Pinakpani Biswas

Optimization of Solvent Extraction Process Parameters of Indian Coal

Medium coking coals from West Bokaro coalfield, India, were extracted with N-methyl-2-pyrrolidone (NMP) and ethylenediamine (EDA) under reflux condition at atmospheric pressure. The objective of the study was to maximize the clean coal yield maintaining the specified clean coal ash content. Experimentations using three level full factorial designs were carried out to elucidate the importance of variables such as extraction time, coal to solvent ratio, and filtration mesh size upon solvent extraction of coal. To determine the significance of the effects, Pareto chart, residual analysis, and surface plots were used. It was found that the maximum extraction yield was obtained for 1 h extraction time and 1:12 coal to solvent ratio. Finer mesh (0.025 mm) size in filtration was found favorable in producing low ash clean coal (CC). Under optimum conditions it was possible to produce clean coal with 6% ash and 55% yield for coals having about 29% ash.

Characterization of Solvent Extract of an Indian Coal

This article describes characterization of a solvent-extracted Indian coal obtained from four different seams of the West Bokaro coal mines. The coal samples were extracted with the solvent N-methyl-2-pyrrolidone. Ethylenediamine was used as co-solvent. Extracts were analyzed for elemental, microscopical and swelling properties. Functional group analysis was conducted using the Fourier transform infrared spectroscopy (FTIR). A comparative study made with parent coal showed that extraction with organic solvent brings about a considerable increase in lower molecular weight organic components, lowers the ash content and improves the swelling property of coal. FTIR studies provided some information about the functional group present in the parent and extracted coals.

Characterization and Utilization of Organo-Refined Extract in Metallurgical Coke Making

ABSTRACT High-ash Indian coals and washery discards were extracted using an organic solvent. Complete characterization study was carried out in order to measure its coking potential. The study revealed that swelling and thermoplastic properties of the extracts are better as compared to the parent coals. A new concept for studying the thermoplastic behavior of coal is introduced to access the coking potential of parent and extracted coal. A series of carbonization tests was performed considering organic extracts as one of the blend components. The carbonization study reflects that the addition of an optimum amount of extracts in the base-coal blends helped in improving the properties of metallurgical coke.

Backstepping control of polymerization reactor

This paper presents adaptive backstepping methodology for controlling polymerization process under parametric uncertainty and input saturation. In general controlling complex chemical processes is a challenging problem due to the structural mismatch and uncertainty of parameters. Adaptive algorithm, whether linear or non-linear, is an essential tool to control such processes. Normally, nonlinear adaptive controllers are designed based on stability of Lyapunov functions. A recursive backstepping design approach is applied here for constructing Lyapunov functions and designing nonlinear control laws for controlling temperature and monomer concentration of polymerization process. The adaptive algorithm is also able to tackle other parametric uncertainties along with input saturation. The controller structure has a strong disturbance rejection capability and also robust to model uncertainties for polymerization process. A number of parameters are adapted for obtaining better result and the controller gives a stable performance in presence of significant parametric uncertainty. The proposed adaptive controller is capable of handling both matched and unmatched uncertainties.