Analysis of coffee cut-stems (CCS) as raw material for fuel ethanol production

Coffee cut-stems (CCS) represent a promising candidate for fuel ethanol production in tropical countries because of their high availability and high biomass yield per hectare. In this work, pretreatment of this agricultural residue with dilute sulfuric acid and liquid hot water (LHW) was integrated in the simulation and economic assessment of the process for fuel ethanol production. High reducing sugars concentration and ethanol yields were obtained with the LHW pretreatment at a high energy cost. Acid pretreatment is still one of the most applied technologies for lignocellulosic materials due to its efficiency and lower energy consumption. For the determination of the pollution environmental impact index of the process with and without cogeneration system, the Waste Reduction Algorithm (WAR) was used. Thus, the high lignin and low water contents of the coffee cut-stems signified a high potential for energy cogeneration.

► The current research is focused on energy generation as biofuels from lignocellulosic biomass in the coffee areas of Colombia.
► CCS is the lignocellulosic solid residues used in this work and they have a high cellulose and hemicellulose content.
► CCS does not have a defined use besides being piled up, but it is a promising alternative for the ethanol production process.
► The implementation of CCS for bioethanol helps the environment by reducing the polluting emissions from fossil sources.