Verallia testing biogas for glass melting process

Saint-Gobain Oberland AG, trading under the Verallia brand name, is testing the use of biogas in the glass manufacturing process at its Bad Wurzach factory.

The objective of this long-term project for the glass container manufacturer is to “guarantee the environmental sustainability of the company.” Energy Manager Simone Spielmann said “As far as we know this makes the factory, which produces around one million glasses and bottles at this site each year, the first glassworks in Europe to use raw biogas in a primary industrial process.”

The manufacture of glass containers is energy intensive. To become less dependent upon fossil fuels such as natural gas and heavy fuel oil, and further reduce CO2 emissions, Oberland will in future rely more heavily on the use of renewable energies. The factory in Bad Wurzach is thereby breaking new ground by using biogas in this way.

The project is beginning to take shape. Since June 2015, following a large amount of preliminary planning work, unpurified biogas is now being injected directly into the core process, where it is used to fire the furnace that produces the molten glass. Testing will take place over a period of six months in order to gather information on how the injection of biogas affects the production process. During the testing phase it is planned to replace up to nearly 50 percent of the fossil fuels – currently burned in one of the furnaces in Bad Wurzach – with raw biogas.

The tests are supported by the German Federation of Industrial Cooperative Research Associations (AiF). This prestigious organisation, which promotes applied research in medium-sized companies, has become an integral player in the Bad Wurzach project. The Essen Institute for Gas and Heat (GWI), part of the Research Association of the German Glass Industry (HVG) is also supporting the tests.

The unpurified biogas is sourced from an existing neighbouring agricultural installation which has to-date used the biogas to generate electricity. This renewable energy plant produces biogas from renewable raw materials. Provided the process of using biogas in the glass manufacturing process can be proven to be feasible during testing, it is also conceivable that gases obtained from waste materials, such as biowaste, could also be used in future.

The extent to which using green energy will also be economically viable is not currently a key consideration during the early days of the long-term test. “We intend to take sustainability seriously”, explains Simone Spielmann. “But we have also identified opportunities for rendering the permanent use of biogas cost-effective.” The company receives no form of financial subsidies or state aids – which would normally be granted when electricity is generated from renewable sources – for this novel use of biogas. Stefan Jaenecke, Chairman of the Management Board of Saint-Gobain Oberland AG, emphasises that the company has taken the decision to “consciously select the best technical and most energy-efficient solution, irrespective of the availability of subsidies.” He said “We have identified a major opportunity for Saint-Gobain Oberland AG, and for the glass manufacturing industry as a whole, to forge ahead once again.”

The large-scale testing phase will provide an indication of the technological changes the Bad Wurzach factory will undergo in future. Using biogas to fire the furnaces directly, and not to generate electricity, is a risk. One that will pay off, hopes Spielmann. In any event she does not expect to see losses in efficiency.

The “invention” of glass recycling was initiated on a large-scale from Bad Wurzach back in the 1970’s, employing the ubiquitous used glass collection bins. Using biogas would now be the “next big step” towards achieving sustainable operations for the glass manufacturing industry, and the idea would again have its origin in this region, said Spielmann.