Section A
Q1.
Explain the concept of multiple steady states in reactor operation. Under what conditions can multiple steady states occur, and what are the implications for reactor stability? If T1 and T2 are respective temperatures of the source and sink, then which of the following cases is more effective way to increase the efficiency of a Carnot engine? Give justification : Discuss the role of diffusion in heterogeneous catalytic reactions. How does pore diffusion resistance affect the overall reaction rate, and what methods are used to minimize this resistance? The analysis of a bituminous coal sample reveals the following composition :
1% sulphur, 5% oxygen, 1% nitrogen, 12% ash and 4% water
The mole ratio of carbon to hydrogen in the residuum is found to be 8:1. Calculate the weight fraction composition of coal, when ash and moisture are excluded.
(a) In a typical chemical process, the reactor effluent is divided into recycle, purge and product streams, with a portion of the feed bypassing the reactor.
(i) What are the advantages and disadvantages of the recycle stream?
(ii) Explain the necessity of a purge stream and the potential consequences of improper purge rates.
(iii) How does a bypass stream affect the process, and when is it useful?
(iv) Discuss the influence of inerts in the feed on the decisions regarding the use of purge and recycle streams.
(c) Case—I : Increasing T1, keeping T2 constant
(case—ii) Decreasing T2, keeping T1 constant
(b) In a typical chemical process, the reactor effluent is divided into recycle, purge and product streams, with a portion of the feed bypassing the reactor. What are the advantages and disadvantages of the recycle stream?
(d) Discuss the role of diffusion in heterogeneous catalytic reactions. How does pore diffusion resistance affect the overall reaction rate, and what methods 8 are used to minimize this resistance? The analysis of a bituminous coal sample reveals the following composition :
(e) 1% sulphur, 5% oxygen, 1% nitrogen, 12% ash and 4% water The mole ratio of carbon to hydrogen in the residuum is found to be 8:1. Calculate the weight fraction composition of coal, when ash and moisture are excluded. 8 \overline2 JBNV-B-CHME/43