Chemical Engineering August 2022 - 15

Zeeco
EcoFornax LE and LEX burners
FIGURE 3. Zeeco's ultra-low NOx technologies
can handle high-hydrogen and other fuels. Recent
enhancements to the technologies make them
more maintainable and make better use of internal
fluegas inside of the furnace
emissions and selective catalytic
reduction (SCR) equipment can be
added to further reduce the pollutant.
" Additionally, any efficiency improvement
you make to combustion
equipment or fired heaters results
in less carbon emissions, because
burning more efficiently uses less
fuel, " notes XRG's Martin. " Improving
efficiency is a quick win when the
goal is reducing CO2. "
In addition, he says, many processors
can see up to a 20% improvement
on the top end in combustion
and fuel efficiency by upgrading their
fired heaters with technologies that
pre-heat combustion air or by revamping
the heat-recovery section
in the heater. " These methods reduce
fuel consumption while allowing
more throughput. So, specific to
CO2 production, the amount of the
pollutant per unit of product goes
down, " says Martin.
Although, returning to that delicate
balance, using pre-heated combustion
air will increase efficiency, therefore
reducing CO2 emissions, but the use
of pre-heated combustion air along
with the use of carbon-based fuels
tends to increase NOx emissions.
For this reason, some companies
are developing technologies
that help processors potentially reduce
both NOx and CO2, while still
increasing efficiency and allowing
flexibility with fuels. " For medium- or
low-temperature process heaters,
we have equipment that will allow us
to have low emissions of NOx and
CO2, even when we preheat combustion
air, " says Hannum. " Our
EcoFornax line is amenable to having
air preheat and still providing really
low emissions " (Figure 1).
both rely on lean premix, while the
LE also employs fuel staging and dilute
combustion mixing technologies
to accomplish emissions and efficiency
goals. " We have put these on
a number of process heaters, such
as glycol heaters, crude oil heaters,
titanium tetrachloride vaporizers and
even some field-erected, high-pressure
boilers, " says Hannum. " Additionally,
they are flexible regarding
fuel, so if a processor wanted to
switch from natural gas to a fuel with
less carbon, this line would have advantages
for CO2 reduction, as well. "
XRG offers its Xceed system, which
provides a modification to the combustion
system for fired heaters, furnaces
and boilers that changes the
way in which combustion takes place
to distributed combustion or disbursed
combustion, allowing for increased
efficiency, as well as NOx and
CO2 reductions by changing the heat
transfer inside the system (Figure 2).
" This is a physical change you
make to your existing system, " says
Martin. " It involves specialized nozzles
that work with the burners in
the combustion system you already
have. This means the existing burner
stays in place, so start-up and shutdown
routines remain the same. After
the system has begun operation and
has reached steady state, the device
is turned on and it changes the nature
of combustion. It is low temperature
and very dilute, so it produces
very little NOx and the heat-transfer
uniformity of the process is greatly
increased. This eliminates hot spots
in the fired equipment, so it can operate
to a higher capacity without exceeding
temperature limits. "
The lower NOx emissions it enables
mean that users can recover
more heat and increase combustion
pre-heat air. " These features make
Xceed an enabling technology for
CO2 reduction, but it does not itself
reduce CO2, " explains Martin. " The
system is capable of firing hydrogen
or ammonia, so it could be used to
replace part of your hydrocarbon
fuels with hydrogen or ammonia firing
in order to reduce CO2 emissions. "
Zeeco, Inc., (Broken Arrow, Okla.;
www.zeeco.com) offers combustion
equipment that features ultra-low
NOx technologies with the ability
to handle high-hydrogen and other
fuels, says Rex Isaacs, chief technology
officer with the company.
" While we have been doing some
high-hydrogen applications for 20 to
30 years, we've recently made some
enhancements to those technologies
to make them more maintainable and
to make better use of internal fluegas
inside of the furnace. The ability to
inert the H2, which burns at a higher
adiabatic flame than other fuels, delays
combustion and also achieves
lower NOx. At the same time, it reduces
the local temperature inside
the burner, which reduces the damage
to the metallurgy, increasing reliability
of the equipment " (Figure 3).
Koch Engineered Solutions also
offers a wall burner for ethylene applications
that enables 100% H2 firing,
with lower NOx performance
compared to traditional ethylene
wall burner technology. This also
eliminates flashback, which can be
an operational concern and cause
maintenance issues for customers,
says KES's Baukal.
" We've also engineered the Solex
Burner, which can achieve singledigit
NOx emissions regardless of the
fuel composition and independent of
furnace temperature, " explains Ryan
Morgan, vice president of OnPoint,
a Koch Engineered Solutions comHoneywell
Thermal Systems
FIGURE 4. Thermal IQ remote monitoring software records, archives and analyzes thermal systems to
provide real-time visibility into the thermal performance of combustion and actionable intelligence
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
AUGUST 2022
15

http://www.zeeco.com http://WWW.CHEMENGONLINE.COM

Chemical Engineering August 2022

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