As part of our commitment to sustainability and innovation we decided to investigate other options in dealing with waste and emissions generated through roasting coffee.
Roasting coffee produces four main types of emissions: dust, chaff, odour, and smoke. Dust is generated during the handling of green beans, while chaff is formed when the silverskins of coffee beans fall off during a roast.
Smoke and odour, meanwhile, are comprised of volatile organic compounds (VOCs). These fumes consist of diacetyl, 2,3-pentanedione, and other less harmful chemicals, along with carbon dioxide and carbon monoxide.
Some roasters use an Afterburner to remove smoke and odour. While this is an effective solution, it is also costly, using huge quantities of gas to incinerate the smoke and odour, and this does nothing to address the carbon footprint of the operation.
After much researching, we reached out to VortX, a new company based in America, using advanced water cyclone technology to achieve the results we were after, with a much smaller environmental footprint.
Vortx’s flagship product, the Ecofilter, is a wet scrubber positioned by the company as an alternative to incineration-based afterburners and other smoke and odor reduction systems for the commercial coffee roasting industry.
The Ecofilter consumes water and electricity instead of gas and operates at lower temperatures while reducing emissions by up to 90%.
When the hot, polluted air exiting a coffee roaster enters an Ecofilter system, it flows through a chamber containing atomized water that flash-evaporates on contact, cooling the contaminants to a temperature low enough that they condense from vapor into droplets. Centrifugal force inside the cyclone then draws the droplets to the walls where they are caught by a flow of water and flushed downward.
Clean steam exits at the top of the stack. At the bottom, the exiting water is filtered and the chaff is separated and compacted. The stack remains clean and clear, Vortx suggests using the wet chaff as a soil amendment in gardening, and the spent water can discharge directly down any grey water drain or be used to water a garden.
As we were installing the first Vortx in NZ, the whole system took a bit of tweaking to get it running efficiently, but a year down the track and we can honestly say that it does achieve the desired results.
We havent had to clean our ducting, which remains cool to the touch throughout the roasting process and the only real emissions from the top of our ducting is white steam as the roast progresses, and the caramelly smell similar to baking bread.