Neste Oil in Large-Scale Test of NExBTL Second-Generation Biodiesel
20 October 2006
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| Simplified NExBTL chemistry. Click to enlarge. |
Neste Oil, Helsinki City Transport (HKL), and the Helsinki Metropolitan Area Council (YTV) have signed a letter of understanding covering extensive trial use of Neste Oil’s second-generation NExBTL renewable synthetic diesel to power buses and waste disposal trucks across Greater Helsinki.
Neste Oil’s refinery-based proprietary NExBTL technology is based on the high-pressure hydrogenation of fatty acids. The product is a synthetic diesel fuel, free of oxygen and aromatic compounds. Side products include propane and gasoline. The process can use a flexible input of any vegetable oil or animal fat to produce a product with characteristics similar to Fischer-Tropsch output. (Earlier post.)
The NExBTL process is different than both the transesterification process used to produced fatty acid methyl ester (biodiesel) and Fischer-Tropsch conversion used in BTL projects.
The trial, to start in fall 2007, will last until the end of 2010 and will embrace around 700 buses and 75 waste trucks. The aim is twofold: to reduce urban emissions and promote the use of biofuels on the road.
Vehicles in the trial will use either a 30% NExBTL – 70% conventional diesel oil mix or 100% NExBTL. Between 5,000 and 10,000 tons of the biofuel will be used annually, equivalent to 15-30% of the fuel used by buses and waste trucks in the Helsinki region. The trial includes the option to test other fuels for comparative purposes.
This public transport trial in Greater Helsinki is an important step for us, as it is a large-scale, highly visible and highly credible public initiative to test the operational and emissions performance of a second-generation biodiesel. We believe that our biodiesel will enable urban transport emissions to be cut significantly.
—Kimmo Rahkamo, Neste Oil Executive Vice President, Components
The trial will require national public funding, and an application will be lodged for a tax concession on the biocomponent to be used. Alternatively, use will be made of incentives linked to biofuel legislation planned for introduction in Finland in 2008 or an investment grant to cover the logistics costs involved.
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| Porvoo Refinery in July 2006. Photo: Suomen Ilmakuva Oy |
The first NExBTL production plant is currently under construction at Neste Oil’s Porvoo refinery. With a rated capacity of 170,000 tonnes/year, the facility is scheduled to come on stream in summer 2007.
Neste Oil intends to extend NExBTL biodiesel trials to public transport in other EU capitals in the future. Neste Oil’s Board of Directors has approved a strategy aimed at making the company the world’s leading producer of second-generation renewable diesel fuel. The company also has NExBTL joint ventures with Total and OMV.
| Fuel Property Comparison | ||||
|---|---|---|---|---|
| NExBTL | GTL | Biodiesel (RME) | EN590/2005 diesel | |
| 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 | ~ 4 |
| Oxygen content (wt %) | 0 | 0 | ~ 11 | 0 |
| Sulfur content (mg/kg) | < 10 | < 10 | < 10 | < 10 |
Resources:
NExBTL—Biodiesel fuel of the second generation (SAE 2005-01-3771)
Biodiesel (Neste Oil presentation)
In terms of feedstock, this competes against fatty acid methyl esters (FAME), known colloquially as biodiesel. Pure FAME is subject to biological contamination. Even blended, FAME is more aggressive toward certain vehicle fuel system components (filters, seals, Bosch unit injectors etc.) than mineral diesel - the vehicle manufacutrer may requrie a relatively inexpensive retrofit. The cloud point is relaitively high, though work on additives is bringing it down so FAME blends can be used in mild winter weather.
The Neste process yields alkanes rather than esters, meaning it can more easily be used for winter diesel blends. Instead of highly viscous glycerol, the by-product is propane gas, which can be used as a feedstock for the steam reformer that yields the neccessary hydrogen.
The whole process is probably less energy efficient that simple transesterification. It's not immediately clear how drastically the plant would need to be modified to accept waste biomass from the forestry industry as a feedstock, rather than more valuable oils and fats.
Posted by: Rafael Seidl | 20 October 2006 at 07:59 AM
I thought Nestle made Iced Tea, not gasoline.
Posted by: Robert Schwartz | 20 October 2006 at 08:32 AM
Rafael,
Just how energy efficient is a "simple transesterification"? You need:
1. Relatively pure feedstock
2. Relatively pure methanol
3. Relatively pure catalyst
Add the energy together for making and purifying the above and I am not so sure you save energy compared to NExBTL. Add to that the fact that the NExBTL product is far superior to biodiesel (FAME).
I guess a key question is: How dirty (read: cheap) a feedstock can NExBTL use?
