Solid Fuel Characteristics of Pellets Comprising Spent Coffee Grounds and Wood Powder

• Published in: Energies (Basel) Vol. 14; no. 2; p. 371
• Main Authors: Woo, Duk-Gam, Kim, Sang Hyeon, Kim, Tae Han
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.01.2021
• Subjects: Alternative energy sources; bio solid refuse fuel; Biofuels; Biomass; Calorific value; Climate change; Coal; Coffee; Coffee industry; Depletion; Durability; Emissions; Energy economics; Energy resources; Feasibility; Fossil fuels; fuel characteristics; Global warming; Hardwoods; Moisture content; Particle size; Particle size distribution; pellet; Pellets; Quality standards; Renewable resources; Sawdust; Size distribution; solid fuel quality standards; Solid fuels; Solid wastes; spent coffee grounds; Water content; South Korea
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en14020371

To help mitigate the effects of global warming and fossil fuel depletion caused by human use of fossil fuels, solid fuel pellets were developed from a mixture of spent coffee grounds (SCG) and pine sawdust (PS). The feasibility of SCG-PS pellets as biofuel was also verified by evaluating its fuel quality. An increase in the proportion of SCG in the pellet led to an increase in its calorific value, owing to the high C, H, and oil contents, and increases in the ash and S contents, owing to the high S content in SCG. Analysis of the feedstock particle size distribution revealed that SCG particles are smaller than PS particles; thus, the durability of the pellet decreases as the proportion of SCG increases. Accordingly, the samples with higher SCG proportions (70 and 90 wt.%) did not meet the moisture content standards for biomass solid refuse fuel (bio-SRF) set by the Korea Ministry of Environment, whereas the samples with lower SCG proportions did. In particular, CP10 (10 wt.% SCG + 90 wt.% PS) satisfied the quality standards of Grade 1 wood pellets, demonstrating the feasibility of using SCG as a raw material for biofuel pellet production.