Life cycle assessment of heat, CO2 from composting for greenhouse applications

Greenhouses play a crucial role in agricultural production, especially in high-latitude regions requiring supplemental heating during winter. This study explores the potential of a Shed-type Greenhouse Composting Device (SGCD) to recover heat and CO 2 from composting agricultural waste (AW) for use in solar greenhouses. A Life Cycle Assessment (LCA) was conducted to evaluate the environmental impacts of the SGCD system, covering its construction, operation, and recycling units. The results show that heat and CO 2 recovery significantly reduce reliance on coal heating and CO 2 cylinders, with heat recovery contributing 30.94 % and CO 2 recovery 17.40 % to impact reduction. Key environmental hotspots include the impacts of construction materials, water, electricity, and diesel use. Sensitivity analysis revealed that the system is most sensitive to freshwater ecotoxicity, toxicity equivalent, and marine ecotoxicity. The impact of AW processing is minimal, contributing only 1.09 % of the total impact. Economically, the SGCD system increases tomato yield by 15.06 %, generating an additional $225.35 in annual revenue, with a payback period of two years and profitability from the third year. Overall, the SGCD system offers both environmental and economic benefits, promoting energy-efficient, low-carbon agricultural practices in high-latitude greenhouses. • Heat and CO 2 Recovery: The SGCD recovers heat and CO 2 from composting agricultural waste, reducing coal heating and CO 2 use. • Environmental Impact: LCA identifies key hotspots in materials, water, electricity, diesel use, and ecotoxicity. • Minimal AW Processing Impact: Agricultural waste processing has minimal impact, contributing only 1.09% to the footprint. • Economic Benefits: The SGCD system boosts tomato yield by 15.06%, generating an additional $225.35 in revenue, with payback in two years. • Sustainable Agriculture: The SGCD system promotes energy-efficient, low-carbon practices, offering environmental and economic benefits for high-latitude greenhouses.