生物反应工程教学课件-Bioprocess Engineering Lesson-3.pptVIP

* 3) Reaction glucose + NH3 biomass + glycerol + ethanol + CO2 + H2O 4) Energy-balance equation ??Hbr ? Mv?hv ? Q + Ws = 0 and Ws = 0; Mv = 0. Therefore : ??Hbr ? Q = 0 3. Calculate As the heat of combustion of CO2 and H2O is zero, the heat of reaction is: * ?Hbr = (n?hc?)G + (n?hc?)A ? (n?hc?)B ? (n?hc?)Gly ? (n?hc?)E (?hc?)G = ?2805.0 kJ gmol?1 = ?1.558 ? 104 kJ kg?1 (?hc?)A = ?382.6 kJ gmol?1 = ?2.251 ? 104 kJ kg?1 (?hc?)B = ?382.6 kJ gmol?1 = ?2.120 ? 104 kJ kg?1 (?hc?)Gly = ?1655.4 kJ gmol?1 = ?1.799 ? 104 kJ kg?1 (?hc?)E = ?1366.8 kJ gmol?1 = ?2.971 ? 104 kJ kg?1 ?Hbr = 36.0 ? (?1.558 ? 104) + 0.4 ? (?2.251 ? 104) ? 2.81? (?2.120 ? 104) ? 7.94? (?1.799 ? 104) ? 11.9 ? (?2.971 ? 104) = ?1.392 ? 104 kJ * Substituting this result into the energy-balance equation: Q = 1.392 ? 104 kJ 4. Finalize Q is positive indicating that 1.392 ? 104 kJ h?1 heat must be removed from the fermenter * Summary At the end of this chapter you should: know which forms of energy are common in bioprocesses; know the general energy balance in words and as a mathematical equation, and the simplifications that can be made for bioprocesses; be familiar with heat capacity tables and be able to calculate sensible heat changes; be able to calculate latent heat changes; understand heats of mixing for non-ideal solutions; * be able to determine standard heats of bioreaction from heats of combustion; know how to determine heats of bioreaction for aerobic and anaerobic cell culture and fermentation processes; and be able to carry out energy-balance calculations for biological system with and without bioreaction. * Chapter 4 Unsteady-State Material  and Energy Balances An unsteady-state or transient process is one, which causes system properties to vary with time. Batch and semi-batch systems are inherently transient; continuous systems