Neste Oil Corporation and Austrian oil and gas group, OMV, are in negotiations to building a joint large-scale plant to produce Neste’s NExBTL bio-based diesel fuel. According to a memorandum of understanding, the 200,000 tonne/year facility will be located at OMV’s Schwechat oil refinery in Austria, with production beginning at the end of 2008 at the earliest.
Neste is currently building its own 170,000 tonne/year NExBTL plant at its Porvoo refinery in Finland, and is working with oil major Total on evaluating the possibilities for a NExBTL plant at a Total refinery. (Earlier post.)
The Neste NExBTL process and resulting product differ from both the transestrification process used to produced fatty acid methyl ester (biodiesel) and the gasification and Fischer-Tropsch conversion used in BTL projects.
The proprietary NExBTL process hydrogenates the vegetable oil or animal fat feedstock (using hydrogen from the refinery) to produce a hydrotreated “biodiesel” that has similar fuel qualities to BTL or GTL. NExBTL in testing reduced PM and NOx emissions even further than GTL.
The process, as scaled for the Porvoo implementation, requires 0.9 to 1.0 tonnes of hydrogen gas per hour for a NExBTL output of about 20 tonnes per hour.
As can GTL and biodiesel, NExBTL can be blended with petroleum diesel. The NExBTL process is less capital-intensive than a Fischer-Tropsch project while producing a comparable high-quality product, according to Neste, and uses relatively easily-transported renewable feedstocks: the best of both GTL and biodiesel.
In essence, NExBTL allows refiners to produce their own biofuel components and blend them into their petroleum diesel stocks at high volume and within the confines of the refinery.
A critical policy component for allowing that to occur is for the regulatory agencies to either accept—or not specifically exclude—the NExBTL fuel.
As a representative for Neste told the California Energy Commission during a recent biofuel energy workshop:
Standards for the use of renewable diesel fuel components need to avoid specifications that specify types of molecules or prohibit the use of second generation renewable diesel components.
Neste Oil claims that its process generates less life-cycle CO2 per kilogram oil equivalent than rapeseed-based biodiesel: 0.5–1.5 kg CO2/kgoe fuel for NExBTL, versus 1.6–2.3 kg CO2/kgoe fuel for biodiesel and 3.8 kg CO2/kgoe for petroleum diesel.
|Fuel Property Comparison|
|Density at +15º C (kg/m3||775 ... 785||770 ... 785||~885||~835|
|Viscosity at +40º C (mm2/s||2.9 ... 3.5||3.2 ... 4.5||~4.5||~3.5|
|Cetane number||~84 ... 99||~73 ... 81||~51||~53|
|Cloud point (ºC)||~ -5 ... -30||~ 0 ... -25||~ -5||~ -5|
|Heating value (lower) (MJ/kg)||~44||~43||~38||~43|
|Heating value (MJ/liter)||~ 34||~ 34||~ 34||~ 36|
|Polyaromatic content (wt %)||0||0||0||0|
|Oxygen content (wt %)||0||0||~ 11||0|
|Sulfur content (mg/kg)||< 10||< 10||< 10||< 10|