Chemical Engineering January 2018 - 6

system that contributes to
improving operating rates
and plant profitability by
continuously monitoring and
analyzing plant operations
and key performance indicators
(KPls) of the plant. The
system has been applied
in a 2,750-ton/d urea plant
owned and operated by PT
Pupuk Sriwidjaja Palembang
in Palembang in South Sumatra,
Indonesia as a subsidiary
of the state-owned
Indonesian fertilizer company,
PT Pupuk Indonesia.
In December 2016, Toyo
and General Electric Co.
(GE; Boston, Mass.; www.
ge.com) signed a memorandum
of understanding
(MoU) for a joint project to
explore digital solutions for
the fertilizer and petrochemicals
industries. Under the
MoU, Toyo and GE jointly
developed Digital Fertilizer
on GE Predix, which
is a unique cloud-based
platform built exclusively
for industry by using Toyo's
expertise in processes and
plant operations as licensor
of urea synthesis and granulation
technologies and as
engineering procurement
and construction (EPC) contractor
of fertilizer and petrochemical
plants. System integration
of Digital Fertilizer
on Predix was conducted
by NEC Corp. (NEC; Tokyo;
www.nec.com), which has
entered into a comprehensive
alliance with GE.
FLUOR PILOT PLANT
The newly-named Fluor Pilot
Plant is now being used by
chemical engineering students
at the University of
Surrey's Department of
Chemical and Process Engineering
(Guilford, U.K.;
www.surrey.ac.uk). A donation
of $300,000, made
through Fluor's philanthropic
organization, the Fluor
Foundation, was provided to
the university earlier this year
to upgrade and refurbish the
plant to produce industryprepared
engineers.
The Fluor Pilot Plant also
provides realistic industry
experience to trainee
chemical weapons inspec(Continues
on p. 7)
6
Foam-dyeing process cuts water and chemicals in
denim production
F
oam dyeing, a new technology for dyeing
cotton yarn that is being applied
to denim production for the first time,
eliminates the use of several chemicals
and can reduce water use by up to 90% compared
to traditional dyeing. The foam-dyeing
process, known as IndigoZERO, was developed
at the Fiber and Biopolymer Research
Institute at Texas Tech University (Lubbock;
www.texastech.edu) and is being commercialized
by Indigo Mill Designs LLC (IMD; Greensboro,
N.C.; www.indigomilldesigns.com).
Traditional dyeing of denim involves dye
baths, in which the indigo dye is treated with a
reducing agent (sodium hydrosulfite) and pHadjusting
sodium hydroxide to render it soluble
in water. The cotton yarns used for making
denim are dipped continuously as ropes into
the baths, and then removed and exposed to
air in a step called skying to oxidize the indigo
back into its raw form to color the yarn.
Making denim typically requires six or more
dip-and-skye cycles and several rinses, all
of which require substantial amounts water,
which then must be treated.
The foam-dyeing process, on the other hand,
uses surfactants to generate an aqueous dyecontaining
foam, which is then pushed into
intimate contact with cotton yarn in an oxygenfree
chamber. The dye is converted back to
indigo in a subsequent oxidation chamber to
new collaboration between PPG
(Pittsburgh, Pa.; www.ppg.com),
SiNode Systems (Chicago, Ill.; www.
sinodesystems.com) and Raymor
Industries (Boirsbriand, Que., Canada; www.
raymor.com) aims to accelerate commercialization
for battery anodes made of a silicongraphene
composite. " These materials can
achieve significantly higher capacities than
current graphite-based anodes, allowing for
higher cell-level energy density, " explains
Kurt Olson, PPG corporate research fellow.
In electric-vehicle batteries, these traits
lead to lighter-weight batteries and increase
the distance vehicles can travel on a single
charge. " Traditionally, the addition of silicon
causes a decrease in a battery's cycle life
because the silicon expands during charging
and breaks into tiny particles that are no
longer effective, " says Olson. Coating silicon
particles with a layer of graphene effectively
increases the life of batteries.
SiNode produces few-layer graphene nanoplatelets
from methane via an atom-by-atom,
" bottom-up " plasma process. The plasma's
high temperature breaks the methane into
A
Indigo Mill Designs
dye the cotton blue. The Texas Tech/IMD process
has allowed foam dyeing to be used to
color yarn with indigo, opening its use in denim
production. Previously it could only be used on
already woven fabric.
The new process has a host of environmental
benefits without adding cost. Traditional denim
production requires 400 gal of water for each
100 yards of fabric, also with 370 lb of NaOH
and 39 lb of reducing agent for 100 lb of raw
indigo dye, explains Sudhakar Puvvada, an
advisor to IMD and the leader of the denim
global innovation center for Wrangler and Lee
brands, which have invested in the technology.
Foam-dyeing eliminates the need for NaOH and
sodium hydrosulfite, and reduces the water requirements
to 3.5 gal per 100 yards of fabric, he
says. Electricity consumption and physical footprint
of the dyeing operation are both reduced
substantially as well, Puvvada adds.
A step closer for graphene-coated anodes
carbon atoms and hydrogen, and in a specially
designed reactor, the carbon atoms are
combined into graphene as they cool. " This
continuous manufacturing process from a
low-cost carbon source results in consistentquality
graphene, " says Olson.
According to the research team, graphene
produced in this manner possesses composition,
morphology and uniformity that make it
better suited to improve anode performance
when compared to other graphene sources.
Graphene
produced
via traditional
" topdown "
batch processes require several liquid
dispersion steps, as well as purification, resulting
in more waste and product variability
when compared to the single-step approach.
Olson expects the plasma-based process to
be quite cost-competitive as production volumes
increase.
In order to lower battery costs and increase
the cycle life of batteries containing the silicongraphene
electrodes, the team is simultaneously
working to scale up the graphene production
process, optimize the particle-coating process
and develop stable dispersion technologies that
are tailored for the anode composition.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
JANUARY 2018
http://www.texastech.edu http://www.indigomilldesigns.com http://www.ge.com http://www.ppg.com http://www.nec.com http://www.sinodesystems.com http://www.raymor.com http://www.surrey.ac.uk http://WWW.CHEMENGONLINE.COM
Chemical Engineering January 2018

Table of Contents for the Digital Edition of Chemical Engineering January 2018
