UnboundLocalError: local variable 'rmeff' referenced before assignment

Question

Hey I'm trying to compute the concentration of a tubular reactor with two reaction, I get this error thrown each time I run the code, I tried putting the variable in the function as global still doesnt work

    RmCO = (KmCO * Cb**q * Cd**p)
    RmCO2 = (KmCO2 * Ca**n * Cb**m)

    
    Phi = (Dp/6)* np.sqrt(((kp+1)/kp)*(KmCO2 * RhoParticle/DCO2eff))
    eff = (np.tanh(Phi))/Phi
    MR = ((RmCO2/1000)*RhoParticle*Dmean*(n+m))/(beta*Ca)
   
    WP = ((Phi*(1/np.tanh(Phi)))-1)*3
    
    rmpore = 1/(eff*RmCO2)
    rmex = 1/(beta*Amext*(Ca-np.real(COeq)))
    rmeff = 1/(rmex+rmpore)
    RmCOeff = 1/(1/(0.001*RmCO))

    
    rCO2 = - rmeff
    rH2 = - ((b/a) * rmeff) - (3 * RmCOeff)
    rCO = ((c/a) * rmeff) - RmCOeff
    rH2O = ((d/a) * rmeff) + RmCOeff
    rCH4 = RmCOeff
    dCO2dz = (RhoBulk * rCO2) / Us
    dH2dz =  (RhoBulk * rH2) / Us
    dCOdz =  (RhoBulk * rCO) / Us
    dH2Odz = (RhoBulk * rH2O) / Us
    dCH4dz = (RhoBulk * rCH4) / Us

ReH = (Us*Dp)/Kinematic_viscosity
Cpavg= (CpCO2(T)*(a/(a+b)) + CpH2(T)*(b/(a+b)))  / 4 #conversion of Kj/kg.k to j/kg.K
Pr = mue(T) * Cpavg / thermalC(T)
U = 0.504 * ((thermalC(T)/Dp) * ((ReH)**0.67) * ((Pr)**0.4) * ((Dp/Di)**0.375))

G = Rho_mix*Us
Ua = (U * (4/Do))


Tw = (950 + 273)

dTdz = ((-rmeff * DelH(T)* RhoBulk) - (Ua*(T-Tw)))/(G*Cpavg)
return [dTdz,dCO2dz,dH2dz,dCOdz,dH2Odz,dCH4dz]