Modélisation et valorisation des rejets (thermique et CO2) d’une production de champignons

Abstract

Controlled environment agriculture, whether in greenhouses or Plant Factories with Artificial Lighting (PFAL), requires substantial inputs of energy and CO₂. In cold climates such as Quebec’s, these needs increase dependence on external resources. This study proposes a circular approach based on a CO₂–thermal exchange synergy between a mushroom farm (MF) and a PFAL for leafy greens. MF release CO₂ through mushroom respiration and require heating, while leafy greens consume CO₂ during photosynthesis and generate excess heat. The interconnection of these two production systems aims to reduce energy consumption and dependence on supplemental CO₂ sources simultaneously. The first part of the research characterizes the CO₂ and heat exchanges of mushrooms to fill gaps in the literature. Two experimental studies were conducted. The first one measured respiration rates and thermal fluxes of shiitake substrate during incubation of a small-scale production in a climatic chamber. The second modelled the respiration rate of a mixed oyster shiitake substrate as a function of indoor temperature during incubation of a full-scale production. Comparing the results of these two studies with existing literature showed that oyster mushrooms emit about twice as much CO₂ as shiitake during incubation and up to five times more during fruiting, while generating significant thermal heat. These experiments enabled the development of a predictive model linking CO₂ emissions to temperature, species, and growth stage. The second part integrates these results into numerical simulation modules of a container-based production complex combining mushrooms and leafy greens, comparing three farming scenarios, a shiitake (scenario S), an oyster (scenario O) and a mixed shiitake-oyster production (scenario M) where air loops between the containers are interconnected to enable CO2 and thermal exchanges. In the CC configuration, the Oyster and Mixed scenarios eliminated the need for external CO2 injection, reduced the heating, ventilation and air conditioning (HVAC) energy use by up to 32% and the peak demand by up to 47%. The analysis highlights a paradigm shift: when mushrooms produce more CO₂ than what crops consume, the PFAL can be cooled with outside air (a process called free cooling), lowering the HVAC energy demand while maintaining the CO₂ setpoint.

Date	12 Jan 2026
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Danielle Monfet (Supervisor) & Diane Bastien (Co-supervisor)