Scientists convert coffee waste into premium fuel in under two minutes

Researchers from the Korea Institute of Geoscience and Mineral Resources and partner organizations reported that wet spent coffee grounds can be transformed directly into high-quality biochar using a flame plasma process, eliminating the need for the energy-intensive drying steps typically required in biomass recycling.

Coffee consumption generates more than 10 million tons of spent coffee grounds worldwide each year. Most of this waste ends up in landfills or is incinerated, contributing to environmental problems and greenhouse gas emissions.

The new technique uses a high-temperature flame plasma jet fueled by liquefied petroleum gas. The process heats coffee grounds containing about 55% moisture to temperatures of roughly 800°C to 900°C, rapidly evaporating water and converting the material into biochar. Unlike conventional methods, which often require lengthy drying and processing times, the conversion is completed in just 90 seconds.

According to the study, the resulting biochar reached a heating value of 29 megajoules per kilogram, about 33% higher than untreated coffee grounds and comparable to, or even exceeding, the energy content of standard anthracite coal.

Researchers said the process reduced the original mass of the coffee grounds by more than 83% while producing a sulfur-free fuel that could generate fewer harmful emissions when burned.

One of the key discoveries was that the moisture naturally present in the coffee grounds actually helped improve the process. As water rapidly turned to steam under the intense heat, it created what researchers described as a "popcorn effect," forming a highly porous structure inside the biochar and increasing its quality as a fuel.

Earlier, Qazinform News Agency reported that coffee does more than boost energy.