Activated Carbons derived by Phosphoric acid Activation of Agricultural waste and their Adsorption of Methylene Blue

Agricultural wastes can be considered as suitable raw materials for activated carbon production, as activated carbon is considered as an economical adsorption material. Seeds from biomass of Ziziphus mauritiana Lam, grown in Algerian have been valorized for activated carbon production by the phosphoric acid, activation method with pyrolysis temperatures of 400, 500 and 600 °C. The effect of changes in pyrolysis temperatures on the yield and quality of the prepared activated carbon was studied. The obtained activated carbons were characterized by FT-IR and MB adsorption, a good yield of 38,625 %, a high BET surface area of 915,58 m2/g. The removal rate of methylene blue was strongly influenced by contact time, adsorbent mass and pH. An excellent removal % of methylene blue (MB) was obtained at the preferred temperature of 500 °C (AC 500).

Carbon Emissions and Brazilian Ethanol Prices: Are They Correlated? An Econophysics Study

Brazil is one of the largest global producers and exporters of ethanol and in 2017 launched RenovaBio, a programme aiming to mitigate greenhouse gas emissions. In parallel to this domestic scenario, there is rapid growth in the world market of carbon production, as well as complex price relations between fossil and renewable energies becoming increasingly important in recent years. The present work aims to contribute to filling a gap in knowledge about the relationship between Brazilian ethanol and other relevant energy-related commodities. We use a recent methodology (Detrended Cross-Correlation Approach—DCCA—with sliding windows) to analyze dynamically the cross-correlation levels between Brazilian ethanol prices and carbon emissions, as well as other possible-related prices, namely: sugar, Brent oil, and natural gas prices, with a sample of daily prices between January 2010 and July 2020. Our results indicate that (i) in the whole period, Brazilian ethanol has significant correlations with sugar, moderate correlation with oil in the short term, and only a weak, short-term correlation with carbon emission prices; (ii) with a sliding windows approach, the strength of the correlation between ethanol and carbon emissions varies between weak and non-significant in the short term.

Brasil nut mesocarp (Bertholletia excels) as a Biomass Source for Activated Carbon Production: Correlation Between Thermal Treatment and Adsorption Performance

The activated carbon investigated in this work was produced from the extractive residues of Brazil nut processing, more specifically from the mesocarp of the Amazonian fruit. The process was performed by muffle pyrolysis, with ZnCl2 impregnation, at 400 and 500 °C. All samples were characterized by X-ray diffractometry, thermogravimetry, CHNS elemental analysis, scanning electron microscopy, and adsorption/desorption of N2. The results were promissory, with 99% removal of methylene blue for the CA25 material, which has a surface area of 1236 m2 g-1, much higher than commercial coal (CAC, 618 m2 g-1). The adsorption kinetics best fit the pseudo-second-order model for all materials. The maximum adsorption capacity obtained was 195.3 mg g-1. Therefore, the extractive residue of Brazil nut has excellent potential for the development of activated carbon, which can be used effectively to mediate environmental contamination in a given aqueous medium.