Posted by: An Engineer | 20 October 2006 at 12:10 PM
Robert -
Neste = Finnish oil company
Nestle = Swiss food company
An Engineer -
Neste has published a white paper documenting the fuel properties but it syas nothing about the required feedstock properties other than that it can be a mix of vegetable oils and animal fats.
http://www.nesteoil.com/default.asp?path=1,41,535,547,3716,3884
Thier biodiesel FAQ suggests the suitability of abatoir wastes considered not suitable for human consumption, presumably due to contamination:
http://www.nesteoil.com/default.asp?path=1,41,535,547,3716,3884,5761
Posted by: Rafael Seidl | 20 October 2006 at 12:33 PM
Jet fuel.
Posted by: allen_Z | 20 October 2006 at 12:37 PM
Then again, it may require some additive, or chemical reformulation to meet safety standards (equivalent to JP-8).
Posted by: allen_Z | 20 October 2006 at 12:39 PM
This is a process for rich countries. Methyl ester is lo-tech hence is being used in Africa, Asia and South America as far as I am aware. However in volume terms I think Fischer Tropsch diesel will eventually dominate if it can be be standardised.
Posted by: Aussie | 20 October 2006 at 01:34 PM
It's not immediately clear how drastically the plant would need to be modified to accept waste biomass from the forestry industry as a feedstock, rather than more valuable oils and fats.
Carbohydrates don't have carbon chains as long as fatty acids, so rigorous hydrogenation would tend to produce light alkanes (pentane, hexane). There was a report here a couple months ago of a process that partially hydrogenates carbohydrates, producing olefins, then condenses the olefins to produce larger hydrocarbons.
Partial hydrogenation of carbohydrates can produce things like tetrahydrofuran, a useful solvent.
I don't know what you get from hydrogenating lignin.
Posted by: Paul Dietz | 21 October 2006 at 08:15 AM
Paul -
interesting, news to me. In the specific case of the Neste process, though, the feedstock is triglycerides aka oil or fat.
Posted by: Rafael Seidl | 21 October 2006 at 04:15 PM
the feedstock is triglycerides aka oil or fat.
And the fatty acids in those are what contribute the carbon chains that end up in the diesel fuel. As the diagram shows, the glycerol gets converted to propane.
Posted by: Paul Dietz | 21 October 2006 at 06:08 PM
Paul -
ah, I see now what you were getting at. Cellulose isn't normally considered a carbohydrate, hence my confusion.
Note that the length of the carbon chains in the feedstock is actually fairly irrelevant in traditional F-T synthesis, since it all gets converted into synthesis gas (H2 + CO) prior to catalytic alkane synthesis.
The key concept in Neste's process is that no synthesis gas is ever produced, the fatty acids are simply chemically reduced to alkanes by adding hydrogen. In that context, the length and structure of the carbon chains in the feedstock are hugely relevant.
Posted by: Rafael Seidl | 22 October 2006 at 06:51 AM
The key concept in Neste's process is that no synthesis gas is ever produced,
Gasification can introduce thermodynamic losses (although maybe those could be reduced with clever techniques, such as one involving hydrogasification) , so I'd hope the Neste process could be energetically more efficient than FT. I suspect it would also be workable on a smaller scale than FT.
Posted by: Paul Dietz | 23 October 2006 at 01:37 PM
Here is the abstract of a recent paper on the conversion of biomass-derived carbohydrates into usable liquid hydrocarbon fuels. The process involves dehydration, aldol condensation, then hydrogenation on bifunctional catalysts. According to the abstract, 90% of the energy of the carbohydrate and hydrogen input streams is retained in the hydrocarbon output stream.
Posted by: Paul Dietz | 30 October 2006 at 01:38 PM
DME developments in China today!
DME is an LPG-like synthetic fuel can be produced through gasification of Biomass. The synthetic gas is then catalyzed to produce DME. A gas under normal pressure and temperature, DME can be compressed into a liquid and used as an alternative to diesel. Its low emissions make it relatively environmentally friendly. In fact, Shandong University completed Pilot plant in Jinan and will be sharing their experience at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:
DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia
Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.
Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe
Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation
For more information: www.iceorganiser.com
Posted by: Cheryl Ho | 23 May 2007 at 09:40 PM
How on earth can Neste keep the cloud point of its NExBTL product so low, once "the corresponding paraffins of triglyceride-bound acyl groups" are being produced via hydrogenation? C12 alkan (dodecan) has a melting point of - 9.6 °C, whereas in naturally occuring triglycerides the "corresponding" lauric acid is present only in minor proportions, and longer (C18-C22) homologues are really characteristic?
Posted by: J. Thesz | 14 October 2007 at 02:49 AM
On account of excessive use of hydrogen (derived from fossils industrially, that is via oxidation of propane/butane) the NexBTL stuff CANNOT be considered as a wholly renewable fuel! (Nor is FAME, as methanol is made from methane! Whereas FAEE is the right thing). Once we decide to replace fossils with renewables, let us not turn a blind eye to such machinations!
Posted by: J.Thesz | 10 May 2008 at 10:37 AM