Equipment Integration
Distillation and Heat Exchange are most extensively used operations in the chemical process industries (CPI), which are highly energy-intensive unit operations, and continuously rising energy costs make them imperative to look for ways to reduce energy requirements. Some energy-saving configurations can increase capital investment costs, so the benefits need to be weighed carefully. Various techniques, such as multi-stream HENs, reactive distillation column, and vapor recompression distillation are useful methods to reduce energy consumption and to save capital and operating costs.
Multi Stream
Heat Exchanger Networks
Design Optimization
Pressure Drop Consideration
Multi-Period Operation
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Over the last decade, continuous demand of low-cost equipment, particularly in petrochemical plants and cryogenic processes has created a challenging situation for process engineers to design efficient and cost-effective plants.
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In this respect, recent developments in the design of Multi-Stream Heat Exchangers (MSHEs) have established a demanding market scope.
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Compared to conventional heat exchangers, the compact structure of MSHEs provides lower capital and operating costs.
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The MSHE is a single process unit, in which simultaneous heat exchange occurs through multiple hot and cold streams.
Reactive
Distillation Column
Heat Integration of
Reactive Distillation Column (RDC)
Optimization & Controllability Analysis
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Reactive distillation (RD) is an efficient process intensification technique that integrates catalytic chemical reaction and distillation in a single apparatus.
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The process is also known as catalytic distillation when a solid catalyst is used.
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RD technology has many key advantages such as reduced capital investment and significant energy savings, as it can surpass equilibrium limitations, simplify complex processes, increase product selectivity and improve the separation efficiency.
Heat Transfer
Enhancement
Heat Exchanger Networks (HENs)
with Tube Inserts
Pressure Drop Consideration
Reduced Fouling
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The use of tube inserts, one type of heat transfer enhancement technique, has been shown to be effective in mitigating crude-oil fouling while at the same time enhancing heat transfer, as there will be axial and radial distributions of local shear stress in the tube-side with the introduction of inserts.
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A well-developed fouling model for tube inserts is being used, combined with the optimization approach of HEN retrofit.
Vapor Recompression
Distillation
&
Dividing Wall Column
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Vapor recompression-assisted distillation is one such technique to reduce energy consumption by utilizing the energy from the column overhead stream, with added external shaft work, to boil the bottom stream.
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Dividing Wall Columns (DWCs) are a type of distillation column that can separate mixtures of several components into three or more high-purity streams.
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A DWC requires much less energy, capital investment, and plant space than conventional columns in series or parallel configurations. In fact, DWCs can have 20–30% lower capital cost requirements than conventional tower designs.