The catalytic activity of Ca/Fe-rich incineration ash in the pyrolysis of epidemic wood

Abstract

The spread of pine nematode disease caused by epidemic wood poses a great challenge to the environment, and there is an urgent need to develop effective processing methods; however, Ca/Fe-rich sludge ash can improve the pyrolysis properties of biomass. Therefore, this paper focuses on the pyrolysis mechanism of epidemic wood with the addition of Ca/Fe-rich sludge ash. The presence of Ca-rich sludge ash was found to extend the pyrolytic temperature window of epidemic wood, intensify the cracking of its volatile constituents, and extend its reaction duration. At the same time, the Ca-rich sludge reduces the pyrolysis activation energy to 152.39 kJ/mol. The Fe-rich sludge ash demonstrated the capacity to lower the energy barriers during the initial phase of pyrolysis. Concurrently, the Ca-rich sludge ash accelerated the dehydration reaction of the epidemic wood, leading to 21.02% and 30.69% increases in the contents of acids and ketones in the pyrolytic oil, respectively. The Fe-rich sludge ash contributed to a notable 14.52% increase in aromatic compounds in the oil and a 19.14% decrease in alcoholic compounds. Additionally, the Ca-rich sludge ash accelerated the decomposition of lipid organic matter at elevated temperatures, enriching the pyrolytic char with more unsaturated bonds. This research lays a theoretical foundation for the safe and efficacious thermal decomposition of epidemic wood, thereby enhancing its utilization within the forestry industry.

Graphical abstract