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Process Heater & Boiler Tune-Up
Training
Mike Sanders
Principal Consultant- Alpha Three Consulting
John Bacon
Project Director- TRC Environmental Corporation
April 2018
Who We Are and What We Do
Mike Sanders:
• B.S. Civil Engineering- Drexel University;
• M.B.A.- Widener University;
• 40 years of energy management experience working for Sunoco and Altran;
• Energy Program Coordinator for Sunoco Refining (1996-2006).
• Currently Principal Consultant for Alpha-Three Consulting.
John Bacon:
• B.S. Geology- Albion College;
• M.B.A., Strategic Leadership- Spring Arbor University;
• Licensed Professional Geoscientist (Louisiana)
• 24 years experience as an environmental and air quality consultant;
• Manage Combustion Services Group at TRC Environmental Corporation
• Conducted Tune Ups on over 600 boilers and Process Heaters in a variety of industries including, refining, petrochemical, pulp and paper, and power generation..
What to Expect From This Course
• Approximately 4 hours of training (4- 50 minute discussions with 10 minute breaks in between)
• No test or quiz;
• If you have questions along the way please speak up;
• We would like to encourage this course to be interactive;
• Let’s try to use specific examples from your site(s) if you have questions.
• Please make sure we have your contact information upon arrival;
• Sign in sheet is by the door of you haven’t already signed in;
Course Summary
• Regulatory Review;
• Cover the technical aspects of combustion tuning;
• Review key aspects of combustion engineering and burner performance;
• Address the regulatory compliance requirements for tune ups;
• Look at MACT DDDDD case studies for which regularly occurring tune ups have been performed;
• Discuss the benefits of heater and boiler tuning including cost savings, energy reduction credits, safety, and alignment with organizational values;
• Briefly summarize a host of other related systems that are also beneficial for energy efficiency improvements.
A Look at the Regulations
Boiler and Heater MACT – 40 CFR 63
Subpart DDDDD
• DDDDD (5D)applies to major HAP sources
• JJJJJJ (6J) applies to minor or area HAP sources
• Authorized under Section 112 of the Clean Air Act (CAA)
• CAA required establishment of National Emission Standards for Hazardous Air Pollutants (NESHAPS)
• Rule applicability:
• >25 TPY of all HAP’s or >10 TPY of any single HAP
• DDDDD = MACT
• <25 TPY of all HAP’s or <10 TPY of any single HAP
• JJJJJJ = GACT
Boiler and Heater MACT-
40 CFR 63 Subpart DDDDD
• Rule was originally drafted in 2001/2002;
• Proposed on January 13, 2013
• Final Rule was published on September 13, 2004;
• Amended Rule was re-proposed on October 31, 2005;
• Final Action and Reconsideration on December 6, 2006;
• Vacatur and remand of Rule in 2007;
• Proposal of new Rule on June 4, 2010;
• EPA Rule Reconsideration (yet again)- 2011 and 2012;
• Final Rule published on February 1, 2013;
• Initial one-time energy assessment and tune-ups due on January 31, 2016;
• Initial compliance reporting due (CDX/CEDRI Reporting) on March 31, 2016.
• Recurring tune-ups annually, biennially, and every 5-years henceforth.
Industrial Applicability
NAICS Code Regulated Entity
211 Extractors of Crude Petroleum and Natural Gas
221 Electric, Gas, and Sanitary Services
316, 326, 339 Manufacturers of Rubber and Plastic Products
321 Manufacturers of Lumber and Wood Products
322 Pulp & Paper Mills
324 Petroleum Refineries and Coal Product Manufacturing
325 Chemical Manufacturers
331 Primary Metal Manufacturing
332 Electroplating, Anodizing, Annealing, and Metal Polishing
336 Manufacturers of Motor Vehicle Parts and Accessories
611 Educational Services and Institutions
622 Health Services and Institutions
Boiler and Heater MACT – Subpart
DDDDD
Definitions:
• Boiler: “An enclosed combustion device using controlled flame combustion and having the primary purpose of recovering thermal energy in the form of steam or hot water”
• Process Heater: “A combustion device in which combustion fuels do not directly contact the process materials or process gas in the combustion chamber (i.e. indirect fired)”
Boiler and Heater MACT
– Subpart DDDDD
What does not meet the definition of a boiler or heater and is otherwise exempt from the Rule?
