Integration of Gas Sensors as an Exhaust Gas Monitoring Device from Green Roasting Process of Various Coffee Beans

Abstract

The exhaust gas monitoring system in the coffee roasting process continues to be developed considering the need for more complex roasting coffee beans information. The integrated gas sensor is designed by utilizing a microcontroller controller to see the exhaust gas during the roasting process. The exhaust gas produced during the roasting process is monitored by integrating sensors device to measure exhaust gases (CO, CO2, NOx and SO2). Furthermore, measurements were made by monitoring exhaust gas during roasting of Arabica, Liberica and Robusta coffee beans from Jambi province. The results showed that the total CO concentration in Liberica coffee was 2,121 ppm, Robusta 1,930 ppm and Arabica 1,535 ppm while for CO2 was Liberica 21.3 ppm; Robusta is 22.2 ppm; Arabica is 22.4 ppm, and for NOx is Liberica 303 ppm; Robusta 304 ppm; Arabica is 287 ppm, and the SO2 content for all types of coffee is 0 ppm. The highest exhaust gas concentration occurs after roasting lasts > 20 minutes and at a temperature of 210 - 230°C. It concluded that the integrated gas sensor can be used for the measurement of exhaust gas in the process of coffee beans roasting with the results of measurement of CO exhaust concentration in Liberica coffee is higher than Robusta and Arabica coffee beans.