Chemical Engineering June 2016 - 8

150,000 electric vehicle batteries
per year (or 20-million/
yr batteries for e-bikes).
zero-power Cooling
A newly introduced coolant
material can reduce temperatures
rapidly from room
temperature to below freezing
with the addition of water.
The material enables the
possibility of industrial cooling
systems that consume
little to no electric power and
do not require the compression
of refrigerant materials,
such as chlorofluorocarbons
(CFCs), according to
developer Frosty Cold LLC
(Overland Park, Kan.; www.
frostycoldtech.com).
Using a patented blend of
solid fertilizers, the product
undergoes an endothermic
reaction when exposed to
any type of water, and cools
by 50°F or more in just 10-20
seconds, depending on the
mix ratio of the powder to
water, explains John Bergida,
the founder and president
of Frosty Cold.
The non-oxidizing, endothermic
salt has numerous
features that allow it to be
used in a broad range of
cooling applications. After
cooling, the water can be
evaporated and the powder
reused for hundreds of
cycles, Bergida says. The
instantly activated material
is flexible, even when frozen,
and is non-toxic, Bergida
says. At the end of its life, it
can be used as a fertilizer.
Frosty Cold developed a
proprietary manufacturing
process for the material and
has set it up at a California
manufacturing plant. In addition
to consumer, medical
and cold-chain applications,
such as ice packs, beverage
coolers and shipping pads,
the company is also pursuing
industrial cooling applications.
These include zeropower
cooling, continuous
refrigeration, air conditioning,
cooling-tower heat removal,
machine chillers and more.
digital meChaniCs
At the Hannover trade fair,
Siemens AG (Munich, Ger(Continues
on p. 10)
8
Diamond-based electrodes allow handling of
difficult-to-treat wastewaters
A
scaled-up version of an electrochemical
cell with boron-doped diamond
electrodes has been introduced,
and the system treats wastewaters
containing difficult-to-oxidize dissolved pollutants.
Known as Diamox, the electrochemical
oxidation cell was developed by Element
Six (www.e6.com), a designer and manufacturer
of synthetic diamond materials and
products. The unit mineralizes the dissolved
contaminants in the water and, via oxidation
by electrochemically generated hydroxyl radicals,
releases them as CO2. The company's
next-generation version increases the oxidation
capacity by five times compared to its
original device, making it more suitable for
industrially relevant scales - up to 2 kg of
chemical oxygen demand (COD) per hour.
Using a microwave plasma-enhanced
chemical vapor deposition (CVD) process
(diagram), the company synthesizes its
solid, free-standing bulk diamond materials
by manipulating conditions at the substrate
surface such that carbon forms diamond
preferentially over graphite. The CVD process
allows Element Six to control the purity
and introduce boron atoms to the diamond
as dopants. " The addition of boron in a ratio
of about 1 atom of boron per 500 atoms
of diamond allows the material to become
a metal-like conductor, " explains Tim Mollart,
applications engineer at Element Six.
This results in an electrode that can perform
electrolysis, but still retain the properties of
diamond, including chemical inertness and
erosion resistance, Mollart continues.
Waveguide
Microwaves
Chamber
Gas inlet
Substrate
Plasma
Window
Antenna
Pressure control
Vacuum
The inertness of the diamond surface is critical
to the material's operation in wastewater
treatment. The current passing through the
electrode generates hydroxyl radicals from
water at the electrode surface, and since the
radicals do not react with the inert diamond,
they exist long enough to oxidize dissolved
pollutant molecules in wastewater.
The Diamox water-treatment system is
best applied to industrial wastewaters containing
phenolic compounds, mercaptans,
dyes, aldehydes and wastewater from pharmaceutical
manufacturing, Mollart says.
Element Six is actively working with watertreatment
technology providers to develop
modular electrochemical advanced oxidation
water-treatment systems.
A direct route for making polycarbonate
from CO2 and diols
A
direct copolymerization of carbon
dioxide and diols has been
achieved by Keiichi Tomishige
and Masazumi Tamura at Tohoku
University (Sendai; www.che.tohoku.ac.jp)
and Hiroshi Sugimoto at Tokyo University
of Science (both Japan; www.sut.ac.jp).
The synthesis takes place with a metaloxide
catalyst using 2-cyanopyridine as
a promotor, and produces alternating cooligomers
with yields and selectivities of
up to 99%.
For example, a polycarbonate with molecular
weight of 1,070 and dispersity (a
measure of the polymer's heterogeneity) of
1.33 is obtained with 97% yield after reacting
1,4-butandiol in an autoclave with CO2
at 5 MPa and a relatively mild temperature
of 403K after 8 h.
The catalyst, which is obtained by calcination,
does not leach into the reaction
solution, and maintains its activity after recovery
from a reaction. The catalyst system
is applicable for a wide variety of diols, including
linear C4-C10 α,ω-diols, producing
corresponding co-oligomers with yields
of 94-99% and higher. These compounds
cannot be made by conventional routes,
such as the copolymerization of CO2 and
cyclic ethers and ring-opening polymerization
of cyclic carbonates.
The chemists believe this new route is
simpler and more environmentally friendly
than alternative methods, which require
expensive or hazardous reagents, such as
phosgene, carbon monoxide and epoxides.
It also opens the door for utilizing CO2 as
a feedstock.
ChemiCal engineering www.Chemengonline.Com june 2016
http://www.e6.com http://www.frostycoldtech.com http://www.che.tohoku.ac.jp http://www.sut.ac.jp http://www.Chemengonline.Com
Chemical Engineering June 2016

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