• Clean Technology
• /
• v.25 no.2
• /
• pp.168-176
• /
• 2019

Spent coffee is one of biomass sources to be converted into bio-oil. However, the bio-oil should be further upgraded to achieve a higher quality bio-oil because of its high oxygen content. Deoxygenation under hydrotreating using different catalysts (catalytic hydrodeoxygenation; HDO) is considered as one of the promising methods for upgrading bio-oil from pyrolysis by removal of O-containing groups. In this study, the HDO of spent coffee bio-oil, which was collected from fast pyrolysis of spent coffee ($460^{\circ}C$, $2.0{\times}U_{mf}$), was carried out in an autoclave. The product yields were 72.16 ~ 96.76 wt% of bio-oil, 0 ~ 18.59 wt% of char, and 3.24 ~ 9.25 wt% of gas obtained in 30 min at temperatures between $250^{\circ}C$ and $350^{\circ}C$ and pressure in the range of 3 to 9 bar. The highest yield of bio-oil of 97.13% was achieved at $250^{\circ}C$ and 3 bar, with high selectivity of D-Allose. The carbon number distribution of the bio-oil was analyzed based on the concept of simulated distillation. The $C_{12}{\sim}C_{14}$ fraction increased from 22.98 wt% to 27.30 wt%, whereas the $C_{19}{\sim}C_{26}$ fraction decreased from 24.74 wt% to 17.18 wt% with increasing reaction time. Bio-oil yields were slightly decreased when the HZSM-5 catalyst and dolomite were used. The selectivity of CO was increased at the HZSM-5 catalyst and decreased at the dolomite.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.3
• /
• pp.362-368
• /
• 2012

This study examined the fatty acid compositions of the fats extracted from 14 commercial coffee creamers and 11 instant coffee mixes, and evaluated the sensory characteristics of the coffees using different coffee creamers. The fat content in the 14 coffee creamers and 11 coffee mixes was 15~28% and 8~14%, respectively. The fats in 12 coffee creamers consisted of 34~45% lauric, 15~19% myristic and 10~18% palmitic acids. The fats in the other 2 coffee creamers consisted of 43% palmitic, 39% oleic and 10% linoleic acids. The fatty acids of the fats in the 11 coffee mixes were almost all saturated with lauric acid being the most abundant (44~45%). Coconut oil or palm kernel oil might have been used to manufacture the 12 coffee creamers and 11 coffee mixes, which had a higher lauric acid content. Palm oil (PO) might be a fat source for the other 2 coffee creamers. The sensory characteristics of five coffee mixes were evaluated based on their fatty acid compositions. The coffees with the creamers, which had a higher lauric acid content, were significantly more acceptable than those with a higher palmitic acid (p<0.05). The sensory evaluation of the coffees made with the creamers composed of hydrogenated coconut oil (HCO) and PO at different ratios showed that the acceptability increased with increasing HCO content. This suggests that PO may have a negative impact on the sensory characteristics.

• Environmental Engineering Research
• /
• v.25 no.4
• /
• pp.470-478
• /
• 2020

Spent coffee grounds (SCG), the residue after brewing coffee beverage, is a promising biodiesel feedstock due to its high oil contents (15-20%). However, SCG should be pretreated to reduce the high free fatty acid content, which hampers transesterification reaction. To overcome this, we explored a direct transesterification reaction of SCG using ultrasound irradiation and identified the optimal sonication parameters. A high fatty acid methyl ester (FAME) content, up to 97.2%, could be achieved with ultrasound amplitude of 99.2 ㎛, irradiation time of 10 min, and methanol to oil ratio of 7:1 in the presence of potassium hydroxide concentration of 1.25 wt.%. In addition, we demonstrated that ultrasound irradiation is an efficient method to produce biodiesel from untreated SCG in a short time with less energy than the conventional mechanical stirring method. The physical and chemical properties of the SCG biodiesel met the requirements for an alternative fuel to the current commercial biodiesel.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.9
• /
• pp.1400-1406
• /
• 2014

This study investigated the quality characteristics of sea salt coated with coffee oil (SCO). Three-year-old salt was used after drying in an oven at $105^{\circ}C$ for 2 hours. Product A was composed of 100 g of sea salt and 8 g of coffee oil, product B was 100 g of sea salt and 16 g of coffee oil, and product C was 100 g of sea salt, 8 g of coffee oil, and 0.3 g of shell powder. The moisture content, ash content, color, peroxide value, acid value, and sensory evaluation of sea salt coated with coffee oil were determined monthly during 5 months of storage at room temperature. The contents of moisture and ash of SCO were 2~3% and 81~83%, respectively, but not significantly different during the storage period. Calcium content of product C was higher than that of product A or B. Coffee flavor in all SCO products was retained for 3 months. Hunter L, a, and b color values in SCO decreased with increasing storage period. However, redness and yellowness of product B were higher than those of other products. The peroxide and acid values of products A and C were lower than those of product B during storage period. Sensory evaluation during the storage period showed that quality of product A and C was maintained for 4 months, whereas product B was preserved for 3 months.

• Applied Chemistry for Engineering
• /
• v.22 no.1
• /
• pp.72-76
• /
• 2011

In this study, we investigated the characteristics of biodiesel using the waste coffee oil which was extracted by waste coffee grounds. We tried to deduce the optimum conditions by defining the operating variables, such as mole ratio between methanol and coffee oil (6~18) and the reaction temperature ($45{\sim}60^{\circ}C$) in the biodiesel production processes. The performance was evaluated in terms of yields, contents of fatty acid methyl ester (FAME), viscosities, and heating values. The optimum reaction temperature was $55^{\circ}C$. Also, the best biodiesel was produced at the mole ratio between methanol and coffee oil of 12. The highest heating value of the produced biodiesel made from coffee oil was 39.0~39.4 MJ/kg, which satisfies the general standard for the biodiesel energy density, 39.3~39.8 MJ/kg.

