AB Energy Canada and GHD Partner to Upgrade Biogas to RNG

Written by AB Energy Canada.

AB Energy Canada, Ltd. (AB) the Canadian branch of Gruppo AB, and GHD are in the final stages of a significant project to upgrade biogas to renewable natural gas (RNG) at the Disco Road Organics Processing Facility (DROPF) in Toronto, Ontario. This collaboration will convert biogas produced from the anaerobic digestion of food waste and various organic materials into pipeline-quality RNG, demonstrating the viability of renewable energy technologies in waste management and energy production.

AB has chosen membrane technology for RNG conversion to ensure the highest possible recovery rate, efficiency, and adherence to stringent environmental standards.

The core components of the upgrading plant include an NH3 removal tower, a pre-treatment skid, VOC scrubbing vessels, H₂S and VOC filtration/polishing filters, a membrane container, and an RNG booster compression system. The BIOCH4NGE® M 12.5 Three-Stage membrane module, central to the system, processes biogas with standard inlet characteristics and converts it into high-purity RNG that meets Enridge’s strict pipeline quality specifications.

Safety and risk mitigation are key aspects of the project’s framework, supported by a detailed Hazard and Operability (HAZOP) study conducted by AB and GHD in collaboration with Enbridge.
This study resulted in numerous safety and operational recommendations, all meticulously implemented to enhance the facility’s security and functionality. Key safety measures include elevating the biogas feed line to prevent flooding, establishing a comprehensive operator rounds checklist for regular visual inspections of all process equipment, heat tracing, and insulation, and instituting a rigorous lockout-tagout (LOTO) procedure for operating drain and manual valves.

Real-time monitoring has been improved with a level transmitter (LIT) on the ammonium sulfate tote, integrated with the SCADA supervision system for continuous monitoring and alarm triggers. A low-level switch (LSL) has been added to the NH3 scrubber, providing an additional safety layer by automatically shutting off the recirculation pump in low-level scenarios.

Low-pressure alarms and gas flow rate discrepancy detection were also implemented, offering early warnings of leaks or malfunctions. To ensure water supply purity, a backflow prevention device has been installed on the potable water line to the NH3 scrubber. Personal gas monitors and strobe lights have been provided to enhance safety in areas with biogas containing H2S. All manual valves are tagged with physical labels indicating the correct configuration, contributing to the safety and efficiency of plant operations.

The partnership between Gruppo AB and GHD at the DROPF represents a significant step forward for sustainable energy production in Canada. Such initiatives are crucial in shaping a diverse and resilient sustainable energy landscape. By addressing potential risks with improved monitoring, enhanced safety protocols, and robust operational practices, the DROPF creates a safer working environment and ensures the continuity of its critical operations. These proactive measures and the diligent approach of all project partners underscore a deep commitment to high safety standards and operational excellence, setting a benchmark for safety and integrity in the biogas and RNG industry in Canada.

To learn more, read our Safety Magazine.