1 SUMMARY REPORT FOR PO1

- PSA305

- BNL
Project Period of Performance : April 25, 2013

– September 30, 2013
BNL Project 89064
Work on this project ended on Sept. 30, 2013. The purpose of this summary report is to review the results of work which was done during the course of this project. The primary activity has involved laboratory testing of retrofit catalysts applied to hydronic heaters. Other, supporting, activities included consultation on up to 5 test reports and technical issues related to testing.
The overall goal of the catalyst work has been to evaluate the potential for retrofit catalyst systems to reduce particulate emissions from outdoor wood hydronic heaters. Two specific heaters were tested during the course of this wo rk. The first (“Two

- Stage”) is a modern hydronic heater which includes two stage, downdraft combustion and an induced draft fan. The second (“Atmospheric”) is a conventional, updraft, single stage unit without an induced draft fan. The Atmospheric unit is typical of many older units which are operating in the field. This unit is not on the current EPA list of units which qualify under Phase II of the voluntary program. This unit also was not qualified under earlier parts of the voluntary program. The Tw o

- Stage unit has lower emissions and is on the list of qualified units.
This work follows preliminary studies which were done using only the Two

- Stage unit. A presentation on the results with that unit and one commercially available catalyst were present ed to EPA on February 28, 2013. At that time the impact of the catalyst was not seen as very significant but two simple, potentially beneficial areas of improvement were identified. The first was an attempt to control the excess air level and force a cata lyst light off event which would reduce emissions. The second point related to the operation of the electric heater just under the stack catalyst. In the first round of testing, the catalyst heater was not powered continuously and this was in accordance w ith the manufacturer’s instructions. During cold starts of the boiler this would make the catalyst ineffective. During this test period the catalyst heater was powered at all times to evaluate the best achievable performance. The reason why the catalyst was not heated at all times normally is because cold start emissions were less of a concern to the manufacturer because the manufacturer saw them as a rare event in the operating cycle of this type of hydronic heater. However, EPA and numerous states are concerned about cold starts and

re

- starts that have generated numerous complains. In this study there was a specific focus on cold start performance.
Two specific commercial retrofit catalyst products were evaluated during this work, simply identified he re as Catalyst 1 and Catalyst 2. The catalyst composition is proprietary. Catalyst 2 included a provision for the injection of fresh air just below the catalyst with a natural draft arrangement. This air is intended to enhance burn

- up of carbon and hydr ocarbons on the catalyst.2

SUMMARY OF RESULTS OF CATALYST TESTS

Testing to force catalyst lightoff with oxygen control (PO Task 1 , Subtask 1 )
This testing was done using the Two Stage hydronic heater and Catalyst 1

. These tests were done but not found to be an effective method of controlling light off. In subsequent tests, with continuous heating of the catalyst, the need for this was seen as minimal.
Testing Catalyst 1 with constant heating to force a light off (PO Task 1, Subtask 2 and 3)
This testing was done using the Two Stage hydronic heater and Catalyst 1 . As in prior tests measurements were made over specific parts of the firing cycle including cold start, post

- reload , hot reload, slumber, and recovery from slumber. Results of tests done are summarized in Figures 1, 2, and 3.

Figure 1. Results of tests with Catalyst 1 with the Two Stage hydronic heater. Particulate Emission Index 0 2 4 6 8 10 12

Start Post-reload 1 Reload Post-reload 2 g/kg fuel

Test Period



## Emission Index

W Cat W/O Cat3

Figure 2. Results of tests with Catalyst 1 with the Two Stage hydronic heater. Particulate Emis sion Factor (lb

. /million Btu of energy output). 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Start Post-reload 1 Reload Post-reload 2 lb/MMBtu

Test Period



# Emission Factor

W Cat W/O Cat4

Figure 3. Results of tests with Catalyst 1 with the Two Stage hydronic heater. Particulate Emission Rate.
The results of these tests did not indicate a consistent potential for emission reduction as signifi cant as was anticipated. Following the completion of these tests and a review with EC/R and EPA staff a decision was made not to pursue additional tests with this boiler and different operating protocols which might have indicated pathways to better perfo rmance. Rather, a decision was made to change focus to the Atmospheric hydronic heater which was considered to be the higher priority retrofit opportunity and greater concern for neighbors

