Fast pyrolysis of coffee ground in a tilted‐slide reactor and characteristics of biocrude oil

Abstract

Coffee grounds are considered to be a promising biomass resource due to the growth of coffee consumption and their high calorific value. In this study, we produced biocrude oil from coffee grounds in a tilted‐slide reactor, which has been previously used for the fast pyrolysis of woody biomass. Various pyrolysis temperatures were tested and the maximum biocrude oil yield was 59% at the pyrolysis temperature of 550°C with a feeding rate of coffee grounds at 17.7 kg/h. In a multistage condenser, the biocrude oil yields and properties were different in each condenser stage. The higher heating value of the biocrude oil from the primary condenser was 7,157 kcal/kg, which was about 60% higher than that from woody biomass. A phase separation was observed when the biocrude oil was stored at the atmospheric condition, and the biocrude oil viscosity became quite larger than that from woody biomass, which could even impede its flow. The viscosity decreased with increasing temperature and was more sensitive to temperature variations at lower temperatures. Mixing of ethanol also significantly improved viscosity characteristics. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 655–661, 2017

Characteristics of Flame Stability and Gaseous Emission of Bio-Crude Oil from Coffee Ground in a Pilot-Scale Spray Burner

“…In the downward injection burner system, the heat transfer from the flame to the fuel spray can enhance the ignition characteristics, and the combustion efficiency can be improved due to the longer residence time of the fuel in the combustion chamber. Bio-crude oil was produced from the fast pyrolysis of coffee ground in the tilted-slide reactor [7]. The viscosity of bio-crude oil is known to be much higher than that of the petroleum fuel [1,3].…”

“…The viscosity of bio-crude oil is known to be much higher than that of the petroleum fuel [1,3]. In particular, the bio-crude oil from coffee ground has a significantly high viscosity in comparison with that from woody biomass [7]. The high viscosity of fuel can cause the clogging of the fuel supply line and the fuel nozzle.…”

“…Energies 2020, 13, 2882 3 of 12 Bio-crude oil was produced from the fast pyrolysis of coffee ground in the tilted-slide reactor [7]. The viscosity of bio-crude oil is known to be much higher than that of the petroleum fuel [1,3].…”

“…In previous studies on the bio-crude oil from coffee ground [6,7], it was found that the bio-crude oil from coffee ground has a considerably larger calorific value than that from woody biomass. But the viscosity of the bio-crude oil from coffee ground is quite high and it increases with time which could even impede its flow [7].…”

“…In previous studies on the bio-crude oil from coffee ground [6,7], it was found that the bio-crude oil from coffee ground has a considerably larger calorific value than that from woody biomass. But the viscosity of the bio-crude oil from coffee ground is quite high and it increases with time which could even impede its flow [7]. Combustion characteristics of bio-crude oil have been studied in thermal and power devices including industrial boilers, gas turbines, and diesel engines [8][9][10][11][12][13][14].…”