Lilla, renowned for its roasters that operate efficiently without catalysts, has always been at the forefront of innovation in the coffee market.

Their unique system of recirculation, which combines stability, safety, oxidation efficiency, and high temperatures, sets them apart. However, recognizing the need for low-emission solutions, Lilla has integrated its innovative system with a catalyst system. This works in tandem with the standard thermal oxidation system, providing an effective solution for those who require it.

Traditionally, the coffee roaster market offers roasters with an additional chamber equipped with an afterburner. In some cases, this extra chamber is replaced with a more complex one, housing both an afterburner and catalyst modules (Figure 1).

The advantage of using catalysts in standard coffee roasters is the reduced temperature required to eliminate smoke in the extra chamber, leading to lower fuel consumption. However, the cost of catalyst modules often outweighs the benefits of reduced fuel consumption over time.

Therefore, companies typically opt for catalyst systems only when emission standards necessitate it. The decision to switch to catalysts is usually driven by the desire to reduce fuel consumption and, consequently, the carbon footprint.

Lilla has introduced a new concept of catalyst system to the market. Essentially, any new roaster can be retrofitted with catalysts in the future without the need for layout changes.

The catalyst is installed in the main chimney stack, after the gases have been oxidized in the furnace (Figure 2). This results in the catalyst operating at higher temperatures and receiving a much lower amount of volatile components to be oxidized compared to traditional catalysts.In traditional systems with catalysts, the catalyst chamber is installed after the cyclone.

This chamber requires a burner to raise the gas temperature to activate the catalysis. However, such a chamber lacks the proper turbulence and temperature to significantly reduce the amount of CO, VOCs, and TOCs. The catalyst does all the work, making the system entirely dependent on the catalysts.

As a result of decades of research on recirculation systems, it’s crucial to ensure proper gas recirculation. If not done correctly, there’s a risk of roasting coffee under a dirty stream, which could affect the sensory qualities of the coffee. Designing a roaster that recirculates gases 100% of the time requires careful consideration of many factors.

The new technology, already implemented in 9 roasters over the last 3 years, has been fully approved in terms of performance and, importantly, cost. While conventional catalysts need to clean a dirty air supply, Lilla provides an almost clean air supply, making the job considerably easier.

Consequently, the number of catalyst modules and layers has been reduced. The new design requires just one layer of catalysts, even for customers who do dark roasts. This would have been unimaginable a few years ago. Another advantage is the reduced pressure drop imposed by the catalysts, resulting in less powerful fans and energy savings.

In addition to the above, the roaster is designed to operate without catalysts and complies with most global standards. If a customer is located in a region with strict emission regulations, Lilla’s roasters are capable of accommodating a catalyst chamber in the future. This will not require any layout changes or significant investment. The system is future-ready.