CHAPTER 4 Understanding Process Conditions Don Scott ENCH 430 1/24/06.
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Transcript of CHAPTER 4 Understanding Process Conditions Don Scott ENCH 430 1/24/06.
The ability to make an economic analysis of a chemical process
based on a PFD is not proof that the process will actually work.
A decision to operate above 400º C must be justified
Microstructure of steel pipe after 28 years service at 773K,
shows several creep pores (dark) and carbides(white).
A decision to operate outside the range of 40°C to 260°C, thus
requiring special heating/cooling media, must be justified.
Conditions outside the favored temperature and pressure ranges
are identified as “conditions of special concern.”
Items for justification
• Favorable equilibrium conversion
• Increase reaction rates
• Maintain a gas phase
• Improve selectivity
Also, consider tables 4.1,2,3 on pages 120-122