Characterization of 60 types of Chinese biomass waste and resultant biochars in terms of their candidacy for soil application

Abstract

The composition and pyrolysis characteristics of 60 types of biomass waste from the following six source categories were compared: agricultural residues, woody pruning waste from gardens and lawns, aquatic plant material from eutrophic water bodies, nutshells and fruit peels, livestock manure and residual sludge from municipal wastewater treatment. The yield and physicochemical characteristics of the biochar produced from these feedstocks at 350°C, 500°C and 650°C were also examined. Results of correlation and canonical correspondence analysis between feedstock composition and biochar properties showed that feedstock type played an important role in controlling yield and properties of biochars. The yields of biochar dry ash-free (daf.) basis were positively correlated with cellulose, lignin and lignin/cellulose content of feedstock; and ash content hampered the biochar production. Furthermore, the intensity of correlation between biochar yield and its feedstock composition was improved with pyrolysis temperature and degree of feedstock decomposition. The fixed carbon content in biochar was also negatively influenced by ash content of feedstock, and it increased with increasing pyrolysis temperature when the ash content was below 34.57% in feedstock and decreased when the ash content exceeded. The fixed carbon production in biochar per unit ash-free mass (af.) was positively related to cellulose, lignin and lignin/cellulose content in feedstock, which were same with the yield of biochar (daf.). But on the contrary, the volatiles content in biochar (af.) had negative correlation with these organic constituents. For most feedstocks, the differences in the biochar characteristics among the biomass categories were greater than within any individual category. C/N, H/C and O/C atomic ratio and bulk density of biochar from different types of biomass were also compared. The results will provide guidance for the reutilization of biomass wastes and production of biochar with specified properties for soil amendment applications.

The Preliminary Study of Water-Retention Related Properties of Biochar Produced from Various Feedstock at Different Pyrolysis Temperatures

“…The carbon contents of CE-, CY-, MB- and SB-derived biochar were larger than those in RH-, PM- and WS-derived biochar, which may have been due to the higher ash content of RH, PM, and WS. As reported in a previous study [28], the biochar from cow manure and wastewater sludge were lower carbon contents.…”

Biochar of residual biomass from eucalyptus (Eucalyptus globulus) by two pyrolysis methods

“…Las pruebas de pirólisis de la biomasa se realizaron en el Laboratorio de Calidad de la Empresa Cementera Industrias Guapan del Ecuador contando con sus equipos de precisión. Para determinar la temperatura óptima de pirólisis se realizaron las pruebas de obtención de biochar, con tres temperaturas: 250, 400 y 550 °C valores que establecieron las investigaciones consultadas (Gilces, 2014;Torres-Sallan et al, 2014;Sun et al, 2017). Las pirólisis fueron realizadas en mufla, comparando después las condiciones del biochar y la ceniza obtenida por tamizado en criba, con material menor de cuatro mm.…”

“…Los valores son coincidentes con lo encontrado con cepas de vid que establece un porcentaje de 0,4% (Torres-Sallan et al, 2014). El estudio de caracterización de 60 tipos de biomasa en China establece rangos de 0,29 a 4,19% (Sun et al, 2017).…”

“…Los rangos de carbono total en el biochar de este estudio varían de 44,56 a 54,91% lo que confirma la capacidad del biochar para conservar buena parte del carbono y mantenerlo en su estructura molecular (Iglesias et al, 2018). En China el estudio de caracterización de 60 tipos de biomasa convertidos en biochar, demostró valores de carbono de 26,61 a 53,26% de acuerdo con la biomasa (Sun et al, 2017). Guerra (2014) encontró valores de carbono en los ocho biochars estudiados con rangos que fluctuaron entre 34,92 y 89,47%.…”

“…El biocarbón se obtiene por un proceso termoquímico de transformación de la estructura molecular de la biomasa y tiene diferentes usos, es un producto alto en contenido de carbono que puede ser producido en hornos, tras calentar biomasa como madera u hojas en un contenedor con poco o ningún aire disponible. En términos generales el biochar se produce mediante transformación térmica de la materia orgánica con un bajo suministro de oxígeno y a temperaturas relativamente bajas con variaciones que dependen del material de pirólisis (Sun et al, 2017). Existen cuatro categorías para la producción de biochar: pirólisis lenta, pirólisis rápida, pirólisis ultrarrápida y gasificación.…”