German consortium starts production of ultra-clean synthetic biofuels

A group of German research organisations has begun [*German] producing the primary feedstock for high-quality synthetic biofuels from different types of biomass. The process to obtain such 'biomass-to-liquid' (BtL) fuels was named 'bioLiq' and consists of two steps: a decentralised phase in which raw biomass is transformed close to the source of harvest into an oil with a high energy density via fast-pyrolysis. The resulting bio-oil can then be transported economically to a central facility where it is gasified and liquefied via Fischer-Tropsch synthesis into a range of finished fuel products. The process allows for the production of fuels with properties similar to diesel or gasoline, with the difference that the synthetic biofuels are ultra-clean and renewable.

The Forschungszentrum Karlsruhe (FZK) and Lurgi AG have been designing and building the fast-pyrolysis pilot plant for the past two years. During the inauguration last week (June 20) both organisations signed an agreement to build the gasification and liquefaction plant needed to perform the second stage of the production. The work is being supported by the Fachagentur Nachwachsende Rohstoffe (Agency for Renewable Materials, of Germany's Ministry of Agriculture, Food and Consumer protection).

The fast-pyrolysis plant can transform 500 kilograms of biomass per hour. It is a test-bed for commercial plants which will convert up to 50 tons per hour. Part of the second-stage of the process (gasification into synthesis gas) is carried out by a third partner, Future Energy in Freiberg.

Synthetic biofuels are based on renewable biomass, which is why they do not add CO2 to the atmosphere when they are combusted. But aside from their carbon-neutrality, they also have properties that far surpass those of petroleum based fuels and other biofuels: they are sulphur-free, low aromatic and odourless fuels that significantly reduce regulated and non-regulated vehicle pollutant emissions (NOx, SOx, PM, VOC, CO). They can be readily used in existing fuelling infrastructures and engines, but they also enable the development of a new generation of internal combustion engine technologies with improved engine efficiency and further reduction of vehicle pollutant emissions. Synthetic biofuels are readily biodegradable and non-toxic.

Decentralised production
The two-stage bioLiq process developed by the FZK is a first step towards the large-scale adoption of synthetic biofuels in Germany, where they are estimated to have the potential to replace up to 15% of all transport fuels by 2015 and 35% by 2030 (estimates by the German Energy Agency - earlier post).

The main bottleneck in the production chain of BtL fuels is the low energy density of biomass feedstocks such as wood chips, straw, paper, pulp and other residues from agriculture, forestry and industry. By placing fast-pyrolysis plants near the biomass source the residues can be transformed into bio-oil (pyrolysis oil) the energy density of which is 13 to 15 times higher. Transporting raw biomass over distances larger than 25 kilometres is economically unattractive, with bio-oil the range can be extended by a factor of 10 and more.

This decentralised concept makes it possible to transform biomass into a bio-oil while using existing agricultural production chains and structures. Part of the added value chain is thus kept local, close to the biomass source. - Dr. Ludolf Plass, Chief of Technological Development of Lurgi AG

The decentralised fast-pyrolysis step consists of heating the biomass in the absence of air to a temperature of 500°C after which pyrolysis oil and tar is obtained. Both materials are then mixed into a liquid suspension ('bioliqSyncrude') ready to be shipped to the gasification and Fischer-Tropsch plant:
bioenergy :: biofuels :: energy :: sustainability :: biomass :: fast-pyrolysis :: Fischer-Tropsch :: synthetic biofuels :: biomass-to-liquids :: Germany ::

Central facility
There, the bioliqSyncrude is gasified in an entrained flow gasifier at temperatures of up to 1200 °C and pressures of 80bar to obtain a tar-free synthesis gas, which consists mainly of hydrogen and carbon monoxide. Future Energy based in Freiberg has tested and improved its 5MW gasifier over the past years in such a way that it has become possible to transfer the high pressure synthesis gas directly to the next synthesis steps. An intermediate compression step - which is costly and risky - is thereby avoided.

The synthesis gas can be converted into a broad range of platform chemicals. Via the Fischer-Tropsch process it can be transformed into synthetic fuels. A process to convert the gas into methanol, an intermediate material for other fuels, was developed as well. This way, a series of 'designer fuels' can be made with properties similar to fuels from the entire spectrum of middle distillates found in traditional oil refining. The synthetic biofuels are much cleaner, less damaging to the environment, and emit far fewer of all the common emissions. Synthetic biofuels are also cleaner than first generation types of biodiesel and bioethanol. They promise to allow countries to reach their targets for the use of low-carbon fuels, part of the effort to mitigate climate change.

Background
The technology to transform synthesis gas into liquid fuels - the Fischer-Tropsch process - was developed in the 1930s in Germany, when oil was scarce. Coal was used as a feedstock, but that would be problematic today. Renewable biomass can readily substitute coal, but it has taken a while before researchers found the most optimal ways to use different types of it as a feedstock. It is important to know and standardize the properties of the primary bio-oil (bioliqSyncrude) obtained from many different sources of biomass, because once this oil has been produced there is no way back and it will be used 'as is' in the gasification and liquefaction stage.

This is why the fast-pyrolysis pilot plays such a crucial role in the entire project. It allows us to test and optimize the transformation of different types biomass. With Lurgi AG we have found a partner who has been developing the technology for years and who has made several key innovations - Professor Dr. Eckhard Dinjus, Director of the Instituts für Technische Chemie, part of the Forschungszentrum Karlsruhe.

Lurgi AG began experimenting with the fast-pyrolysis of coal and petroleum products in the 1970s. Today it is a leader in the use of the same process on biomass. The same company has also been instrumental in the growth of the biodiesel and bioethanol industry and has built a large number of plants throughout Europe.

The two-stage bioliq process has received a lot of attention from the political, industrial and business communities. Besides the German auto-industry and players in the petrochemical sector, investors from across Europe and beyond have shown interest, partly because the bioliq-concept received the prestigious "BlueSky Award" from the UNIDO, in 2006. The UNIDO is a UN agency that deals with industrial development; the award is given to organisations which develop breakthrough technologies that might benefit mankind as a whole.

The award points to the fact that the technology can be used in the developing world, where large streams of unused biomass are available. Transforming these raw resources into bio-oil allows for the creation of an export oriented biofuels industry, in which the Global South benefits from its competitive advantages in the agricultural sector.

The costs for the production of these next-generation synthetic biofuels is estimated to be around 50 eurocent. To this must be added the costs for the raw biomass which are estimated to be slightly lower but in the same range. This way, the total costs for the high-tech fuels will be below 1 Euro per liter.

The Forschungszentrum Karlsruhe is a member of the Helmholtz-Gemeinschaft, an organisation uniting 15 of Germany's top research institutions. Its annual budget is around €2.1 billion, making it the largest scientific organisation in the country. A total of 24,000 scientists, researchers and other staff work for the Helmholtz-Gemeinschaft in fields ranging from materials sciencies, the environment and Earth sciences, transport, health, energy and new key technology fields such as nanotechnology.

Translated and adapted by Jonas Van Den Berg and Laurens Rademakers

Image: the fast-pyrolis plant at the FZK in Karlsruhe. Courtesy: Forschungszentrum Karlsruhe.

References:
Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft: bioliq® – Stroh im Tank! - June 20, 2007.

Lurig AG: Lurgi making fuel from biomass - June 21, 2007.

Biopact: German Energy Agency: biomass-to-liquids can meet up to 35% of Germany's fuel needs by 2030 - December 15, 2006