Coffee grounds waste emerging as powerful heating fuel, fertilizer

Millions of tons of residue from espresso machines and Turkish coffee dregs end up in landfills, polluting the environment. Projects are springing up all over the world for the production of fuel and fertilizer from the overlooked commodity. The participation of restaurants and cafés and raising awareness among coffee lovers are crucial for the activity to become sustainable.

At least two billion cups of coffee are consumed every day on the planet, according to a study conducted all the way back in 2011, so the current number is likely to be much bigger. Excluding waste from the agricultural production segment and all the packaging, the amount is equivalent to six million tons of waste grounds. Numerous scientific institutions, civic organizations, and companies are starting projects for using the resource in line with circular economy standards.

Nonprofit enterprise InCommOn – Innovative Communities Onwards recently expanded its activities in Greece. Profitability in the said segment is still a long way away in general. However, InCommOn’s representative Valia Zourna stressed the model needs to become sustainable even if there is no net income.

Pellets from used coffee have a high calorific value

Seventy cafés in Thessaloniki and Kilkis collect the coffee residue in plastic boxes that they get. The material is transported by an electric van to the Kilkis regional unit, where it is dried naturally. Then it is turned into pellets of a high calorific value for heating purposes in households and incineration in biomass-fueled boilers.

InCommOn developed the process in cooperation with the Centre for Research and Technology Hellas – CERTH, known also for its Greek acronym EKETA. The country’s Green Fund supported the endeavor, which includes producing drinking straws from stalks of wheat plants.

Coffee dregs are efficient in smaller quantities for fertilizing flowers, mushrooms and gardens and to repel parasites, or the residue can be composted

An algorithm determines the optimal route for the van. The pilot project began last year in Kilkis. InCommOn plans to add all chains that serve coffee so that no spent coffee grounds end up in landfills.

The organic waste harms the environment if it is disposed of in bulk, as it contains caffeine, tannins, and chlorogenic acid. Rich in nitrogen, it is a useful fertilizer for flowers, mushrooms, and vegetables. It prevents fungal infections and molds from forming and repels insects and snails. The pulverized remains can be composted with other food waste.

Role of awareness-raising

The main factor in efforts to utilize coffee dregs is raising awareness among consumers and producers of coffee and coffee-based drinks.

Citizens and companies participated in an initiative launched by Paulig in 2017 to collect coffee waste for generating electricity to illuminate the Christmas tree in the center of Kaunas in Lithuania. The company recovered 15 tons and 8 GWh of power was produced. It was almost three times more than necessary for the goal.

The initiative continued the following year when a street and church were illuminated in the capital city, after which 50 tons of the commodity was collected in 2019 for the Vilnius Light Festival.

Biogas, biodiesel production

In another research, scientists found spent coffee grounds have a share of oil of 10% to 15% that can be turned into biodiesel. Just as other organic waste, the material can be processed to get biogas and reduce harmful methane emissions. The leftovers can again serve as fuel or fertilizer.

Bio-bean from the United Kingdom is running one of the largest projects. The company recovers coffee residue to manufacture biodiesel and other products. Its plant has the capacity to cover one-tenth of the volume generated in the country.