• Boilers used for research and development;
• Boilers used in military propulsion systems;
• Boilers used as “control devices” and already comply with another MACT Rule;
• Boilers otherwise subject to “Utility MACT” in 40 CFR 63 Subpart UUUUU (Electric Generating Units).
Types of Fuels Regulated by DDDDD
• Coal
• Biomass
Solid Fuels
• No.6, No.4, No. 2 fuel oils (Heavy)
• Other distillate oils (Light)
Liquid Fuels
• Gas 1 = Natural gas and refinery fuel gas
• Other gases (bio-gas, landfill gas, coal gas, etc.)
Gaseous Fuels
Pollutants Regulated by DDDDD
If you were combusting something other than natural gas or refinery fuel gas; and,
• If that “other fuel”, comprised more than 10% of the total gross heat input of the unit, then you would be subject to specific emission limits for:
• Particulate Matter (Filterable PM)
• Hydrogen Chloride (HCl)
• Mercury (Hg)
• Carbon Monoxide (CO)
Subpart DDDDD Emission Limits
Refinery Gas ~ Gas 1
• Subpart DDDDD considers refinery gas to be the gases created by cracking or reforming and includes methane, ethane, ethylene, butane, butylene, hydrogen and their equivalents
• Therefore EPA saw fit not to apply emission limits to natural gas and refinery gas -----> “inherently low emissions.”
• EPA did apply work practice standards however!
Boiler & Heater Tune
Ups
• Required initially for all boilers and heaters (major sources were due by Jan 2016)
• Annually for units >10 MMBtu/hr. • Biennially for heaters and boiler >5 MMBtu/hr. but
<10 MMBtu/hr.• Every 5 years for heaters and boilers <5MMBtu/hr.• Every 5 years if an O2 trim system is in place• Every 5 years if permitted as limited use
Links below to boiler tune-up literature and guidance
http://www.epa.gov/ttn/atw/boiler/imptools/area_tuneup_info_only.pdf
http://www.epa.gov/ttn/atw/boiler/imptools/tune-up_guide.pdf
https://ecenter.ee.doe.gov/EM/tools/Pages/BoilerTuneUp.aspx
Boiler & Heater Tune Ups
Schedule is
important
Annual Tune Ups must be completed within 13 months of the previous tune up;
Biennial tune ups must be completed within 25 months of the previous tune up;
5-years tune ups must be completed within 61 months of the previous tune-up.
If combustion source is not operating at the time your tune up is due, you have 30 days from startup to conduct your tune up.
Boiler and Heater Tune Up Requirements
As applicable, inspect the burner, and clean or replace
any components as necessary;
Inspect the flame pattern, as
applicable, and adjust the burner as necessary to
optimize the flame pattern.
Inspect the system
controlling the air-to-fuel ratio,
as applicable, and ensure that
it is correctly calibrated and
functioning properly;
Optimize emissions of CO consistent with
manufacturer’s specifications, and with any NOx requirement
to which the unit is subject .
DDDDD Tune Up
Requirements
• Measure CO and oxygen before and after the adjustments are made.
• May use a portable CO/O2 analyzer;
• Maintain on-site and submit, if requested, a report containing:
• The CO and oxygen measured at high fire or typical operating load before and after the adjustments;
• Description of any corrective actions taken; and
• Type and amount of fuel used over the prior 12 months.
Note: Must conduct tune-up while burning fuel that provided majority of heat input over previous 12 months.
DDDDD Tune Up
Requirements
• So…..to perform a tune-up, should the boiler/heater be operational or non-operational?
• Operational!!!!
• Facilities can get hung up on the following:
“inspect the burner, and clean or replace any components as necessary;”
• The burners/boiler/heater do not have to be down and off for this to occur
• You can tell more about burner performance when the burners are up and running!!!
DDDDD Tune Up Requirements
The biggest issue that we see in facilities already performing tune-ups using their burner vendor or heater/boiler maintenance vendor?
• The report doesn’t include all of the regulatory requirements. It is a great report but often doesn’t include:
▪ Before and after tuning combustion emissions
▪ And more often than not does not specifically discuss optimization of CO emissions
▪ Also important to note ---- NOx trumps CO --- so a unit should not be optimized to lower
• CO emissions at the expense of NOx emissions -------
▪ Tuning to lower excess air will potentially increase CO, but will reduce NOx and improve overall thermal efficiency.
