To turn the corner, we must indicate a direction

Time is ticking down for the switch to glass manufacturing without fossil fuels. René Meuleman examines the challenges and consequences for the glass industry, and those who will be running it in the future. The full version of this article appears in the Sept/Oct issue that has been mailed globally and is also now available free of charge in the digital archive*.

To turn the corner, we must indicate a direction

Everyone involved in glass manufacturing is on the edge of perhaps the biggest challenge since the production of glass manufacturing began on an industrial scale. We are facing the fact that we will have to do without the use of fossil fuels. Something that most of us have never done before, never thought of until lately, and we have only 29 years to go to succeed. Can it be done? Yes, it can (simply) because we must.

Fortunately, there is a range of alternatives from full electric melting, to hybrid and hydrogen firing, perhaps even combustion of biofuels. The first reflex most of us will have is to stick as closely as possible to any kind of combustion. It is a natural human trait to stay close to what we do today and what we ever did with fossil fuel. Be aware; don’t make the mistake of putting all your eggs in one basket or all your research on one solution as it is yet not clear which of the alternative energy sources will be available and commercially viable. Most likely we will have to face different furnace designs, a mix of different energy sources, upgrades of our infrastructures and educating our operators and maintenance people to control and maintain the system smoothly after this massive changeover.

Additional hurdles

Lobbyists keep on telling us that natural gas will be replaced in the near future by hydrogen using the traditional pipelines but it seems that this is not so easy. Most probably we will have to face major changes in our internal fuel and electrical infrastructure, in addition to finding ways to manage the water content in the combustion space and perhaps even making oxygen available to avoid unwanted NOx emissions. The same can be said about electrical energy as most of our utilities and governments are struggling to get the electrical grid up to the capacity needed in near future. Within the plant it will not be different compared to hydrogen as we will have to refurbish, replace, and most probably extend the internal electrical installations as well.

As said before, the long intervals in between furnace overhauls may also work against us as there will not be that many opportunities to introduce a new melting technology before 2050, specifically for the smaller glass manufacturers. We will have to live with what we do today for at least another 10 years of furnace lifetime to come, perhaps even more. However, we are used to incremental changes per furnace campaign, a rhythm that now may need to accelerate during the energy transition.

Last but not least, most probably there will be no overall, standardised and commercially viable global solution as availability and price levels of alternative energy sources will differ from region to region. We have to act quickly as time is moving fast.

Better decision making

So is there no positive news? Yes, there is! We have a bunch of new sophisticated tools to assist us to face these challenges. One of the most important is mathematical or CFD modelling of furnaces. Thanks to the availability of today’s computing power and smart people who put together tools like GTM-X (pictured), we can get a clear view of the performance of newly designed furnaces even before the first brick is laid. Extensive modelling studies are already the foundation of ruling out design errors and reducing risks, resulting in better decision making. Based on GTM-X studies, rMPC advanced control strategies of the furnaces of the future can also be integrated into process control.

As a fully integrated tool these will assist our operators in managing new designs from day one of furnace operation. Supported by data collection, data storage systems and analytics, rMPC can be optimised during the first months of operation and EBM (energy balance model) will support furnace operations to keep an eye on energy consumption and furnace performance. Lately, new sensor technologies have also arrived and today we ‘look’ into furnaces from a completely new perspective, being capable of sensing temperatures, analysing batch behaviour, detecting refractory wear, checking burner settings and pointing out potential NOx emission sources. Burning new green fuels can be controlled better as well, with the help of laser CO, H2O, O2 and temperature sensors.

Awareness has increased rapidly over the last two years and it is great to see that most suppliers to the industry are working hard to find solutions to support the demands of tomorrow. These range from new refractory material, hydrogen burner technology, electric power supplies for boosting, etc.

New generation of glass geeks

The biggest positive result is that it starts showing an impact on young employees as the industry is and will become much more innovatively attractive for them. Apart from meeting environmental targets, our biggest achievement most probably will be to secure a new generation which wants to become the next glass geeks. With the help of the established, experienced workforce, the new generation will make an impact by helping us to avoid tunnel vision and introducing new technologies and ways of thinking into the rather traditional glass making procedures.

The industry has already mastered a lot of challenges and those with a long history in the glass will most probably agree that overcoming the problems of introducing new technologies were perhaps their finest hours. Industry 4.0, new sophisticated modelling tools, process control systems, refractory materials, rMPC, EBM, new sensors and our ongoing dedication is key.

We at CelSian have a daily discussion on those subjects trying to find the best ways to support the industry. Our team, a combination of highly experienced people and a bunch of innovative youngsters, is working extremely hard on designing new tools and ideas to solve customers’ current and future glass manufacturing problems. It shows that working on real challenges provides purpose, which is valid for old and young and also provides a lot of fun. We, at CelSian, are in the middle of it and we intend to stay in that position.

Solving the glass industry’s future problems will become the finest hours of the new ones – the youngsters, the new generation, as it is clear that the world cannot do without ‘green’ glass, which will remain one of the most intriguing and challenging materials around. How much more can you ask for your future and from your job than being challenged?

About the Author: 

René Meuleman is Business Development Director at CelSian

Further Information: 

CelSian Glass & Solar BV, Eindhoven, The Netherlands
tel: +31 40 249 0100


* The full version of this article appears in the Sept/Oct issue that has been mailed globally. The digital version of this issue can also currently be read free of charge in its entirety alongside back copies in the Digital Archive (sponsored by FIC) at To receive the paper copy, all future issues and a free copy of the Who’s Who / Annual Review 2021-22 yearbook, subscribe now at

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