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Despite many advantages of the utilization of biomass as a renewable energy source, certain bottlenecks during biomass plant operation can be identified. Transport and collection of biomass as well as non-uniform material characteristics are issues related to decreasing efficiency of logistics and fuel manipulation which can also cause economic problems with biomass collection, transport, and storage. Since biomass is an especially reactive fuel, this has raised concerns over its safe handling and utilization. Fires, and sometimes explosions, are a risk during all stages of fuel production as well as during handling and utilization of the product. This paper presents a novel method for assessing ignition risk and provides a ranking of relative risk of ignition of biomass fuels. Tests within this method include physical and chemical properties of biomass, thermal analysis measurements, and the calculation procedure steps which were made using characteristic temperatures from thermogravimetry recordings. The results of thermogravimetry analysis were used for determination of tangent slope of the mass loss rate curves in devolatilization zone at considered heating rates for all tested samples. Linear interpolation of the data obtained by tangent slope analysis and used heating rates may provide unique straight line for each sample in the ignition testing. Thermogravimetry index of spontaneous ignition (TGspi) is obtained for all samples based on newly established formula. By varying gradient of linear dependence of self-heating coefficient against reference temperatures, mass and heat transfer limitations for various biomasses were discussed. The proposed method is accurate as well as relatively simple and quick, enabling determination of data necessary for design and application of appropriate measures to reduce fire and explosion hazard related to operation of biomass.

Slow pyrolysis (gradual heating over a wide range of temperatures) characteristics of various biomasses (corn brakes, wheat straw, and hazelnut shell) were investigated by simultaneous thermal analysis (STA-TGA-DTG-DSC), coupled with mass spectrometry. Thermal decomposition of these samples was divided into three stages corresponding to removal of water, devolatilization, and formation of bio-char. It was found that differences in thermal behavior of the samples are due to differences in their composition. The mass spectrometry results showed that H2, CH4 , H2O, CO2 (C3H8), CO, and C2H6were main gaseous products released during pyrolysis. Within the pyrolysis processes, it was found that CO can be used on the large scale for production of CO-rich syngas.

The development of carbon materials with desirable textures and new aqueous electrolytes is the key strategy to improve the performance of supercapacitors. Herein, a deep eutectic solvent (DES) was used for in situ templating of a carbon material. A carbon material was characterized (XRD, N2-physisorption, FTIR, SEM and EDS) and used as an electrode material for the first time in multivalent-based supercapacitors. In situ templating of carbon was performed using a novel DES, which serves as a precursor for carbon and for in situ generation of MgO. The generation of MgO and its roles in templating of carbon were discussed. Templating of carbon with MgO lead to an increase in surface area and a microporous texture. The obtained carbon was tested in multivalent-ion (Al3+ and Mg2+) electrolytes and compared with H2SO4. The charge-storage mechanism was investigated and elaborated. The highest specific capacitance was obtained for the Al(NO3)3 electrolyte, while the operating voltage follows the order: Mg(NO3)2 > Al(NO3)3 > H2SO4. Electrical double-layer capacitance (versus pseudocapacitance) was dominant in all investigated electrolytes. The larger operating voltage in multivalent electrolytes is a consequence of the lower fraction of free water, which suppresses hydrogen evolution (when compared with H2SO4). The GCD was experimentally performed on the Al(NO3)3 electrolyte, which showed good cyclic stability, with an energy density of 22.3 Wh kg−1 at 65 W kg−1.

The preliminary thermogravimetric studies of co-pyrolyzed low rank coals (lignites Kostolac and Kolubara) with waste materials (spent coffee ground and waste rubber granulate) in a form of blends have been performed. Thermal analysis measurements of blend samples were carried out in a nitrogen, atmosphere at three different heating rates of 10, 15, and 20 K per minute. The coal-waste blends were prepared in the percentage ratios of 90:10, 80:20, and 70:30. This work analyzed the synergy analysis for considered blends shown via descriptive parameters during co-pyrolysis process. According to the performed analysis, the presence of synergistic effect was identified, where strong interactions were also observed. For lignite-spent coffee ground blends, it was found that two factors which affect the synergy effect with coal are concentration of added biomass material and the heating rate. For lignite-tire rubber granulate blends, the blending ratio take on a decisive role for positive consequences of a synergistic effect (ratios below 30% of tire rubber granulate in coals are desirable). Also, in this work the influence of micro-scale condition parameters such as heating rate (as the experimental regulatory factor) was analyzed on the magnitude response of synergism during co-pyrolysis.

The pyrolysis process of various types of biomass (agricultural and wood by-products) in non-isothermal conditions using simultaneous thermal analyses (STA) was investigated. Devolatilization kinetics was implemented through combined application of model-free methods and DAEM (distributed activation energy model) using Gaussian distribution functions of activation energies. Results obtained were used in the curve prediction of the rate of mass loss against temperature at various heating rates by numerical optimization. The possible calculation of biomass samples behavior under pyrolytic conditions as the summation of their pseudo-components, hemicelluloses, cellulose, and lignin is also explored. The differences between experimental and calculated data are less than 3.20% offering a quality test of applicability of proposed model on the kinetic studies of a wide range of biomass samples. It seems that the most physically realistic model is the decomposition of biomass in three reactions, depending on the composition of the biomass regarding hemicelluloses, cellulose, and lignin. Kinetic model applied here may serve as a starting point to build more complex models capable of describing the thermal behavior of plant materials during thermochemical processing.

Goal of this work is to establish technical feasibility and fundamentals of producing activated carbon from plane tree seeds biomass for porous materials derivation. Bio-chars produced via carbonization from plane tree seeds precursor were activated in CO2 at 750 and 850?C, during various residence times. Their surface area and porosity were characterized by N2 adsorption at 77 K. Surface areas of activated carbons can be correlated with kinetics mechanism and activation energy magnitudes of oxidation reaction by CO2, which are closely related to applied activation temperature. Result showed that high temperature activated carbon had higher gas adsorption as compared to activated carbon obtained from lower temperature during two-hour residence time. Breakthrough behavior was detected at 850?C where surface reactions dominate, and it is characterized by autocatalytic kinetic model under designed conditions. Both, temperature and CO2 concentration in vicinity of solid surface effect on breakthrough time of adsorbent. Derived bio-chars are converted into high quality activated carbons, with surface area of 776.55 m2/g, where micro-pores with pore diameters less than 2 nm prevail. Produced activated carbons have properties comparable with commercially available activated carbons, which can be successfully used for removal of harmful gaseous pollutants toward air purification.