Solar thermal biochar gasification has also been studied at the University of Colorado (see Problem P8-16B). (Chemical Engineering and Processing: Process Intensification 48, 1279 (2009) and AIChE J., 55, 286 (2009).) While this process follows a shrinking core model (see Chapter 14), for the purposes of this example, we will use the following sequence:

a. Plot and analyze F_Ch, F_L, F_W, F_CO, and F_H2 down the length of a plug-flow reactor.
b. Repeat (a) for the concentrations C_C, C_Ch, and so on.
c. and analyze the selectivity S˜C0/H2 and yields Y˜W and Y_L down the PFR.
d. At what point is the char molar flow rate a maximum? How does it change with changing feed conditions, such as the ratio of (F_W0/F_L0), C_T0, and so on? Describe what you found in parts (a) through (d).

Transcribed Image Text:

(1) Lignin: C10H12O3(L)+ 3H 2 O(W) 3H2+3CO + Char (e.g., cresol) (2) Char: Char(Ch)+ 4HO 10H2 + 7CO The rate laws at 1200C are hypothesized to be -r1L=k1LCLCW2x with k1L-3721(dm3mol)2/s-r2Ch-k2ChCChCW2x with k2Ch-1000(dm3mol)2/s The entering molar flow rates are FLO=0.0123 mol/s, Fwo = 0.111 mol/s, the total entering concentration is CTO = 0.2 mol/dm, and the reactor volume is 0.417 dm.