Development of an online monitoring and control system for decentralized anaerobic digesters | |
| Author | Silva, Kadupitige Naleen Dhananjaya |
| Call Number | AIT Thesis no.ET-18-10 |
| Subject(s) | Monitoring Control systems Anaerobic digestion (Sewage purification) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Energy |
| Publisher | Asian Institute of Technology |
| Abstract | Decentralized anaerobic digesters have several advantages compared to centralized anaerobic digesters, i.e. in decentralized digesters, each community can select a suitable type of waste, transportation related costs are avoided, and also it enables easy designing and controlling. However, digester processes would be inhibited if the process parameters deviate away from the acceptable ranges. Thus, it is essential to monitor these process parameters to observe process disturbances. It might not be efficient to have monitoring stations at each plant since the number of decentralized digesters is higher and it won’t be financially beneficial too. Also, conventional online monitoring systems usually cost more and using these systems in small scale anaerobic digesters will not make the overall system financially feasible. Therefore, the requirement of developing a low cost centralized monitoring system to measure crucial process parameters and performance indicators in each established decentralized digester, was identified since the idea is to establish many decentralized digesters in multiple communities. As a solution, this study proposes a centralized online monitoring system using microelectronic components, micro controllers, especially designed sensors to integrate with micro controllers, an open source webserver and a mobile application. The major advantages of the developed system are its low cost (total cost of 24,000 baht), accuracy, less energy consumption (70Wh per day), fast response, and ability for buzzing, emailing and messaging if the parameters are out of appropriate ranges. Another major advantage is that the developed system can simply be upgraded to a self-sufficient system by powering the system using a solar power. Moreover, it is advantageous if it’s possible to control the decentralized digesters in the centralized monitoring station. Therefore, this study also developed an automatic feeding system that works through the cloud network with an online dashboard created to indicate equipment operation and working volume of the digester, that helps the centralized station to know whether the feeding operation works fine. Afterwards, automatic technologies are used to manipulate process parameters in the digester to generate stable and higher biogas yield. Digester temperature is regulated by using a thermos bath controller unit whereas digester pH is controlled through the feeding system by warning or restricting to feed if the pH is not within acceptable limits. Ultimately, this study also developed a biogas leakage warning system by measuring atmospheric methane concentration. Overall, there is a significant financial benefit to the plant since microcontroller units are used in process controlling. |
| Year | 2018 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Salam, Abdul P.; |
| Examination Committee(s) | Kumar, Sivanappan;Visvanathan, C.; |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2018 |