Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-IV-10Exergy analysis:In the present work, the effect of changing the reference temperature between 16°C and32 °C in reference to reactors units (typical processes condition 45-55°C) was studied. Gasphase composition was defined similar to Baehr and Schmidt 6 N 2 : 0.7559, O 2 : 0.2035,Ar: 0.0090, H 2 O: 0.0313, CO 2 : 0.0003 (molar fractions) with a reference pressure of 1 atm.Water was defined in equilibrium to saturated water vapour at pressure and temperature of theproximities, which implies that exergy of pure liquid water is zero.0.45390000.4385000.35380000.337500Perdidas deexergetita0.250.20.150.1CSTRPFRPerdidas deexergetita3700036500360003550035000CSTRPFR0.053450000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32340000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32Temperatura(ºC)Temperatura(ºC)Fig. 1. Efficiency of exergy vs. Referencetemperature of reactor CSTR (Δ) and PFR (▪)Fig. 2. Losses of exergy vs. Reference temperatureof reactor CSTR (Δ) and PFR (▪)These were the components in the exergy balance: exergy of useful products, exergylosses and exergy of matter that enters the system. The exergetic efficiency of the thermalprocess as the relationship between actual energy efficiency and the maximum energyefficiency was calculated. PFR was more efficient than CSTR for enzymatic reactions as seenin figure 1 and 2. As reference temperature increases the efficiency decreases and loss-workincreases. So the exergy analysis methodology can be useful to determine the energy losses ofenzymatic reactors and for the appropriate design of industrial production of environmentalfriendly fuels from renewable sources.References:1. M.G. Adsula, J.E. Ghuleb, H. Shaikhb, R. Singhb, K.B. Bastawdea, D.V. Gokhalea, J. Varmab Enzymatichydrolysis of delignified bagasse polysaccharides. Carbohydrate Polymers 62 (2005) 6–10.2. Wall G. Exergy: a useful concept within resource accounting. Goteborg, Sweden: Institute of TheoreticalPhysics, Chalmers University of Technology and University of Goteborg; 1977.3. Wright, J.D. «Evaluation of enzymatic Hydrolisis processes», Energy from biomass and wastes, Ed. D.L.Klass, 1989.4. Knauf - Moniruzzaman. Lignocellulosic biomass processing: A perspective. Genencor International.5. Kenney, w.f.Energy Conservation In The Process Industries. W.f. Kenney: Academia press, 1969, 329p.6. Baehr, H, Schmidt, E. Definition und Berechnung von Brennstoffexergien, vol.15, no.8, Exergy, Fuels.1963, pp. 375-381159