Researches on grape husk waste obtained from the winery and its use as pellets for combustion

Nowadays, there is a tendency to find new sources of biomass and to efficiently use old sources, especially to find renewable fuels. The paper aims to use grape husks resulting from the preparation of wine as pellets for combustion. Oven dry grape husk were used to be crushed and graded with the sieve of 1×1 mm in order to obtain dust for pelletizing. The pellets obtained from grape husk winery have a good density of 979 kg. m-3; a good ash content of 4.53% and a better high and low calorific value of 20.150 MJ. kg-1 and 19.850 MJ. kg-1, respectively. All over, the obtained results showed that this kind of raw material (pellets) can be use successfully when they are pelletized.

Energy characteristics of wood and charcoal of selected tree species in Mexico

This study determines the main energy characteristics of wood and charcoal within five tree species of the forest of Ixtlán de Juárez, Oaxaca, México: Alnus acuminata, Arbutus xalapensis, Myrsine juergensenii, Persea longipes and Prunus serotina. Basic density, moisture content, charcoal yield, volatile material, ash content, high heating value, fixed carbon and fuel value index were determined for each one. The average results of the species are in the range of 0.372 to 0.498 g. cm-3 for wood density; 26.19 to 34.12% for charcoal yield; 77.29 to 83.66% for wood volatile matter and 28.40 to 34.25% for charcoal volatile matter; 0.56 to 1.50% for wood ash and 1.13 to 4.83% for charcoal; 19.50 to 24.99 MJ. kg-1 for high heating value of wood and 29.38 to 32.11 MJ. kg-1 for charcoal. It was determined that these species provide a good alternative for burning wood and charcoal. Additionally, these remain untapped resources in the Sierra Juárez region, meaning that awareness and inclusion in management plans could be of relative importance to the development of the forestry sector.

Elimination of adhesive impurities of the recovered paper in flotation process

The article presents results of the elimination of sticky impurities from recovered paper in laboratory flotation of three pulp suspensions with different whiteness, obtained directly from the production line before entering flotation. A combination of commercial agents releasing undesirable substances from recovered paper and means for regulation and stabilization of froth and modified micronized bentonit was used. In the flotation purification of pulp suspension with a whiteness of 53%, the combination of Prodeink Extra, Prodeink AS10 and Hydrocol OT reduced the macrostickies content by 58%, the ash content decreased from 18.5% to 4.5%, the whiteness increased from 53% to 56.4% and the residual color content was reduced from 385 ppm to 294 ppm. The pulp suspension with a whiteness of 64% showed a reduction in the content of macrostickies by 66%, a reduction in the ash content by 23.2%, an increase in whiteness by 1.4% and a reduction in the residual color content from 245 ppm to 194 ppm. The pulp suspension with a whiteness of 68.3% showed a decrease in the content of macrostickies by 58.1%, the ash content decreased from 35.7% to 6.3%, the whiteness increased by 1.1% and the content of residual color decreased from 157 ppm to 117 ppm.