Seveneq2a

Name:	Seveneq2a -Esterification Reaction in Two Consecutive CSTRs - Original Form.
Source:	Seadet, J. D. et al., Computers chem. Engng.,14 71(1990).
Reference/s	Gupta, Y.P. (1995). Ind. Eng. Chem. Res. 34, 536-544
Model:	7 implicit equations, indep. variables A, B, C, D, E, F and G
	Higher difficulty level
	Constraints: All the variables must be >=0
	Discontinuities: Undefined when any of the denominators =0 (like A-B-C=0)
	Initial estimates: 1. (80, 7, 60, 7, 0.5, 4, 0.05 ); 2. (100, 10, 50, 10, 0.5, 4, 0.05);
	3.(50, 5, 25, 5, 0.5, 4, 0.05);
Solved by	Shacham, M., POLYMATH 5.1, build 19, April 15, 2001
Model Eqs.	Esterification Reaction in Two Consecutive CSTRs - Original Form. |POLVER05_3
EXCEL FILE	f(A) = 5.5*(D-B)/(A-B-C)-B/(B+C) #
TEXT FILE	f(B) = 3.5*(0.888*A-C-D)/(A-B-C)-C/(B+C) #
POLYMATH FILE	f(C) = 5.5*(0.0986*A-0.01*(1.098*A-B-9*D-E-F+G)-(B+E))/ (1.098*A-B-9*D-E-F+G)-E/(E+F) #
	f(D) = 3.5*(0.986*A-9*D-F-0.0986*A+0.01*(1.098*A-B-9*D-E-F+G))/ (1.098*A-B-9*D-E-F+G)-F/(E+F) #
	f(E) = 150.2*133.7*0.32^2/(A-B-C)-D*(A-B-C)/(0.0986*A-D)^2 #
	f(F) = 446.8*133.7*0.0032^2/(1.098*A-B-9*D-E-F+G) -(A*0.0986-D)/(1.098*A-B-9*D-E-F+G) +0.01 #
	f(G) = 0.04*(74.12*(0.986*A-10*D)+222.24*(0.0986*A-D) +18*(D-B)+278.84*D+98.09*0.0136*A)/98.01-0.0136*A-G #
	A(0)=80
	B(0)=7
	C(0)=60
	D(0)=7
	E(0)=0.5
	F(0)=4
	G(0)=0.05
Variable/function values	Variable	Value	f(x)
	A	80	-1.0448E-01
	B	7	1.9217E-01
	C	60	-6.7384E-03
	D	7	1.8958E-01
	E	0.5	4.2780E+01
	F	4	-1.0634E-02
	G	0.05	5.1322E-02
Solution	Variable	Value	f(x)
	A	80.5340430736936	9.7145E-17
	B	6.9725465115675	-1.7764E-15
	C	61.1190817582544	-2.7756E-17
	D	7.2042004491716	-9.9920E-16
	E	0.5476701839101	2.8422E-14
	F	3.6532933311347	2.6021E-17
	G	0.0597027236971	-5.5511E-17
Additional information	Most algorithms won't converge from initial guesses 2 and 3.
	There are several inconsistencies between the two formulations
	of the model equations appearing in the original source. We
	attempted to correct the equations to obtain solution close
	to the one shown in the original source.