No abstract

Sheets from banana trunks were opened out and dried for several weeks in air. Pulp was obtained by the nitric acid process with a yield of 37.7% while fibres were obtained according to the modified standard Japanese method for cellulose in wood for pulp (JIS 8007) with a yield of 65% with respect to oven dried plant material. Single fibre obtained by the JIS method had an average diameter of 11.0 μm and Young's modulus, tensile strength and strain at break-off 7.05 GPa, 81.7 MPa and 5.2% respectively. Modification of the fibres was carried out by grafting ethyl acrylate in the presence of ammonium nitrate cerium(IV). Optimisation of the copolymerisation reaction conditions was studied by measuring the rate of conversion, the rate of grafting and the grafting efficiency. The results showed that at low values of ceric ion concentration (0.04 M), at ambient temperature, after three hours and at a concentration of 0.2 M ethyl acrylate, maximum values of the parameters cited were obtained.

This work presents the thermal, physical and chemical characterization of Coffee canephora, from littoral region of Cameroon, for their use as reinforcement for polymeric materials. The infrared of coffee hulls shows the presence of a large peak intensity at 3299 cm −1 that can be attributed to O-H stretching group of alcohol (cellulose content in coffee pulp). The intensity 2926 cm −1 can be attributed to C-H stretching group of alkanes or the vibration of methoxy group of lignin. Thermo gravimetric analysis shows that around 440˚C, the biomass has been completely consumed; the temperature profiles show a peak at 86˚C that could correspond to the loss of water as evaporation at a percentage of 8%; the peak at 321˚C is accompanied by a water loss of 64.50%; this temperature is assimilated to the degradation of hemicelluloses; the temperature range from 321˚C to 401˚C is accompanied by a loss of mass of 22.80%, which would be due to the degradation of cellulose. SEM images of the surface of raw coffee hulls, coffee hulls treated with caustic soda respectively clearly reveal gaps between the fibers. The results showed that the incorporation of coffee hulls fiber in LLDPE matrix might result in composites with suitable property application for various industrial fields; especially those that were mechanical features are crucial, such as the replacement of engineering plastics.

The production of biogas as an energy source from organic waste is a viable option for waste recovery and reduction of greenhouse gases. Before any use of biogas, however, hydrogen sulfide and carbon must be removed to preserve consumer health and the life of the equipment. In this work, we were talking about purifying the biogas by washing on a column with an alkali solution produced from wood ash and ash from the wood stalk. To do this, a functional analysis of the purification system was made. After characterization of the samples, the alkalis were extracted, which were subsequently characterized. The next step was to carry out biogas purification tests from the alkali crystals. The extraction yield of alkali is 7% for the ash of meat grillers and 12% with the ash of banana stalk. The biogas was washed with an alkali concentration of 0.1 g/ml. The optimal residence time offering the best washing is 23 min for CO 2 and 32 min for H 2 S. This study found that the alkali on the banana boom is better. During the washing test, a CO 2 absorption capacity of 4.52g/ml of the alkali solution and 20.45 ppm / ml of H 2 S was recorded. By making an extrapolation It follows that for these quantities of CO 2 and H 2 S absorbed per milliliter, during a domestic installation, for a volume of alkali of 1000 ml, we will have a volume of CO 2 of 2,53m 3 and a biogas volume of 6.33 m 3 .

In this work fibers derived from coffee, hulls have been incorporated into Linear Low Density Polyethylene (LLDPE). The influence of the filler content on the thermal and physicomechanical properties of the composites obtained was assessed. The results showed that the incorporation of fibers was able to improve the thermostability of LLDPE/Coffee hulls fibers; comparing the treated fiber composite with untreated fiber composites, the chemical treatment reduces by 58.3% the water absorption, while increasing the elongation and tensile strength by about 48% and 17% respectively. Moreover, due to better interfacial interaction induced by MAPE, the corresponding composite exhibited better properties compared to the untreated fiber composite. Results are indicative of the fact that both mercerization and MAPE (coupling agent) have significant positive effects on the fiber-matrix interaction in terms of adhesion, wetting and dispersion, this treatment produced a better fiber distribution and consequently a more uniform composite morphology without voids and gaps between the fibers and the matrix, allowing the possibility to use higher fiber contents (up to 30% wt.) with acceptable mechanical properties.