Producing soda ash more sustainably

In an effort to reduce plastic waste, you’ve probably begun or are considering using more reusable and recyclable glass. But did you know that even glass is on a journey towards more sustainability? And soda ash production is key in achieving this. Ernest Solvay revolutionized soda ash manufacturing in 1863, so it only makes sense that the company he left behind continues his legacy by pioneering more environmentally-friendly ways to produce soda ash.

Soda ash is a vital component in glass, as it reduces the melting temperature of sand, the primary ingredient used in glass formulation, significantly cutting down energy use and related CO2 emissions. As a result, glass manufacturing accounts for over 50% of the total soda ash production.

Soda ash is used in two types of glass: container and flat glass. Container glass holds food, beverages and other concoctions and is 100% recyclable, unlike its plastic counterparts that remain one of the biggest environmental concerns. 

Flat glass is found in solar panels, and the automotive and construction industries, of which the latter is the largest consumer of glass – construction, for example, represents 20% of Solvay’s total soda ash sales. Many of these end products positively serve the environment. In construction, double glazing drives tremendous energy savings –  millions of tons of CO2 emissions can be cut simply by installing proper windows. 

There’s no doubt that soda ash is a key ingredient in a wide variety of sustainable solutions. And today we are taking the lead to overhaul its carbon-intensive manufacturing process. 

The chemical industry may be part of the [environmental] problem, but it’s also part of the solution!

Solvay CEO Ilham Kadri

Securing the future of synthetic soda ash

Solvay has been a global leader in soda ash ever since founder Ernest Solvay pioneered his commercially viable ammonia-soda process. Today, our Group comprises seven soda ash plants, of which six are located in Europe and one in the US, using so-called “synthetic” (Solvay) and “natural” trona manufacturing processes respectively to supply global demand.

And that global demand is high. It is in fact so high, that natural soda ash derived from trona minerals alone cannot meet that demand. To keep the soda ash - and subsequently glass supply - running, the industry needs to find a way to produce its synthetic variant in a manner that meets stringent sustainability standards. “We have a duty to bring the Solvay process, which is over 150 years old, to the next generations,” Philippe Kehren, President of Solvay Soda Ash & Derivatives, explains. As our CEO Ilham Kadri often says: “The chemical industry may be part of the [environmental] problem, but it’s also part of the solution!”

Mapping out the road to carbon neutrality in soda ash

We’ve joined industries and countries across the globe in committing to the urgent mission of reaching carbon neutrality before 2050, revealing the three stages to reach that goal earlier this month. For soda ash specifically, the roadmap focuses on pioneering innovative ways to sustain the future of synthetic soda ash for generations to come – in true Ernest Solvay form.

Our Group has set out a three-phase plan for its soda ash plants, starting with a total coal exit at all sites by 2030. 

“The first phase of our carbon neutrality journey relies on energy transition, phasing out coal to more sustainable energy,” says Jean-Charles Djelalian, Strategic Marketing and Sustainability Director, Solvay. “We are confident that by doing so, we can reduce our CO2 emissions by 30% by 2030.

And our Rheinberg plant in Germany is leading the charge. By 2025, biomass boilers will replace coal, using scrap waste wood chips as fuel to produce steam and electricity. This makes the site the first-ever soda ash plant in the world primarily powered by renewable energy. The project will reduce our global greenhouse emissions by 4%, and set a new sustainability reference: Greenhouse gases emitted in Rheinberg will reach levels below plants producing natural trona soda ash. And this is only one example of Solvay’s many energy transition projects taking shape: 


Of course energy transition is only the first step: “phasing out coal isn’t enough to reach carbon neutrality,“ Jean-Charles explains. “To achieve  this goal, we need process innovation as the second phase, which means innovating the way we manufacture soda ash. For both the Solvay process in Europe and the natural process in the US, we’ve already started phase two, and innovative research projects are ongoing to further improve our carbon emissions and environmental footprint by pioneering soda ash production.” 

Finally, the third phase will see the Group moving into: energy innovation. As a final step Solvay wants  to develop  new sources of energy that will be even more sustainable than the ones in use today, and will eventually power all soda ash plants in the future. 

Keeping renewable energy sources local

We believe that renewable energy sources should be a local matter. Over 150 years ago, Solvay built its soda ash plants where raw materials – salt, lime and coal – were readily available. Today, we want to return to sustainable local resources to produce energy.  “If you really want to limit the environmental impact and CO2 emissions, it’s best to have short supply chains and have producers and customers as close as possible to each other,” Philippe explains. “We need to go back to that original model and promote a local value chain.”

This means finding the right solution for each location. Our Rheinberg site has set the tone by utilizing used wood from industrial residues and demolitions for its biomass boilers. At Dombasle, the RDF boilers will be fueled by local Municipal Solid Waste (MSW), and energy-rich materials such as paper, plastics, and objects made of wood. And our site in Wyoming will be powered by natural gas, which is readily available in the US and does not require import. 

And it’s not just the environment that benefits, customers do too. The recent energy crisis has resulted in volatile energy prices and there’s nothing to say such crises won’t happen again in the future. “Switching to local energy means we are less exposed to energy price fluctuation, and instead have long-term visibility, and sustainable and secure supply chains,” Philippe explains. Which in turn means competitive production costs and customer prices.

We want to demonstrate that we have the solutions to reduce environmental impact. We want to be transparent with our customers. And we want our employees to be proud to work for Solvay’s Soda Ash Global Business Unit.

Philippe Kehren, President of Solvay Soda Ash & Derivatives

Walking the talk towards more sustainable glass

Promoting environmental sustainability across our soda ash sites has been a constant and continuous effort, ever since Ernest Solvay replaced the severely polluting Leblanc method with his own more sustainable method. Beyond CO2, our Group has also significantly invested in solutions to reduce water consumption, to treat flue gas and effluents, and to recycle by-products. 

To secure a sustainable future for soda ash, more than just environmental promises are needed. We are actually doing it. “Sustainability has always been a priority for Solvay. We are walking the talk,” Philippe stresses. “We want to demonstrate that we have the solutions to reduce environmental impact. We want to be transparent with our customers. And we want our employees to be proud to work for Solvay’s Soda Ash Global Business Unit.”

Solvay’s determination to transform the synthetic and natural soda ash industry is what will ultimately make our glass more sustainable in every way, across the whole life cycle.