Biomass to Liquids (BtL)
Status update of selected demonstration plants (thermochemical value chains) - updated February 2013
Ingvar Landälv, Vice-chair EBTP Steering Committee, Vice-chair of WG2; Lulea University of Technology & CTO, Chemrecthermochem
The term BtL is applied to synthetic fuels made from biomass through a thermochemical route. The objective is to produce fuel components that are similar to those of current fossil-derived petrol (gasoline) and diesel fuels and hence can be used in existing fuel distribution systems and with standard engines. They are also known as synfuels.
Although the processes for production of BtL are well known and have been applied using fossil-feedstocks, such as methane (GtL) or coal, commercial advanced biofuels based on these technolgies are not currently widely available in the market place. However, BtL R&D&D in Europe continues.
Note: Some European demonstration projects on gasification have been discontinued in recent months for various reasons, however summary information on the 'project history' and technology developed is retained on this page for reference purposes.
Two BtL advanced biofuels projects to be supported under the first NER300 call
On 18 December 2012 it was announced that the UPM Stracel BTL project, France, has been selected to receive counterpart funding of €170m under the first call for proposals of the NER300 funding programme for innovative low-carbon technologies. The Project concerns the construction and operation of a second generation Biomass-to-Liquid (BtL) plant on the Strasbourg site of the UPM Group, which already owns and operates a paper mill on the same site (Stracel). The Project is based on a prototype developed in cooperation with the technology provider using a gasification process. The Project is based on the application of novel pressurized oxygen blown biomass gasification technology. The BtL plant will be integrated into the paper & pulp production line, enabling exchanges of energy and products. The plant will use about 1 million tonnes of woody biomass and will have an annual output of 105 000 tons of biofuel. Using mainly wood feedstock, the Project aims to produce and sell biodiesel (80%) and bionaphtha (20%). The proposed technical solution is based on the following main components: feedstock handling, gasification, raw gas cleaning, gas-to-liquid conversion, liquid treatment and storage, and power generation.
It was also announced that the AJos BtL project, Finland, has been selected to receive counterpart funding of €88.5m under the first call for proposals of the NER300 funding programme for innovative low-carbon technologies.The Project concerns the design, construction and operation of a biofuel-to-liquid (BtL) plant in northern Finland, with a gasification capacity of 320 MW and an annual output of 115000 t/y of biofuel using close to 950000 t/y of woody feedstock and 31000 t/y of tall oil. The
technical solution is based on the following main components: biomass pre-treatment, gasification island (comprising two gasification lines of 160 MW each and an air separation
unit), gas cleaning and compression, gas-to-liquid conversion (Fischer-Tropsch) including
refining, processing and storage of products. The Project will produce and sell biodiesel and bionaphta in the Baltic Sea area, with a focus on Finland and Sweden. Principal off-takers are expected to be diesel and petrol retailers.
The preparation work in the project has been carried out by the Forest BtL Project established by Metsäliitto and Vapo.
Other BtL demonstration projects in Europe
The BioTfuel BtL demonstration project
BioTfueL is a joint project launched by five French partners and Uhde. BioTfueL aims to integrate all the stages of the BTL process chain and bring them to market. This involves the drying and crushing of the biomass, torrefaction, gasification, purification of the synthesis gas and its ultimate conversion to second generation biofuels using Fischer-Tropsch synthesis.
The project will use Uhde's proprietary PRENFLOTM™ gasification process with direct quench (PDQ). The procees can utilise a wide range of feedstocks, allows high energy efficiency and enables very pure synthesis gas to be produced.
The overall budget for the BioTfueL project is 112.7 million euro. The project includes the construction and operation of two pilot plants in France to produce biodiesel and biokerosene based on biomass gasification.The plants are scheduled to go into operation in 2012 [Source: Uhde GmbH].
Forschungszentrum Karlsruhe GmbH in partnership with LURGI GmbH is constructing a pilot plant for production of BtL and "gasoline type fuels". The three-stage process consists of flash pyrolysis, entrained-flow gasification, and synfuel production.
CEA Bure Saudron Pilot Plant
In December 2009, CEA (Atomic and Alternative Energy Commission) France announced the construction of a pilot BTL plant in Bure Saudron. The plant will use 75000 tonnes per foresty and agricultural residues to produce ~23000 tonnes/year of biofuel (diesel, kerosene and naptha). The Bure Saudron project will add hydrogen during the synthesis stage to optimise the ratio with carbon monoxide [Source CEA].
