• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.185-194
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• 2022

Coffee is one of the most consumed beverages in the world and is the second largest traded commodity after petroleum. Due to the great demand of this product, large amounts of waste is generated in the coffee industry, which are toxic and represent serious environmental problems. This study aims to study the possibility of recycling spent coffee grounds (SCG) as a mineral admixture by replacing the cement in the manufacturing of concrete. To recycle the coffee g rounds, the SCG was dried to remove moisture and fired in a kiln at 850 ℃ for 8 hours. Carbonized coffee grounds are produced as coffee grounds ash (CGA) through ball mill grinding. The chemical composition of the prepared coffee grounds ash was investigated using X-ray fluorescence (XFR). According to the chemical composition analysis, the major elements of coffee grounds ash are K₂O(51.74 %), CaO(15.92 %), P₂O₅(14.39 %), MgO(7.74 %) and SO₃(6.89 %), with small amounts of F₂O₃(0.66 %), SiO₂(0.59 %) and Al₂O₃(0.31 %) content. To evaluate quality and mechanical properties, substitutions of 5, 10, and 15 wt.% of coffee grounds ash (CGA) were tested. From the quality test results, the 28-day activity index of CGA5 reached 80 %, and the flow value ratio reached 96 %, which is comparable to the minimum requirement for second-grade FA. From the test results of the mortar, the optimal results have been found in specimens with 5 wt-% coffee grounds ash, showing good mechanical and physical properties.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.15-22
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• 2022

In this study, the hydration reaction and strength characteristic of cement mortar with spent coffee ground(SCG) was investigated. As a result of the study, it was found that as the firing temperature of the SCG increased, the mass loss due to the combustion of organic matter increased, but the density increased. In addition, when the SCG were mixed, SCG interfered with the hydration reaction and the compressive strength was significantly lowered. On the other hand, the coffee grounds ash(SCG_Ash) calcined at 800 ℃ showed a hydration reaction and a compressive strength equivalent to or higher than that of OPC mortar.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.1-14
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• 2024

As awareness of environmental issues continues to grow, there is an escalating demand for recycling and repurposing byproducts of agricultural and food production processes and their conversion to high-value products. Coffee is the most widely consumed beverage globally; during coffee beverage processing and consumption, byproducts such as coffee silverskin (CS), spent coffee grounds (SCGs), and oil are generated. Despite containing beneficial materials such as cellulose, hemicellulose, lignin, lipids, and bioactive substances, these byproducts are typically discarded in landfills or incinerated. The utilization of CS, SCGs, and oil in the development of packaging materials holds significant potentials toward the realization of a sustainable society. To this end, considerable research efforts have been dedicated to the development of high-value materials derived from coffee byproducts, including functional fillers, polymer composites, and biodegradable polymers. Notably, CS and SCGs have been employed as functional fillers in polymer composites. Additionally, lipids extracted from SCGs have been used as plasticizers for polymers and cultured with microorganisms to produce biodegradable polymers. This review focuses on the research and development of polymer/CS and polymer/SCG composites as well as cellulose extraction and utilization from CS and SCGs and its applications, oil extraction from SCGs, and cultivation with microorganisms using extracted oil for polyhydroxyalkanoates(PHA) production.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.15-21
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• 2016

This experiment was conducted to test desorption and recycling characteristics for silver ion adsorbed into waste coffee grounds by using various desorbing agents such as nitric acid, ethylene diamine triacetic acid (EDTA) and nitrilo triacetic acid (NTA). It is appeared that the highest desorption efficiency for silver ions was obtained as about 97.8 % by 1.0 M of nitric acid solution. Also, in the case of less than 1.0 of the ratio of solid and liquid (S/L) (g/L), silver ions adsorbed onto coffee grounds was desorbed as about 98~100 %, and most of desorption process was completed within 60min. In addition, adsorption capacity of reused waste coffee grounds for silver ions was highly maintained as about 43.9 mg/g until the $2^{nd}$ cycle, as compared with the adsorption capacity with 45.9 mg/g of the adsorption capacity for virgin waste coffee grounds.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.855-860
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• 2021

Coffee is a popular beverage not only in Korea but also around the world, and its consumption is on the rise. As coffee consumption increases, coffee waste are also increasing, and recycling is attempted in various fields. However, these recycling methods require complex recycling processes and specialized skills. However, in this study coffee waste, agar powder, and powdered glue were mixed in an appropriate ratio and used as a cement building finishing material. This recycling method has a simple manufacturing method and was shown to improve indoor air quality by delaying radon emitted from cement walls for 2.5 hours with one application and 3.9 hours with two applications. In addition, it was shown that after applying the coffee waste mixture, it was applied twice to close the cracks that occurred during the drying process, thereby prevent the coffee waste from falling off the wall for aesthetic perfection.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.44-49
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• 2014

In order to remove the heavy metals from synthetic wastewater containing Pb, Cr, and Cd, the experiment was conducted with a variety of concentration and pH by using the washed and dried coffee grounds as adsorbent. Almost of the heavy metals were removed in thirty minutes and the removal efficiency was maximized to the 80 percents following the different pH conditions. Furthermore, in the case of Cr, the removal efficiency was declined with the increasing of pH. As a result of this study, coffee grounds is proved to be a very good adsorbent to remove the heavy metals.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.14-22
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• 2017

Coffee consumption has been increased all around world as well as in South Korea. Coffee by-products occurred from the coffee consumption also have been rapidly increased, but the technology and methods to handle the by-product have not been much developed, resulting the severe environmental problems in soil and water. In order to solve this environmental problem, using the coffee by-product, eco-friendly and cheap methods for the recycling have been actively discussed and suggested. In this article, we discussed the types and characters of the coffee by-product and investigated the trend about the methods for utilizing the coffee by-product. In addition, we figured out the current status of coffee waste in Seoul, South Korea and discussed plans that Seoul government is working on to handle the coffee waste.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.22-28
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• 2017

BACKGROUND: There is very limited knowledge of the effects of biochar derived from exhausted coffee residue on metal adsorption processes. Furthermore, only limited information is available on the adsorption mechanism of copper. The aim of this study was to evaluate the absorption behaviors of copper by biochar derived from exhausted coffee residue. METHODS AND RESULTS: Biochars produced by pyrolysis of exhausted coffee residue at $300^{\circ}C$(CB300) and $600^{\circ}C$(CB600) were characterized and investigated as adsorbents for the removal of copper from aqueous solution. The results indicated that the adsorption equilibrium was achieved around 2 h and the pseudo-second-order kinetic model fit the data better than the pseudo-first-order kinetic model. The maximum Cu adsorption capacities of CB600 by Freundlich and Langmuir isotherms were higher than those of CB300. The adsorption data were well described by a Langmuir isotherm compare to Freundlich isotherm. CONCLUSION: Our results suggest that exhausted coffee residue can be used as feedstock materials to produce high quality biochar, which could be used as adsorbents to removal copper.

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

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