Environmental Technology Verification Program Verification Statement External Combustion Boilers and Furnaces A-55 Clean Fuels

** CfJH UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
OIRl Office of Research and Development

Washington, D.C. 20460

ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM
VERIFICATION STATEMENT

TECHNOLOGY TYPE:
APPLICATION:

TECHNOLOGY NAME:

COMPANY:

ADDRESS:

PHONE:

AIR POLLUTION CONTROL TECHNOLOGY

EXTERNAL COMBUSTION BOILERS AND
FURNACES

A-55® CLEAN FUELS

A-55 LIMITED PARTNERSHIP

5270 NEIL ROAD
RENO, NEVADA 89502

702-826-8300

The U. S. Environmental Protection Agency (EPA) has created a program to facilitate the
deployment of innovative technologies through performance verification and information
dissemination. The goal of the Environmental Technology Verification (ETV) Program is to further
environmental protection by substantially accelerating the acceptance and use of improved and more
cost-effective technologies. The ETV Program is intended to assist and inform those involved in the
design, distribution, permitting, and purchase of environmental technologies. This document
summarizes the results of a demonstration of A-55® Clean Fuels for use in boilers.

PROGRAM OPERATION

The EPA, in partnership with recognized testing organizations, objectively and systematically
evaluates the performance of innovative technologies. Together, with the full participation of the
technology developer, they develop plans, conduct tests, collect and analyze data, and report findings.
The evaluations are conducted according to a rigorous demonstration plan and established protocols
for quality assurance. EPA's National Risk Management Research Laboratory which conducts
demonstrations of air pollution control technologies, conducted the performance verification of A-
55® Clean Fuels for boiler applications.

DEMONSTRATION DESCRIPTION

During the period of August through November 1997, the performance of two A-55® Clean Fuels
was evaluated by comparing the pollutant emissions and thermal efficiency from the combustion of
these fuels with the emissions and efficiency from the combustion of the same, but non-emulsified,
fuel in a single boiler. The boiler chosen for the tests was a full scale, 2.5xl06 Btu/hr firetube package
boiler, similar in design to boilers used in light industrial, commercial, and institutional applications.
The boiler was fully instrumented to measure emissions of carbon monoxide (CO), nitrogen oxide
(NO), sulfur dioxide (SO2), and total hydrocarbons (THC). In addition, extractive sampling of the
combustion flue gases provided information on emissions of particulate matter (PM). Temperature
and flow measurements were made to allow calculation of thermal efficiency. The operating
conditions of the boiler were chosen to be typical of those used in actual practice, both for the
emulsified and non-emulsified fuels. The fuels combusted were a standard #2 (diesel) fuel oil, an A-
55® emulsified #2 oil formulated using the same #2 oil, and an A-55® emulsified fuel naphtha. The
fuels were combusted at three loads, with four test runs per load. Details of the demonstration,
including a data summary and discussion of results, may be found in the report entitled "Verification
Testing of Emissions from the Combustion of A-55® Clean Fuels in a Firetube Boiler," EPA Report
EPA-600/R-98-035.

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TECHNOLOGY DESCRIPTION

Extensive literature documents the effects of emulsified fuels on combustion emissions in a variety
of system types. Such emulsions have been shown to be able to reduce emissions from combustion
sources; however, the impacts of oil/water emulsions on particular pollutants vary. With distillate oils,
PM and nitrogen oxides (NOx) have been shown to be reduced when using an oil/water emulsion
compared to using the same oil without emulsification, but CO emissions were not significantly
changed. The use of an emulsified fuel results in improved secondary atomization of the fuels, often
allowing operation at a reduced stoichiometric ratio, and also tends to reduce the peak combustion
temperature. Both of these effects result in lower NOx emissions, and the improved atomization can
also result in lower CO and PM emissions.

The impact of these fuels on operating efficiency will vary according to the particular characteristics
of the fuel and the system in which it is used. For combustion systems (such as gas turbines) that rely
on expansion of the gases, the water contained in the emulsified fuel can provide additional expansive
energy as it is heated along with the combustion products. In other systems, where heat transfer is the
primary mode of energy transfer, too much water can cause the thermal efficiency to drop due to the
energy required to heat the water, rather than that energy's being transferred to the process.

However, the ability to operate at lower stoichiometric ratios when using emulsified fuels can reduce
the energy required to heat the atmospheric nitrogen and excess oxygen. In short, the thermal
efficiency of a unit using emulsified fuels may either increase or decrease compared to the efficiency
of the unit using the non-emulsified base fuel, depending upon the combustor type and the
characteristics of the fuel.

A-55® Clean Fuels are essentially emulsions of water suspended in fuel oil, with small amounts of an
emulsifying agent designed to maintain the stability of the mixture. This effort was designed to
verify the performance of A-55® Clean Fuels in package boilers.

