Question

For the reactions below, describe the reactor system and conditions you suggest to maximize the selectivity to make the desired species, D, which is a very small molecule. For full credit, support your suggestions with clear calculations, explanations and sketches where appropriate. Rates are in mol/L.s and concentrations are in mol/L. Reaction 1: A+B  D -r1A= 10 exp[-8000 K/T]CACB Reaction 2: B+D  U -r2B= 109 exp[-10,000 K/T]CBCD BELOW – make sure to note highlighted question number for answers on Exam Paper. 4. Describe the reactor system and conditions: ___ Answer written on Exam paper AND in BB

Answer 1

hello your question lacks the required reaction pairs below are the missing pairs

Reaction system 1 :

A + B ⇒ D
`-r_(1A) = 10exp[-8000K/T]C_(A)C_(B)`

A + B ⇒ U
`-r_(2a) = 100exp(-1000K/T)C_(A) ^(1)/(2)C_(B) ^(3)/(2)`

Reaction system 2

A + B ⇒ D
`-r_(1A) = 10exp( -1000K/T)C_(A)C_(B)`

B + D ⇒ U
`-r_(2B) = 10^9exp(-10000 K/T) C_(B)C_(D)`

Answer : reaction 1 : description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

reaction 2 :

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal

Step-by-step explanation:

Reaction system 1 :

A + B ⇒ D
`-r_(1A) = 10exp[-8000K/T]C_(A)C_(B)`

A + B ⇒ U
`-r_(2a) = 100exp(-1000K/T)C_(A) ^(1)/(2)C_(B) ^(3)/(2)`

the selectivity of D is represented using the relationship below

`S_(DU) = (-r1A)/(-r2A)`

hence SDu = 1/10 *
`(exp(-800K/T))/(exp(-1000K/T)) * C_(A) ^(0.5) C_(B) ^(-0.5)`

description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1

condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2

Reaction system 2

A + B ⇒ D
`-r_(1A) = 10exp( -1000K/T)C_(A)C_(B)`

B + D ⇒ U
`-r_(2B) = 10^9exp(-10000 K/T) C_(B)C_(D)`

selectivity of D

`S_(DU) = (-r1A)/(-r2A)`

hence Sdu =
`1/10^7 * (exp(-1000K/T))/(exp(-10000K/T)) *(C_(A) )/(C_(D) )`

description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1

condition to maximize selectivity:

to increase selectivity the concentration of D should be minimal