DDDDD Tune Up Requirements
• Other tune-up issues:
• Annual tune-ups have a 13 month window in which to be completed
• Tune-ups are to be completed at high fire conditions, or typical operating conditions
• We try to tune at both high fire and medium firing conditions (i.e. 100% load and 50% load if possible)
• Can your tune-up schedule flex based upon turnaround or shutdown schedules ---- yes
Recent MACT DDDDD Court Challenge
• On March 16, 2018 the DC Circuit Court of Appeals issued a decision on two separate challenges to MACT DDDDD.
• The first challenge concerns emission limits in the rule for carbon monoxide as a proxy for non-dioxin organic HAPs.
• The court rejected EPA’s justification for setting the lowest level of CO emissions within the rule at 130 ppm, and remanded the EPA to “reconsider its decision to adopt the 130 ppm CO limits.”
• The limits will not be vacated during the reconsideration, meaning that the 130 ppm standard will continue to be in effect until EPA finishes the next rulemaking.
• The second challenge addresses how boilers are to be operated during startup and shut down.
• The court upheld the startup and shutdown provisions of the rule, rejecting the petitioners’ claim that the provisions developed in the 2015 rulemaking were “arbitrary and capricious,” and determining that EPA’s justification for the startup and shutdown provisions were technically sound.
• As such, this portion of the current Boiler MACT rule will remain unchanged from the version finalized in November 2015.
• 10 Minute Break
Technical Aspects of Tuning
Testo 350 XLCombustion
Analyzer
Air Flow & Velocity Meter
IR Camera
Boiler & Heater Tune UpsSo what really happens during a tune-up?
Typically in the stack with combustion analyzer ---- before and after flue gas values (O2, CO, NOx, CxHy, temp, delta P)
Three things:1) Thermal imaging the burners
(optional)2) Inspecting the flame (orange vs.
blue/green3) Adjusting primary burner air
dampers/registers
Typical Combustion Analysis Data
• Data during “typical operating conditions”
• Corroborated with CEMS or other monitoring data
Tune Up Data/Results
82.5
83.0
83.5
84.0
84.5
85.0
85.5
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87
O2% Eff % Linear (O2%) 2 per. Mov. Avg. (O2%)
% O
2
Time
% Efficien
cy
Boiler & Heater Tune Ups
• Part of the tune-up deliverable is the before and after tuning results
Optimal load vs. emission
performance curve.% O2 CO ppm
Load
Typical Elements of Combustion Efficiency
Heat energy to process
Fuel to burners; loss upon ignition
Heat loss to dry air as a function of temp (Cp dry air)
Heat loss to water vapor in flue gas as a function of temp
(Cp water + Cp vapor)
CxHy combustible losses assumed as un-
combusted methane
Radiative heat loss to dry air (all
directions)
Stack Gas
Radiative heat loss to dry air (all
directions)
Calculating Combustion
Efficiency (Corroboration
of Analyzer Data)
Stack heat losses:
Uncombusted HCs (measured via combustion analyzer)
Heat loss to dry air out stack (based on measured stack temp; combustion analyzer or facility data)
Heat loss to moisture in air (based on temperature and combustion calculations)
Calculating Combustion Efficiency (Corroboration of Data)
• Ignition loss: 4.6% of fuel heating value• Based on EPA combustion analysis study
• Radiative losses• Based on Stefan-Boltzmann Law: q = εα(Ts
4 - Ta4)
Ts Ta
Calculating Combustion Efficiency (Corroboration of Data)
• We’ve seen values from ~70% (Old, poorly insulated heaters) up to ~90% (Boilers and newer heaters; units with energy recovery devices)
Combustion Engineering Basics
CH4 + 2O2 ---------> CO2 + 2H2O
C3H8 + 5O2 --------> 3CO2 + 4H2O
It really is all chemistry!!!
Combustion Engineering- The
Basics
While combustion chemistry is important, it also relies upon:
Time, Temperature and Turbulence: The combustion process is extremely dependent on time, temperature, and turbulence. Time is important to combustion because if a fuel is not given a sufficient amount of time to burn, a significant amount of energy will be left in the fuel. Too much time to burn on the other hand will produce very long flames, which can be a function of bad mixing. The correct balance of time and mixing will achieve complete combustion, minimize flame impingement (boiler maintenance hazard), and improve combustion safety. In addition, a properly controlled combustion process strives to provide the highest combustion efficiency while maintaining low emissions of combustion gases and pollutants.
