"Don't Throw Away Coffee Grounds" Transformed into 'High-Grade Fuel' in Just 90 Seconds [Reading Science]

KIGAM Develops World's First "Flame Plasma Pyrolysis" Technology
Removes Sulfur Content and Boosts Processing Speed by Up to 240 Times

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A technology that can convert discarded wet coffee grounds into high-grade fuel equivalent to anthracite in just 90 seconds without a separate drying process has been developed in Korea. This technology can also be applied to the treatment of high-moisture organic waste such as food waste or sludge, drawing attention as a carbon-neutral waste-to-resource solution.

The Korea Institute of Geoscience and Mineral Resources (KIGAM) announced on May 20 that a research team led by Senior Researcher Park Taejun at the Resources Utilization Research Division, in collaboration with Godtech Co., Ltd., has developed, for the first time in the world, a 'Flame Plasma Pyrolysis (FPP)' technology that converts coffee grounds containing approximately 55% moisture into high-quality biochar without any drying or degreasing process.

Flame plasma process treatment. Provided by the research team

The results of this research were published in the Chemical Engineering Journal, an international journal in the field of chemical engineering.

Conventional pyrolysis processes for high-moisture organic waste require a preliminary drying step for moisture removal, resulting in high energy costs and process complexity.

Comparative Diagram of Existing and New Processes for Producing Biochar Using Coffee Grounds (Existing Process Vs. Flame Plasma Process). Provided by the Research Team

The research team developed a method of directly treating wet coffee grounds using flame plasma generated at atmospheric pressure at about 800 to 900 degrees Celsius by combusting LPG (liquefied petroleum gas) and compressed air. The principle takes advantage of the 'popcorn effect,' where internal moisture is instantaneously vaporized in the ultra-high temperature environment, rapidly accelerating the carbonization reaction.

In particular, the research team explained that, during this process, moisture acts not merely as a substance to be removed but as a steam activator that promotes the reaction, contributing to the formation of a porous structure and enhancing the reaction rate.

Experimental results showed that the team was able to achieve a calorific value of 29.0 MJ/kg—approximately 33% higher than that of conventional coffee grounds (21.8 MJ/kg)—with only 90 seconds of processing. This is similar to the solid fuel characteristics of standard anthracite.

Taewoon Park, Senior Researcher. Provided by KIGAM

The fixed carbon content increased by approximately three times compared to conventional methods, and the sulfur content was completely removed, confirming its eco-friendly characteristic of producing no sulfur oxides (SOx) during combustion. The specific surface area also increased significantly, suggesting potential applications as a precursor for activated carbon or as an adsorbent material in the future.

According to the research team, this technology can reduce processing time by up to 240 times compared to conventional hydrothermal carbonization processes, and by more than 20 times compared to torrefaction processes. Additionally, it can reduce energy consumption compared to electrically based plasma devices, achieving both economic efficiency and environmental friendliness.

Senior Researcher Park Taejun stated, "This presents a new technological paradigm that transforms waste from a simple disposal target into a high-value-added energy resource," adding, "We plan to expand the scope of application to various types of high-moisture organic waste such as food waste and sludge, and to advance this into a commercialized technology through demonstration research."

This content was produced with the assistance of AI translation services.