Energy from straw

Nicolaus Dahmen wants to obtain high-quality petrol from straw, waste wood and other waste material from agriculture and forestry. In a large pilot facility on the grounds of the Karlsruhe Institute of Technology (KIT), this has already become reality. In five years, the procedure should be ready to put into practice.

There are frequently reasons for celebration at the Karlsruhe Institute of Technology (KIT). But the event that brought many guests of honour to the facility exactly one year ago was a special highlight. After one-and-a-half decades of scientific preparation, a pilot facility was put into operation that transformed surplus biomass from the fields into high-quality synthetic fuel. The new procedure was supposed to be an important contribution to the energy transition, according to the ceremonial speeches, and the economy in rural areas can also profit.

“We need five more years – then the procedure is ready to be put into practice,” says Nicolaus Dahmen. The professor for chemical engineering has been conducting research for ten years in the large pilot facility on the grounds of the Karlsruhe Research Centre. It is operated jointly with four industrial partners and was established based on the funding from the Federal Government, State and the EU. About eighty scientists and technicians work in the facility. They are currently producing high-quality petrol, and fuels for diesel motors and airplanes, and raw materials for the chemical industry should follow soon. Dahmen: “In the next few years the issue is to make the procedure dependable and economical enough that it can survive on the market.”

The procedure thereby, called “bioliq” (see box), is already capable of scoring points today with numerous advantages. It exploits straw, waste wood and other scarcely-used by-products from agriculture and forestry, of which many millions of tonnes accumulate in Germany each year. This is different compared to biomass fuels of the first generation, which are produced from individually cultivated agricultural crops such as rapeseed or corn. “We don’t have to compete with the production of nutrition and animal feed and can depend on a constant supply,” says Nicolas Dahmen.

The new technology is interesting as well for countries such as China, India and Brazil that have tremendous quantities of natural waste materials at their disposal. In Europe, this is particularly suitable for the countries Poland, Rumania and Bulgaria where a lot of biomass accumulates. We actually receive here in Karlsruhe queries from foreign countries almost on a daily basis, and in the pilot facility international delegations of observers arrive one after the other. They are all motivated by the same question: How can the rising consumption of fuel be covered in a dependable, economical and, at the same time, climate-friendly manner?

The answer might be bioliq. The new bio-petrol is unproblematically compatible with today’s vehicle technology and is suitable as well as an admixture with petroleum-based fuels. Moreover, the procedure is for the most part climate neutral: “Theoretically speaking, during the processing of renewable raw materials, only as much carbon dioxide is released as the plants had previously taken from the air,” says Nicolaus Dahmen. In practice though, the Karlsruhe pilot facility currently still needs small quantities of fossil-fuel energy.

A good eco-balance in the procedure is important to the 53-year old professor. He comes from Moers, a city in the western Ruhr district. His father worked in the chemical industry, which influenced the son just as much as the immediate vicinity to steel and coal. “I was interested in chemistry at an early age, but equally as much in the environment,” says Nicolaus Dahmen. After completing his studies in chemistry with a subsequent PhD programme at the University of Bochum, he went to KIT in 1992, which at that time was called “Kernforschungszentrum Karlsruhe” (Nuclear Research Centre). The young scientist wanted to conduct application-oriented research, and in Karlsruhe he was able to do just that: He contributed with his idea to lower-emission and more economical processes in industry, and subsequently assumed, in 2005, the scientific coordination of the bioliq facility.

Nicolaus Dahmen is proud of his facility, which he considers to be primarily a research platform. This is attractive to scientific new-comers – currently 25 doctoral candidates are puzzling over improvements to the bioliq process. Occasionally one can also see Dahmen’s students here, whom he instructs at the universities of Heidleberg and Karlsruhe in the departments Technical Chemistry and Chemical Engineering.

The chemist likes to pursue his rather unconventional hobby in his leisure time – he  reconstructs historical events with tin figures so that he can, in this manner, better understand past epochs. He is by no means alone in this pursuit: There is even a Deutsche Gesellschaft für Freunde und Sammler kulturhistorischer Zinnfiguren e.V., whose palatine section is led by Nicolaus Dahmen himself. 

With his wife, a trained master dressmaker, and the two children, the extremely busy scientist lives in Bruchsal in Kraichgau. Will his offspring continue the family’s chemical tradition? That has not yet been decided, says Dahmen, at least the 16-year-old son is keeping all options open. 

The bioliq procedure  

Step-by-step exploitation of surplus biomass with the aid of heat and chemistry and transformation of this into synthetic liquid fuels – this is the gist of the bioliq (biomass to liquid) procedure. The concept involves the following steps: First, farmers deliver dry straw or wood to a conversion facility in their region. There, the raw material is heated to about 500 degrees in just two to three seconds. Pyrolysis oil and pyrolitic coke are left over, which are mixed into a black pulp – the so-called bioliqSynCrude®. The energy-rich mixture is then transported to a large facility and transformed into synthetic gas at temperatures of more than 1,000 degrees Celsius. This consists of 50% hydrogen and 50% carbon monoxide, which can be converted into fuels or basic materials for the chemical industry – such as ethylene or propylene.

30.11.2015 , Lilo Berg
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