Influence of pyrolysis temperature and bio-waste composition on biochar characteristics

L. A. RODRIGUEZ ORTIZ; ERICK DAVID TORRES; DANIELA ZALAZAR GARCÌA; HUILI ZHANG; ROSA A. RODRIGUEZ; GERMÁN D. MAZZA

RENEWABLE ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2020 vol. 155 p. 837 - 847

0960-1481

The aim ofthis work was to analyse the influence of the pyrolysis temperature andfeedstock composition on biochar yield and physicochemical properties. The rawmaterials to be pyrolyzed were characterized, and an experimental design was applied to carry out astatistical study. Three operating temperatures (673, 773 and 873 K) and twobio-wastes (nut and almond shells) were used.Several correlations linking the values of differentphysicochemical properties of the biochar with the two variables were proposed.On the basis of these correlations, itwas found that almost all physicochemical characteristics of both almond andnut shell-based biochars depended on both thepyrolysis temperature and bio-waste composition, and an interaction of the twovariables was observed in our experiments. Only the biochar yield did notexhibit an interaction between these two variables.The biochars presented H/C and O/C ratios and higher heating values similar to those of bituminous coal, confirmingtheir potential as solid bio-fuels. They also presented high K and Ca contents.The obtained values for thearomaticity factor, stable C mass fraction and recalcitrance potential,indicated that the biochars could also be used for soil amendments, especiallyas acidic or basic compounds, according to their pHvalues.