Ein experimenteller Ansatz zur Dynamik von Abgasen aus der aeroben Vergärung und Biogas für den Einsatz in der Mikroalgenkultivierung
Chemische und Thermische Verfahrenstechnik
Pflanzenbau, Pflanzenernährung, Agrartechnik
Zusammenfassung der Projektergebnisse
There are global efforts to reduce greenhouse gas emissions and mitigate the effects of climate change. One area that can contribute to reducing or achieving net zero emissions is the management of organic waste. Aerobic digestion, or composting, is recognised as an effective means of converting high moisture organic matter into compost. Compost is usually returned to the soil to improve fertility. While the production of compost has been used for decades to manage organic waste and reduce landfill, little has been done to close the emissions loop from composting, particularly the flue gas consisting of CO2 and varying concentrations of methane and nitrous oxide. In addition, there is little financial incentive for composting, which discourages investment. Although the CO2 released during composting is biogenic, preventing its release into the atmosphere will offset other emissions or contribute to net negative emissions. The project titled ‘An experimental approach to the dynamics of off-gas from aerobic digestion and biogas for use in microalgae cultivation’ was aimed at developing a closed-loop system in the biochemical conversion of biomass, finding an economic use for the off-gas and eliminating the cost of CO2 in the cultivation system of photosynthetic microorganisms. To capture the CO2 from the off-gas, a novel composting process called 'staged composting' was developed to increase the CO2 concentration. The high CO2 off-gas was used in spirulina cultivation to close the emissions loop. While previously reported off-gas CO2 concentrations were less than 5%, the staged composting resulted in CO2 concentrations of up to 16%. The availability of ready-to-use CO2 from composting avoids the associated costs and emissions of capturing and transporting of CO2 from other sources. Additionally, preliminary experiments using off-gas CO2 (up to 4.9%) and air (CO2 – 0.04%) to grow spirulina (Arthrospira platensis), a photosynthetic micro-organism, showed higher biomass productivity using off-gas than the use of air. The use of wastewater/sewage showed promising results that can reduce the water footprint and close the resource loop for organic waste management, carbon sequestration and spirulina production. The potential economic value of integrated composting and spirulina production provides an incentive for investment in waste management operations.
Projektbezogene Publikationen (Auswahl)
-
Composting off-gas as alternative source of carbon dioxide for spirulina cultivation – a preliminary study. SSRN Electronic Journal.
Anyaoha, Kelechi Ezenwa; Dornack, Christina; Hodgkinson, Isla; Krujatz, Felix & Maletz, Roman
-
Microalgae contribution in enhancing the circular economy drive of biochemical conversion systems – A review. Carbon Resources Conversion, 7(2), 100203.
Anyaoha, Kelechi E.; Krujatz, Felix; Hodgkinson, Isla; Maletz, Roman & Dornack, Christina
-
Potentials for microalgae sequestration of carbon dioxide (CO2) from composting off-gas; a review. Resources, Conservation & Recycling Advances, 22, 200213.
Anyaoha, Kelechi E.; Maletz, Roman; Rückert, André & Dornack, Christina
