Mitsuhiro Sakawa

Small angle X-ray scattering study on change of fractal property of Witbank coal with heat treatment

Abstract Change in the surface fractal dimension ( D s ) of Witbank coal with heat treatment was studied using small angle X-ray scattering. It was found that D s changes systematically depending on the temperature and the heating rate. Especially in the pre-softening stage, D s decreased with increasing temperature. From thermogravimetric and differential scanning calorimetric analyses, we concluded that this was derived from a physical structural change in coal. It was also found that there are lower limits ( F min ) of fractal distribution of pore surface. Further, these limits change greatly at the threshold of the coal softening temperature. It is concluded that the physical structural change of coal takes place at lower temperatures than that thought so far, and that D s and F min are valuable parameters for representing the structural changes with heat treatment.

Influence of aluminium chloride on carbonization of coal model compounds and coal derivatives

Abstract Changes in spin concentration during carbonization of coal model compounds and coal components in the presence of AlCl 3 , a known carbonization catalyst, were studied with an e.s.r. spectrometer equipped with a high-temperature cavity. On addition of AlCl 3 the spin concentration during carbonization increased for compounds with three or fewer aromatic rings and decreased for those with four or more. Only the spin concentration of the quinoline-soluble component of a low-reflectance coal increased during carbonization in the presence of AlCl 3 . These phenomena are discussed in terms of molecular orbital theory.

E.s.r. study of formation of coke texture

Abstract The optical coke texture is a major factor in the high-temperature properties of metallurgical coke but the mechanism of formation of coke texture is not established yet. By studying the carbonization process during the formation of optically anisotropic coke with an e.s.r. spectrometer fitted with a high temperature cavity a relation between the concentration of the free-spins during carbonization and coke texture has been inferred for some organic compounds used as the model materials and for coals covering a range of coal rank.

Observation of Swelling Behavior during Carbonization by Coke Oven with X-ray Computerized Tomographic Scanner

Publisher Summary This chapter discusses the observation of swelling behavior during carbonization by coke oven with X-ray computerized tomographic scanner. Physical and chemical changes occur in the coal carbonization process in a coke oven chamber. Coal and coke are mainly composed of carbon, hydrogen, and oxygen, which are similar to the elemental constituents of the human body. The swelling of semicoke during carbonization is measured at a mean value divided into three points in the X-ray computerized tomographic scanner. The swelling of semicoke during carbonization is not only influenced by the caking properties such as total dilatation but also influenced by coal rank such as the reflectance of vitrinite. Swelling and shrinkage during carbonization are researched by the special coke oven equipped with an X-ray computerized tomographic scanner.

A study of coal utilization process by flash pyrolysis.

Coal flash pyrolysis is one of the most interesting future coal utilization technology, because the flash pyrolysis has tendency to volatilize more coal substance than that from conventional slow heating.Coal pyrolysis has been studied under various conditions by high pressure thermogravimetry and estimation model of products from coal pyrolysis.Authers proposed the conditions of coal pyrolysis from controlling products and economic points.Small scale reacters with these conditions have been constructed for getting basic and engineering data of the pilot plant.