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

Duk-Gam Woo,Sang Hyeon Kim,Tae Han Kim

doi:10.3390/en14020371

Duk-Gam Woo, Sang Hyeon Kim + Show 1 more

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https://doi.org/10.3390/en14020371

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Journal: Energies	Publication Date: Jan 11, 2021
Citations: 10	License type: CC BY 4.0

Affiliation: Hokkaido University, Kyungpook National University

Abstract

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.

Highlights

The careless use of fossil fuels is responsible for issues such as global warming and energy resource depletion
In the spent coffee grounds (SCG)-pine sawdust (PS) mixture, the higher the proportion of particles smaller than 500 μm, which increased from 13.8% (CP10) to 76.8% (CP90)
This study verified the feasibility of using SCG-mixed pellets as an alternative fuel source to replace wood pellets

Summary

Introduction

The careless use of fossil fuels is responsible for issues such as global warming and energy resource depletion. Coal is a major global primary energy source, accounting for 27.8% of all primary energy sources, as of 2017. According to the Korea Institute for Energy Economics, coal is the most used energy source after petroleum, accounting for 28.5% of all energy sources in Korea, and its use increases annually [4]. To address these problems, there is growing interest in new and renewable energy sources that can replace fossil fuels. Biomass and agro-industrial waste, which are renewable energy resources with environmental and economic benefits, are emerging as practical alternative energy resources [5]

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