Dr. Patrick Hettiaratchi, Professor, Department of Civil Engineering, Schulich School of Engineering, University of Calgary

SHELL/ASTech OUTSTANDING ACHIEVEMENT IN ENVIRONMENTAL TECHNOLOGY AND INNOVATION
Managing Garbage to Solve Big Problems

Dr. Patrick Hettiaratchi has a mission to change the way people think about garbage. He’s designed a revolutionary landfill ‘biocell’, which will contribute to solving some of the major problems the world is facing.
“The biocell can help control climate change by reducing methane emissions,” he explains. “It can reduce dependence on non-renewable energy by creating energy from the garbage, which will also affect oil and gas prices; and it addresses land use because most of the garbage will be converted to a usable product and we can reuse the landfill cell and reduce traditional landfill use.”

The biocell is a large pit lined with clay and plastic. It is loaded with tonnes of ordinary garbage. When it is filled, the biocell is sealed with a plastic cap. To enhance natural breakdown of waste either water is added, or “leachate” collected at the bottom of the landfill is re-circulated. The gas is captured and used to make electricity.

When the methane production dwindles, oxygen is pumped back into the biocell and it becomes a giant composter, a process that may take about a year. The biocell is opened, compost is removed, recyclable material is harvested and the rest, about 30 per cent of the original volume, is moved to a traditional landfill. Then a new biocell is set up on the same location.

Before Dr. Hettiaratchi’s biocell can accomplish the ambitious agenda, municipalities have to buy into the concept – starting with Calgary.