Treated Biosolids in a Hot Hydrogen Environment By Richard Pinder A Thesis Presented to The University of Guelph In partial fulfillment of requirements for the degree of Master of Applied Science in Engineering Guelph, Ontario, Canada © Richard Pinder, September, 2012 ABSTRACT TREATED BIOSOLIDS IN A HOT HYDROGEN ENVIRONMENT Richard Pinder Advisor: University of Guelph, 2012 Professor Richard Zytner A laboratory scale Gas Phased Reduction (GPR) Process unit was designed, fabricated, built and tested to prove that the GPR process was capable of treating biosolids and producing energy. Two different types of biosolids were treated; digested sludge (Cake) and waste activated sludge (WAS). In addition to the biosolids test program, a sample of organic solid food waste was tested; a brand name hamburger. The GPR process converts all of the organic matter in the biosolids and organic solid food waste into hydrogen-enriched methane gas, converting the residue into biologically inert material that has soil-like properties allowing for easy disposal. The process destroys pathogens, does not produce odors, enables recovery of valuable inorganic materials and reduces the requirements for land filling. More importantly, the ability to apply the process to both dried sludge cake or digested sludge taken directly from the digesters, even waste activated sludge, provides many opportunities to make wastewater treatment plants more efficient. In addition, the GPR process does not create tar, an undesirable by-product of some other treatment technologies. Overall, the GPR process can achieve a mass solids reduction of approximately 53% and in the process generate 0.4 L CH4/g of sludgedwb. This methane is a high energy fuel that can be used to make wastewater treatment plants energy self-sufficient by producing electricity on-site. Acknowledgements I would like to give thanks to my advisor Dr. Richard Zytner, and advisory committee member Ed McBean. Both have provided exceptional guidance and support throughout my experience as a Master’s student. I would like to thank Natural Energy Systems Inc. for providing the necessary equipment for the experiments. I would like to extend my extreme gratitude to Craig McEwen of Natural Energy Systems Inc. Mr. McEwen provided essential technical support and feedback for the design and fabrication of the equipment. Mr. McEwen also spent endless hours in the laboratory during the experiments. Special thanks to the Region of Waterloo for the in-kind support of the testing facility. In particular I would like thank Nancy Kodousek and Jorge Cavalcante for their support and understanding during the research. I would also like to thank the staff at the Kitchener Wastewater Treatment Plant as well as the staff of the Ontario Clean Water Agency. Particularly, the on-site support from Khalid Mehmood, Trevor Brown, Nathan Morris and Brian Runstedler. Thank you to the Ontario Centre of Excellence for the financial support and Balinder Rai for her understanding and patience throughout the research. My greatest thanks is extended to my family. To my young boys Declan and Paxton you are my world, and my ever supporting wife, Julie, whose support has meant more to me than I can express. The research was supported with an Ontario Centre of Excellence grant. Financial supporting partners were Natural Energy Systems Inc. and the University of Guelph. iii Table of Contents Acknowledgements ...............................................................................................................................iii 1 Introduction .................................................................................................................................... 1 1.1 Project Objectives .................................................................................................................. 2 2 Background ...................................................................................................................................... 4 2.1 History of Biosolids .............................................................................................................. 4 2.2 Typical Characteristics of Biosolids ............................................................................... 6 3 The Gas Phased Reduction Process ........................................................................................ 9 3.1 The GPR Process Overview ................................................................................................ 9 3.2 Process Flow......................................................................................................................... 10 3.2.1 Front End System ...................................................................................................... 11 3.2.2 Reactor ........................................................................................................................... 11 3.2.3 Gas Scrubbing, Compression and Storage ........................................................ 12 3.2.4 GPR Process Input and Output Parameters ..................................................... 13 4 Literature Review – Treatment of Biosolids with Pyrolysis Process and Influences ................................................................................................................................................ 15 4.1 Typical Pyrolysis Process ................................................................................................ 15 4.2 Biosolids Products through Pyrolysis ........................................................................ 15 4.3 Treatment Processes and Moisture Content Influence ....................................... 16 4.4 Temperature Influence .................................................................................................... 20 4.5 Heating Rate Influence ..................................................................................................... 22 5 Methodology ................................................................................................................................. 24 5.1 Objective 1 – Design, Fabricate and Build a Laboratory Scale GPR Process Unit 24 5.1.1 Heating Ovens ............................................................................................................. 25 5.1.2 Solids Batch Vaporizer ............................................................................................. 25 5.1.3 Reactor ........................................................................................................................... 26 5.1.4 Scrubbing System and Product Gas Burner..................................................... 26 5.1.5 Data and Product Gas Collection and Analysis ............................................... 27 5.1.6 System Carrier, Purge and Calibration Gases ................................................. 27 5.1.7 Water Input .................................................................................................................. 28 5.1.8 Other Equipment ....................................................................................................... 28 5.1.9 Safety Parameters...................................................................................................... 29 5.1.10 Kitchener Waste Water Treatment Plant ......................................................... 29 iv 5.2 Objective 2 – Biosolids Testing Using the GPR Process Unit ............................. 29 5.2.1 General Overview of Experimental Procedure .............................................. 29 5.2.2 Commissioning and Project Program ................................................................ 31 6 Results and Discussion ............................................................................................................. 33 6.1 Design, Fabricate and Build the Laboratory Scale GPR Process ...................... 33 6.1.1 Design and Fabrication ............................................................................................ 33 6.1.2 Final Laboratory Scale Unit ................................................................................... 46 6.2 Commissioning of the Laboratory Scale GPR Process .......................................... 48 6.3 Destruction of Biosolids using Laboratory GPR Process .................................... 50 6.3.1 Experiment Summary .............................................................................................. 50 6.3.1 Experiment Improvements and Parameter Alterations ............................. 52 6.3.1 Temperature Profile ................................................................................................. 53 6.3.2 Solids Reduction ......................................................................................................... 55 6.3.1 Biosolids Laboratory Analysis .............................................................................. 59 6.3.2 Off-gas Composition ................................................................................................. 61 6.3.3 Energy Production .................................................................................................... 65 7 Engineering Application .......................................................................................................... 68 8 Conclusions ................................................................................................................................... 69 9 Recommendations ....................................................................................................................