TO INVESTIGATE THE LIQUEFACTION OF INDIVIDUAL MACERALS AND MACERAL CONCENTRATES IN A REACTOR WHERE PRODUCTS ARE CONTINUOUSLY SWEPT OUT OF THE REACTION ZONE BY FLOW OF SOLVENT SO AS TO MINIMIZE RETROGRESSIVE REACTIONS OF PRODUCT SPECIES.
Pyrolysis and liquefaction experiments were performed on sets of whole coals and maceral concentrates and work done on the analytical characterisation of the products. The liquefaction behaviour of individual coal maceral concentrates was investigated using a novel flowing solvent reactor. The design of the reactor enables time and temperature profiles to be accurately specified and closely controlled. In order to minimise secondary reactions of product species, reaction products are continuously swept out of the reaction zone by a flow of liquefaction solvent vehicle. Conversions from the flowing solvent reactor were compared with results from a minibomb reactor and the effect of extended residence times of products in the reaction zone of batch reactors was investigated. Parallel atmospheric pressure and vacuum pyrolysis experiments were carried out in a wire mesh reactor (similarly designed to minimise secondary reactions of products of primary release) in order to compare product yields and structures between pyrolysis and liquefaction.
A DESCRIPTION OF THE PRIMARY LIQUEFACTION REACTIONS OF COAL MACERALS WOULD BE ADVANTAGEOUS IN PREDICTING THE LIQUEFACTION BEHAVIOUR OF DIFFERENT COALS AND MIGHT ENABLE MORE EFFECTIVE LIQUEFACTION REACTORS AND LIQUEFACTION CATALYSTS TO BE DEVELOPED. A NOVEL SWEPT-BED REACTOR (DEVELOPED UNDER CONTRACT EN3V003700) WILL BE USED TO STUDY THE LIQUEFACTION BEHAVIOUR OF COAL MACERALS AND MACERAL CONCENTRATES AS A FUNCTION OF HEATING RATE, PEAK TEMPERATURE, PRODUCT RESIDENCE TIME IN THE REACTION ZONE, PRESSURE AND SOLVENT CHARACTERISTICS, UNDER CONDITIONS WHERE SECONDARY REACTIONS ARE MINIMIZED.
PYROLYSIS PRODUCT DISTRIBUTIONS OF WHOLE COALS AND INDIVIDUAL COAL MACERALS WILL BE MEASURED IN A " WIRE-MESH" PYROLYSIS REACTOR, CAPABLE OF PYROLYSIS OVER A VERY WIDE HEATING RATE RANGE: VITUALLY ZERO TO 6000K/S.
THE ADVANTAGE OF THIS REACTOR IS THE MINIMIZATION OF SECONDARY REACTIONS UNDERGONE BY PYROLYSIS PRODUCTS. THE UTILITY OF PYROLYSIS PRODUCT DISTRIBUTIONS IN PREDICTING LIQUEFACTION YIELDS WILL BE ASSESSED BY CORRELATING RESULTS BETWEEN THE TWO REACTORS CITED ABOVE.
THE PROJECT IS BEING CARRIED OUT COLLABORATION WITH THE LABORATOIRE REACTIVITE DE SURFACE ET STRUCTURE, UNIVERSITY OF PARIS VI, WHERE COMPLEMENTARY MACERAL LIQUEFACTION EXPERIMENTS WILL BE PERFORMED USING A MICROBOMB REACTOR.