Effects of temperature and carrier gas on physico-chemical properties of biochar derived from biosolids

• Published in: Journal of analytical and applied pyrolysis 2022-06, Vol.164, p.105542, Article 105542
• Main Authors: Aktar, Shefali, Hossain, Md Afzal, Rathnayake, Nimesha, Patel, Savankumar, Gasco, Gabriel, Mendez, Ana, de Figueiredo, Cicero, Surapaneni, Aravind, Shah, Kalpit, Paz-Ferreiro, Jorge
• Format: Article
• Language: English
• Subjects: Biochar; Biosolids; Carrier gases; Pyrolysis; Temperature
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/j.jaap.2022.105542

This study investigated the influence of temperature (400 ºC, 500 ºC and 600 ºC) and –carrier gas (N2 and CO2) on biochar yields, physicochemical, and structural attributes. Higher temperatures resulted in less functional groups, higher surface area and lower H/C and O/C ratios. The biochar produced under N2 environment was more alkaline and showed higher salinity whereas the biochar produced under CO2 environment had higher surface area. The FTIR spectra of biochar produced in CO2 atmosphere indicated the decrease of functional groups such as –OH, CO, –CONH– and CC with increasing pyrolysis temperature. However, the band intensity for Si–O–Si or Si–O–C and aromatic and hetero-aromatic structures were more prominent in biochar obtained in CO2 environment than N2 environment. The presence of calcium carbonate (CaCO3), quartz (SiO2) and magnesium calcite (MgCO3) in biosolids and their biochars was confirmed by XRD spectrum. The outcomes from this research, particularly the stark contrast in biochar characteristics due to the variation in production conditions, inform the tailoring of biochars prepared under different conditions to environmental applications. [Display omitted] •Biochar produced from slow pyrolysis under two carrier gases (N2 and CO2).•Temperature and carrier gas had significant effect on the properties of biochar.•Biochar produced under N2 exhibit higher alkalinity, salinity and CEC.•Biochar under CO2 had higher surface area and aromaticity.•XRD spectrum confirmed the presence of CaCO3 and SiO2 in biosolids and biochar.