NSE Biofuels BtL Demonstration Plant
NSE Biofuels Oy - a joint venture between Neste Oil and Stora Enso operated a BtL demonstration plant at Stora Enso’s Varkaus Mill in Finland. The output was 656 t/a from a 12 MW gasifier. As well as providing test data and operating experience, the plant also reduced greenhouse gas emissions as wood-based gas from the plant replaced oil in the pulp mill’s lime kiln, making the Varkaus integrate virtually fossil fuel free. NSE Biofuels (in partnership with Foster Wheeler and VTT) planned to develop a commercial production plant at one of Stora Enso’s mills with a projected output capacity of 100000 t/a and a potential launch date of 2016.
However, in August 2012 Neste Oil and Stora Enso announced that they had decided not to progress with their plans to build a biodiesel plant, for which the two companies had applied for funding under the EC's NER 300 programme. Although the technology has worked well at the demonstration plant (above), the project was not among those listed [in the NER300 intermin report] as scheduled to receive funding. Even with public funding, significant investment would also have been required for the commercial plant. [Source: Neste Oil website].
© Copyright Stora
The NSE Biofuels BtL demonstration plant.
Previously, the world's first commercial BtL Plant was under construction in Frieberg Saxony, utilising the Choren Carbo-V ® Process. Choren Industries filed for insolvency in July 2011. A new investor for Choren Components was announced in October 2011. On 9 February 2012 Choren's biomass gasification technology was sold to Linde Engineering Dresden, who will further develop the Choren Carbo-V® technology used to produce syngas.
The Choren Carbo-V ® Process
The Carbo-V® Process is a three-stage gasification process resulting in the production of syngas:
- low temperature gasification,
- high temperature gasification and
- endothermic entrained bed gasification.
The Fischer-Tropsch (FT) process is then used to convert the synthesis gas into an automotive fuel SunDiesel®.
The Choren plant used the proprietary Shell Middle Distillate Synthesis (SMDS) technology. Syngas production is followed by a modified version of the Fischer-Tropsch process. This favours the production of long chain waxy molecules, which are unsuitable for transport fuels, but substantially reduces the amounts of unwanted smaller hydrocarbons or gaseous byproducts. The hydrocarbon synthesis step is followed by a combined hydro-isomerisation and hydrocracking step to produce the desired, lighter products [Source: Shell Middle Distillate Synthesis: Fischer Tropsch catalysis in Natural Gas Conversion to High Quality Products, J. Ansorge, Shell International Oil Products B.V.].
The SMDS process has been implemented on a commercial scale at the $18 billion fossil gas-to-liquids (GTL) plant, developed by Qatar Petroleum and Shell, with a capacity of 260,000 barrels oil equivalent a day.
The Choren website listed a number of advantages for SunDiesel®:
- High cetane number and therefore much better ignition performance than conventional diesel fuel,
- No aromatics or sulfur and significantly reduces pollutants from exhaust emissions,
- Can be used without any adjustment to existing infrastructure or engine systems,
- Largely CO2-neutral.
The Dutch Biorefinery Initiative (DBI)
In 2009, a demonstration facility was initiated in the Port of Rotterdam by WUR and ECN with support from the Netherlands government. This included a 10 MWth entrained-flow gasification based syngas production platform for heat and power, base chemicals and BtL. Information on this project was included in the IEA Bioenergy Task 42 publication on Biorefineries
European Research on BtL, thermochemical conversion and 'sustainable biodiesel'
BRISK is a €10.84M four-year initiative with €8.98M funded under EC FP7 (Ref: 284498). BRISK aims to develop a European Research Infrastructure for Thermochemical Biomass Conversion, supporting R&D on innovative processes to convert sustainable feedstocks (agricultural/forestry wastes and energy crops) into liquid, gaseous or solid fuels.
The €3.73m DIBANET project is being co-ordinated by Carbolea at the University of Limerick and is a response to the Energy 2008 Call - "Significant enhancement of the cooperation between key researchers & industries from the EU & Latin America in the field of biofuels". DIBANET stands for the "Development of Integrated Biomass Approaches NETwork" & the title of the Project is "The Production of Sustainable Diesel Miscible Biofuels from the Residues & Wastes of Europe & Latin America". There are 13 partners in the group, 6 from the EU & 7 from Latin America (LA). The total budget for the project is €3.7m. DIBANET will develop technologies to help towards eliminating the need for fossil diesel imports in the EU & LA by advancing the art in the production of ethyl-levulinate from organic wastes and residues. Ethyl levulinate (EL) is a novel diesel miscible biofuel (DMB) produced by esterifying ethanol with levulinic acid.