. Testing Catalyst 2 with the Atmospheric Hydronic Heater (PO Task 1, Subtask 4 and 5)
Detailed baseline testing and testing with Catalyst 2 was done with this unit over different parts of the normal operating cycle, including cold start, as planned. Figures 4, 5, and 6 provide a summary of the impact of the catalyst on particulate emissions during different parts of the firing cycle. In contrast to Figures 1

- 3 these charts show the results for each of the two sampling systems (Box 1 and Box 2) separately. For Figures 1

- 3 these were averaged. 0 50 100 150 200 250 300 350

g/hr

Test Period



## Emission Rate

W Cat W/O Cat5

Figure 4. Results of t ests with Catalyst 2 with the Atmospheric hydronic heater. Particulate Emission Index 0 5 10 15 20 25 30 35 40 45 50 g/kg fuel

Test Period



## Emission Index

Box 1 (with catalyst) Box 2 (with catalyst) Box 1 (without catalyst) Box 2 (without catalyst)6

Figure 5. Results of tests with Catalyst 2 with the Atmospheric hydronic heater. Particulate Emission Factor (lb/million Btu of energy output).7

Figure 6

. Results of tests with Catalyst 2 with the Atmospheric hydronic heater. Particulate Emission Rate.
The results of the catalyst with this hydronic heater show improvements under some conditions especially if best burn practices are used by the operator, e.g., small partial loads spread over longer time . Most notable is post

- reload

– however, caution should be used in drawing conclusions from this specific result. In the baseline testing the post

reload particulate emissions were very high and this was likely simpl y a result of the combustion conditions in the fire box at that time. A factor here could be the higher stack temperature with the catalyst which can increase draft and make more oxygen available for combustion during this time. Atmospheric draft units ar e very sensitive to draft conditions and low exhaust oxygen conditions were observed at some periods during this test work. The different results in the post

- reload results may be an artifact of the test simply because the two tests are not temporally al igned precisely and/or the process of the burning of the wood charge simply occurred differently.
Results of all measurements made with Atmospheric hydronic heater have been assembled in a presentation which is included as an appendix to this report. It is planned to review these with EC/R and EPA staff prior to development of final conclusions on the effectiveness of the catalysts and future steps.8

CONSULTATION ON TEST REPORTS AND TECHNICAL ISSUES
Specific work done under this task included:

 Review of t he test report for the Wood Boiler LLC Model E4 hydronic heater. A technical note was submitted to EPA for this review.

 Review of the test report for the Woodpecker 45 kW hydronic heater made by Webiomass. A brief email note was submitted to EPA for this unit. Very few concerns were identified.

 Review of the test report for the Steeltech Model G100 hydronic heater. A technical note was submitted to EPA for this review.

 Review and comments on a request for an extension of the approval of the Central Boiler Maxim 250 hydronic heater.

 Participation in discussion with the test labs and EPA on a technical question related to the time interval for measurement and averaging to determine hydronic heater efficiency using the stack loss method where the hydronic hea ter is cycling. A presentation was made on this issue and presented during a webinar with the commercial test labs.9

Appendix I

– Presentation on the Results of Tests with Catalyst 2 with Atmospheric Hydronic Heater. Prepared for review with EC/R and EP A staff.

