Dissertation > Excellent graduate degree dissertation topics show

Study on Mass Transfer Property and Optimization of Stirring form for High Solids Anaerobic Digestion

Author: YangHao
Tutor: DengLiangWei
School: Chinese Academy of Agricultural Sciences
Course: Environmental Engineering
Keywords: Biogas fermentation High solids Stirring Optimization Mass transfer property
CLC: X703
Type: Master's thesis
Year: 2011
Downloads: 151
Quote: 1
Read: Download Dissertation

Abstract


As an important unit operation in high solids biogas fermentation process, mixing could improve contact between the microorganisms and the biodegradable wastes, and maintain a stabilized anaerobic digestion process. However, as far as now, lack of support of enough experiment results hold back application of mixing technology in biogas engineering for some questions about mixing had not been totally answered: effect of mixing, especially mechanical stirring, on anaerobic digestion process of bioreactors with different D:H ratios, materials flow regime when mixing and the relation of flow regime and mass transfer, comparison of different mechanical stirring forms. So, in view of the above problems, the mass transfer property and the optimization mechanical stirring form were research in this paper with the support of the national plan supportted by science and technology （2008BADC4B15）.（1） Mixing had a positive influence on improving anaerobic digestion process and increasing biogas production: the biogas production rate (L·L-1·d-1) and the maximum bio-chemical reaction rate of all bioreactors with different D:H ratios increased after the application of mixing, however, the main biogas production location could not be dislocated with mixing.（2） With the mixing intensity enhanced, the totally mixing time of top agitation, tilting agition, and bottom agitation shortened, when the mixing speed at 70rpm, tilting agitation got the shortest totally mixing time– 215s. The Morrill Dispersion Index of top agitation, tilting agitation, and bottom agitation were 23.38, 10.90, and 30.95, and totally mixed bioreactor could hold a better volume efficiency under top agitation conditions.（3） Tilting agitation could gain the off-bottom suspension of materials at a lower mixing speed （40rpm）, and the critical suspension speed of top agitation was above that of tilting agitation, and bottom agitation was generally incapable of getting the off-bottom suspension of materials completely at the speed among 50rpm130rpm. As for the mixing effects, both top agitation and tilting were better than bottom. Meanwhile, top agitation and tilting agitation were likely to be more effective in terms of scum breaking.（4） Relative to the two TS concentrations of 8.0±0.2% and 2.0±0.2%, anaerobic digestion materials could get a better mixing performance under TS concentration of 4.0±0.2%. In addition, compared to chicken manure, pig manure and cow manure got better mixing performance on the whole.（5） Increase in energy consumption for mixing could promote the mixing performance of materials at different locations of the bioreactor to some extent. Both tilting agitation and bottom agitation had superior material energy consumption per unit volume to top agitation.

Related Dissertations

  1. Development of the Platform for Compressor Optimization Design and Aerodynamic Optimization Design in the Transonic Compressor,TH45
  2. Investigation of Turbine S2 Stream Surface Direct Problem Aerodynamic Optimization Design,V235.11
  3. The Basic Research of Axial Flux Inductor Type High Temperature Superconducting Motor,TM37
  4. Research on Stability of Hierarchical Sattellite Network,TN927.23
  5. Research on Feature Extraction and Classification of Tongue Shape and Tooth-Marked Tongue in TCM Tongue Diagnosis,TP391.41
  6. Studies on Fermentation Optimization, Purification and Enzyme Characteristics of Lipase from Aspergillus Oryzae FS-1,TQ925.6
  7. Computing Minimum Distance between Curves/Surfaces Based on PSO Algorithm,O182
  8. Analysis of Nutritional Compositions and Quality of Shishen (Eremurus Chinensis Fedtsch.),S647
  9. Optimization of Fermentation Conditions, Purification, Cloning and Expression of a Cold-active Lipase from Pseudomonas Sp.RT-1,TQ925
  10. Breeding of Fungal α-amylase High-producing Strain by Genome Shuffling,TQ925
  11. On Governance Optimization in the Vision of the Network Politic,D630
  12. The Research of Land-Use Optimization Approach Based on Non-Point Source Pollution Controlled,X24
  13. Finite Element Analysis and Optimization Design of a Tractor Cab,S219.02
  14. Studies on Optimization Technology of Fermentation with Corn Straw and Cow Dung Mixed Material,S216.4
  15. Screening of Phosphate Solubilizing Bacteria, Optimization of Phosphate Dissolving Conditions and Its Promotion to Maize Growth,S513
  16. Medical Application of a Wireless Communication Platform Based on RFID and GPRS,R319
  17. Research on K-means Optimization Clustering Algorithm,TP311.13
  18. Research on Fuzzy C-Mean Clustering Algorithm Based on Particle Swarm Optimization and Shuffled Frog Leaping Algorithm,TP18
  19. Research of Power System Reactive Power Optimization Based on Immune Ant Colony Algorithm,TP18
  20. Primary Research on Strring Culture and Storing of Human Dermal Fibroblasts,R329
  21. Screening of Pigment-free Pullulan High Producing Microorganism and Research of Optimal Culture Media,TQ920

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > General issues > Wastewater treatment and utilization
© 2012 www.DissertationTopic.Net  Mobile