One of the largest scale dehydrogenation reactions is the production of styrene

Question

One of the largest scale dehydrogenation reactions is the production of styrene by dehydrogenation of ethylbenzene (EB), given in reaction I below. Overall conversion of ethylbenzene to styrene is high due to a catalyst. There is a side product of toluene (T, from reaction II), which then acts as an inert species that must be removed, along with the associated methane (M). The hydrogen is easily removed in a first separation step, and the styrene is then removed from the un-reacted ethylbenzene and toluene and methane, which are recycled and mixed with the fresh EB stream. We will use a basis that the fresh EB stream into the process is 100% pure and is 100 mol/h. The toluene and methane must ultimately be removed. The MW of styrene = 104. At the reaction temperature of 900 K, the equilibrium constant is K_1 = y_Sy_H/y_EB = 0.34, K_II = y_Ty_M/y_EBy_H = 0.0008 (I) C_6H_5CH_2CH_3 ethylbenzene (EB) = C_6H_5CH=CH_2 +styene (S) H_2 hydrogen (H) (II) side reaction C_6H_5CH_2CH_3 + H_2 = EB C_7H_8+ toluene (T) CH_4 methane (M) What is the equilibrium output of EB, styrene (S), and toluene (T)? n_EB, out= mol/h n_S, out = mol/h n_T, out mol/h

Explanation / Answer

Answer: As per the given question here we must know that wen we combined the reaction the equilibrium constants are multiplied each other

hence , here we have given the K1 and K2 hence the final Kequl.will be = K1 * K2

so the Keq = 0.34 * 0.0008 = 0.000272 = [concentration of styrene] / [EB]

Note here the final equation is becomes = [EB] <---> [styrene] [ because others are pure hence count 1]

so , we get -> [EB] = 104/1000*0.000272 = 382.35mol/h

hence it is all about the given question and the outcomes of [EB]

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.