# Preliminary Highlights Test of Central Boiler 5036 with 

# Clear Skies Exhaust Catalyst

T. Butcher

# Events With Clear Skies Cat Sept

. 29 th



## , 2013

Time (min) Event

0 Gas analyzers started sampling (CO, O 2 

### stack and DT, HC) 1.00

– 3.69 150 lb fuel test charge added

4.70

– 10.23 Start

- up PM sampling phase #1 Wohler PM analyzer sampling (30

minutes)

12.66

– 15.93 Start

- up PM sampling phase #2 Wohler PM analyzer still sampling

18.11

– 21.05 Start

- up PM sampling phase #3 Wohler PM analyzer still sampling

63.64

– 93.58 Slumber PM sampling period Wohler PM analyzer sampling

103.89

– 127.37 Relight from slumber PM sampling period 212.40

– 214.49 100 lb fuel test charge #2 added

215.59

– 245.60 Reload PM sampling period Wohler PM analyzer sampling



### 262.37

– 292.34 Post

- reload PM sampling period Wohler PM analyzer sampling0

300 600 900 1200 1500

0 100 200 300 400 Temperature (F)

Time (min) Flue Gas Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling 

## With Clear Skies Cat Sept

. 29 th



## , 2013 

# Flue gas temperature and events

Post

- reload sampling

# Catalyst light

- off With Clear Skies Cat Sept

. 29 th



## , 2013

0 300 600 900 1200 1500 1800

0 100 200 300 400 Temperature (F)

Time (min) Flue Gas Temp Post Cat Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling Post

- reload sampling

# Catalyst pressure drop With Clear Skies Cat Sept

. 29 th



## , 2013

0 2 4 6 8 10 12 14

0 300 600 900 1200 1500 1800

0 100 200 300 400 Catalyst pressure drop (Pa) Temperature (F)

Time (min) Flue Gas Temp

Post Cat Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling
Cat Delta P Post

- reload sampling

# Flue gas oxygen With Clear Skies Cat Sept

. 29 th



## , 2013

0 5 10 15 20 25 30

0 300 600 900 1200 1500 1800

0 100 200 300 400 O2 (%) Temperature (F)

Time (min) Flue Gas Temp

Post Cat Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling Flue Gas Oxygen (O2) Post

- reload sampling

# Dilution Tunnel CO With Clear Skies Cat Sept

. 29 th



## , 2013

0 1000 2000 3000 4000 5000 6000

0 300 600 900 1200 1500 1800

0 100 200 300 400 CO ( ppm ) Temperature (F)

Time (min) Flue Gas Temp

Post Cat Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling
Dilution tunnel CO Post

- reload sampling

# Flue HC With Clear Skies Cat Sept

. 29 th



## , 2013

0 2000 4000 6000 8000 10000 12000 14000 16000

0 300 600 900 1200 1500 1800

0 100 200 300 400 Hydrocarbons ( ppm ) Temperature (F)

Time (min) Flue Gas Temp

Post Cat Temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Reload sampling Steady state sampling Flue Hydrocarbons (ppm) Post

- reload sampling

# Events Baseline Test Sept

. 20 th



## , 2013

Time (min) Event

0 Gas analyzers started sampling (CO, O 2 

### stack and DT, HC) 6.12

– 8.39 150 lb fuel test charge added

8.47

– 15.94 Start

- up PM sampling phase #1 Wohler PM analyzer sampling (30 minutes)

17.95

– 20.21 Start

- up PM sampling phase #2 Wohler PM analyzer still sampling

26.59

– 30.02 Start

- up PM sampling phase #3 Wohler PM analyzer still sampling 96.44

– 115.55 Slumber PM sampling period 117.57

– 147.59 Relight from slumber PM sampling period 160.08

– 160.84 100 lb fuel test charge #2 added

193.96

– 196.05 Post

- reload PM sampling period Wohler PM analyzer sampling

# Flue gas temperature and events Baseline Test Sept

. 20 th



## , 2013

0 300 600 900 1200 1500

0 100 200 300 400 Temperature (F)

Time (min) Flue gas temp Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Steady state sampling Post

- reload sampling

# Flue gas oxygen Baseline Test Sept

. 20 th



## , 2013

0 5 10 15 20 25

0 300 600 900 1200 1500

0 100 200 300 400 Oxygen (%) Temperature (F)

Time (min) Flue gas temp

Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Steady state sampling Flue gas oxygen (O2) Post

- reload sampling

# Dilution Tunnel CO Baseline Test Sept

. 20 th



## , 2013

0 1000 2000 3000 4000 5000 6000

0 300 600 900 1200 1500

0 100 200 300 400 CO ( ppm ) Temperature (F)

