Glass is literally everywhere. Like steel, it is produced in huge furnaces where sand, and nowadays also recycled glass shards, are heated to more than 1500 degrees. Near Saint Gobain, near Aachen, Germany, there is such an oven, called Marie Louise. It burns 24/7 and consumes as much natural gas every year as a small city. However, Marie Louise is retiring soon. Partly because they will reach the retirement age of 22 for a glass kiln in 2027, but mainly because Saint Gobain, and the government of Nord-Rhein Westfalen, have decided that the time is right for climate neutral production of glass. All of this, of course, in the context of the, as it is called in Germany ‘Klimatwende’.
Electric oven not an option
Like so many products that depend on fossil fuels for their operation or production, you might think that (green) electricity is the solution here too. However, that turns out not to be entirely correct. The heat that must be generated for melting glass – a minimum of 1500 degrees – ensures that it is not possible to ‘fire’ it completely electrically for a furnace of such a scale.
Saint Gobain has therefore opted for a different, innovative, climate-neutral solution. The new ‘Marie Louise’, which must be operational by 2030 at the latest, will be ‘fired’ on hydrogen gas. As a fuel as climate neutral as it can be, since the only emission is literally water vapour. However, the production of hydrogen is not exactly climate neutral and is even very energy-intensive. Saint Gobain has also thought of that. Green electricity is used for the production of the required hydrogen.
Subsidy from NRW
This of course has the necessary technological and financial consequences. For the technological challenges, the glass factory has entered into a partnership with the regional technical university of Aachen (RWTH). Together they will work on a solution to make the mass production of ‘green hydrogen’ profitable. However, because hydrogen as a fuel is (much) more expensive than natural gas, the production of glass will also have to be improved and made more effective. To prevent glass from becoming unaffordable in the future. “Hydrogen is expensive and so the production process will also become more expensive, but given the climate requirements that will be set from 2030, we will have to change with it,” said the director of Saint Gobain in Herzogenrath.
The government of Nord-Rhein Westfalen has awarded a subsidy of 3.6 million euros for this, with the return that other large consumers of fossil fuels in the German Ruhr area can also benefit from this in the future. If Saint Gobain and the scientists at the RWTH succeed in setting up a profitable mass production of hydrogen, the glass factory will even see opportunities to continue life as an energy supplier, in addition to making glass.