Do roasteries need waste air purification?

Esther Gibbs
July 3, 2023
An image of a coffee roaster roasting coffee and checking coffee roasting emissions in an article on whether roasteries need waste air purification

When entering an industrial estate where coffee roasters are present, there is often a subtle aroma. It resembles toast that has just freshly popped from the toaster. While modern roasters no longer billow smoke the way they used to, there are still small amounts of fumes being emitted into the local area. 

This is a challenge many roasters face when trying to set up businesses in residential areas. Additionally, the flues have to be metres taller than the highest residential living area. Even then, the smell may gather complaints from neighbours. 

In more industrial areas, coffee emissions are unlikely to cause problems. However, some roasters may come across difficult landlords or neighbours that have complaints about the smell and the often minimal amounts of smoke.

So, is there any solution? And are they worth investing in?

To learn more about whether roasteries should invest in waste air purification, I spoke with Tom Osbourne from Giesen Roasters UK and Coffee Roasting Solutions.

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Why should roasters consider waste air purification systems?

Coffee roasting is often accompanied by exhaust air pollution and odours. However, the technology used in waste air purification systems is constantly developing and there are now several solutions available. That said, without regular maintenance and cleaning, an air purification system will be redundant.

It is essential for roasters to reduce smoke and emissions by having regular maintenance done on their equipment. This includes following all instructions provided by the manufacturer, especially cleaning protocols. Additionally, it means having the machine serviced at the recommended intervals by a technician. 

Regular maintenance ensures the roaster is not building up residue. A dirty roaster leads to reduced airflow through the machine and the flue system, leading to heavier smoke. 

An image of a coffee roaster releasing freshly roasted coffee beans and coffee roasting emissions in an article on whether roasteries need waste air purification

What is the problem with emissions from the exhaust?

Roasting is a process that combines many physical and chemical reactions fuelled by a heat source – typically gas. These reactions create the flavour compounds that are enjoyed in the cup. However, the by-products of these reactions often include:

  • Carbon Monoxide
  • Carbon Dioxide
  • Nitrogen Monoxide
  • Nitrogen Dioxide
  • Volatile Organic Compounds
  • Particulate Matter

“Although they dissipate in the atmosphere, these gasses are toxic,” says Tom, who is the director at Coffee Roaster Services LTD. “Unless these gasses are treated, these emissions contribute to global warming.” He adds that emission cleaners such as the Catalytic Emissions Cleaner used by Giesen can assist, whereas afterburners are more likely to aggravate the issue.

As well as imparting smokey flavours on the coffee, these fumes pose a health risk if inhaled. Carbon dioxide also contributes to global warming as it builds up in the atmosphere, which traps heat and causes the temperature of the planet to rise. This is likely to result in plants developing diseases, as they are unable to fight pests and deal with environmental stresses. In turn, this may lead to a reduction in growth and the survival of seedlings, resulting in reduced yields.

An image of customised coffee packaging, sustainable coffee packaging, custom-printed coffee bag, in an article on whether roasteries need waste air purification

Afterburners vs. waste air purification

Afterburners normally operate between 700 and 800° and use more gas than the roaster,” Tom elaborates. “The emissions are often obscene. Often, landlords are less bothered by the environmental perspective, but the council is concerned and more regulations are being put in place.”

He explains that catalytic emissions cleaners are normally situated in places like central London. “They help to remove 90% of the smell, 90% of smoke and 90% of emissions. Additionally, they often have a low operating cost as it only has to heat a small vessel to around 400°. The catalytic converters work by using accelerated oxidation at lower temperatures. It uses a carrier, special coating, precious metal, and heat. The metal acts as a catalyst to enable reactions between carbon atoms and can cause several chemical reactions.

“Hydrocarbon, carbon monoxide, formaldehyde, and caffeine go into the catalyst, which oxidises and reduces these compounds,” Tom explains. Nitrogen oxides are generated in the roasting process but are also generated in a typical afterburner, as they increase in production with higher temperatures.

As catalysts use less heat, they will naturally produce less nitrous oxides. Carbon monoxide, odours, and volatile organic compounds (VOCs) are also reduced in the process. A similar system is used in the ReiCat Waste Air Purification for coffee roasters. Toxic emissions and particulate matter are converted into harmless substances such as water vapour and carbon dioxide.

The term SFE refers to electrostatic filters which charge the suspended particles in the waste gas stream and separates them. Then, through vibration, the particles are detached from the electrode and discharged.

Smoke suppressors use an electrostatic precipitator (ESP), which includes an Ion electronic precipitator in each model. It has a pre-filter to catch particles, and a secondary filter with an air ioniser which attracts particles to the electrode collection plate, similar to static electricity. These also have an option for ultra-violet (UV) odour control. Research suggests high-energy UV light can reduce the causes of most odours, making this an affordable and efficient option for roasters.

Most roasting manufacturers are offering solutions that allow customers to reduce emissions and increase efficiency. More so, they are improving the technology within the product itself. While it is not currently compulsory to reduce your carbon footprint, it may be required in the future

It is also to consider how global warming has an impact on the production of coffee and lives of coffee producers. Roasters must play their role in making sure they are not contributing to the problems their suppliers are already experiencing. Roaster can also move towards becoming carbon neutral by focusing on other aspects of the business, such as the packaging process. Investing in biodegradable, compostable, or recyclable coffee packaging and takeaway cups can be one of the most effective ways to improve sustainability credentials.

At MTPak Coffee, we are aware of the need for coffee roasters to find sustainable solutions. We offer a range of 100% recyclable coffee packaging options made from renewable materials such as kraft paper, rice paper, or multilayer LDPE packaging with an environmentally friendly PLA lining, all of which minimise waste and contribute to a circular economy.

Our design team is readily available to help you create the ideal coffee packaging that reflects your commitment to sustainability. Plus, we are able to custom-print coffee bags using innovative digital printing technology, with a quick turnaround time. We offer a wide range of customisation techniques, including spot UV with a glossy, satin, or matte finish, embossing and debossing, as well as hot foil stamping in a variety of colours, to name a few.

MTPak Coffee also offers low minimum order quantities (MOQs) to micro-roasters who are looking to remain agile while showcasing brand identity and a commitment to the environment.

For more information on sustainable, custom-printed coffee packaging, contact our team.

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