Influence of physical-anatomical wood variables on charcoal physical-mechanical properties

This research assessed the relationship between wood physical-anatomical variables and charcoal physical-mechanical properties.Nine trees were harvested and mechanically processed into standard pieces for laboratory analysis.The following variables were determined:wood density,fiber length and width,fiber lumen diameter and wall thickness,fiber wall fraction,and vessel frequency.The charcoal was produced in a laboratory and gravimetric yield,relative density,and mechanical properties established.Pearson’s correlation coefficients,multivariate statistical analysis of canonical correlation,and principal component analysis were used to evaluate the relationship between wood and charcoal properties.Fiber width was not significantly correlated with charcoal properties.Charcoal bulk density,hardness,and strength were positively correlated with wood density,fiber length,wall thickness,and wall fraction.Charcoal properties were negatively correlated with fiber lumen diameter and vessel frequency.These results will help identify the best wood with adequate physical-mechanical properties for industrial charcoal proces sing.

Study of the Influence of the Intrinsic Parameters of Charcoal Pellets and Relative Humidity on Compressive Strength and Moisture Adsorption

In this study,charcoal fines mixed with wheat starch or arabic gum were used to produce pellets.Moisture adsorption increased greatly by increasing relative humidity.Moisture adsorption depends also on the binder type used.All charcoal pellets had compressive strength above 1.0 MPa and their moisture adsorption reached 3%to 12%depending on relative humidity conditions.In authors’experiment field,statistical analysis showed that binder type and the rate of binder had more significant effects on compressive strength.The moisture adsorption was more influenced by relative humidity and binder type.

Effect of sewage sludge and sugarcane bagasse biochar on soil properties and sugar beet production

Recently, biochar has shown to be an alternative to waste disposal and a source of nutrients, acting as a soil amendment. The effects of two types of biochar on soil properties and sugar beet production as well as potential for carbon(C) sequestration were evaluated: biochar produced from sewage sludge(SB) and biochar produced from a 1:1 mixture of sewage sludge and sugarcane bagasse(MB). A greenhouse pot experiment was conducted using a sandy loam soil from the Brazilian savanna under treatments of MB applications at 2.5%, 5.0%, 7.5%, and 10.0%, SB application at 5.0%, and a conventional fertilization(CF) using lime and mineral fertilizers, with no fertilization as a control. After incubation for 45 d, seedlings were transplanted into each pot and cultivated for 55 d. Biochar characterization showed that pyrolysis reduced the biomass volume drastically, but concentrated the trace elements per unit of biochar weight. The MB treatments increased soil total C(by 27.8%) and pH(by 0.6), reduced the concentrations of nutrients, except for potassium(K), and chromium(Cr), and did not significantly alter lead(Pb) and cadmium(Cd) concentrations. Results of stable isotopes showed that all biochar treatments increased the total soil C stock and stability, suggesting a potential for application in C sequestration, and improved overall soil fertility. However, the biochar treatments also increased the concentrations of trace elements in the soil and plants. The sugar beet yields at 10.0% MB and 5.0% SB corresponded to 55%and 29% of the yield obtained in the CF treatment, respectively. These results may be due to biochar nutrients not being bioavailable when required by plants or to biochar nutrient adsorption.