Utilization Prospects of Carbon Concentrate – a Product of Aluminium Smelting Carbon Dust Processing

The possibilities of utilization of technogenic products of aluminum production: coal foam and carbon concentrate (СС) are considered. It is proposed to utilize CC in order to extract valuable components. The regularities of the utilization process of CC by the combustion method have been studied. It was found that the content of germanium in ash is determined by the temperature and the oxygen partial pressure in the system. Gallium is concentrated in ash in an amount of 0.8 wt.% during the combustion in a fluidized bed at a temperature of 1200 °C, the germanium extraction into sublimates reaches 90 %. The results of the leaching of gallium from the ash residue in acidic and basic media are presented; the maximum gallium extraction was 90 and 94 %, respectively.

Assessment of the Efficiency and Safety of the Process for Utilization of Formaldehyde-Containing Solid Waste by the Method of Medium Temperature Dry Pyrolysis

An assessment of the efficiency and safety of the formaldehyde decontamination process containing solid waste of wood-chip boards by method of medium-temperature dry pyrolysis at the installation developed by the authors was evaluated. Sawdust of chip boards and coke ash residue after their pyrolysis were subjected to biological examination. The test objects were Daphnia magna Straus, algae Scenedesmus quadricauda and luminescent bacteria. It was revealed that pyrolysis of these wastes at the proposed plant will reduce the load on the hydrosphere and reduce the ratio of dilution of water extracts by more than half. Analysis of the composition of pyrolysis gases showed that the mass concentration of nitrogen oxides and carbon in the air of the working zone does not exceed the MPC of the working zone and MPC of settlements. The conclusion on environmental safety of the process of pyrolysis of formaldehyde-containing solid wastes at the proposed installation is made.

Physical Treatment of Oil Palm Shell for Briquette Production as Bioenergy at Remote Area

The daily needs of energy in remote areas, Indonesia, is dominated by biomass waste. The abundant types of biomass waste for heat transfer is empty fruits shell (EFS) of oil palm as briquette. This research discussed a brief analysis of oil palm shell by using physical treatment at different crushing pressure. It was also to examine the adequate size of particle for improving the heating value of briquette. The crushing pressure had a height dimension of 20 cm, as well as the briquette mold with a diameter of 2 cm and a height of 1 cm. The oil palm shell which was applied physical treatment at different crushing pressure of 400 J, 550 J, and 700 J, that resulted in particle size is smaller than 800 µm, 800 µm to 1 700 µm, 1 700 µm to 2 000 µm, and bigger than 2 000 µm. The adequate size of particle for briquette was found to be < 800 µm, which reached the heating value of 20 042.32 J g–1 and ash residue of 20 %. This study showed the advantages of oil palm shell briquette by using physical treatment is suitable and sustainable alternative to daily life use in Indonesia.

Kinetics of Pyrolysis of Date Kernels

The kinetics of pyrolysis of ground date kernels was investigated using thermogravimetric analysis in order to provide the necessary information for proper biochar formation and bioreactor design. Pyrolysis was carried out at heating rates of 5, 10, 15 and 20oC.min-1 in a flow of nitrogen. One main DTG peak was obtained that corresponded to formation of bio-char. A second diffuse peak corresponds to constant rate cracking of the char formed and complete elimination of carbon leaving an ash residue. The composition of biochar was determined using EDX. Four different methods were used to follow up the kinetics of the three steps, namely, the Kissinger, the Flynn-Wall-Ozawa, the Coats-Redfern methods and multi-regression analysis. The activation energy of the main decomposition step was determined and the values obtained using different kinetic models compared. The decomposition step simply followed first order kinetics.

Potencial de aplicação do resíduo de cinza de casca de arroz

The use of agricultural waste has become a necessity due to its high environmental cost. As an example of this, we have rice husk ash (CCA), produced by the indiscriminate burning of rice husk, as well as the need to look for alternatives to reuse the waste sustainably, either by applying it to nanomaterials or by extracting SiO2 present in rice husk ash. This study addresses the use of characterization techniques for rice husk ash residue, showing the quality of SiO2 present in the residue.