Experimental Investigation of Pyrolysis Process of Agricultural Biomass Mixture

This paper describes an experimental investigation of pyrolysis process of agricultural biomass mixture, without the addition of inert gas. The mixture consists of corn stalk, wheat straw, soy straw and oat straw with equal mass fractions. During the experiment, the mass of biomass sample inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650ºC at average heating rates of 21, 30 and 54ºC/min. The sample mass before, during and after pyrolysis was determined using a METTLER P1000 digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas, achieved at 650ºC, was in the range from 74 to 81%, while char yield ranged from 19 to 26%. Heating rate of biomass mixture sample has significant influence on the pyrolytic gas and char yields. It was determined that higher heating rates in the reactor induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650ºC produced 1.3-1.8 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as agricultural biomass pyrolysis equipment

EXPERIMENTAL EXAMINATION OF SULPHUR DIOXIDE SEPARATION FROM MIXTURE OF GAS IN DRY PROCEDURE WITH THE AID OF CALCIUM CARBONATE

This paper refers to an experiment of SO2 absorption to the particles of sorbent CaCO3, the mass of sample was 100 g with fractional composition of 500-700µm and 1100-1300μm. During the experiment the temperature varied from 200 and 400°C. The aim of this experiment described in this paper, is to examine the influence of lower reaction temperature, the size of sorbent particles and reaction time to the degree of SO2 absorption and determining the degree of CaCO3 sorbent utilization. The results show that at the reaction temperature of approximately 200°C and average diameter of sorbent particles ≈600μm, the absorption degree of SO2 absorption to the particles of sorbent is between 42-66%.Reaching temperature of 400°C and with the same fractional composition of the sorbent, ≈600μm, the absorption degree of SO2 is slightly higher and it is somewhere around 45-78%. With greater diameters sorbent particle of ≈1200μm, absorption degree of SO2 is a bit lower.The determined degree of utilized sorbent CaCO3 is considerably lower and it reaches up to 6.87%.The acquired results indicate that besides CaO,Ca(OH)2 and CaMg(CO3)2 it is reasonable to inject the CaCO3 sorbent, in the areas of lower temperatures i.e. in the flue channel of the thermal power plant

Qualitative analysis of coal combusted in boilers of the thermal power plants in Bosnia and Herzegovina

In this paper we have looked into the qualitative analysis of coals in Bosnia and Herzegovina (B-H). The analysis includes the following characteristics: moisture (W), ash (A), combustible matter (Vg) and lower heating value (Hd). From the statistic parameters we have determined: absolute range (R), arithmetic mean (X), standard deviation (S) and variations coefficient (Cv). It has been shown that the coal characteristics (W, A, Vg, Hd) have normal distribution. The analysis show that there are considerable deviations of ash characteristics: moisture (36.23%), ash (34.21%), combustible matter (16.15%) and lower heating value (25.16%) from the mean value which is shown by the variations coefficient (Cv). Large oscilations of mass portions: W, A, Vg and Hd around the mean value can adversely influence the function of a boiler plant and an electric filter plant in thermal power plants in B-H in which the mentioned types of coal burn. Large ash oscilations (34.21%) around the mean value point out to the inability of application of dry procedures of desulphurisation of smoke gasses (FGD) due to the additional quantity of ash. It has been shown that the characteristics of Bosnian types of coal do not deviate a lot from the characteristics of coal in the surrounding countries (coals of Serbia and Monte Negro). The results can be used in analysis of coal combustion in thermal power plants, optimisation of electrical-filtre, reduction of SO2 in smoke gas and other practical problems