Abstract
The aim of this work is the development of a simulation model for the anaerobic digestion process of source-sorted organic fractions of municipal solid wastes. In particular, a detailed model simulating both biological and thermal behaviors of the process was developed. The biological model is based on the Anaerobic Digestion Model 1 (ADM1), which allows one to evaluate the dynamic trends of the concentrations of the main components and the biogas production as a function of the digester operating temperature. The work also includes a detailed thermal model which is developed considering the geometrical and structural features of the digester. The thermal behavior of the digester was also modeled, considering a purposely designed heat exchanger immersed inside the digester. Therefore, the thermal behavior of the process was evaluated by the well-known heat exchange equations and thermal energy balances. The combination of these two models is used to analyze the different possible operating conditions of the system. The model is also able to consider that the reactor operating temperature and the biogas production dynamically depend on a plurality of parameters: inlet hot water temperature and flowrate of the heating system, outdoor temperature, flowrate of organic fraction. The numerical resolution of the obtained differential equations and thermal balances of the model was carried out in the MATLAB® environment. The result shows that the calculated biogas production is 0.132 Nm3 per kg of OFMSW. In addition, the model also shows that the inlet hot water temperature must be increased by about 1.5 °C, to increase by 1.0 °C the digester temperature.
Highlights
The disposal of wastewater and wastes without treatment in water bodies and on land is no longer allowed for the majority of countries, as it produces harmful effects on the health of humans, animals and environment [1]
Assuming the formation of a limestone fouling varying in thickness from 1 × 10−4 to 5 × 10−3 m with a thermal conductivity λCaCo3=1.6 W/m K and considering an additional thermal resistance Rfouling,est =2 × 10−3 m2 K/W caused by organic deposits on external side of the heat exchanger pipes, both internal and external fouling are taken into account
The model evaluates the dynamic trend ofpipe the rated diameter DN in the calculation of UHE,n, assuming that fouling occurs along the whole concentrations internal surface:of the main components and estimates the production of biogas according to the operating temperature of the digester, depending occurring inside the digester
Summary
The disposal of wastewater and wastes without treatment in water bodies and on land is no longer allowed for the majority of countries, as it produces harmful effects on the health of humans, animals and environment [1]. Since the wastewater treatment plants require large amounts of electrical and thermal energy, such systems are extremely intensive energy consumers [2]. The electrical demand for wastewater treatment represents about 1% of total consumption in almost all countries (Germany, Italy, etc.) [3]. The high energy consumption is mainly due to their heavy mechanical systems necessary to move and manage wastewater, such as pumps and aeration systems [4]. Due to the energy intensive processes involved with wastewater treatments plants, more energy efficient and sustainable treatments
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
