Chemical Engineering July 2013 - 12

CHEMENTATOR
Burner technology enables reduced NOx
with short flame length
o comply with increasingly stringent
regulations for NOx emissions, operators
of industrial plants often turn to low-NOx
burners to avoid much more costly postcombustion
treatment approaches like selective
catalytic reduction (SCR). But low-NOx
burners are plagued by significant losses in
efficiency and process throughput.
ClearSign Combustion Corp.
T
(Seattle,
Wash.; www.clearsign.com) has developed
patent-pending technologies to address
this issue. The technologies can effectively
reduce the formation of NOx to less than
5 ppm during combustion without compromising
fuel efficiency. ClearSign's Electrodynamic
Combustion Control (ECC),
uses computer-controlled electric fields to
manipulate the movement of charged particles
within and around burner flames. The
high-voltage, low-power fields are pulsed to
precisely control the physics and chemistry
of the flame, including its shape and heattransfer
properties, explains ClearSign CEO
Rick Rutkowski. ECC can be applied to new
or existing burners.
ClearSign has also developed a novel
burner architecture with an upper and
lower tier (diagram) that allows the anchor
position of the flame to be manipulated so
that a large amount of fluegas is entrained
E Power & Water (Trevose, Pa.; www.
ge.com) has introduced a novel, dualpronged
approach to corrosion inhibition
for boiler and steam-condensate systems in
petroleum refineries. The technology is designed
to prevent attack by acidic species on
steam-system surfaces, providing reliability
to the refining process and helping to maximize
profitability.
Tradenamed Steamate Low Salt Amine
(LSA), this new series of products involves
a specially designed set of volatile amines
to neutralize acidic contaminants, primarily
CO2, in steam condensate. In addition, the
Steamate LSA series products can include a
unique, volatile, surface-corrosion inhibitor,
referred to as a " polyamine, " that forms a robust
barrier film on boiler system surfaces
to restrict access of corrosive species.
Using newly developed chemical structures,
the volatile neutralizing amines raise
the pH level of the acidic steam condensate
into the mild alkaline range (~9), which is the
within the combustion
gas. The effect of the
entrained fluegas is to
dilute ionic and free-radical
species that would
otherwise react to generate
NOx. Because the NOx-forming species
are less likely to come into contact and
react, lower levels of NOx are formed in the
combustion. The so-called Duplex burner
can maintain a stable flame over a large
operating range (natural gas through propane)
even with low levels of excess oxygen
(1-3%) while dramatically reducing flame
length, says Rutkowski.
Using ClearSign's ECC and Duplex technologies,
operators can realize overall efficiency
gains of 20-30% and NOx emissions
less than 5 ppm. In addition, particulate
matter generated during combustion agglomerates
into pieces that are easy to remove.
Major applications include petroleum
refining, electric power generation, ethane
cracking and other hydrocarbon processing.
ClearSign has demonstrated ECC with
the Duplex burner at scales approaching
250,000 Btu/h, and is now looking for
partners in the burner manufacturing
space to help move the technology toward
commercialization.
Improved corrosion control in refinery steam systems
G
(Continued from p. 11)
catalyst and activated clay technology
for the hydrogenation of
edible oils and fatty acids that
improves activity with the same
level of metal. The greater catalyst
activity allows food processors
to shorten batch times, or
run reactions at lower temperatures,
which reduces formation
of " trans fats " in processed oils.
Also for the edible oil market,
BASF has developed an acidactivated
clay for the oil purification
process. The more active
clay allows users to employ
lower doses of clay to achieve
the same level of color removal
from the oil, the company says.
The sulfuric-acid-activated clay
is available in two grades, one
for standard oils and another for
tougher-to-bleach oils.
ideal range for protecting the steel and copper
alloys used in steam condensate systems,
explains Tony Rossi, GE product manager for
boiler chemicals. Further, GE uses specialized
modeling to select amines based on the
property of salt-point temperature - amines
with lower salt-point temperatures have
reduced potential to form corrosive aminechloride
salt deposits on the interior of crudeoil
distillation towers, where boiler steam is
used to improve fractionation efficiency.
Meanwhile, GE's polyamine barrier film -
which Rossi likens to a protective wax finish
on a washed automobile - also inhibits dissolved
oxygen pitting, and is compatible with
the new neutralizing amines used in GE's integrated
boiler and process-steam treatment.
" An advantage of this protective barrier is
that it is more volatile than traditional filming
corrosion inhibitors, " says Rossi, " so it leaves
the boiler very efficiently with the steam, and
provides very effective coverage of the steam(Continues
on p. 15)
12 CHEMICAL ENGINEERING WWW.CHE.COM JULY 2013
Graphite HEX
Last month, SGL Group (Wiesbaden,
Germany; www.
sglgroup.com) launched the
world's largest graphite-plate
heat exchanger, which provides
flowrates of up to 250 m3/h,
the company says. Used for
heating or cooling of corrosive
liquids, the large Diabon plate
heat exchangers are said to
require up to 75% less heat
exchanger area for the same
performance, compared to
annular-groove, block or shelland-tube
heat exchangers. The
new exchangers are available,
globally, through SGL's partner,
Alfa Laval AB (Lund, Sweden;
www.alfalaval.com).
Benign fertilizer
Sandia National Laboratory (Albuquerque,
N.M; www.sandia.
gov) researcher Kevin Fleming
has developed a formulation
for the widely used crop fertil(Continues
on p. 14)
http://www.clearsign.com http://www.sglgroup.com http://www.ge.com http://www.alfalaval.com http://www.sandia http://WWW.CHE.COM
Chemical Engineering July 2013

Table of Contents for the Digital Edition of Chemical Engineering July 2013
