Emission Reductions from Woody Biomass Waste for Energy as an Alternative to Open Burning

Abstract

Woody biomass waste is generated throughout California from forest management, hazardous fuel reduction, and agricultural operations. Open pile burning in the vicinity of generation is frequently the only economic disposal option. A framework is developed to quantify air emissions reductions for projects that alternatively utilize biomass waste as fuel for energy production. A demonstration project was conducted involving the grinding and 97-km one-way transport of 6096 bone-dry metric tons (BDT) of mixed conifer forest slash in the Sierra Nevada foothills for use as fuel in a biomass power cogeneration facility. Compared with the traditional open pile burning method of disposal for the forest harvest slash, utilization of the slash for fuel reduced particulate matter (PM) emissions by 98% (6 kg PM/BDT biomass), nitrogen oxides (NOx) by 54% (1.6 kg NOx/BDT), nonmethane volatile organics (NMOCs) by 99% (4.7 kg NMOCs/BDT), carbon monoxide (CO) by 97% (58 kg CO/BDT), and carbon dioxide equivalents (CO2e) by 17% (0.38 t CO2e/BDT). Emission contributions from biomass processing and transport operations are negligible. CO2e benefits are dependent on the emission characteristics of the displaced marginal electricity supply. Monetization of emissions reductions will assist with fuel sourcing activities and the conduct of biomass energy projects.

Forest biomass diversion in the Sierra Nevada: Energy, economics and emissions

“…The energy of the diesel fuel used in collection, grinding and transport is only 2.5% of the available energy of the biomass wastes delivered to BVBP; and 4.6% of the energy of the natural gas (that would be required for producing an equivalent amount of electricity in a combined cycle natural gasfired generation facility) that is displaced by the BFRS-BVBP bioenergy project. This is consistent with displaced generation found in other studies (e.g., Jones et al 2010;Pan et al 2008;Springsteen et al 2011). …”

“…Emissions factors for PM 2.5 , CO and CH 4 were consistent with those reported in the literature (see Springsteen et al (2011) for a recent compilation of forest residue open pile burn emission factors). Emission factors for NOx and NMOC were 50% to 75% and 0% to 75% lower, respectively, than other studies.…”

The Optimum Slash Pile Size for Grinding Operations: Grapple Excavator and Horizontal Grinder Operations Model Based on a Sierra Nevada, California Survey

“…In a previous study, the Placer County Air Pollution Control District (PCAPCD) and the Sierra Nevada Conservancy demonstrated a significant reduction in air emissions through the diversion of forest biomass that had been scheduled for open pile burning [4]. In the project entitled 'Forest Biomass Diversion in the Sierra Nevada' as a next step, the PCAPCD sponsored research that tracked the economic costs and air emissions generated from the collection, processing, and transport of forest harvest residuals generated at the Blodgett Forest Research Station, the Center for Forestry, the University of California, Berkley in 2012, with the objective of quantifying the emissions reductions gained from using the biomass for energy production compared to open pile burning ( Figure 1).…”

“…In contrast, in Japan, following the 'Feed-in Tariff Scheme for Renewable Energy (FIT)' that was put into practice in 2012, the building of power-generation plants that accept unused forest biomass (such as thinnings and logging residues) and the initiation of the plants' operation are progressing, since the purchase price of electricity from unused forest biomass has been set higher than that from for energy production is an appealing option for biomass disposal that can contribute to density management, forest health, and fire hazard reduction. In a previous study, the Placer County Air Pollution Control District (PCAPCD) and the Sierra Nevada Conservancy demonstrated a significant reduction in air emissions through the diversion of forest biomass that had been scheduled for open pile burning [4]. In the project entitled 'Forest Biomass Diversion in the Sierra Nevada' as a next step, the PCAPCD sponsored research that tracked the economic costs and air emissions generated from the collection, processing, and transport of forest harvest residuals generated at the Blodgett Forest Research Station, the Center for Forestry, the University of California, Berkley in 2012, with the objective of quantifying the emissions reductions gained from using the biomass for energy production compared to open pile burning ( Figure 1).…”

“…The energy (diesel fuel) expended for processing and transport was 2.5% of the biomass fuel (energy equivalent); • Based on measurements from a large pile burn, air emission reductions of 98-99% for PM2.5, CO, NMOC, CH 4 , and BC, and 20% for NO X and CO 2 -equivalent greenhouse gases were observed; • The delivered cost of $70/BDT exceeds the biomass plant gate price of $45/BDT. Under typical conditions, the break-even haul distance would be approx.…”