VERIFICATION OF PERFORMANCE

The performance characteristics of the A-55® Clean Fuels include:

NO emissions: Emission concentrations of the A-55® emulsified #2 oil and emulsified naphtha
were consistently lower than NO emissions from the non-emulsified #2 oil. Emission
concentrations for the A-55® emulsified #2 oil and emulsified naphtha ranged between 62 and
88 ppm (corrected to 3% O2). Reductions in emission concentrations of 34% at high load and
15% at low load were measured for the emulsified #2 oil compared to the non-emulsified #2 oil.
For the emulsified naphtha, emission concentrations were reduced by 51% at high load and 33%
at low load compared to the non-emulsified #2 oil. NO emission factors were measured at 0.063
to 0.070 lb/106 Btu for the A-55® emulsified #2 oil and 0.048 to 0.055 lb/106 Btu for the A-55®
emulsified naphtha.

• PM emissions: PM concentrations from the A-55® Clean Fuels were slightly higher in general for
the emulsified #2 oil and the emulsified naphtha compared to the non-emulsified #2 oil. For the
A-55® emulsified #2 oil and emulsified naphtha, the PM emission concentrations were less than
4.88 mg/dscm (corrected to 3% O2) for all cases, and PM emission factors for these two fuels were
1.9x10-3 to 3.8x10-3 lb/106 Btu.

PM size distribution: Optical measurements of particle size distributions in the stack emissions
indicated that combustion of the A-55® Clean Fuels generates greater amounts of particulate
matter smaller than 2.5 (im in aerodynamic diameter (PM2.5) than the non-emulsified #2 oil.
Although the tests were unable to measure the mass emissions of PM2 5, changes in the particle
size distributions of the emulsified fuels indicated greater particle mass in the sizes less than 0.1
(im and less particle mass in the sizes greater than 0.3 (im compared to the non-emulsified #2 oil.
The tests showed that the emulsified #2 oil did not exhibit a distinct minimum in the size
distribution near 0.06 (im as does the non-emulsified #2 oil. The size distribution for the
emulsified #2 oil showed a minor decrease near 0.06 (im and a second minor decrease near 0.7

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(im, but was roughly flat for particle sizes greater than 0.04 (im. The emulsified naphtha showed
a maximum near 0.05 (im and a minimum near 0.2 (im.

CO emissions: Measurements of the CO emission concentrations resulting from the combustion
of the A-55® Clean Fuels did not meet the data quality requirements established for precision, as
measured by the variation in measurements during each test run. While the continuous CO
monitor was found to be in calibration for all test runs, the measured levels of CO were at or near
the instrument's quantitative detection limit. Due to the uncertainties in the quantitative
measurements, comparisons between quantitative values may not be statistically significant.
Nevertheless, the measured values are reported in the accompanying test report for completeness.
For all cases, average CO emissions were less than 10 ppm at 3% O2. Testing indicated additional
optimization could result in even lower CO emissions.

Thermal efficiency: Boiler thermal efficiency dropped by an average of 2.5 percentage points
when using the A-55® emulsified #2 oil and by an average of 3.4 percentage points when using
the A-55® emulsified naphtha, compared to the non-emulsified #2 oil. These decreases were
almost entirely due to the additional water in the fuel.

Applicability: The A-55® emulsified #2 oil and emulsified naphtha operated well in the test
boiler. During initial use of the A-55® emulsified #2 oil, solid residues in the fuel lines from
previous operations were entrained into the fuel, probably due to the solvent properties of the
emulsifying agent. Following a flushing of the fuel lines over a period of 2-3 hours, no
additional difficulties in operation were noted. The A-55® emulsified #2 oil and the emulsified
naphtha maintained stability for the duration of the test program. No changes in burner nozzles
or fuel feed equipment were necessary for use of the fuel, although greater volumetric fuel flows
were required to maintain Btu input. Systems that operate near capacity with respect to
volumetric fuel flow may require changes in fuel feed equipment to maintain constant energy
feed into the boiler.

The A-55® Clean Fuels demonstrated reductions in NO for all test cases. While duplication of the
quantitative results is unlikely at other facilities using different equipment and different operating
conditions, the trends in emissions are expected to be similar to these tests. Both emission levels and
thermal efficiency are likely to be improved by optimizing the system in which the A-55® Clean
Fuels are used. The A-55® Clean Fuels can provide reduced emissions of NO without significant
increases in CO, but with a potential increase in operating costs associated with reduced thermal
efficiency. No evaluation of total costs associated with the use of A-55® Clean Fuels was conducted
under this series of tests.

E. Timothy Oppelt Date

Director

National Risk Management Research Laboratory
Office of Research and Development

NOTICE: EPA verifications are based on an evaluation of technology performance under specific, predetermined
criteria and the appropriate quality assurance procedures. EPA makes no expressed or implied warranties as to the
performance of the technology and does not certify that a technology will always, under circumstances other than
those tested, operate at the levels verified. The end user is solely responsible for complying with any and all
applicable Federal, State, and Local requirements.

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