Combustion Engineering-
The Basics
Combustion takes place when fuel, most commonly a fossil fuel, reacts with the oxygen in air to produce heat. The heat created by the burning of a fossil fuel is used in the operation of equipment such as boilers, furnaces, kilns, and engines. Along with heat, CO2 (carbon dioxide) and H20 (water) are created as byproducts of the exothermic reaction.
• CH4 + 2O2 --------> CO2 + 2H2O + Heat
• C + O2 --------------> CO2 + Heat
• 2H2+ O2 -----------> 2H2O + Heat
Combustion Engineering- The Basics
• By monitoring and regulating some of the gases in the stack or exhaust, it is easy to improve combustion efficiency, which conserves fuel and lowers expenses.
• Combustion efficiency is the calculation of how effectively the combustion process runs. To achieve the highest levels of combustion efficiency, complete combustion should take place.
• Complete combustion occurs when all of the energy in the fuel being burned is extracted and none of the Carbon and Hydrogen compounds are left unburned.
• Complete combustion will occur when the proper amounts of fuel and air (fuel/air ratio) are mixed for the correct amount of time under the appropriate conditions of turbulence and temperature.
Combustion Engineering-
The Basics
• Complete Combustion – Complete combustion occurs when 100% of the energy in the fuel is extracted. It is important to strive for complete combustion to preserve fuel and improve the cost efficiency of the combustion process. There must be enough air in the combustion chamber for complete combustion to occur. The addition of excess air greatly lowers the formation of CO (carbon monoxide) by allowing CO to react with O2. The less CO remaining in the flue gas, the closer to complete combustion the reaction becomes. This is because the toxic gas carbon monoxide (CO) still contains a very significant amount of energy that should be completely burned.
• Stoichiometric Combustion –Stoichiometric combustion is the theoretical point at which the fuel to air ratio is ideal so that there is complete combustion with perfect efficiency. Although stoichiometric combustion is not possible, it is striven for in all combustion processes to maximize profits.
Combustion Engineering- The Basics
• Although theoretically stoichiometric combustion provides the perfect fuel to air ratio, which thus lowers losses and extracts all of the energy from the fuel; in reality, stoichiometric combustion is unattainable due to many varying factors. Heat losses are inevitable thus making 100% efficiency impossible.
• In practice, in order to achieve complete combustion, it is necessary to increase the amounts of air to the combustion process to ensure the burning of all of the fuel. The amount of air that must be added to make certain all energy is retrieved is known as excess air.
• In most combustion processes, additional chemical/combustion by-products are formed. Some of the reaction products created such as CO (carbon monoxide), SO2 (sulfur dioxide), NO (Nitric Oxide), NO2
(Nitrogen Dioxide), soot, and ash are indictors of good combustion performance (or not).
Combustion Engineering- The Basics
Fuel - Air Ratio – The fuel-air ratio is the proportion of fuel to air during combustion. The optimal ratio (the stoichiometric ratio) occurs when all of the fuel and all of the oxygen in the reaction chamber balance each other out perfectly. Rich burning is when there is more fuel than air in the combustion chamber while lean burning occurs when there is more air than fuel in the combustion chamber.
Not so perfect Perfect
Combustion Engineering-The Basics
What is Draft?
The pressure of the gases in the stack must be carefully controlled to ensure that all the gases of combustion are removed from the combustion zone at the correct rate. This draft pressure can be positive or negative depending of the boiler design; natural draft, balance draft, and forced draft boilers are the most commonly used in the industry.
Monitoring draft is important not only to increase combustion efficiency, but also to maintain safe conditions. Low draft pressures create build-ups of highly toxic gases such as carbon monoxide and highly explosive gases. These build ups may take place in the combustion chamber or may even be ventilated indoors creating the risk of injury and death. Conversely, extremely high draft pressures can cause unwanted turbulences in the system preventing complete combustion. Unwanted high draft pressures tend to damage the combustion chamber and heat exchanger material by causing flame impingement.
