Effect of Heating Time and Temperature on the Chemical Characteristics of Biochar from Poultry Manure

Abstract

Poultry manure (PM) chars were obtained at different temperatures and charring times. Chemical-physical characterization of the different PM chars was conducted by cross-polarization magic angle spinning (CPMAS) (13)C NMR spectroscopy and thermal analysis. CPMAS (13)C NMR spectra showed that the chemical composition of PM char is dependent on production temperature rather than on production duration. Aromatic and alkyl domains in the PM chars obtained at the lowest temperatures remained unchanged at all heating times applied for their production. The PM char obtained at the highest temperature consisted only of aromatic structures having chemical nature that also appeared invariant with heating time. Thermogravimetry revealed differences in the thermo-oxidative stability of the aromatic domains in the different PM chars. The PM char produced at the highest temperature appeared less stable than those produced at the lowest temperatures. This difference was explained by a protective effect of the alkyl groups, which are still present in chars formed at lower temperature. The analysis of the chemical and physicochemical character of poultry manure chars produced at different temperatures can increase understanding of the role of these materials in the properties and behavior of char-amended soils.

Effects of Environmental Conditions on Rice-straw Biochar Adsorption of Nitrate

“…And the results showed a slight difference between SN6 and SN8 while SN8 had a slender lead on adsorption capacity in a given environmental condition. It is generally accepted that increase in pyrolysis temperature may improve the sorption ability of biochars to aqueous nitrate because of the higher aromaticity, weaker polarity and higher specific surface areas [17,18,19]. However, results in this study showed biochars made at a relatively lower temperature (400 ℃) had the strongest adsorption capacity.…”

Mineralização e efeitos de biocarvão de cama de frangosobre a capacidade de troca catiônica do solo

“…A maior estabilidade de C no biocarvão é resultante de perdas variáveis de H, O, C e N durante a pirólise, em que se preserva relativamente mais C e, assim, se reduzem as relações H/C, O/C e (O+N)/C (Novak et al, 2009). Essas alterações da pirólise da cama de frango correspondem ao incremento do pico principal de arilas (compostos aromáticos) e redução das alquilas, metilenos e carboidratos (celulose e hemicelulose), em que estes últimos tendem a zero a temperaturas acima de 350 o C. (Cimò et al, 2014).…”

Mitigation of Greenhouse Gas Emissions from Tropical Soils Amended with Poultry Manure and Sugar Cane Straw Biochars

“…With pyrolysis temperature at 650˚C, aliphatic chains, aromatic rings and elemental composition of C, N and O are reduced, making the biochar more recalcitrant [44]. Many characteristics, such as ash content, CEC and C/N ratio, vary according to the raw material [45] and [46], which justifies similar CO 2 emission values for the BCS, whether pyrolyzed at 350˚C or 650˚C.…”