Introduction to Landfill Gas Flow

Landfills are the most common form of waste disposal in North America. The waste decomposition generates methane, a flammable greenhouse gas, requiring careful collection and neutralisation. This session will introduce the landfill’s unique flow system: a puzzle of porous media flow, pipe flow, non-negligible gravity, and inconsistent flow controllability. Historically, the evolving engineering practices and mathematical support tools seem to have never met until very recently. Learn what happens deep inside the landfill, how engineers made it work without math, when intuition fails, and how innovative mathematics behind landfill gas flow explains strange system responses in the field.

Dr. Yana Nec, P.Eng.,
Canada Research Chair, Thompson Rivers University

Learning Objectives

Upon the completion of this session participants will be able to:

• Position the landfill as a man-made system with a significant impact on the environment.
• Discuss which aspects of the landfill as an engineering system are under-researched.
• Describe the general principle of operation of a landfill, name the types of extraction wells used, and their respective conceptual peculiarities; compare qualitatively to hydraulic wells.
• Differentiate between porous medium flow and continuum flow.
• Identify the disparate flow domains on a drawn schematic of the landfill.
• Give ranges of permeability for each porous landfill sub-domain.
• Recognize Darcy’s law and turbulent pipe flow equations and all parameters therein.
• Explain why gravity cannot be comprehensively neglected.
• Discuss the relation between medium/boundary permeability and gas flow.
• Explain when the flow within a cross-section might be approximated as planar; explain why this simplification significantly advance sourability to model the landfill system.
• Recognize the radial and spherical flow solutions.
• Examine planar flowvisuals: axisymmetric and non axisymmetric, discuss head loss and radius of influence.

Target Audience

Engineers or Geoscientists working or interested in the area of fluid dynamics or solid waste management industry(from civil, mechanical, aeronautical, or environmental disciplines)

Speaker

Dr. Yana Nec, P.Eng.

Canada Research Chair, Thompson Rivers University

Dr. Yana Nec graduated with a B.Sc. degree in aeronautical engineering (Technion, IIT) and worked as a flight test engineer for 4 years (IDF Flight Test Centre). She acquired a M.Sc. degree and PhD in applied mathematics (Technion, IIT), completed a post-doctoral fellowship at the University of British Columbia and eventually took the position of Canada Research Chair at Thompson Rivers University, BC.

Her research harnesses mathematics for the solution of engineering problems in collaboration with local industry. Two current long-term modelling projects are: landfill gas flow (GNH Consulting Ltd., Delta, BC) and river flow subject to dam operation (Golder Associates Ltd., Castlegar, BC). Yana is particularly interested in unclassifiable problems that escape the conventional analysis tools.