CFM International has successfully carried out an initial test of a CFM56-7B engine using an ester-type biofuel at Snecma’s Villaroche facility near Paris. The CFM56-7B is the exclusive engine for the Boeing Next-Generation Single-aisle airliner: 737-600/-700/-800/-900. Thrust ranges from 18,500 to 27,300 lbs.
The biofuel used for this test is a 30% vegetable oil methyl ester blended with 70% conventional Jet-A1 fuel. This test was designed to check the operation of a jet engine using a fuel made from biomass, without making any technical changes to the engine.
With this type of biofuel, the target is a net reduction of 20 percent in carbon dioxide (CO2) emissions compared with current fuels.
Our goal is to support the industry in identifying replacements for traditional hydrocarbon-based fuels, including synthetic fuels that use a mixture of biofuels and jet fuel.—Pierre Thouraud, Snecma Vice President, Engineering
CFM is also running engine tests to develop solutions based on mixtures of jet fuel and second-generation biofuels. It is currently focusing on the evaluation of alternative fuels made using biomass which offer properties closer to those of jet fuel than do first-generation fuels such as the methyl ester (i.e., biodiesel), and which also offer better environmental performance.
Along with its parent companies, CFM International is participating in a number of emissions-focused initiatives, including the US CAP (Climate Action Partnership), French Calin, and European Alpha-Bird programs.
For alternative fuels to be used in the aviation industry, there are a number of major technology challenges that must be met, including energy density, thermal stability (avoiding coking at high temperature), use at very low temperatures (freezing) or high temperatures, lubricating effect with materials used, and the availability of mass production facilities worldwide.
More than 500 airlines fly CFM56-7B-powered 737s and, since entering service in the mid-90s, the engines have accumulated more than 50 million flight hours. All CFM56-7B engines delivered beginning in mid-2007 are compliant with CAEP/6 (Committee on Aviation Environmental Protection) environmental requirements.
CFM56 engines are produced by CFM International (CFM), a 50/50 joint company of Snecma (SAFRAN Group) and General Electric Company.