Assessing the Costs and Emissions of Disposing Forest Residues using Air Curtain Burners

Transcription

1 Assessing the Costs and Emissions of Disposing Forest Residues using Air Curtain Burners Eunjai, Lee and Han-Sup Han Humboldt State University, Department of Forestry and Wildland Resources, Arcata, CA, U.S. COFE, Vancouver BC, 20. September 2016

2 Introduction Forest residues Tree tops, limbs, small-diameter trees, other tree parts, and drought/insect damaged standing trees Generated during the forest operations (timber harvests, fuel reduction thinnings) and mill process Piled and left in forest and mills, low economic value Cause fire hazard and obstructions to tree regeneration (Graham et al. 2010) Source: Chad Hanson

3 Introduction Slash pile burning (= open pile burning) Most common method of disposing forest residues Negative effects on air quality including CO, human health with PM, escaping ember, burning scar and soil impacts (burn scars) Source: Springsteen et al Difficult to utilize because it allowed in narrow condition (i.e. limitation season, temperature, wind speed, and relative humidity) Burn scar (USDA. 2015)

4 Introduction Air Curtain Burner (ACB) 6 m 1 m 2 m 2 m 1 m 4 m Source: S-220 BurnBoss

5 Introduction Air blower Air Curtain Burner (ACB) Principle Air curtain Air circulation Air curtain Air blower Air circulation

6 Introduction Air Curtain Burner (ACB)

7 Objectives 1. Evaluate cost of disposing forest residues using an ACB operations (S-220 and BurnBoss) 2. Compare emissions including carbon monoxide (CO) and particulate matter (PM) with slash pile burning

8 Materials & Methods Jackson, Florida Groveland, California Volcano, California Machine type Source: Material type Material diameter, cm Softwood, Hardwood, Mixed Ponderosa pine (80%) with Manzanita shrubs (20%) Ponderosa pine 6.0 ± 0.3 (Small) 7.2 ± 0.3 (Small) 22.5 ± 1.2 (Large) 18.6 ± 1.5 (Large) Air temp., C Relative Humidity, % Wind speed, km/hour S-220 BurnBoss BurnBoss with an ember screen N/A

9 Materials & Methods Pre-burn measurements Measuring of diameter and weight of forest residues (wheel load scale, PT300 TM RFX) Moisture content (oven-dried for 48 hour at 105 C)

10 Materials & Methods Burning consumption rates Time and motion methods Burning time recording was started when air blower turned on and ended when the last materials were loaded Flame temperature (10 minute interval, every experiments) - Infrared camera (ThermaCAM SC640) - Infrared thermometer (IR-750)

11 Materials & Methods First loading smaller materials for kindling Igniting with torch Turn on the air blower Burning down to ash Second loading

12 Materials & Methods Cost of disposing forest residues Cost factors S-220 Loader BurnBoss Pickup truck Water Truck Purchase price, (US $) Economic life, (year) Fuel consumption, (liter/hour) Schedule machine hour, (SMH/year) 106, ,000 48,900 40,000 40, , ,600 1,600 1,600 Utilization rate, (%) Hourly cost, (US $/SMH)

13 Materials & Methods Emissions (CO and PM): Literature Review ACB buring - Field measuring: Lambert, 1972; Fountainhead Engineering and Deruiter Environmental, Inc. 2000; Zahn, 2005; Miller and Lemieux, 2007; and Air Burner, Inc Slash pile burning - Field measuring: Fritschen et al. 1970; Sandberg et al. 1975; Hardy, 1996; U.S. Environmental Protection Agency AP-42 report, 1992; Lemieux et al. 2004; Zahn, 2005; and Springsteen et al Laboratory simulation: - Wind tunnel (Jenkins et al. 1996) - Fourier transform infrared (FTIR) spectrometer (Goode et al. 1999) - Combustion chamber (Yokelson et al. 1997; Chen et al. 2007; Freeborn et al. 2008; McMeeking et al. 2009; Burling et al. 2010)

14 Results - Cost of disposing forest residues S-220Firebox and Loader experiment Location Burning consumption rate (GT/SMH) Moisture content Operation cost (U.S. $/SMH) Cost of disposal forest residues (U.S. $/GT) Jacksonville, Florida (S-220FireBox and Loader) Softwood a % Hardwood a % Mixed a % a logging residues and material diameter ranged from 18 cm to 45 cm GT: Green metric ton

15 Results - Cost of disposing forest residues BurnBoss and manual loading experiment Location Burning consumption rate (GT/SMH) Moisture content Operation cost (U.S. $/SMH) Groveland, California (BurnBoss), Ponderosa pine 80% and Manzanita shrubs 20% Thinning residues Cost of disposal forest residues (U.S. $/GT) small size % large size % Volcano, California (BurnBoss with an ember screen), Ponderosa pine 100% Thinning residues large size % Drought/insect damaged standing tree small size % large size % small size 5 cm (2-10 cm) and large size 19 cm (10-35 cm) GT: Green metric ton

16 Results - Cost of disposing forest residues BurnBoss and manual loading experiment Location Burning consumption rate (GT/SMH) Moisture content Operation cost (U.S. $/SMH) Groveland, California (BurnBoss), Ponderosa pine 80% and Manzanita shrubs 20% Thinning residues Cost of disposal forest residues (U.S. $/GT) small size % large size % Volcano, California (BurnBoss with an ember screen), Ponderosa pine 100% Thinning residues large size % Drought/insect damaged standing tree small size % large size % small size 5 cm (2-10 cm) and large size 19 cm (10-35 cm) GT: Green metric ton

17 Results BurnBoss and hand-pile burning Location Burning consumption rate (GT/SMH) BurnBoss Hand-pile burning Groveland, California (BurnBoss), Ponderosa pine 80% and Manzanita shrubs 20% small size (thinning residues) large size (thinning residues) Volcano, California (BurnBoss with an ember screen), Ponderosa pine 100% large size (thinning residues) small size (Drought/insect damaged standing tree) large size (Drought/insect damaged standing tree) small size 5 cm (2-10 cm) and large size 19 cm (10-35 cm) GT: Green metric ton BurnBoss units, more efficiency ( times) Flame temperature ranged from 820 C to 921 C

18 Results - Smoke Hand-pile burning ACB burning ACB burning Hand-pile burning Groveland, CA Volcano, CA

19 Results - Emissions (literature review) Biomass disposal option Sampling method Emissions (g/kg) CO PM 2.5 PM 2.5/10 Opacity (%) Air Curtain Burner Field measuring Slash pile burning Field measuring Laboratiry sampling N/A Biomass conversion a Field measuring N/A 20 a Emissions collected from grinder, excavator, and transport and average transport distance of 190 km

20 Conclusions ACB burning consumption rates (0.44 GT/SMH 5.23 GT/SMH) and cost of disposing forest residues ($18.57 /SMH $68.21 /SMH) depending on the machine capacity, species, pile size, and moisture content ACB units, air emissions reductions were more than 90% for CO and PM, and less opacity ACB units, helps minimize emissions (air quality, risk of wildfire, and soil impact) and has high burning efficiency, compared to slash pile burn

21 Discussion ACB application limitation High volume area - logging residues Recommendation for ACB use High wildfire risk areas Disposing drought/insect standing trees in National or State Park Disposing small volume around residential areas Expensive and inaccessible area by biomass harvesting machines (i.e. chipper, chip-van, and excavator)

22 Acknowledgement Funding: Agricultural Research Institute, California State University: Award number Collaborators: Brian O Connor (Air Burners Inc.), Rick Whybra and Lester Scofield (PURFIRE), Stephen Bakken (California State Park)

23 Thank you!