Pierre Girods

Activated carbons prepared from wood particleboard wastes: characterisation and phenol adsorption capacities.

The problems of valorisation of particleboard wastes on one hand, and contamination of aqueous effluents by phenolic compounds on the other hand, are simultaneously considered in this work. Preparation of activated carbons from a two steps thermo-chemical process, formerly designed for generating combustible gases, is suggested. The resultant carbonaceous residue is activated with steam at 800 degrees C. Depending on the preparation conditions, surface areas within the range 800-1300 m(2)/g are obtained, close to that of a commercial activated carbon (CAC) specially designed for water treatment and used as a reference material. The present work shows that particleboard waste-derived activated carbons (WAC) are efficient adsorbents for the removal of phenol from aqueous solutions, with maximum measured capacities close to 500 mg/g. However, most of times, the adsorption capacities are slightly lower than that of the commercial material in the same conditions, i.e., at equilibrium phenol concentrations below 300 ppm. Given the extremely low cost of activated carbons prepared from particleboard waste, it should not be a problem to use it in somewhat higher amounts than what is required with a more expensive commercial material. Phenol adsorption isotherms at 298 K were correctly fitted by various equations modelling type I and type II isotherms for CAC and WAC, respectively. Phenol adsorption isotherms of type II were justified by a 3-stages adsorption mechanism.

Fast Pressing Composite Using Tannin-Furfuryl Alcohol Resin and Vegetal Fibers Reinforcement

Experimental investigations have been carried out on the potential use of tannin-furfuryl alcohol resin for biobased composites using vegetal fiber reinforcement. Results showed that a mixture containing 54% furfuryl alcohol, 45% modified quebracho extract and 0.9% paratoluenesulfonic acid as a catalyst yields a resin that can be used with a nonwoven flax fiber mat to manufacture lightweight composites with good mechanical properties and a very short curing time with a regular hot press. The panels made were tested for tensile and flexural modulus and strength, water resistance and thermo-degradation.

Thermogravimetric analysis of anningre tannin resin

Three formulations of aningre tannin resins containing in order the paraformaldehyde powder, hexamethylenetetramine and aqueous glyoxal as hardeners were developed. Their thermogravimetric analysis have shown that they begin to decompose respectively from 135°C, 145°C and 140°C. About 24%, 40% and 39 % solid residues of their initial masses exist at the end of the analysis. Thermomechanical analysis has shown that the formulation containing paraformaldehyde powder as hardener has the best rigidity and the worst contains the hexamethylenetetramine. All formulations have different thermal degradation, differences were more significant between 400 and 900°C.The decomposition of hardeners become more significant from 400°C.