Showing papers on "Carbochemistry published in 2011"
TL;DR: In this article, a review of studies on coal pertinent to carbon dioxide (CO2) sequestration in coal with specific reference to Victorian brown coals is presented, and coal gas permeability and gas sorption are considered, and the physical factors which affect them are examined.
Abstract: This paper presents reviews of studies on properties of coal pertinent to carbon dioxide (CO2) sequestration in coal with specific reference to Victorian brown coals. The coal basins in Victoria, Australia have been identified as one of the largest brown coal resources in the world and so far few studies have been conducted on CO2 sequestration in this particular type of coals. The feasibility of CO2 sequestration depends on three main factors: (1) coal mass properties (chemical, physical and microscopic properties), (2) seam permeability, and (3) gas sorption properties of the coal. Firstly, the coal mass properties of Victorian brown coal are presented, and then the general variations of the coal mass properties with rank, for all types of coal, are discussed. Subsequently, coal gas permeability and gas sorption are considered, and the physical factors which affect them are examined. In addition, existing models for coal gas permeability and gas sorption in coal are reviewed and the possibilities of further development of these models are discussed. According to the previous studies, coal mass properties and permeability and gas sorption characteristics of coals are different for different ranks: lignite to medium volatile bituminous coals and medium volatile bituminous to anthracite coals. This is important for the development of mathematical models for gas permeability and sorption behavior. Furthermore, the models have to take into account volume effect which can be significant under high pressure and temperature conditions. Also, the viscosity and density of supercritical CO2 close to the critical point can undergo large and rapid changes. To date, few studies have been conducted on CO2 sequestration in Victorian brown coal, and for all types of coal, very few studies have been conducted on CO2 sequestration under high pressure and temperature conditions.
97 citations
TL;DR: In this paper, two Chinese coals were used for coal blending to study the effects of mineral matter and coal blending on gasification, and the Fourier transform infrared (FTIR) spectrum indicated the existence of iron oxides, which was verified by FactSage.
Abstract: Two Chinese coals were used for coal blending to study the effects of mineral matter and coal blending on gasification. The transformational behaviors of blending coals were studied with FactSage thermodynamic calculation. Most mineral matter was transformed into Ca aluminosilicates and mullite at high temperatures. High-temperature gasification was performed from 1100 to 1500 °C to examine the gasification behavior of blended chars. Considering the viscosity results of coal ash from blending coals, the melting ash was assumed to hinder the gasification reactions at high temperatures. The Fourier transform infrared (FTIR) spectrum indicated the existence of iron oxides, which was verified by FactSage, and iron oxides led to thermal carbon reactions that promoted the gasification reactions.
37 citations
TL;DR: In this paper, the association of the minerals and macerals in individual coal particles is discussed. But, the focus is on the coal that is suited to beneficiation techniques that can be employed to produce the low-ash value coals required for these markets.
Abstract: Emerging coal markets such as the use of coal for conversion to liquid fuels and its use in fuels cells and as coal water slurries in diesel engines require coal products with different coal quality specifications than those applicable to traditional coal markets of coke making and conventional power generation As well as quantifying coals in terms of their chemical and physical properties, detailed knowledge of the mineral inclusions within the coal particles is required to identify coals that are suited to economically produce the low-ash value coals required for these markets Hence, it is necessary to understand the associations of the minerals and macerals in individual particles as these give a particular coal not only its chemical attributes and utilization performance but also its washability (density distribution) and contribute to its surface chemistry characteristics These attributes pinpoint the coals that are suited to beneficiation techniques that can be employed to produce economic amount
21 citations
Patent•
21 Jul 2011
TL;DR: In this paper, a composite process for coal gasification is presented, which is a process for the simultaneous use of a fluidized bed gasification method and a slag entrained bedgasification method.
Abstract: The title of the present invention is a composite process for powered coal gasification, which belongs to the field of the coal chemical industry. It is a process for the simultaneous use of a fluidized bed gasification method and a slag entrained bed gasification method in a coal gasification system to solve the problems of the coal gasification system, in having a very complicated structure, heavy investment, being difficult to maintain, and having high energy consumption and high operating costs. These make it simple for raw material coal to be treated, transported and added, with no need for special nozzles for coal gasification of raw material coal, thereby making it easy to separate gas from slag. Thus the complexity of the coal gasification system is reduced, thereby reducing energy consumption and the manufacturing and operating costs of the coal gasification system. The present invention can be applied to various powdered coal gasification processes.