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Proceedings ArticleDOI

Gasification of Indian Coal in a Tubular Coal Gasifier

TL;DR: In this paper, the numerical simulations have been performed on gasification performance of three types of Indian coals in atmospheric as well as pressurized conditions in an entrained flow, air-blown tubular gasifier.
Abstract: In spite of the high ash content, Indian coals have been widely used for the generation of power and industrial steam in India. Being considered as the technology for future in terms of efficiency and cleaner environment, coal gasification carries much importance since India has a large amount of coal reserves. In this paper, the numerical simulations have been performed on gasification performance of three types of Indian coals in atmospheric as well as pressurized conditions in an entrained flow, air-blown tubular gasifier. In the model, continuous phase conservation equations are solved in an Eularian frame and those of particle phase are solved in a Lagrangian frame, with coupling between the two phases incorporated through interactive source terms. Phenomena such as devolatilisation, combustion of volatiles, char combustion & gasification and the dispersion of coal particles due to turbulence are taken into account. The P-1 model has been adopted for radiative heat transfer in which scattering is taken into account for the particles. It is observed that as the ash percentage increases, the heat and mass transfer are strongly affected and the gasification performance decreases. This is attributed to the lower char reactivity due to thick ash layers and lower oxygen and other gas diffusion rates. Various regions such as devolatilisation, combustion and gasification zones inside the gasifier have been identified using the temperature plots, devolatilisation plots and mass depletion histories of coal particles. The overall gasification performance indices such as carbon conversion, heating value of the exit gas and cold gas efficiency have been predicted.Copyright © 2007 by ASME
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Journal ArticleDOI
TL;DR: A review of the literature pertaining to petcoke gasification has been extensively analysed and a state-of-the-art review has been written that includes: (1) the importance of pet coke (petcoke) gasification in the present petroleum refining scenario; (2) petcoce gasification reaction mechanism, kinetics, and typical product profile; (3) parametric sensitivity of the operating variables such as temperature and pressure; (4) various gasifiers for PETCOKE gasification; (5) modelling efforts on different types of gasifiers and
Abstract: The production of petroleum coke (petcoke) in the refineries is progressively peaking up because of the trend of processing heavy crudes and in turn, a renewed interest in delayed coking process. Therefore, an efficient, economical, and environmentally safe utilisation of petcoke has become imperative in the current petroleum refining scenario. Gasification of petcoke has emerged as one of the attractive options and is gaining increasing attention to convert the petcoke to value-added products. The process offers the refiners a variety of product slates mainly via synthesis gas route. The products include steam, hydrogen, electricity, chemicals (viz. methanol, ammonia, etc.), liquid fuels via Fischer–Tropsch (F-T) synthesis and so on. Petcoke has been identified as a potential feedstock for about 15% of the total planned gasification capacity worldwide. In the present communication, the published literature pertaining to petcoke gasification has been extensively analysed and a state-of-the-art review has been written that includes: (1) the importance of petcoke gasification in the present petroleum refining scenario; (2) petcoke gasification reaction mechanism, kinetics, and typical product profile; (3) parametric sensitivity of the operating variables such as temperature and pressure; (4) various gasifiers for petcoke gasification; (5) modelling efforts on different types of gasifiers and (6) future prospects of petcoke gasification. An attempt has been made to get the afore-mentioned aspects together in a thematic framework so that the information is available at a glance and is expected to be useful as a single point source to the researchers and practicing refiners.

95 citations

Journal ArticleDOI
TL;DR: Wang et al. as mentioned in this paper put forward several suggestions to promote the modernization of the coal chemical industry: 1) The responsibilities, supervision tasks, scope, and implementation rules of local environmental law enforcement and supervision agencies should be improved and clarified at all levels.
Abstract: The current situation of China's coal chemical industry faces many problems: 1) This industry causes environmental pollution; 2) employs inadequate environmental management system, wastewater pollution control standards, and energy consumption standards; 3) lacks environmental standards applicable to the coal chemical industry; 4) suffers from poor implementation of technical standards for coal use; 5) and lacks top-level design of a high salinity wastewater standard. A modern coal chemical industry demonstration area should be established to promote industrial agglomeration and development. Therefore, several suggestions are put forward to promote the modernization of the coal chemical industry: 1) The responsibilities, supervision tasks, scope, and implementation rules of local environmental law enforcement and supervision agencies should be improved and clarified at all levels; consequently, law enforcement and supervision work would be backed up by relevant laws. 2) To decrease the treatment cost of highly saline wastewater, a corresponding subsidy scheme should be formulated. 3) Research on the top-level design of the standard system for saline wastewater should be accelerated to standardize the treatment of saline wastewater. 4) Coal chemical enterprises should integrate environmental management into their daily production management system, constantly improve their management level, and reduce pollution generation and emission. 5) Furthermore, it is necessary to consider the recycling of wastes and both the separation and recovery of valuable resources as part of the treatment of wastewater from the coal chemical industry. 6) Moreover, economic policies can be used because economic leverage may be more effective than administrative orders or even regulations. 7) Finally, cooperation should be increased to promote the “green development, circular development, and low-carbon development” of the modern coal chemical industry.

70 citations

01 Jan 2010
TL;DR: In this paper, the authors present a Dissertation that is protected by copyright and/or related rights, which is brought to you by ScholarWorks@UNO with permission from the rights-holder(s).
Abstract: This Dissertation is protected by copyright and/or related rights. It has been brought to you by ScholarWorks@UNO with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself.

5 citations


Cites background from "Gasification of Indian Coal in a Tu..."

  • ...Ajilkumar et al. (2007) performed numerical study of gasification of Indian coal which has high ash content. They observed that as the ash content increases, the heat and mass transfer are affected and the gasification performance decreases. They suggested that this is attributed to the lower char reactivity due to thick ash layers and lower oxygen and other gas diffusion rates. They also found that increasing the temperatures of inlet air and steam reduces CO, but increases H2, CO2, and carbon conversion. Steam addition decreases the temperature but increases H2 production at the expense of CO. Govind and Shah (1984) conducted a numerical study on Texaco downflow entrainedflow which used coal liquefaction residues and coal-water slurries as feedstocks....

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  • ...Ajilkumar et al. (2007) performed numerical study of gasification of Indian coal which has high ash content....

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  • ...Ajilkumar et al. (2007) performed numerical study of gasification of Indian coal which has high ash content....

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