Combustion Engineering- The BasicsExcess Air – In order to ensure complete combustion, combustion chambers are fired with excess air. Excess air increases the amount of oxygen and nitrogen entering the flame increasing the probability that oxygen will find and react with the fuel. The addition of excess air also increases turbulence, which increases mixing in the combustion chamber. Increased mixing of the air and fuel will further improve combustion efficiency by giving these components a better chance to react. As more excess air enters the combustion chamber, more of the fuel is burned until it finally reaches complete combustion. Greater amounts of excess air create lower amounts of CO but also cause more heat losses. Because the levels of both CO and heat losses affect the combustion efficiency, it is important to control and monitor excess air and the CO levels to ensure the highest combustion efficiency possible.
Combustion Engineering- The Basics
Calculating Excess Air
• As discussed earlier, under stoichiometric (theoretical) conditions, the amount of oxygen in the air used for combustion is completely depleted in the combustion process. Therefore, by measuring the amount of oxygen in the exhaust gases leaving the stack we should be able to calculate the percentage of excess air being supplied to the process.
• The following formula is normally used to calculate the excess air:
• % Excess Air = %O2 measured x 100
20.9-%O2 measured
10 Minute Break
Combustion Engineering- The BasicsTypical Excess Air Values
Fuel Type of Furnace Excess Air %
Pulverized Coal Partially Water Cooled Furnace 15-40%
Coal Spreader stoker 30-60%
Coal Underfeed Stoker 20-50%
Fuel Oil Oil-Burners, register type 5-10%
Fuel Oil Multi-fuel burners & flat-flame 10-20%
Natural Gas Register type Burners 5-10%
Other than managing fuel flow, controlling excess air has the greatest impact on both thermal and combustion efficiency!!
Combustion Engineering- The BasicsAlthough combustion efficiency can not be measured directly, it can be calculated by identifying all of the losses that occur during combustion. It is important to consider all factors including sensible heat losses, unburned gases, radiation, and unburned particles. In most instances, the values of the skin losses and latent heat losses are not taken into account. The following equation can be used to calculate combustion efficiency:
%Efficiency = 100% - Total Heat losses x 100 Fuel heating value
Combustion Engineering- The Basics
Fired Heaters
• Most fired heaters are bottom “up-fired” configurations with tall and “relatively” narrow combustion chambers --- fuel aside, since time, turbulence, and temperature (3T’s) are keys to optimal combustion, is a process heater an efficient configuration?
Fired Heaters
All shapes and sizes and can be up-fired, wall fired, and even down draft.
Fired Heaters
Numerous process burner and heater manufacturers
Boiler TypesFire-tube boilers
Firetube boilers consist of a series of straight tubes that are housed inside a water-filled outer shell. The tubes are arranged so that hot combustion gases flow through the tubes. As the hot gases flow through the tubes, they heat the water surrounding the tubes. The water is confined by the outer shell of boiler. To avoid the need for a thick outer shell firetube boilers are used for lower pressure applications. Generally, the heat input capacities for firetube boilers are limited to 50 MMBtu per hour or less, but in recent years the size of firetube boilers has increased.
Water-tube boilers Water tube boilers are designed to circulate hot combustion gases around the outside of a large number of water filled tubes. The tubes extend between an upper header, called a steam drum, and one or more lower headers or drums. In the older designs, the tubes were either straight or bent into simple shapes. Newer boilers have tubes with complex and diverse bends. Because the pressure is confined inside the tubes, water tube boilers can be fabricated in larger sizes and used for higher-pressure applications
Boiler Types“D” Type Boilers
• “D” type boilers have the most flexible design. They have a single
steam drum and a single mud drum, vertically aligned. The boiler
tubes extend to one side of each drum. “D” type boilers generally have
more tube surface exposed to the radiant heat than do other designs.
“Package boilers” as opposed to “field-erected” units generally have
significantly shorter fireboxes and frequently have very high heat
transfer rates (250,000 Btu per hour per sq. foot). For this reason it is
important to ensure high-quality boiler feed water and to chemically
treat the systems properly. Maintenance of burners and diffuser plates
to minimize the potential for flame impingement is critical.
