehydrogenation with
CO2 is an alternative route to conventional
propane dehydrogenation,
but existing catalysts for this conversion
are not very efficient. Now, in a study described
in a recent issue of Nature Catalysis,
researchers at the Institute for Catalysis,
Hokkaido University (Sapporo, Japan; www.
cat.hokudai.ac.jp) have developed a highly
efficient catalyst - a Pt-Co-In ternary nanoalloy
on a ceria (CeO2) support - that exhibits
a very high catalytic activity, C3H6 selectivity,
stability and CO2-utilization efficiency.
Each of the three metals were chosen
for their specific properties: Pt as the main
active metal due to its ability to break C-H
bonds; Co for accelerating CO2 capture and
activation; and In to enhance the selectivity.
The researchers tested the catalyst's activity
at 550°C and compared the results
with existing catalysts. They also performed
a mechanistic study to understand the
functions of the different components and
found the catalyst links the propylene-forming
reaction to the deoxygenation of CO2,
and ensures the catalytic activity is specific
to propane; water and carbon oxides are
formed as byproducts. They also found that
the catalyst increased the reaction rate approximately
five-fold compared to the typical
values reported from other systems. The
reaction produced a higher ratio of propylene
and utilized more CO2 at 550°C compared
to previous catalysts. The stability of
the catalyst is greatly enhanced by combining
the strong CO2 activation ability of the
alloy with the oxygen-releasing ability of the
ceria support, which facilitates Mars-van
Krevelen-type coke combustion.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
MARCH 2022
Solar clinker produced for the first time
ast month, Cemex, S.A.B. de C.V.
(Cemex; Monterrey, Mexico; www.
cemex.com) and Synhelion SA (Lugano,
Switzerland; www.synhelion.
com) successfully connected the clinker
production process with the Synhelion solar
receiver to produce solar clinker. The milestone
is a first step towards fully solar-driven
cement plants.
L
Clinker - a solid material used for making
Portland cement - is produced by fusing
together limestone, clay and other materials
in a rotary kiln at temperatures nearing
1,500°C. Because fossil fuels are typically
used to heat the kiln, they are responsible for
approximately 40% of direct CO2 emissions
of the process. Replacing fossil fuels entirely
with solar-thermal energy is a gamechanger
in the industry's efforts to achieve carbon
neutrality by 2050.
The Synhelion and Cemex R&D teams set
up a pilot batch-production unit to produce
clinker from concentrated solar radiation by
connecting the clinker production process
Separation unit
Excess CO2 stream
CO2
H2O
Preheating
tower
Return stream to receiver
Thermal energy
storage (TES)
Sensible heat recovery stream
Precalciner
Kiln
Receiver
Grate cooler
Sensible heat recovery stream return
with the Synhelion solar receiver. The pilot
was installed at the Very High Concentration
Solar Tower of IMDEA Energy, located near
Madrid, Spain. Synhelion's solar receiver
consists of a cavity filled with a greenhouse
gas (GHG; typically water vapor or mixtures
of H2O and CO2) flowing from the aperture
towards the back of the cavity. Solar radiation
coming from the 1,000-m2 field of 169
mirrors enters the cavity through a transparent
window and is absorbed by the black
surface of the cavity walls. The energy is
then thermalized and reradiated back into
the cavity to heat up the GHGs, which is
then used as a heat-transfer fluid to deliver
process heat for clinker production. With
this design, record-breaking temperatures
above 1,500°C are achieved.
The pilot, which produced a few kilograms
per batch, is the first successful calcination
and, more importantly, the first successful
clinkerization ever achieved using only
solar energy. The next step this year will
target continuous production (during daytime),
which will be followed by
a dedicated pilot facility with a
ten-fold increase in capacity. A
first small-scale industrial plant
is envisioned by 2026 and a
full-scale industrial plant (150
MWth solar input power, 900
ton/d production capacity) by
2028. The process (diagram)
will use Synhelion's thermalenergy
storage, which will enable
continuous operation -
even at night.
Synhelion/Cemex
Receiver outlet
stream
http://www.covestro.com http://www.cemex.com http://www.synhelion.com http://www.vocanbiotech.com https://www.cat.hokudai.ac.jp/index-e.html http://WWW.CHEMENGONLINE.COM
Chemical Engineering March 2022

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