Relative humidity monitoring system in tray trap of CaCl2water scrubber column system in biogas purification

摘要

Biogas is a gas from decomposition of organic substances such as rotting leaves and cow dung in anaerobic conditions. Forming gas component of biogas is composed of methane (CH₄), carbon dioxide (CO₂), hydrogen sulfide (H₂S), ammonia (NH₃) hydrogen (H2), nitrogen (N2), carbon monoxide (CO) and oxygen (O₂). However, some components of biogas are gas-forming gas impurities such as H₂O, H₂S, CO₂, and particulates must be removed to achieve a better quality gas. Therefore, created a biogas purification tool by spraying cold water with nozzle. Water is sprayed from noozle cause water vapor to go up to the biogas output so as to reduce the levels of H₂O is done by passing the biogas in a column consisting of CaCl₂. The sensor used is a DHT-22 as the temperature and humidity sensors, Arduino Uno R3 as program data, Visual Studio 2013 as a data monitoring interface on the PC, as well as media XAMPP and MySQL data acquisition. Based on test results, it was found that the moisture monitoring system has expanded uncertainty value of ± 2.100 with a confidence level of 90%. Accuracy of humidity measuring instrument is 96.85%. From the monitoring records, the use of silica gel to work in the biogas purification process. Humidity can affect the content of the biogas released mainly a decrease in H2S content because the lower temperatures used to reduce the H2S content, the higher the moisture contained in the scrubber, thus requiring silica gel to reduce the moisture.