Design of a Hybrid Grease Trap for Reduced Energy Consumption and Improved Fog Retention in Hot Wastewater

Abstract

The present research focuses on heat recovery from hot kitchen wastewater to fulfil the dual objective of reducing energy consumption and CO2 emissions, while simultaneously improving the fat, oil and grease (FOG) removal efficiency of the grease trap (GT). A GT was retrofitted with a novel heat exchanger design (termed as a hybrid GT device) to enhance wastewater thermal recovery and FOG removal capabilities. Hot wastewater containing FOG was assessed in a full-scale experimental GT. The governing parameters of temperature, mass flow rate and FOG content were monitored. Results indicate that the hybrid GT improves FOG removal performance by lowering the temperature of GT hot wastewater by approximately 25%. The hybrid GT enables improvement in energy efficiency and cost savings for commercial kitchens/wastewater generators, lowering the carbon footprint and cost of food preparation.