Coal has an exceptional position in the Polish economy both as a major indigenous source of energy and an important raw material for chemical and carbon industries. This review outlines the current situation and prospects in production and utilization of solid fossil fuels in Poland. Principal research centers dealing with science and technology of coal and related materials are presented. Some recent research activities in the field are summarized, particularly concerning fundamental studies on the structure and properties of coal, metallurgical coke manufacture, clean coal technologies, coal liquefaction, and the use of coal and its derivatives as precursors of carbon materials.
The effects of mild acid and/or tetralin treatments on the flash pyrolysis reactivity of Wandoan coal were investigated in order to improve the product distribution as well as to modify the properties of the char. The reactivity of Wandoan coal at 590°C for 5sec by Curie-point pyrolyzer was improved by hydrogen chloride or acetic acid aq./20 vol% alcohol pretreatment, the char yield being decreased with increased yields of gas and tar. Impregnation of tetralin also reduced the char yield to 63.5%. A combination of acid and tetralin pretreatments slightly reduced further the char yield. The porosity (area) of the pyrolyzed char was influenced very much by the acid treatment. The macropores of which areas ranging from 205 to 411μm2 were increased significantly by the acetic acid pretreatment. These results revealed that such acid pretreatments may enhance the gasification and the volatilization of tar fraction and improved the fusibility of coal to enlarge the porosity.
Hot surface ignition of methane-air mixtures has been experimentally studied in normal gravity and microgravity. The primary aim of this research is to explain the effects of natural convection and catalytic reaction on the hot surface ignition in a closed vessel. The hot surfaces used are platinum wire for catalyst and nickel wire for non-catalyst. In order to define the initial condition and make the analysis simple, the following control unit was developed; which heats the wire to the setting temperature in a very short time, and maintains the wire temperature constant until ignition. From experimental results, ignition temperatures with platinum wire are higher than those with nickel wire by the catalytic inhibition of ignition due to the reactant depletion on the surface of the wire. Ignition temperatures with platinum wire are highest near the stoichiometric mixture ratio and decrease with equivalence ratio depart from stoichiometric mixture ratio, while those with nickel wire increase with equivalence ratio. Ignition temperatures in normal gravity are higher than those in microgravity. Natural convection supplies reactants to the platinum wire surface, and therefore reactants are consumed because of promoting catalytic reaction in normal gravity.