초록 열기/닫기 버튼
Coffee drinks are one of the most popular beverages around the world, and coffee beans are grown in about 80 countries. In addition, the consumption of coffee beans in Korea is about 150,000 tons as of 2018, the world's sixth largest, and theannual consumption of coffee per capita by people over 20 years old is about 353 cups, up 21 percent from 291 cups in2015, which is about three times the consumption per capita of 132 cups by the world's population. However, despite thecontinued increase in coffee bean consumption, 99.8% of the coffee beans used remain as dregs, with the cost of handlingthem reaching 764.2 billion won a year, and environmental problems caused by CO2 from the process cannot be ignored. Common coffee wastes have the advantage of high moisture content and high absorbency due to porous surface. Here,hydrothermal carbonization (HTC) is one of the thermal treatment methods and is a method of carbonation usingtemperatures of 180 ~ 300oC and high pressure in a closed environment with limited oxygen. Unlike other pyrolysismethods, thermo-degradation methods have the advantage of cost-benefit that does not require pre-treatment of drynessbecause they conduct at a relatively low temperature and use water vapor pressure caused by evaporating moisture in theraw material itself. Therefore, it is suitable to recycle coffee wastes effectively using thermal water pressure carbonationreaction. We also want to evaluate the performance of adsorption by generating Activated Biochar through chemicalactivation as a method of utilizing Biochar produced after HTC reaction. Therefore, in this study, the optimum generationconditions of Biochar are derived by applying HTC method, which is suitable for utilizing the high moisture content andporous properties for recycling coffee wastes, and after deriving the optimal generation conditions for chemical activationof the Biochar produced, PAC(Powdered Activated Carbon) is compared with the characteristics analysis of coffee wastesand Biochar and Activated Biochar to check and evaluate the absorption performance of heavy metals.
