Single Adiabatic Tubular Reactor Systems with Gas Recycle

Remember, the tube length is set at 8.51 m so that the pressure drop is small. Increasing tube length would reduce the number of tubes and vessel size at the expense of an increase in compression cost due to the higher pressure drop. 

Now that some insight has been gained in looking at adiabatic and cooled tubular reactors in isolation, we are ready to explore an entire process that contains reactors, compressors, separators, heat exchangers, makeup feedstreams, a recycle stream, and a product stream. This material is taken from the paper by Jaisathapom and the author.1 

4 SINGLE ADIABATIC TUBULAR REACTOR SYSTEMS WITH GAS RECYCLE 

We start by studying the steady-state design and economics of a process with a single adiabatic reactor. The design considers the entire plantwide process reactor, heat exchangers, gas recycle compressor, preheat furnace, condenser, and separator. The economic objective function is total annual cost, which includes annual capital cost (reactor, catalyst, compressor, and heat exchangers) and energy cost (compressor work and furnace fuel). 

Optimum operating conditions and equipment sizes are found. The effect of catalyst cost on the steady-state design is considered. 

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