The Response of Electronic And Energetic Properties of Two Types of The Sp-hybridised Carbon-Carbon Bonds To An External Uniform Electric Field

The susceptibility of electronic and energetic properties of two sets of molecules to perturbation in a uniform electric field was investigated. The molecules of one set were (10)cumulenes terminated with two functional groups, R1 and R2; those of the second set were (10)polyyenes substituted with the same R1 and R2 groups. The cumulene and polyyne molecules had similar lengths of the system of conjugated bonds between the two most extreme carbon atoms. Dipole moments and polarizabilities of the molecules were used as determinants of the overall charge transfer between polar groups and their modifications due to the application of an external electric field. The field was directed along the main (longest) axis of the molecules from the negative to the positive pole. Comparison of the polarizability values revealed that they were higher in the (10)cumulenes than in the (10)polyynes. Parabolic dependence of the molecular energy as function of field strength can be interpreted in terms of the response of electron density to an electric field.

Evaluation of Mechanical and Energetic Properties of the Forest Residues Shredded Chips during Briquetting Process

The briquetting process is one of methods of solid biofuel production. During the briquetting of raw material, it can be noticed that material is viscoelastic, and reflects the effect on the volume and the final effect of the agglomerate during mentioned treatment. The research aimed to evaluate the mechanical and energetic properties of shredded pine forest residues during the briquetting process. The shredded fragments of the forest residues were compacted by the principal stresses with determination of the energy value consumed during the briquetting process. Tests were carried out using a specially designed compacting tube, with additional equipment directly mounted on the testing machine. The compaction process was carried out using the presented material and through continuous monitoring of the process parameters. During the study, it was estimated that the moisture content of the compacted material should be equal from 10 to 15%. The calculated average value of the unit energy consumption during the briquetting process (WB) was equal to 0.14 MJ·kg−1. In future research, the mathematical model can serve as an algorithm in a computer program in order to calculate the flow of biomass in the extrusion process.

Analysis of briquettes and pellets obtained from two types of Paulownia (Paulownia tomentosa and Paulownia elongata) sawdust

Sawdust specimens of two Paulownia species, namely Paulownia tomentosa and Paulownia elongata, were evaluated in order to obtain briquettes and pellets. Briquettes and pellets were manufactured from the sawdust, and their physical properties (density), mechanical properties (the resistance of the briquettes to breaking, and the shear resistance of the pellets), and energetic properties (caloric value, black ash content, and calcined ash content) were determined. The densities of the P. elongata and P. tomentosa briquettes were 790 kg/m3 and 934 kg/m3, respectively, while the pellets had densities of 1268 kg/m3 and 1266 kg/m3, respectively. These values were within the standardized limits, and the ash content had good values. The high calorific value of 16815 kJ/kg and the low calorific value of 16669 kJ/kg was acceptable, since they were greater than other vegetable resources. In conclusion, it was found that the two types of wood biomass are suitable for the production of briquettes and pellets, due to their good physical, mechanical, and energetic properties.