Coffee parchment as potential biofuel for cement industries of Ethiopia

This study explores the biofuel potential of raw coffee parchment and its pellets to supplement the energy demand of the cement industries of Ethiopia by characterizing their combustion characteristics and ash qualities for clinker production. The raw and pelletized coffee parchments were characterized for ultimate and proximate composition, calorific value, heavy metals, and ash oxides. The ultimate analysis confirmed higher carbon (45.5%) and hydrogen (6.5%) content and lower nitrogen (0.4%) and sulfur (0.1%) content in the pellets as compared to the commonly used biomass fuels. The moisture content (11.2%) and ash content (5.97%) of the pellets meet the ISO standard for non-wood pellets (ISO 17225-6, 2014). Pelletization of the coffee parchment enhanced the gross heating value of the biomass. The ash analysis revealed that the ash may supplement a sufficient amount of oxides of calcium, silica, aluminum, and iron required for clinker production. Overall, the results signify that coffee parchment and its pellets have suitable properties to be used as cheap, sustainable and eco-friendly bio-fuel for the cement industries of Ethiopia.