Boiler Types“A” Type Boilers
• This design is more susceptible to tube starvation if bottom blows are
not performed properly because “A” type boilers have two mud
drums symmetrically below the steam drum. Drums are each smaller
than the single mud drums of the “D” or “O” type boilers. Bottom
blows should not be undertaken at more than 80 per cent of the
rated steam load in these boilers. Bottom blow refers to the required
regular blow down from the boiler mud drums to remove sludge and
suspended solids.
Boiler Types• “O” Type Boilers
O” design boilers have a single steam drum and a single mud drum.
The drums are directly aligned vertically with each other, and have a
roughly symmetrical arrangement of riser tubes. Circulation is more
easily controlled, and the larger mud drum design renders the boilers
less prone to starvation due to flow blockage, although burner
alignment and other factors can impact circulation.
Boiler Types
Packaged boilers
• Boilers are occasionally distinguished by their method of fabrication. Packaged boilers are assembled in a factory, mounted on a skid, and transported to the site as one package, ready for hookup to auxiliary piping. Shop assembled boilers are built up from a number of individual pieces or subassemblies. After these parts are aligned, connected, and tested, the entire unit is shipped to the site in one piece. Field erected boilers are too large to be transported as an entire assembly.They are constructed at the site from a series of individual components. Sometimes these components require special transportation and lifting considerations because of their size and weight.
• The packaged boiler is so called because it comes as a complete package. Once delivered to the site, it requires only the steam, water pipe work, fuel supply and electrical connections to be made for it to become operational. Packaged boilers are generally of shell type with fire tube design so as to achieve high heat transfer rates by both radiation and convection.
The features of packaged boilers are:
• Small combustion space and high heat release rate resulting in faster evaporation. • Large number of small diameter tubes leading to good convective heat transfer. • Forced or induced draft systems resulting in good combustion efficiency. • A number of passes resulting in better overall heat transfer. • Higher thermal efficiency levels compared with other boilers.
Boiler Types
Type D Type O Type A
Burners
Every burner is different ---- even the same exact burner can be different than the one immediately adjacent --- talk to the experts!!!
Yes!No
Burners
• Many of the heater and boiler burners are low NOx or ultra low NOx.
• Burner maintenance and management is essential.
Benefits of Boiler and Heater TuningImprove Efficiency, Reduce Pollution, & Save Money
Case Studies
Why Complete Boiler and
Heater Tune Ups
Value Beyond the Rules: Optimize performance while maintaining compliance
Combustion Optimization:
Tune-ups target CO & HAPs, but typically reduces NOx emissions
Our data indicates the cost of tune-up is typically paid for by improved combustion unit efficiency- simple payback has been as little as 1-2 months
Fuel savings has been up to $12,000- $75,000 per unit annually on average depending on the size of the boiler or heater.
Emission decrease can be monetized into highly valued Emission Reduction Credits (ERC’s) in non-attainment areas
Recommended by the U.S. Department of Energy as a means to improve process efficiency and safety
Often aligns with the mission, vision, and values of our clients’ energy, environmental, safety and sustainability goals
Tuning as a Best Management Practice
True optimization can be overshadowed by the goal of the compliance demonstration
Full optimization to 3-5% O2 can generate additional savings
Based on the observed relationship between O2 and efficiency, linear extrapolation can estimate potential efficiency
Specific to each heater and boiler
10 Minute Break
Tuning as a Best Management Practice
Actual Savings after Tuning $
𝑦𝑟
= 𝐹𝑖𝑛𝑎𝑙 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 % − 𝐵𝑎𝑠𝑙𝑖𝑛𝑒 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦(%)
100 (%)
× 𝑃𝑟𝑖𝑐𝑒 𝑜𝑓 𝑁𝑎𝑡𝑢𝑟𝑎𝑙 𝐺𝑎𝑠 $
𝑀𝑀𝐵𝑡𝑢 × 𝐹𝑖𝑟𝑒𝑑 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦 𝑜𝑓 𝑆𝑜𝑢𝑟𝑐𝑒
𝑀𝑀𝐵𝑡𝑢
ℎ𝑟
× 24 ℎ𝑟
𝑑𝑎𝑦 × 365
𝑑𝑎𝑦𝑠
𝑦𝑟
▪ MACT DDDDD focuses on reducing emissions, but gives us insight into the benefits of process heater and boiler tuning.
▪ Flue gas data indicates notable fuel savings from a tune-up focusing on improved efficiency rather than emissions.
