Journal of Scientific and Technical Research (Sharda University, Noida)

Rupsha Bhattacharyya ¹

Affiliations
1 Heavy Water Division, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra, IN

Abstract

Desalination of sea water using selectively permeable reverse osmosis membrane modules has emerged as a possible long term solution to the global problem of potable water shortage. These aromatic polyamide based modules have a useful working life of about 2-3 years and the spent membranes will have to be handled at the desalination plant site itself. An on-site incineration plant with advanced flue gas conditioning and immobilization provision has been proposed as the solution to this problem. The polymeric membrane modules will be completely converted to carbon dioxide, nitrogen and water vapour upon combustion, thereby significant reduction in solid waste volume will be attained. This work presents a simplified analysis to estimate the quantity of waste to be handled by the incinerator, material and energy balances for conceptual design of the incineration plant and its carbon dioxide capture system and addresses the associated techno-commercial feasibility aspects of such a facility. Energy recovery from the combustion chamber has also been considered in this study. The methodology presented here will be useful for quick sizing and feasibility study of an incineration plant for other kinds of solid wastes with known combustion characteristics as well.

Keywords

Desalination, Flue Gas, Incinerator, Reverse Osmosis, Spent Membrane, Waste to Energy.

Full Text

     

Rupsha Bhattacharyya ¹

Affiliations
1 Heavy Water Division, Bhabha Atomic Research Centre, Mumbai, IN

Abstract

Simulation studies of batch distillation of some non-ideal binary systems have been carried out and reported in this work. Differential distillation as well as batch distillation at total reflux has been simulated through a semi-rigorous unsteady state mathematical model, implemented via codes developed in-house. The Wilson model has been used to represent non-ideality in the liquid phase and predict-vapour-liquid equilibrium (VLE) data. Parametric studies of the composition and temperature profiles have been carried out. Heating and cooling requirements for batch distillation operation have also been estimated. The model presented here can be used for simulating the start-up of any distillation column for even multi-component non-ideal systems, as long as the VLE data are available for them, without requiring any commercial simulation software. The model can also be extended to simulation of batch distillation columns with a finite value of reflux ratio after suitable modification of the governing equations. Thus it can be used for preliminary design work as well.

Keywords

Batch distillation, Non-ideality, Wilson equation.

Full Text

     

Rupsha Bhattacharyya ¹

Affiliations
1 Heavy Water Division, Bhabha Atomic Research Centre Trombay, Mumbai, Maharashtra, IN

Abstract

Purification of heavy water used as the moderator and coolant of pressurized heavy water nuclear reactors (PHWRs) is a vital step in ensuring its adequate isotopic content that maintains neutron economy in the reactor core. This process is carried out in a packed vacuum distillation column which requires condensers and reboilers as essential heat transfer components. A vertical thermosiphon reboiler is used to minimize operating costs of the distillation system by eliminating the fluid recirculation pump and improving system reliability and safety by minimizing leakages and heavy water losses. This work presents a simple, direct methodology for optimizing the design and operation of such a reboiler using codes developed in-house and based on heuristics and two-phase heat and momentum transfer correlations from literature. The methodology is general and can be applied to any application requiring a thermosiphon reboiler. Parametric analysis and cost calculations have also been performed along with exergy analysis of reboiler performance.

Keywords

Optimization, Parametric analysis, Thermosiphon reboiler, Water distillation.

Full Text