Question

In: Chemistry

Coke can be converted into CO in following reaction CO2(g) + C(s) -> 2CO(g). A coke...

Coke can be converted into CO in following reaction CO2(g) + C(s) -> 2CO(g). A coke that contains 84% carbon by mass and the balance noncombustible ash is fed to a reactor with a stoichiometric amount of CO2. The coke is fed at 77 oF, and the CO2 enters at 400 oF. Heat is transferred to the reactor in the amount of 5200 btu/lbm coke fed. The gaseous products and the solid reactor effluent (the ash and unburned carbon) leave the reactor at 1830 oF. The heat capacity of the solid is 0.24 btu/(lbm.oF) Calculate the percentage conversion of the carbon in the coke. (Provide your answer in decimal format, NOT percentage format!)

Solutions

Expert Solution

First write down the basis for the calculation:

Basis: 100 lb of coke feed (84 lb carbon, 16 lb of ash)_Mass basis.

So convert into mole basis. Molecular weight of carbon is 12, so 84 / 12 = 7 lb moles of carbon.

From the reaction, 1 mole of CO2 is fed for each moles of Carbon.

Therefore,

Let us first findout the Heat of reaction;

(Del.H)r (77 °F) = (Del.H) CO2 - (2(Del.H))CO

It is at 25 ° C (77 ° F), so the standard heat of formation of CO2 is -393.5 kJ/mol and of CO is -282.99 kJ/mol.

= [-393.5 -(2*(-282.99))](kJ/mol)*0.9486(Btu/kJ)*453.6(mols/lbmole) = 74210 Btu / lb mole.

Let us assume x - fractional conversion of C and CO2:

n1 = 7x (lb moles Carbon reacted) * 2 lb moles CO formed / 1 lb mole C reacted = 14x lb moles of CO.

n2 = 7 * (1 - x) lb moles of CO2

n3 = 7 * (1 - x) lb moles of C

Let us get the Enthalpies from the references,

CO2 @ 400 ° F, HCO2 = 3130 Btu / lb mole

CO2 @ 1830 ° F, HCO2 = 20880 Btu / lb mole

CO @ 1830 ° F, HCO = 13280 Btu / lb mole

Solid @ 1830 ° F = HS = m. Cp . Del. T

Since, Cp = 0.24 Btu / lb ° F

HS = 0.24 * (1830 -77) = 420 Btu / lb

Mass of solids (emerging),

= 7 (1 - x) lb moles of C * (12 lb / 1 lb mole) + 16 lb = (100 - 84x) lb

Energy balance:

Q = Del.H = (Del.H)S +(ΣniHi)out −(ΣniHi)in

520000 Btu = (7x * 74210) + [(7*(1-x)*20880) + (14x*13280) + ((100-84x)*420)] - (7*3130)

Conversion, x = 0.67516 (i.e. 67.52 %)


