Evaluation of Gas, Oil and Wood Pellet Fueled Residential Heating System Emissions Characteristics

Technical Report · Tue Dec 01 00:00:00 EST 2009

DOI:https://doi.org/10.2172/1015127· OSTI ID:1015127

McDonald, R

This study has measured the emissions from a wide range of heating equipment burning different fuels including several liquid fuel options, utility supplied natural gas and wood pellet resources. The major effort was placed on generating a database for the mass emission rate of fine particulates (PM 2.5) for the various fuel types studied. The fine particulates or PM 2.5 (less than 2.5 microns in size) were measured using a dilution tunnel technique following the method described in US EPA CTM-039. The PM 2.5 emission results are expressed in several units for the benefit of scientists, engineers and administrators. The measurements of gaseous emissions of O{sub 2}, CO{sub 2}, CO, NO{sub x} and SO{sub 2} were made using a combustion analyzer based on electrochemical cells These measurements are presented for each of the residential heating systems tested. This analyzer also provides a steady state efficiency based on stack gas and temperature measurements and these values are included in the report. The gaseous results are within the ranges expected from prior emission studies with the enhancement of expanding these measurements to fuels not available to earlier researchers. Based on measured excess air levels and ultimate analysis of the fuel's chemical composition the gaseous emission results are as expected and fall within the range provided for emission factors contained in the US-EPA AP 42, Emission Factors Volume I, Fifth Edition. Since there were no unexpected findings in these gaseous measurements, the bulk of the report is centered on the emissions of fine particulates, or PM 2.5. The fine particulate (PM 2.5) results for the liquid fuel fired heating systems indicate a very strong linear relationship between the fine particulate emissions and the sulfur content of the liquid fuels being studied. This is illustrated by the plot contained in the first figure on the next page which clearly illustrates the linear relationship between the measured mass of fine particulate per unit of energy, expressed as milligrams per Mega-Joule (mg/MJ) versus the different sulfur contents of four different heating fuels. These were tested in a conventional cast iron boiler equipped with a flame retention head burner. The fuels included a typical ASTM No. 2 fuel oil with sulfur below 0.5 percent (1520 average ppm S), an ASTM No. 2 fuel oil with very high sulfur content (5780 ppm S), low sulfur heating oil (322 ppm S) and an ultra low sulfur diesel fuel (11 ppm S). Three additional oil-fired heating system types were also tested with normal heating fuel, low sulfur and ultralow sulfur fuel. They included an oil-fired warm air furnace of conventional design, a high efficiency condensing warm air furnace, a condensing hydronic boiler and the conventional hydronic boiler as discussed above. The linearity in the results was observed with all of the different oil-fired equipment types (as shown in the second figure on the next page). A linear regression of the data resulted in an Rsquared value of 0.99 indicating that a very good linear relationship exits. This means that as sulfur decreases the PM 2.5 emissions are reduced in a linear manner within the sulfur content range tested. At the ultra low sulfur level (15 ppm S) the amount of PM 2.5 had been reduced dramatically to an average of 0.043 mg/MJ. Three different gas-fired heating systems were tested. These included a conventional in-shot induced draft warm air furnace, an atmospheric fired hydronic boiler and a high efficiency hydronic boiler. The particulate (PM 2.5) measured ranged from 0.011 to 0.036 mg/MJ. depending on the raw material source used in their manufacture. All three stoves tested were fueled with premium (low ash) wood pellets obtained in a single batch to provide for uniformity in the test fuel. Unlike the oil and gas fired systems, the wood pellet stoves had measurable amounts of particulates sized above the 2.5-micron size that defines fine particulates (less than 2.5 microns). The fine particulate emissions rates ranged from 22 to 30 mg/ MJ with an average value of 25 mg/MJ for the three stoves tested.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: NYS ENERGY R& D AUTHORITY
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 1015127
• Report Number(s): BNL-91286-2009-IR; 600301010; TRN: US201111%%725
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
09 BIOMASS FUELS
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
BOILERS
CAST IRON
CHEMICAL COMPOSITION
COMBUSTION
DIESEL FUELS
EFFICIENCY
ELECTROCHEMICAL CELLS
FURNACES
HEATING
HEATING OILS
HEATING SYSTEMS
LIQUID FUELS
NATURAL GAS
PARTICULATES
RAW MATERIALS
STOVES
SULFUR
SULFUR CONTENT
TEMPERATURE MEASUREMENT
WOOD FUELS