Tuning as a Best Management Practice
Rated Firing Capacity of Source
(MMBtu/Hour)
Number of Units Tunes
Average Cost Savings from DDDDD Tune Up Per Unit
($/Unit-Year)
Additional Estimated Cost Savings from Tuning to Optimized Conditions ($/Unit-Year)
<10 42 $3,061 $12,458
10 < x <25 83 $5,017 $31,478
25 < x < 40 72 $8,706 $25,655
40 < x < 80 138 $9,781 $38,610
80 < x < 100 54 $11,065 $49,343
100 < x < 150 53 $8,813 $18,617
150 < x < 200 28 $40,243 $74,416
>200 98 $20,081 $65,602
Case Study #1• Facility utilizes seven natural gas-fired process heaters.
• Annual tuning is required per MACT DDDDD.
• Cost of Project $15,630
Unit ID Rated Heating Capacity (MMBtu/Hr.)
Actual Savings ($/year)
Simple Payback Period (Months)
PH-01 10 $3,132 8.6
PH-02 11 $15,634 1.7
PH-03 11 $4,505 5.9
PH-04 14 $11,467 2.3
PH-05 62 $23,897 1.9
PH-06 94 $58,876 0.4
PH-07 94 $52,083 0.5
Facility Total(1) or Average(2)
-- $169,594(1) 1.1(2)
Case Study #2• Facility utilizes two natural gas-fired boilers and one process heater.
• Annual tuning is required per MACT DDDDD.
• Cost of Project= $10,450
Unit ID Rated Heating Capacity (MMBtu/Hr.)
Actual Savings ($/year)
Simple Payback Period (Months)
B-01 227 $131,242 0.3
B-02 227 $54,684 0.8
PH-03 40 $11,563 3.6
Facility Total(1) or Average(2)
-- $197,489(1) 0.6(2)
Case Study #3• Facility utilizes three natural gas-fired boilers and one process heater.
• Annual tuning is required per MACT DDDDD.
• Cost of Project= $10,750
• B-03 was already optimized at the tine of the tune up so no adjustments were made.Unit ID Rated Heating Capacity
(MMBtu/Hr.)Actual Savings
($/year)Simple Payback Period (Months)
B-01 97.8 $110,732 0.3
B-02 95.5 $62,116 0.7
B-03 242.5 $0 NA
Facility Total(1) or Average(2)
-- $172,848(1) 0.75(2)
Case Study #4• Facility utilizes twenty five natural gas-fired boilers and process heaters.
• Annual tuning is required per MACT DDDDD.
• Cost of Project= $42,500
# of Units Total Fired Capacity (MMBtu/Hr.)
Actual Savings ($/year)
Simple Payback Period
(Months)
Potential Additional Est. Savings from
Further Tuning
25 1551 $339,669 1.5 $1,482,459
Limitations to Data Study
Natural Gas
• Study focused on natural gas fueled boilers and heaters;
• $2.75/MMBtu used in these calculations
• Savings vary as price fluctuates
• Similar efficiency improvements are possible where units burn RFG
• Value of RFG per MMBtu is lower, so total savings would be less in these units.
Limitations to Data Study
Efficiency
•Limited data available to correlate efficiency excess oxygen.
•Linear extrapolation is a crude estimation.
•Actual potential savings estimates are less accurate for larger O2 adjustments.
•Adjustments to airflow also affect temperature which impacts efficiency based on how the Testo 350 calculates it.
•Growing body of data and detailed efficiency studies will help refine these estimates.
Limitations to Data Study
Firing Rate
MACT 5D only requires tuning at high-fire or typical operating load.
Units with highly variable fueling rates may not operate at optimal conditions throughout their cycle.
Establish optimized airflow at multiple loads.
Maximized savings require a fairly well defined operating protocol and continual attention, particularly when process requires variable loads.
Key Takeaways
• Simple payback on a 5D tune-up can be realized in a matter of months.
• Going beyond the minimum compliance requirements can realize two to six fold savings in just a few hours of extra labor.
• Excellent savings potential for natural gas fired units.
• Growing body of data and more detailed efficiency studies will improve savings estimates.
Other Notable Systems Relative to Boiler/Heater Operating Efficiency
Boiler feed water economizer and deaerators;
Steam super heaters;
Combustion air pre-heaters;
Steam systems;
Steam Systems
Discussion
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