The Cutec institute Cutec operates a pilot plant to investigate the thermochemical conversion of different types of biomass to synthesis gas and the separation of elements of the biomass step-by-step via a hot gas filter, water-based scrubber, sulferox scrubber, etc.
The greasoline® technology converts oily and fatty raw and waste materials to hydrocarbon mixtures consisting of chemical substances occurring in fossil gasoline, kerosene and diesel fuels. These products may be used as fuels and fuel components but also as chemical raw materials. The procedure was developed at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen, Germany. The GREASOLINE project was supported under FP6. In contrast to biodiesel, the product is chemically identical with fossil fuels. [Source: Fraunhofer Instiute].
US research on thermochemical conversion
In the US, Primus Green Energy has started construction of a $7m demonstration plant to produce drop-in fuels using proprietary technology based on an enhanced version of the Mobil Process. Gasification is followed by Carbon dioxide separation and scrubbing of the syngas, before a four-stage catalytic system to produce the drop-in biofuel.
Purdue University has developed H2Bioil technology, whereby biomass is rapidly heated in the presence of pressurised hydrogen. Catalysts are then used to convert the gas to "biogasoline" molecules.
BtL fuels may be produced from almost any type of low-moisture
biomass, residues or organic wastes such as short rotation trees, perennial
grasses, straw, forest thinnings, bark from paper-pulp production, bagasse,
waste paper or reclaimed wood or fibre based-composites.
It is estimated that over 4m3 of BtL-fuels can be produced per hectare of land per annum. Hence, in future if 4-6 million hectares of land were used to grow energy crops, one could replace 20-25 % of the liquid transport fuel currently used.
The advantage of the BtL route to liquid transport fuels lies in the ability to use almost any type of biomass, with little pre-treatment other than moisture control. This is because the feedstock is gasified in the first stage of the process. The gas produced is then treated further to clean it, remove tars, particulates and gaseous contaminants, and to adjust the ratio of the required gases (hydrogen and carbon monoxide) to that required. The result is a balanced syngas that can be used in the second, catalytic, stage. Syngas may also be obtained by pyrolysis to form charcoal. The hot charcoal is then reacted with steam to produce watergas.
The two main catalytic processes for BtL production are Fisher-Tropsch and the Mobil Process
The Fischer-Tropsch process is a catalyzed chemical reaction in which carbon monoxide and hydrogen are converted into liquid hydrocarbons of various forms. Generally the catalysts used, for the following reaction, are based on iron and cobalt.
(2n+1)H2 + n(CO) -> CnH2n+2 + nH2O
The FT process is an established technology and is already applied on a large scale from coal or natural gas. Developed in the 1920s in Germany, it was used by both Germany and Japan during World War II and later by South Africa and to a lesser extent in the United States.
One problem is the high capital cost of the multistage process. This may be greater when biomass is used as feedstock, since the scale of operation may be limited by the distance over which biomass can be transported to the factory at an economic price. Hence, the economy of scale is decreased compared to a large coal or gas-based operation. Running and maintenance costs are also comparatively high.
This is a two stage catalytic process. In the first stage LINK
methanol is produced. The methanol is then used as feedstock to generate
hydrocarbons of varying chain length, using a zeolite catalyst. In the conversion,
a number of reactions take place in the gas phase. The conversion is initiated
by the removal of water to produce dimethyl ether:
2CH3OH(g) -> CH3OCH3(g) + H2O(g)
This is followed by various other reactions in which further molecules of water are removed resulting in gradual increase in chain length.
These reactions include the following.
2CH3OCH3(g) + 2CH3OH(g) -> C6H12(g) + 4H2O(g)
3CH3OCH3(g) -> C6H12(g) + 3H2O(g)
As a result of other dehydration reactions occuring in parallel a mixture of hydrocarons is produced of which about 80% is suitable for petrol production. The mixture contains (w/w) around 50% highly branched alkanes, 12% highly branched alkenes, 7% cycloalkanes and 30% aromatics. This process has been commercialised by Methanex in New Zealand using methanol produced from natural gas.