Time (min) Flue gas temp

Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Steady state sampling
Dilution tunnel CO Post

- reload sampling

# Flue HC Baseline Test Sept

. 20 th



## , 2013

0 2000 4000 6000 8000 10000 12000

0 300 600 900 1200 1500

0 100 200 300 400 Flue Hydrocarbons ( ppm ) Temperature (F)

Time (min) Flue gas temp

Fuel charge added Start up sampling Slumber sampling Relight from slumber sampling Steady state sampling
Flue HC Post

- reload sampling

# CATALYST VS. NO CATALYST EMISSION PERFORMANCE

# Flue gas temperature and events

9/20 Events 9/29 Events Post

- reload sampling

# Flue gas oxygen

9/20 Events

9/29 Events

Post

- reload sampling

# Dilution Tunnel CO

9/20 Events

9/29 Events

Post

- reload sampling

# Mass burned

9/20 Events

9/29 Events

Post

- reload sampling0

1 2 3 4 5 6 7 8 9 10

Start Up #1 Start Up #2 Start Up #3 Total Start Up Steady

State Slumber Recover from Slumber Reload #2 lb/MMBtu

Test Period 

## Emission Factor

Box 1 (with catalyst) Box 2 (with catalyst) Box 1 (without catalyst) Box 2 (without catalyst)

Post

Reload0

500 1000 1500 2000 2500

Start Up #1 Start Up #2 Start Up #3 Total Start Up Steady

State Slumber Recover from Slumber Reload #2 g/hr

Test Period 

## Emission Rate

Box 1 (with catalyst) Box 2 (with catalyst) Box 1 (without catalyst) Box 2 (without catalyst)

Post

Reload0

5 10 15 20 25 30 35 40 45 50

Start Up #1 Start Up #2 Start Up #3 Total Start Up Steady

State Slumber Recover from Slumber Reload #2 g/kg fuel

Test Period 

## Emission Index

Box 1 (with catalyst) Box 2 (with catalyst) Box 1 (without catalyst) Box 2 (without catalyst)

Post

ReloadSeptember 29th, 2013 September 20th, 2013

Box 1 (with catalyst) Box 2 (with catalyst) Box 1 (without catalyst) Box 2 (without catalyst)

State Emission

Factor lb/ MMBtu Emission

Rate g/hr Emission

Index g/kg fuel Emission

Factor lb/MMBtu Emission

Rate g/hr Emission

Index g/kg fuel Emission

Factor lb/ MMBtu Emission

Rate g/hr Emission

Index g/kg fuel Emission

Factor lb / MMBtu Emission

Rate g/ hr Emission

Index g/kg fuel
Start Up #1 5.242 680.144 26.257 5.634 731.055 28.222 4.481 429.959 22.69 4.855 465.819 24.582
Start Up #2 4.982 793.731 24.957 5.717 912.141 28.639 9.134 2239.899 46.253 8.287 2027.035 41.961 Start Up #3 3.978 632.677 19.924 4.848 771.07 24.283 7.397 1879.076 37.458 6.365 1654.429 32.232

Total Start Up 4.752 697.2 23.805 5.423 797.058 27.164 7.6 1174.524 38.486 6.448 1070.449 32.649

Post

Reload 0.192 23.429 0.963 0.18 21.98 0.903 3.698 734.551 18.726 3.008 597.521 15.233

Slumber 0.753 6.85 3.772 0.852 7.751 4.268 4.482 19.32 22.696 4.681 20.175 23.701 Recover from Slumber 0.964 76.815 4.828 0.721 76.885 3.61 1.19 45.973 6.028 1.137 43.906 5.757

Reload #2 0.205 32.901 1.029 0.119 31.9 0.998

- - - - - -

# Initial hot coal bed & 150 lb fuel charge

# Visual start up emissions (2 mins & 8 mins after addition of wood)

# Second coal bed before 100 lb fuel charge

# Visual emissions after reload