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Emissions characteristics from the combustion of five date palm residues, DPR, (Date Palm Leaflets, Date Palm Rachis, Date Palm Trunk, Date Stones and fruitstalk prunings) in a laboratory scale furnace were investigated. Release of gaseous products such as CO 2 , CO, VOC, NO x and SO 2 were measured at 600–800 °C. The main goal was to analyze thermal behaviors and gaseous emissions in order to select the most convenient biofuel for an application in domestic boiler installations. Regards to biofuel characteristics, date stone have the highest energy density (11.4 GJ/m 3 ) and the lowest ash content (close to 1.2%). Combustion tests show that among the tested date palm residues, date stone may be the promising biofuel for the design of combustion processing system. However, a special attention to the design of the secondary air supply should be given to prevent high emissions of CO and volatile matters.

The aim of this work was to study the thermal behavior of two herbaceous crops ( Miscanthus giganthus , Arundo donax ) obtained from energy plantations. Thermogravimetric analyses were performed at 5 °C min −1 under air atmosphere. The thermal degradation rates in devolatilization and combustion steps, the initial degradation temperature, and the residual weight were determined. The gas emissions and Particle Matter (PM) were also quantified. The thermal behavior of energy crops depends on the chemical composition. In fact, the initial degradation temperature for A. donax under air atmosphere was lower than for M. giganthus . However, the thermal degradation rate was higher for M. giganthus . Kinetic expressions for the degradation rate in devolatilization and combustion steps have been obtained for both energy crops. The comparison of the gas and PM emissions showed the same order of magnitude for both energy crops. In fact, 26.8 mmol/g of CO, CO 2 , VOC and 1.8 × 10 13 particles/g were mainly emitted.

The increase of the price of fossil means, as well as their programmed disappearing, contributed to increase among appliances based on biomass and energy crops. The thermal behavior of Arundo donax by thermogravimetric analysis was studied under inert atmosphere at heating rates ranging from 5 to 20 degrees C min(-1) from room temperature to 750 degrees C. Gaseous emissions as CO(2), CO and volatile organic compounds (VOC) were measured and global kinetic parameters were determined during pyrolysis with the study of the influence of the heating rate. The thermal process describes two main phases. The first phase named active zone, characterizes the degradation of hemicellulose and cellulose polymers. It started at low temperature (200 degrees C) comparatively to wood samples and was finished at 350 degrees C. The pyrolysis of the lignin polymer occurred during the second phase from 350 to 750 degrees C, named passive zone. Carbon oxides are emitted during the active zone whereas VOC are mainly formed during the passive zone. Mass losses, mass loss rates and emission factors were strongly affected by the variation of the heating rate in the active zone. It was found that the global pyrolysis of A. donax can be satisfactorily described using global independent reactions model for hemicellulose and cellulose in the active zone. The activation energy for hemicellulose was not affected by a variation of the heating rate with a value close to 110 kJ mol(-1) and presented a reaction order close to 0.5. An increase of the heating rate decreased the activation energy of the cellulose. However, a first reaction order was observed for cellulose decomposition. The experimental results and kinetic parameters may provide useful data for the design of pyrolytic processing system using A. donax as feedstock.

Olive oil mill wastewater (OMWW) generated by the olive oil extraction industry constitutes a major pollutant, causing a severe environmental threats because of the high chemical oxygen demand and the high content of polyphenol. This work studied a combined process of absorption on sawdust, a low-cost renewable absorbents, and an energetic valorisation via combustion was studied. The thermal behaviour of different OMWW/sawdust blends was studied under inert and oxidative atmosphere from 20 to 900 degrees C using thermogravimetric analysis (TGA). Gaseous emissions such as CO(2), CO and volatile organic compounds (VOCs) were measured under oxidative conditions at 600 degrees C in a fixed-bed reactor. Kinetic parameters were obtained and compared for the different mixtures of OMWW and sawdust. The absorption of the organic content of OMWW on sawdust improves the decomposition of cellulosic compounds at low temperatures in both atmospheres. Compared to sawdust, absorption of the organic content of OMWW on sawdust favours a combustion process with lower molar ratio of CO/CO(2) in the exhaust. Combustion of an impregnated sawdust containing 40 wt.% of the organic content of the OMWW generates the same amount of gas in the exhaust as sawdust. OMWW/sawdust blends may therefore be a promising biofuel with low environmental impacts.