Chemical Engineering February 2014 - 11

Edited by Gerald Ondrey
February 2014
A self-cleaning electrolytic cell that
converts waste streams into disinfectants
D
ealing with wastewater streams in
petroleum refineries and petrochemical
operations is often a trying task
- environmentally, economically and
logistically - especially as regulations
on salinity in waste streams are tightened.
However, many waste streams
actually contain useful components,
such as chloride compounds that can
be converted electrolytically to oxidizers
or disinfectants, such as sodium hypochlorite
(diagram), which can then be
used downstream in other aspects of the
waste-treatment process.
MIOX Corp. (Albuquerque, N.M.; www.
miox.com) is running pilot case studies
where a chloride-concentrated waste
stream is processed through a novel electrolytic
cell to generate a chlorine-based
oxidant. This generated stream is, in
turn, recycled and used elsewhere in the
process to remove other contaminants
and provide disinfection. By using this
process, disposal and raw-material costs
could be significantly reduced.
However, an issue that arises with
NaOCl
Anode
many electrolysis processes is
the effect of fouling on electrode
efficiency - the basic conditions
at the cathode make it prone to
scale buildup and many processes
seek ever-purer (and more
expensive) salt compounds to
minimize fouling. MIOX claims
to eliminate the need for highpurity
salt through the electrolytic
cell's proprietary " selfcleaning "
mechanism, which
effectively reverses polarity on
the cell with each cycle. As impurities
are built up on the cell
during operation, the polarityreversal
process flushes particles
from the cell, after which the cell
is returned to normal mode and ready to
begin a new cycle.
Potential applications for this process
include wastewater-treatment plants,
water-management at hydraulic fracturing
sites and industrial desalination facilities.
MIOX expects for this process to
reach commercial status in the next year.
Rare-earth magnets enhance filtration of engine lubricants
FilterMag's patented non-invasive deF
ilterMag
International (Scottsdale,
Ariz.; www.filtermag.com) has developed
neodymium magnetic devices that
can boost the performance of lubricant filters
for mining vehicles and industrial machinery.
When the device is in place, filters
retain 50-75% of contaminant particles
that would otherwise be missed, a level
that translates into a 30-60% increase in
engine life, says the company. The results
have been verified in third-party testing
laboratories, reports CEO Herb Martin.
The magnetic device is applied directly to
the outside of an oil filter, and works by attracting
micron-scale metallic particles to
the interior of the filter canister, retaining
them there. Particles in the range of 3-14
microns are routinely generated by engine
wear, and can significantly damage engine
components. However, particles of that size
range would pass through conventional lubricant
filter designs, says Martin.
Note: For more information, circle the 3-digit number
on p. 60, or use the website designation.
vice includes a shield to focus the neodymium's
magnetic field inward, where
it works to capture particles, rather than
outward, where it could affect surrounding
engine components. The device has
been shown to capture particles that become
charged in the fluid stream. This
aspect of Filtermag's Nd-magnetic device
allows the capture of soot, sand and other
non-magnetic contaminants in addition
to metallic particles.
The newly launched company has deployed
the devices in mining applications,
where they extend engine life on
haul trucks; in oil-and-gas applications
on land-based compressors; and in mud
pumps on offshore oil rigs. The company
is set to extend the use of the magnetic
filtration devices into the lubricant and
hydraulic systems of stationary industrial
machines.
H+ + ClO-
HO-
HO-
HCl + HOCl
Cl2
H2
Cl-
Cl-
Na+
Na+
O
H2
O
H2
Cathode
NaCl
Cellulose nanocrystals
New research from Purdue
University (West Lafayette,
Ind.; www.purdue.edu) has
shed some light on the physical
properties of cellulose nanocrystals.
The nanocrystals,
which are about 3-nm wide and
500-nm long, have historically
been difficult to analyze, but
the Purdue researchers used
quantum mechanical calculations
to make some predictions
about the crystals' properties
and behavior.
Cellulose from trees is
known to possess high
strength and resilience, while
remaining a lightweight material,
but the new discoveries
show that the nanocrystals
exhibit stiffness properties
similar to those of steel. These
findings indicate that cellulose
nanocrystals could be a feasible
" green " alternative to carbon
nanotubes. Applications
could include biodegradable
plastic films, batteries, drugdelivery
systems and more.
Membrane technology
Fouling-resistant membrane
technology from Lanxess (Cologne,
Germany; www.lanxess.
com) is being used at the Dam(Continues
on p. 12)
ChemICAL eNGINeerING WWW.Che.Com FebrUAry 2014 11
http://www.miox.com http://www.purdue.edu http://www.filtermag.com http://www.lanxess http://WWW.Che.Com
Chemical Engineering February 2014

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