A precious liquid
Article from TÜV SÜD Journal 4/2010
 | Climate neutral, clean, sustainable, economical – this sounds like squaring the circle. CHOREN Industries demonstrates that energy supplies of the future can be just that. Its process technology converts biomass into valuable fuel. |
Around 65,000 tons of wood chips, 584 components for producing synthetic gas, 127 pressure vessels and complex chemical processes – this is the recipe for success that CHOREN Industries, a company in the eastern Germany city of Freiberg, intends to use in developing energy supplies for the future. The company specializes in the gasification of biomass and has developed the unique Carbo V process: solid biomass is converted into a tar-free fuel or synthetic gas that can then serve as the basis for green electricity, biogenic chemical agents or biofuels.
»The SUNDIESEL* we produce comes close to being an ideal fuel. It can be used by conventional diesel engines without new equipment being installed, burns soot free and has improved ignition behavior,« says Olaf Schulze, the Technical Managing Director of CHOREN Industries. Compared with fossil fuels, the diesel fuel made from biomass emits 30 percent to 50 percent fewer emissions. Biomass-to-liquid, or BtL, is the name for such fuels.
A solid becomes liquid
The basis of SunDiesel is wood that comes from the forests in the eastern German state of Saxony. In recent years, biofuels have gained something of a bad name because energy plants like sugar beets and corn are also used in food production – this has resulted in a conflict of usages. But this is not the case for the new generation of power producers. »There is enough biomass around,« Schulze says. The fuel is produced from waste wood and fast-growing trees like willows or poplars. In further stages of development, so-called biogenic waste material like straw is to be processed. Twenty percent to 40 percent of fuel demand in the EU could be met by biomass, the CHOREN executive says.
The production process works this way: The biomass is delivered to the facility as wood chips and unloaded into an underground bunker. Metal and rocks are removed. Wet wood is dried using waste heat from the production process. It is then stored in silos until time for production. The three-stage Carbo V process then produces a high-purity, tar-free, low-methane gas.
From pilot scale to full scale
It is no accident that the facility was set up in the city of Freiberg: Coal refining has been extensively carried out in the mining and technology location since the 1960s. The engineers at CHOREN are drawing on this know-how. From 1998 to 2006, the company operated a pilot facility. Today, the »beta plant« is operated as a demonstration facility. Following the successful test operation of synthetic-gas production, the company will initiate Fischer-Tropsch synthesis, in which the gas will be converted into hydrocarbons. »With this commercial plant, we expect annual production to reach 18 million liters of BtL,« Schulze says. »This doesn't amount to a whole lot because our customers think in terms of production units comparable to coal and refinery facilities. CHOREN provides them with the technology and comprehensive engineering services.«
Immense pressure is created during the production operation, and highly explosive gases develop in the chemically closed processes. »The factor of safety plays a critically important role at a plant equipped with such innovative technology,« Schulze says. For this reason, CHOREN Indus-tries has been relying for years on the expertise of TÜV SÜD Industry Services – for the certification of steam boilers and pressure vessels, for inspections conducted in accordance with the German Ordinance on Industrial Safety and Health and for help with issues involving occupational safety and health. In addition, it acts in an advisory capacity as a process partner in the development of facilities, test runs and final assessment. Schulze believes in the potential of re-newable energy: »We are conducting research into a huge topic, the energy basis for future generations.«
*Trademarks SUNDIESEL and SUNDIESEL-Logo are registered trademarks by Volkswagen Aktiengesellschaft in the European Community and additional Countries and are used under license of Volkswagen Aktiengesellschaft.