32 Techno-Economic Analysis of a Hybrid Solar-Hydrogen-Biomass …
491
where c, x, and y are given as mole fractions of the biomass feedstock such as glucose.
w refers to the mass flow rate of water used in the gasification reaction. The element
balances of carbon, hydrogen, and oxygen elements are given below:
x 1 + x 3 + x 5 − c = 0
(32.26)
x + 2w − 2x 2 − 2x 4 − 4x 5 = 0
(32.27)
y + w − x 1 − 2x 3 − x 4 = 0
(32.28)
Since there are just three element equations for five variables, two equations
should be more defined. In this study, two thermodynamic equilibrium reactions of
water-gas shift and methanation are considered, and their equilibrium constants are
defined as the function of their partial pressures [18]:
K 1 =
x H 2 x CO 2
x H 2 O x CO
(32.29)
K 2 =
x CH 4
x H 2
2
(32.30)
The values of K 1 and K 2 can be estimated by using the following formulas
(Castello 2014):
ln K 1 =
7082.848
T
+ (−6.567) ln T
+
−2.164 × 10
−6
6
T
2
+
0.701 × 10
−5
2T
2
+ 32.541
(32.31)
ln K 2 =
5870.53
T
+ 1.86
− 2.7 × 10
−4 T +
58200
T
2
− 18.007
(32.32)
32.4 Results and Discussions
The developed simulation model was used to estimate the amount of electrical
power which can be generated by the proposed HRES to satisfy the electrical load
requirements in the selected household area.
491
where c, x, and y are given as mole fractions of the biomass feedstock such as glucose.
w refers to the mass flow rate of water used in the gasification reaction. The element
balances of carbon, hydrogen, and oxygen elements are given below:
x 1 + x 3 + x 5 − c = 0
(32.26)
x + 2w − 2x 2 − 2x 4 − 4x 5 = 0
(32.27)
y + w − x 1 − 2x 3 − x 4 = 0
(32.28)
Since there are just three element equations for five variables, two equations
should be more defined. In this study, two thermodynamic equilibrium reactions of
water-gas shift and methanation are considered, and their equilibrium constants are
defined as the function of their partial pressures [18]:
K 1 =
x H 2 x CO 2
x H 2 O x CO
(32.29)
K 2 =
x CH 4
x H 2
2
(32.30)
The values of K 1 and K 2 can be estimated by using the following formulas
(Castello 2014):
ln K 1 =
7082.848
T
+ (−6.567) ln T
+
−2.164 × 10
−6
6
T
2
+
0.701 × 10
−5
2T
2
+ 32.541
(32.31)
ln K 2 =
5870.53
T
+ 1.86
− 2.7 × 10
−4 T +
58200
T
2
− 18.007
(32.32)
32.4 Results and Discussions
The developed simulation model was used to estimate the amount of electrical
power which can be generated by the proposed HRES to satisfy the electrical load
requirements in the selected household area.