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Since coal washeries generate huge quantities of high-ash rejects as waste, effective utilization of coal rejects help in sustainable coal preparation. Out of different coal rejects, tailings from froth-flotation process can be a potential material for the extraction of clean coal due to its fine size, availability in the slurry form, presence of good carbon values, and better liberation properties. In the present study, three different methodologies i.e., chemical method, chemico-physical method, and physical method are explored to separate clean coal with >49.8% yield for their utilization in coke making process. The chemical method of demineralization by alkali-acid leaching shows a high clean coal yield of 65.4%; however, the alteration of vitrinite-group macerals makes it unsuitable for coke making process. Chemico-physical method of clean coal separation by hydrothermal extraction followed by density separation results in clean coal at 49.8% yield with an increase in vitrinite group macerals, which shows a positive impact on rheological and coking properties. The physical separation method by ultrafine grinding followed by density-gradient-centrifugation resulted in 58.2% of clean coal yield with coking properties similar to the clean coal obtained in conventional coal beneficiation plants. By adopting chemico-physical method and physical method of coal cleaning, the overall clean coal yield of the washery can be improved by >5.1%. Also, there is no deterioration in coke properties such as coke strength after reaction and coke reactivity index by using the prepared clean coal in coal blend. [ABSTRACT FROM AUTHOR]

Handling and disposal of high volume of fine coal tailings is a biggest challenge for coal washeries. Separation of clean coal by density separation and flotation shows limited yields of 23–28% and 13–14% respectively. Chemical leaching process has a challenge with the formation of insoluble salts. The present investigation aimed to separate clean coal by a combination of chemical-physical separation technique, i.e. alkaline hydrothermal process followed by density separation. Hydrothermal extraction of humic substance causes dissociation of coal aggregated structure (Mineral-Maceral-Pore structure), thus improves the separation. Experiments performed as per design of experiments and reduced design of experiments, where 100 µ particle size, 50% (w/w) pulp density, 4.5% KOH (w/w), and 140°C reaction temperature found to be optimum, at which 16.2% ash clean coal at 40.7% yield and humic acid by-product at 18.3% yield were obtained. Use of swelling agent such as tetrahydrofuran shown negative impact on clean coal recovery. Material balance and cost data were presented to show the techno-commercial viability of this technology. [ABSTRACT FROM AUTHOR]

Present effort intends to improve the performance of gelatin based casted-films for controlled delivery of hydrophobic drugs. To achieve this goal, Piperine (a model drug) was loaded into gelatin (type A) casted-films by solvent evaporation method. Glutaraldehyde was used as a cross-linker for the gelatin films to modulate the drug release behavior and to prolong the rate of degradation of the film.In-vitrodegradation study under physiological conditions and thermal analysis through differential scanning calorimetry were performed to confirm stability of the gelatin casted-film matrix. Aim was to control the drug release from films by varying the cross-linking degree and the gelatin concentration. Optical microscope analysis was performed to study the surface topography of the sample. In order to understand the drug–polymer interaction in the film, attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) analysis was done. Thein-vitrorelease study gave an overall idea of the role of cross-linkers, gelatin concentration, and effect of pH on the release profiles of Piperine. Results show that one can effectively use gelatin casted-film based drug delivery systems for a wide range of release requirements, i.e., from fast release to delayed release. [ABSTRACT FROM PUBLISHER]

Despite the established superiority in finding the global as well as well-spread Pareto optimal (PO) points, the need of more numbers of function evaluations for population based evolutionary optimization techniques leads to a computationally demanding proposal. The case becomes more miserable if the function evaluations are carried out using a first principle based computationally expensive model, making the proposal not fit for online usage of the application. In this work, a Kriging based surrogate model has been proposed to replace a computationally expensive model to save execution time while performing an optimization task. A multi-objective optimization study has been carried out for the bulk vinyl acetate polymerization with long-chain branching using these surrogate as well as expensive models and Kriging PO solutions similar to those found by the first principle models are obtained with a close to 85% savings in function evaluations. [ABSTRACT FROM PUBLISHER]

Inclusion of long chain branching (LCB) in polymers is a challenging and important task in any free radical polymerization as LCB influences polymer product quality. In the present case, batch optimization study for the bulk polymerization of vinyl acetate has been considered to find optimal process conditions for imparting LCB in polymer architecture. A theoretical study has been conducted with a validated model to observe the effect of live radical concentration on LCB as this is an important factor for branching in polymer via chain transfer to polymer route. In order to obtain better polymer product in less time at various temperatures, a need was observed to perform a multi-objective optimization study as the selected objectives were conflicting in nature. Owing to the complex nature of moment-based species balance equations and molecular weight distribution function, elitist non-dominated sorting genetic algorithm II (NSGA II), a well-established multi-objective evolutionary algorithm, has been employed as an evolutionary computation method to find out the Pareto optimal solutions. Minimization of polymerization time, maximization of molecular weight and maximization of number average degree of branching (Bn) can be simultaneously achieved, while the solutions were obtained within the experimental range of polydispersity index and weight average molecular weight (Mw) given in the open literature. Results show a wide range of process choices satisfying process objectives and constraints, both in low as well as high temperature regions. [ABSTRACT FROM PUBLISHER]

Tetrabutoxytitanium (TBOT) is a proven catalyst for the esterification step of the polypropylene terepthalate (PPT) polymerization process. Previous studies show that the performance of TBOT is superior in terms of the enhanced degree of polymerization and less processing time to other competitive catalysts. But, interesting observation left was to investigate whether with other process objectives like by-product minimization and controlled growth of desired functional groups, any other catalyst offers better system performance or not. Present study carries out the exercise of searching other catalytic options along with TBOT for the process improvements and gives a detailed process analysis through different sets of optimized operations. A well-validated kinetic model for esterification step of PPT polymerization process and the advanced Real-Coded Nondominated Sorting Genetic Algorithm-II (Real-Coded NSGA-II) optimization routine have been used in this current effort. For process objectives like by-product minimization, TBOT though become a marginal winner, Sn- and Zn-based catalysts compete with each other. Zn-based catalyst is found probably the most suitable catalyst in terms of the overall process performance with excellent by-product minimization (∼10 times better), higher degree of polymerization (∼1.75 times better), and tight quality control (∼5 times better). [ABSTRACT FROM AUTHOR]