Voith SteamBooster slashes gas dependency at Koehler Paper Kehl mill

The thermal drying process remains the undisputed heavyweight of energy consumption in any paper mill. For decades, the industry accepted the massive natural gas requirements of coating and drying as an unavoidable cost of doing business. But as carbon taxes bite and energy security remains a volatile variable in 2026, the calculus has shifted. The recent operational data from Koehler Paper’s Kehl mill in Germany provides a compelling blueprint for tackling Scope 1 emissions without waiting for grid-scale electrification.

At the heart of this shift is Voith’s SteamBooster technology. Integrated into the mill's offline coating machine SM 8—a line dedicated to machine-glazed specialty papers—the system has been quietly proving its worth since it came online in June 2025. The engineering premise is straightforward but highly effective: capturing the intense exhaust heat generated by the coating process and upgrading it back into usable utility steam.

Turning 300°C exhaust into utility steam

Specialty paper coating is notoriously energy-intensive. The SM 8 line utilizes Voith’s non-contact MCB dryers, which generate exhaust air temperatures reaching up to 300°C. Historically, a significant portion of this thermal energy was vented into the atmosphere—a literal evaporation of capital.

By retrofitting the SteamBooster, Koehler Paper has closed the thermal loop. The hot exhaust air is now routed through a specialized heat exchanger, boiling condensate to generate approximately one ton of process steam per hour. This recovered steam is fed directly back into the mill's production cycle. The immediate operational benefit is a proportional reduction in the load on the mill's primary gas boilers.

The environmental and financial metrics are hard to ignore. The three-stage heat recovery setup at Kehl is currently saving up to 1,500 tons of CO2 annually. According to Voith, systems of this type typically offer a payback period of under two years, depending on the specific configuration and local energy costs. For an industry operating on tight margins, a sub-two-year ROI on a decarbonization project is a rare and highly attractive proposition.

A pragmatic bridge to decarbonization

What makes the Kehl installation particularly relevant for the broader global market in 2026 is its pragmatism. While the industry continues to research fully electrified drying cylinders and alternative fuels, these technologies often require massive capital expenditure and infrastructure upgrades. In contrast, waste heat recovery leverages existing assets.

Martin Dauner, Product Manager Steam & Condensate at Voith Paper, highlighted that the technology—originally patented for tissue machine hoods—has now been adapted for any paper machine generating exhaust temperatures above 100°C. Crucially, the system is designed as a turnkey solution that can be retrofitted during standard maintenance shutdowns, minimizing costly production downtime.

The successful integration at Koehler Paper underscores the value of long-term supplier partnerships. Dr. Mario Vollmer, Innovation Manager Energy at Koehler Group, noted that the fast and easy installation achieved the targeted energy efficiencies without disrupting the mill's complex specialty paper output.

As European mills face increasingly stringent environmental regulations, the ability to squeeze every megajoule of utility out of existing fuel consumption is no longer just a sustainability initiative; it is a fundamental requirement for cost competitiveness. The SteamBooster demonstrates that significant efficiency gains are still hiding in plain sight within the exhaust stacks of legacy equipment.

The transition to a low-carbon paper industry will not be achieved overnight by a single miracle technology, but rather through the systematic deployment of smart, circular engineering like Voith's heat recovery systems. If a mill can recover its own waste heat to offset baseload boiler demand with a two-year payback, what is stopping the rest of the industry from making thermal circularity a standard operating procedure rather than an optional upgrade? Follow The Paper for daily news, market signals and key updates from the global paper, corrugated and packaging industry. — Sigue toda la actualidad del sector en www.thepaper.ai