CFD Simulation of Methane Optimization at different Slurry Temperature and for different Number of Baffle Plates in Fixed Dome Shaped Digester for Optimum Methane Production

This Paper is numerical study of methane optimization in fixed dome shaped digester. The parameters of study are slurry temperature, and number of baffle plates. Simulated results are validated with the available data provided by the Urja Biotech System Pvt. Ltd.. Results are generated in the form of variation in methane gas generation. Fluent 6.2.16, a finite volume flow solver is used for solving the set of governing equations for the present geometry, in order to compute % of methane collection at the outlet of digester and to visualize the velocity contours in the digester Large enough cell count and domain size is used to obtain numerical results. Appropriate boundary conditions are imposed under natural mode. Fluid flow characteristics are presented in the form of velocity vectors and velocity contours .Anaerobic processes are used to treat the cow dung for the production of biogas. This paper developed a three-dimensional CFD model to predict the effects of geometry and operating conditions on methane output in fixed dome shaped digester. The work was carried out by changing the number of baffle plates and with different slurry temperatures. The model is based on the principles of conservation of mass, conservation of energy, and species transport with volumetric reaction approach. Here only one chemical reaction is considered out of the 21 different chemical reactions which are used in biogas generation process. k-€ model is used to predict the forward reaction rate in the digestion process. The inclusion of baffles in the digester with diameter 15 m increased the methane output for constant slurry temperature. Validation is done with the experimental results provided by Urja Biotech System Pvt. Ltd, Pune. Results are obtained in the form of methane production in the digester.