UDF for sorption of CO2
 

Please can someone with knowledge of UDF sorption look at this code that I created for the sorption of CO2 with the rate equation as follows

r = -kCCO2es . eqn is K2CO3 + CO2 + H2O = KHCO3, a reversible reaction.

code:
/*adsorption model for gidaspow (r = -kCO2e) */
#include "udf.h"
#define index_CO2_secondary 1 /* CO2 species index in secondary phase */
#define index_CO2_primary 0 /* CO2 species index in primary phase */
#define prim_index 0 /* primary phase index */
#define sec_index 1 /* secondary phase index */
real k = 1.95; /* rate constant */
static int INDEX_PHASE_CO2 = 0, INDEX_SPECIES_CO2 = 0,
INDEX_PHASE_K2CO3 = 0, INDEX_SPECIES_K2CO3 = 0,
INDEX_PHASE_AIR = 0, INDEX_SPECIES_AIR = 0,
INDEX_PHASE_H20 = 0, INDEX_SPECIES_H20 = 0,
INDEX_PHASE_KHCO3 = 0, INDEX_SPECIES_KHCO3 = 0;
DEFINE_HET_RXN_RATE(sorption_rate,c,t,hr,mw,yi,rr, rr_t)
{
Thread **pt = THREAD_SUB_THREADS(t);
Thread *tp = pt[0]; /* gas phase */
Thread *ts = pt[1]; /* solid phase */

real concentration_CO2_prim_index = C_YI(c,tp,INDEX_SPECIES_CO2)*C_R(c,pt[0])/mw[INDEX_PHASE_CO2][INDEX_SPECIES_CO2];

//real concentration_CO2_sec_index = C_YI(c,ts,INDEX_SPECIES_CO2)*C_R(c,pt[1])/mw[INDEX_PHASE_CO2][INDEX_SPECIES_CO2];

*rr = k*concentration_CO2_prim_index*C_VOF(c,ts);

}

Issue is my temperature in the reactor is not increasing as the reaction is exothermic.

Thanks