(321b) Analysis of the Effect of Solar Pyrolysis Parameters on the Physicochemical Properties of Biochar

Carbon materials can be produced by different methods. One of them is solar pyrolysis, which is attaining renewed interest due to simplicity to transform biomass with environmental advantages. However, pyrolysis operation parameters are decisive factors that determine the morphological and chemical properties of carbon.

This work aims to study the influence of temperature and heating rate of solar pyrolysis in the properties of carbon. Pyrolysis experiments were carried out in the 25 kW solar furnace of IER-UNAM. Agave angustifolia biomass was processed in a glass spherical solar reactor. Temperatures between 500 and 900°C were employed, as well as heating rates between 4 and 30°C/min. The char produced was analyzed with several techniques, which include elemental analysis (CHONS), surface area by BET and DFT models and capacitance by cyclic voltammetry.

The results of the experiments suggest that solar pyrolysis temperature and heating rate scarcely impact the carbon composition, nevertheless the structure, surface area and electrochemical response are highly affected by both. The control of the operation conditions allows to produce carbon materials that exhibit promising properties to be used as catalyst supports for polymer electrolyte membrane fuel cells and electrolyzer cells applications. Consequently, the use of concentrated solar energy represents an attractive method to produce these valuable materials.