Related Solutions

Coke can be converted into CO in following reaction CO2(g) + C(s) -> 2CO(g). A coke...
Coke can be converted into CO in following reaction CO2(g) + C(s) -> 2CO(g). A coke that contains 84% carbon by mass and the balance noncombustible ash is fed to a reactor with a stoichiometric amount of CO2. The coke is fed at 77 oF, and the CO2 enters at 400 oF. Heat is transferred to the reactor in the amount of 5800 btu/lbm coke fed. The gaseous products and the solid reactor effluent (the ash and unburned carbon) leave...
Coke can be converted into CO�a fuel gas�in the reaction CO2 (g) + C (s) ?...
Coke can be converted into CO�a fuel gas�in the reaction CO2 (g) + C (s) ? 2 CO (g) a coke that contains 84% carbon by mass and the balance noncombustible ash is fed to a reactor with a stoichiometric amount of CO2. The coke is fed at 77�F, and the CO2 enters at 400�F. Heat is transferred to the reactor in the amount of 5859 Btu/lbm coke fed, the gaseous products and the solid reactor effluent (the ash and...
Consider the following reversible Hetererogenes reaction: C(s) + CO2(g) -><- 2CO(g) When equalibrium is reached at...
Consider the following reversible Hetererogenes reaction: C(s) + CO2(g) -><- 2CO(g) When equalibrium is reached at a certain point the total pressure of the system is found to be 4.98 atm. If the equilibrium constant Kp for this reaction is equal to 1.67 at this temperature, calculate the equilibrium partial pressures of CO2 and CO gases? P(CO)eq= ?      P(CO2)eq=?
The equilibrium constant KcKc for C(s)+CO2(g)⇌2CO(g)C(s)+CO2(g)⇌2CO(g) is 1.9 at 1000 KK and 0.133 at 298 KK....
The equilibrium constant KcKc for C(s)+CO2(g)⇌2CO(g)C(s)+CO2(g)⇌2CO(g) is 1.9 at 1000 KK and 0.133 at 298 KK. A. If excess CC is allowed to react with 25.5 gg of CO2CO2 in a 3.00 LL vessel at 1000 KK, how many grams of COCO are produced? Express your answer using two significant figures. B. How many grams of CC are consumed? Express your answer using two significant figures. C. If a smaller vessel is used for the reaction, will the yield of...
Calculate the value of Kp for the equation. C(s) + CO2(g) 2CO(g) Kp=? Given that at...
Calculate the value of Kp for the equation. C(s) + CO2(g) 2CO(g) Kp=? Given that at a certain temperature: C(s) + 2H2O(g) CO2(g) + 2H2(g) Kp1= 3.53 H2(g) + CO2(g) H2O(g) + CO(g) Kp2 = 0.699 Kp=?????
The reaction CO2(g)+C(s)⇌2CO(g) has Kp=5.78 at 1200 K. A) Calculate the total pressure at equilibrium when...
The reaction CO2(g)+C(s)⇌2CO(g) has Kp=5.78 at 1200 K. A) Calculate the total pressure at equilibrium when 4.71 g of CO2 is introduced into a 10.0-L container and heated to 1200 K in the presence of 3.90 g of graphite. B) Repeat the calculation of part A in the presence of 0.31 g of graphite. Express your answer to three significant figures and include the appropriate units.
CO2(g) + C(s) = 2 CO(g) a) Using the Bouduard reaction, calculate gas composition in a...
CO2(g) + C(s) = 2 CO(g) a) Using the Bouduard reaction, calculate gas composition in a furnace under 1 atm total pressure and 1100 K. b) Under the same furnace conditions, is it possible to reduce VO to V by CO? ( VO + CO = V + CO2 ) C(s) + O2(g) = CO2(g) o GT = - 394100 – 0.84 T J/mol C(s) + ½ O2(g) = CO(g) o GT = - 111700 – 87.65 T J/mol V(s)...
Calculate ΔrH for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Use the following reactions and given ΔrH's. C(s)+O2(g)→CO2(g), ΔrH=...
Calculate ΔrH for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Use the following reactions and given ΔrH's. C(s)+O2(g)→CO2(g), ΔrH= -393.5 kJmol−1 2CO(g)+O2(g)→2CO2(g), ΔrH= -566.0 kJmol−1 2H2(g)+O2(g)→2H2O(g), ΔrH= -483.6 kJmol−1 Express your answer using one decimal place.
Consider this reaction between solid carbon and carbon dioxide gas. C(s) + CO2(g) ⇌ 2 CO(g);...
Consider this reaction between solid carbon and carbon dioxide gas. C(s) + CO2(g) ⇌ 2 CO(g); ΔH = +172.5 kJ/mol Please explain the following: When chemical systems are subjected to stresses, the equilibrium position may shift toward the reactants or products, or it may be unaffected. How would each of the following changes affect this equilibrium? 1. decreasing the temp 2. increasing the CO2 3. increasing the volume of the container 4. adding C 5. adding a catlyst Options: Would...
Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) In the preceding reaction, _____ is...
Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) In the preceding reaction, _____ is in elemental form and has a standard enthalpy of ______ . This reaction is a ______ reaction (think heat). The standard enthalpy for the reaction is _______ kJ (3 S.F.)
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT