EPA Renewable Fuel Standard
What is the EPA Renewable Fuel Standard?
The RFS program is a national policy that requires a certain volume of renewable fuel to replace or reduce the quantity of petroleum-based transportation fuel, heating oil or jet fuel. The four renewable fuel categories under the RFS are:
- Biomass-based diesel
- Cellulosic biofuel
- Advanced biofuel
- Total renewable fuel
The 2007 enactment of EISA significantly increased the size of the program and included key changes, including:
- Boosting the long-term goals to 36 billion gallons of renewable fuel
- Extending yearly volume requirements out to 2022
- Adding explicit definitions for renewable fuels to qualify (e.g., renewable biomass, GHG emissions)
- Creating grandfathering allowances for volumes from certain existing facilities
- Including specific types of waiver authorities
Thermal Pathways and Use of Wood Chips and Pellets Under the RFS
Currently, the EPA RFS2 does not include a fuel pathway for woody biomass as a heating fuel; however, this Rule includes numerous pathways that use biomass, including forest residue, as feedstock to produce liquid biofuels which replace fossil fuels. Woody biomass itself is a source of energy if burned in wood stoves or boilers, and can reduce greenhouse gas (GHG) emissions if substituted for fossil fuels such as heating oil and natural gas. Since woody biomass is categorized under the RFS2 as a renewable source of energy when sustainable forest practices are employed, and since its use results in significantly lower GHG emissions compared to fossil fuels, the use of biomass as a heating fuel under the RFS2 would be consistent with the application of the Rule. Moreover, since heating oil from cellulosic biomass has a defined pathway under RFS (L, D7), and wood pellets and wood chips are substitutes for fossil heating oil, woody biomass replacing heating oil or natural gas should qualify for a pathway under the RFS2.
GHG Benefits of Wood Chips and Pellets
Biomass fuels result in a 65 to over 100% reduction in GHG emissions in comparison to conventional heating fuels (natural gas, heating oil), which exceeds the targeted 60% GHG reduction requirement for cellulosic biofuels under the RFS2 (EPA, 2010). Since wood pellets and wood chips meet the GHG reduction targets under the RFS, are often made from waste biomass sourced from forest product mills, forest residue, fire hazard reduction, and culling of insect-infested standing dead trees, and have a significantly lower CI compared to heating oil and natural gas, BTEC recommends that EPA reevaluate the RFS and consider creating a pathway for thermal conversion of biomass as heating energy.
The figure below illustrates the cradle to boiler emissions and the avoided emissions associated with each woody biomass feedstock relative to the emissions associated with heating oil and natural gas. Comparing only the life cycle boiler to displaced fossil fuel emissions demonstrates a three to thirty-fold reduction, depending on which scenarios are compared. Accounting for the avoided emissions in the respective bioenergy scenarios results in GHG emission reductions of at least 66%, and up to 117.5 g CO2e/MJ. Note that not collecting forest residues, and insect-killed standing trees may increase the risk of wildfire. Therefore, for the forest residue and fire hazard reduction/insect-killed standing trees bioenergy scenario, it is reasonable to not account for biomass combustion emissions, since the aforementioned increase the risk of wildfire and generates emissions equal to or greater than those. In this case, the CI of wood pellets/chips would be even lower than current estimates presented in the Study.
Impact of Thermal Pathways for Wood Chips and Pellets
If biomass-based thermal energy were included under the RFS2, it could generate a D3 RIN, valued in the Study at $1.50/RIN. For 1 MMBtu on an HHV-basis or 77,000 Btu on an LHV-basis, this would generate 12 RINs or $312 per ton of biomass (dry basis ).
|RIN Value||$1.50/D3 RIN|
|Energy per RIN||77,000 Btu, LHV|
|LCFS Credit||$190/tonne CO2e|
|Biomass LHV||16.08 MMBtu/BD ton, LHV|
|LCFS Baseline||92 g CO2/MJ|
|CI||12 g CO2/MJ|
|GHG Savings||1.22 tonne GHG|
|LCFS Value||$231.64/BD ton|
Heating oil and natural gas are two major sources of energy for space heating. Wood pellets and wood chips are two renewable substitutes for heating oil and natural gas. Wood pellets and wood chips are made from various waste sources such as lumbermill waste, forest residue, fire hazard reduction and salvaged material including insect-killed standing dead trees, and urban wood waste that would otherwise generate GHGs either through the process of decomposition or burning. LCA results showed that the CI of wood pellets/chips from all biomass sources considered in this study was significantly lower than that of fossil heating oil and natural gas (without considering the conversion efficiencies), indicating that wood pellets/chips are a promising alternative for heating oil and natural gas.
Since wood pellets/chips are made from pulpwood and waste biomass such as lumbermill waste and forest residue, and they have a significantly lower CI compared to heating oil and natural gas, it would be consistent with the prior pathways approved under the RFS, if EPA would reevaluate the RFS and consider creating a pathway for thermal conversion of biomass from federal and non-federal lands as heating energy.
Steering Committee Members
The Biomass Thermal Energy Council, Life Cycle Associates, and US Forest Service extend their appreciation to the Steering Committee Members for their review and insights into biomass harvesting, transportation and processing operations, including field and plant equipment and associated fuel use.
- Lew McCreery, USDA Forest Service
- Dan Wilson and Steve Knobeloch, Wilson Engineering Associates
- Peter Thompson, Biomass Thermal Energy Council
- Bill Strauss, Future Metrics
- Adam Sherman, Biomass Energy Resource Center
- Ken Adler and John Ackerly, Alliance for Green Heat
- Terrence Sauve, OMAFRA/EMB
- Timothy Volk, SUNY ESF
- Becky Phillips, Agricultural Utilization Research Institute
- Maura Adams, Northern Forest Center
- Rob Davis, Forest Energy Corporation
- Norbert Senf, MHA,
- Jeremy Mortl, Messersmith Manufacturing
- Dane Floyd, Biomass Engineering and Equipment
- Sabina Dhungana, Heating the Midwest