Fat, oil and grease reduction in commercial kitchen ductwork: A novel biological approach. (March 2017)

• Record Type: Journal Article
• Authors: Mudie, S.; Vahdati, M.
• Is Part Of: Waste management. Volume 61(2017)
• Page Start: 28
• Page End: 39
• Publication Date: 2017-03
• Subjects: Grease -- Commercial kitchen -- Ventilation -- Ductwork -- Bacillus subtilis -- Sustainability; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2017.01.041
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: The greatest barrier to heat recovery in commercial kitchen ductwork is grease. A new system reducing grease in commercial kitchen ductwork is proposed & evaluated. A biological reagent containing B. subtilis is injected into the duct as a mist. Grease deposit thickness was reduced by 47% within 7 weeks of the trial. Average operating temperature of the duct air was reduced by 7 °C (post treatment). Abstract: Recent research has characterised emissions upon cooking a variety of foods in a commercial catering environment in terms of volume, particle size and composition. However, there has been limited focus on the deposition of solid grease in commercial kitchen ductwork, the sustainability of these systems and their implications on the heat recovery potential of kitchen ventilation extract air. This paper reviews the literature concerning grease, commonly referred to as Fat, Oils and Grease (FOG) abatement strategies and finds that many of these systems fall short of claimed performances. Furthermore these technologies often add to the energy cost of the operation and reduce the potential application of heat recovery in the ventilation ductwork. The aim of this study was to develop and evaluate a novel FOG removal system, with a focus on low environmental impact. The novel FOG removal system, utilises the biological activity of Bacillus subtilis and associated enzymes. The biological reagent is delivered via a misting system. The temperature, relative humidity and FOG deposit thickness were measured in the ductwork throughout a 3 month trial period. FOG deposit thickness was reduced by 47% within 7 weeks. The system was found to be effective at reducing the FOG deposit thickness with minimal energy cost and impact upon the kitchen and external environment. Internal ductwork operating temperature was measured with respect to future heat recovery potential and a reduction of 7 °C was observed.