For this energy-saving project, Ross Group Engineering worked with a private client to benefit from a previously untapped energy source within their existing biodiesel plant. In the plant, industrial wastewater was being treated onsite for safe discharge into a municipal sewer; however, the biogas byproduct resulting from this process was being burned by a flare. Working closely with the client, Ross Group Engineering devised a solution to repurpose this biogas stream as an alternative fuel source for a natural gas-fired boiler within the plant.

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Before design began, Ross Group Engineering completed a 3D laser scan of the site to ensure we had the most accurate data and as-built information for the existing equipment. Our team’s design connected a new 4” pipeline to the wastewater treatment scrubber tanks to deliver the biogas stream to the boiler. Major equipment for the new biogas fuel system included a new blower/compressor with a variable frequency drive (VFD), a cooler/heat exchanger, a knockout drum with mist pad, and a fuel conditioning/blending train for the boiler feed. Our engineers had to consider a number of additional variables during the design, including the placement of liquid traps with drains at transitions and low points, electric heat trace and insulation, and the possibility of corrosion within the system. The system is also vapor-tight to prevent hydrogen sulfide from leaking or escaping. With our team’s proactive approach to data collection and detail-oriented design, the project was successfully completed and provides ongoing energy and cost savings for the client.