Methanol is formed from carbon monoxide and hydrogen in the gas-phase reaction The mole fractions of the
Question:
Methanol is formed from carbon monoxide and hydrogen in the gas-phase reaction The mole fractions of the reactive species at equilibrium satisfy the relation where P is the total pressure (atm). Ke the reaction equilibrium constant (atm-2) and T the temperature (K) The equilibrium constant Ke equals 10.5 at 373 K. and 2.316 x 10-4 at 573 K. A semi log plot of Ke (logarithmic scale) versus 1/ T (rectangular scale) is approximately linear between T = 300 K and T = 600 K.
(a) Derive a formula for Ke (T) and use it to show that Ke (450K) 0.0548 atm-2.
(b) Write expressions for nA. nB. and nC (gram-moles of each species), and then yA, yB and yC, in terms of nA0, nB0 and nC0 the molar extent of reaction. Then derive an equation involving only nA0 nB0, nC0, P. T. and where (mol) is the value of the extent of reaction at equilibrium.
(c) Suppose you begin with equimolar quantities of CO and H2 and no CH3OH and the reaction proceeds to equilibrium at 423 K and 2.00 atm, Calculate the molar composition of the product (yA. yB and yC) and the fractional conversion of CO.
(d) Write a set of equations for yA. yB, yC and fA (the fractional conversion of CO) in terms of yAB, yB0 T. and P (the reactor temperature and pressure at equilibrium). Enter the equations in an equation-solving program. Check the program by running it for the conditions of part (c) then use it to determine the effects on fA (increase, decrease, or no effect) of separately increasing (I) the fraction of CO in the feed (ii) the fraction of CH3OH in the feed (in) temperature and (iv) pressure.
(e) Write a computer program to take as input yA0. yB0. T, and P (the reactor temperature and pressure at equilibrium) and to calculate and print out yA, yB, yC, and fA (the fractional conversion of CO) Test your program with the data of part (c). [Suggestion: Write the equilibrium relations derived in part (b) as a cubic equation in and use Newton’s rule—Appendix A.2—to obtain the solution.]
Step by Step Answer:
Elementary Principles of Chemical Processes
ISBN: 978-0471720638
3rd Edition
Authors: Richard M. Felder, Ronald W. Rousseau