Stanisław Porada

Formation of C1C3 hydrocarbons during pressure pyrolysis and hydrogasification in relation to structural changes in coal

A comparative study on pyrolysis and hydrogasification of a bituminous coal was conducted under non-isothermal heating at 3 K min−1 to 1200 K. The kinetics of C1C3 hydrocarbon formation were measured and total yields of the products were evaluated. The chemical and optical structures of the coal chars obtained at different temperatures were also investigated. At temperatures > 750 K, the influence of gas atmosphere (Ar or H2) on the kinetics of hydrocarbon formation was found significant. The use of hydrogen atmosphere even at the relatively low experimental pressure of 2.5 MPa resulted in a high conversion (40%) of carbon to C1C3 hydrocarbons as well as in inhibition of the formation of optical anisotropic structures in the char.

The influence of coal rank on formation of gaseous hydrocarbons in hydrogasification of coal

The kinetics of the formation of C1C3 hydrocarbons in hydrogasification of six coals covering a range of metamorphism were investigated. All experiments were carried out under non-isothermal heating conditions at the rate of 3 K min−1 from ambient to 1200 K and under 2.5 MPa of hydrogen. Conversion ratios of carbon to the hydrocarbons as well as yields of the hydrocarbons in hydrogasification of the coals were calculated. Highest conversions to total gaseous products were observed for the medium-rank coals. Highest yields of methane were obtained with the older coals, whilst maximum yields of ethane and propane were obtained with the medium-rank coals.

Studies of catalytic coal gasification with steam

Abstract One of the promising processes, belonging to the so-called clean coal technologies, is catalytic coal gasification. The addition of a catalyst results in an increased process rate, in which synthesis gas is obtained. Therefore, the subject of this research was catalytic gasification of low-ranking coal which, due to a high reactivity, meets the requirements for fuels used in the gasification process. Potassium and calcium cations in an amount of 0.85, 1.7 and 3.4% by weight were used as catalytically active substances. Isothermal measurements were performed at 900°C under a pressure of 2 MPa using steam as a gasifying agent. On the basis of kinetic curves, the performance of main gasification products as well as carbon conversion degree were determined. The performed measurements allowed the determination of the type and amount of catalyst that ensure the most efficient gasification process of the coal ‘Piast’ in an atmosphere of steam.

Kinetics of the formation of C1-C3 hydrocarbons in pressure pyrolysis of coal

Abstract The kinetics of the formation of C 1 -C 3 hydrocarbons and hydrogen in the pyrolysis of one soft brown coal and two hard coals were investigated under pressures of 0.1–10 MPa, utilizing comparable residence times for the volatile pyrolysis products in the reaction zone. Both methane and hydrogen were found to be formed in several groups of reactions occurring over relatively broad temperature intervals. Increased pressures caused higher yields of saturated hydrocarbons and lower yields of hydrogen. The best fit of the kinetics curves was obtained using the second-order reaction approximation. Based on that, formal kinetic parameters of the reactions were calculated.