Life Cycle Analysis of Camelina-based Renewable Jet and Diesel Fuels Shows 84-89% GHG Savings Compared to Petroleum Fuels
|Greenhouse gas emissions for all fuels in this study, using one of the cultivation scenarios (Forward cultivation). Source: Shonnard and Koers (2009). Click to enlarge.|
A life cycle analysis (LCA) comparing camelina-derived renewable jet and diesel fuels to petroleum fuels and biodiesel found that the green jet and green diesel fuels are lower in fossil energy demand and also lower in GHG emissions compared to biodiesel, and that all the biofuels are lower in these impact categories compared to their fossil fuel counterparts.
Dr. David Shonnard and Kenneth Koers at Michigan Technological University conducted the LCA in collaboration with UOP, a Honeywell company. The study was based on camelina grown in Montana by Sustainable Oils and processed into renewable jet and diesel fuels using UOP hydroprocessing technology. (Earlier post.)
The study found GHG emissions for camelina green jet (GJ) shows nearly an 84.4% savings compared to petroleum jet. Camelina green diesel (GD) shows a 89.4% GHG reduction compared to petroleum diesel. Biodiesel exhibits savings of GHGs compared to petroleum diesel of 78.5%. No effects of land use change on possible GHG emissions were included in this analysis, although the authors noted that the anticipated cultivation as a rotation energy crop with wheat that displaces fallow weeds suggest negligible adverse land use change impacts, since no food production is displaced by camelina seed cultivation.
Future research might investigate camelina seed feedstock supply chain more thoroughly, and focus on a detailed investigation of farming practices to reduce N2O emissions from soils. Another important research question is to investigate camelina cultivation methods to assure that no adverse land use change impacts will result from biofuels production.—Shonnard and Koers (2009)
One of the LCA indicators is cumulative energy demand (CED), consisting of fossil energy use; renewable biomass energy use; and other energy resources, which includes nuclear, solar, geothermal, and hydroelectric power. In general, although all of the fuels in the study have a higher total CED than petroleum-derived fuels, the biofuels require substantially less fossil energy than biomass energy through the life cycle. The higher CED for biofuels is due to the relatively greater amount of processing required to obtain the various petroleum substitutes, “which are generally less efficient than the highly mature and technologically advanced petroleum refining industry.”
The software used for this LCA was SimaPro 7.1, which contains a large database of inventory data for material, chemical and energy inputs. The impact assessment method used in SimaPro was Eco-indicator 95, the output of which is in CO2 equivalents for all of the GHG emissions. The three primary gases that make up the CO2 equivalence are CO2, methane (CH4), and nitrous oxide (N2O).
|“Camelina green jet exhibits one the largest greenhouse gas emission reduction of any agricultural feedstock-derived biofuel I’ve ever seen. This high number is the result of the unique attributes of the crop—its low fertilizer requirements, high oil yield and the use of co-products, such as meal and biomass, for other uses.”|
—Professor David Shonnard
Camelina is well-suited to be a sustainable biofuel crop, as it naturally contains high oil content; its oils are low in saturated fat; it is drought resistant and requires less fertilizer and herbicides. Most importantly, it is an excellent rotation crop with wheat, and it can also grow in marginal land. Camelina does not displace other crops or compete as a food source.
It is estimated that the state of Montana alone could support between 2 and 3 million acres of camelina, generating 200 to 300 million gallons of oil each year.
In January, Japan Airlines (JAL) became the first airline to conduct a demonstration flight using a biofuel primarily refined from camelina. (Earlier post.) The demo flight tested a blend of 50% biofuel and 50% traditional Jet-A jet (kerosene) fuel in one of the four Pratt & Whitney JT9D engines of a JAL-owned Boeing 747-300 aircraft.
Camelina is one of the most promising sources for renewable fuels that we’ve seen. It performed as good if not better than traditional jet fuel during our test flight with Japan Airlines earlier this year, and supports our goal of accelerating the market availability of sustainable, renewable fuel sources that can help aviation reduce emissions. It’s clear from the LCA results that camelina is one of the leading near-term options and, even better, it’s available today.—Billy Glover, managing director, Environmental Strategy, Boeing Commercial Airplanes
Sustainable Oils has just completed its 2009 contracting season working closely with farmers to maximize oil production per acre. The company expects to deliver most of its 2009 production for use as a biojet fuel feedstock.
The quickest way to reduce carbon emissions from aviation is to begin replacing petroleum fuel with fuel made from renewable and sustainable camelina oil. The acreage that we have contracted for 2009 will be used primarily to continue to develop the promising biojet market. Our success this year in planting thousands of acres of camelina specifically for this use will prepare us to supply the hundreds of millions of gallons of fuel we will need within five years. No other potential feedstock can provide as much fuel in as short a horizon.—Scott Johnson, general manager of Sustainable Oils
David Shonnard Kenneth Koers (2009) Life Cycle Assessment of Camelina-Derived Transportation Fuels: Comparison of Biodiesel, Green Diesel and Green Jet