• Applied Chemistry for Engineering
• /
• v.34 no.4
• /
• pp.426-433
• /
• 2023

Capacitor performance was considered using coffee grounds-based activated carbon produced through oil extraction and KOH activation to increase the utilization of boiwaste. Oil extraction from coffee grounds was performed by solvent extraction using n-Hexane and isopropyl alcohol solvents. The AC_CG-Hexane/IPA produced by KOH activation after oil extraction increased the specific surface area by up to 16% and the average pore size by up to 2.54 nm compared to AC_CG produced only by KOH activation without oil extraction. In addition, the pyrrolic/pyridinic N functional group of the prepared activated carbon increased with the extraction of oil from coffee grounds. In the cyclic voltage-current method measurement experiment, the specific capacitance of AC_CG-Hexane/IPA at a voltage scanning speed of 10 mV/s is 133 F/g, which is 33% improved compared to the amorphous capacity of AC_CG (100 F/g). The results show improved electrochemical properties by improving the size and specific surface area of the mesopores of activated carbon by removing components from coffee grounds oil and synergistic effects by increasing electrical conductivity with pyrrolic/pyridinic N functional groups. In this study, the recycling method and application of coffee grounds, a bio-waste, is presented, and it is considered to be one of the efficient methods that can be utilized as an electrode material for high-performance supercapacitors.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.443-450
• /
• 2019

We studied to find the optimal manufacturing conditions of coffee grounds sludge RDF with oil drying method. We expanded the lab scale to pilot scale to compare the efficiency of the oil-drying equipment and The selection of the ratio of coffee grounds and oil, the setting temperature, and the temperature change and water content with time were measured. In order to analyze the characteristics of the research results, characteristics of solid fuels produced(Coffee grounds of oil-dried) by calorimeter, TGA, combustion equipment, and combustion gas measuring instrument were analyzed. As a result, the ratio of oil to coffee grounds was 4: 1, and when the setting temperature was set to $300^{\circ}C$, the water content reached 10wt.% or less within 20 minutes. ln addition, it showed high calorific value of 6,273kcal/kg. However, coffee grounds had a similar composition to wood and showed high luminance and produced a lot of CO in combustion gas. As a result, it is considered to be unsuitable for thermoelectric power plant and camping fuel, but the initial ignition speed is high and the heat generation is high, so it is considered that it can replace the fuels for current use.

• Journal of the Korean Home Economics Association
• /
• v.24 no.3
• /
• pp.119-127
• /
• 1986

To investigate differences in fatty acid composition in green coffee beans and roasted coffee beans, the extracts of two beans were subjected to analysis of fatty acid composition by GC and HPLC. The results showed that palmitic and liolneic acid were the main fatty acids of coffee oil and their contents were about 40%. Minor components, such as capric acid, lauric acid and myristic acid were detected in both samples by GC, but nut HPLC.

• Journal of Nutrition and Health
• /
• v.11 no.1
• /
• pp.9-16
• /
• 1978

A Comparison of the analysis of the green and roast coffee of Arabica and Robusta compositions and regular instant coffee has been investigated by chromatography. The coffee oil were obtained by extracting the green and roast coffee with ethyl ether by soxhlet methood. Instant coffee samples were accurately weighted into 100ml beaker (ca. 0.5g regular coffee and 1.5g decaffeinated coffee) and add ca. 50ml water, heat and boil, remove from heat, and mechanically stried ca. 15min. and filtered of one sample and another sample were without filtrated and proceed with liquid chromatographic separation. The fatty acid compositions of green and roast coffee were compared by gas liquid chromatography and general chemical compositions of sample were analysed. Some similarities between green and roast coffee fatty acids were found in the case of green and roast coffee of both kinds acid methyl esters. They contained stearic, oleic, linoleic, and unknown fatty acid, and palmitic ana linoleic acid were rich.

• Journal of Nutrition and Health
• /
• v.19 no.4
• /
• pp.224-232
• /
• 1986

This study was performed to investigate the effects of different kinds of dietary protein [plant protein ; Isolated Soy Protein(ISP), animal protein ; casein] on protein and lipid metabolism in rats fed with coffee and/or methionine in diet during four weeks of growing period after weanling. Forty male growing rats fo Sprague-Dawley strain, weighing 92.5$\pm$1.8g, were distributed into 8 groups by randomized complete block design, and fed diets containing 15% of protein by weight either as ISP or casein and 10% ofcalories as corn oil, supplemented with coffee and /or methionine for 4 weeks. Coffee were added at a concentration of 1.4% of diet as instant coffee, and methionine were added to ISP or casein diet to be 0.6% of diet as DL-methionine. Results were followed ; Body weight gain, F.E. R and P.E.R tanded to be higher in methionine added groups than non-methionine groups. The nitrogen content of feces was significantly higher in coffee groups than non-coffee groups, and tended to be higher in ISP groups than casein groups. but was not significantly different with or without methionine. thus, apparent protein digestilbity was significantly lower in coffee groups than non-coffee groups and was significantly lower in ISP groups than cesein groups, but was not significantly different with or without methionine. Total cholesterol content of serum tended to be higher in coffee groups than non-coffee groups, and tended to be lower in methionine groups than non-methionine groups.