immediatewrite18{makeindex jobname.nlo -s nomencl.ist -o jobname.nls}
documentclass[preprint,12pt,3p,numbers,sort,compress]{elsarticle}
usepackage{subcaption}
usepackage{mathtools}
usepackage{nccmath}
usepackage{array}
usepackage{caption}
usepackage{float}
usepackage{multicol}
usepackage{booktabs}
usepackage{makecell}
usepackage[utf8]{inputenc}



 begin{document}



begin{table}[htbp]
centering
caption{ parameters }
label{tab:Parameters 2}
begin{tabular}{ l c c c }
toprule
Parameters & Value & Parameters & Value\
midrule
  P1  & 500 & K1 & 0.01  \
 P2 & 2200 & K2 &  0.01 \
  P3 & 6 & K3 &  33 \
  P4 & 20$times$$10^{-3}$ &    K4 &  0.15 \
 P5 & X & K5 & 0.1 \
 P6  & 24.2 & K6 &  0.1\
 P7 & 40.3 & K7 &  40\
 P8 & 12.1  & K8 &  0.23\
 P9 & 1 & K9 &  0.52\
 P10 & 1$times$$10^{4}$ & K10 &  0.9\
  P11 & 24  & K11 &  0\
    P12 & 50  & 0 &  0\
bottomrule
end{tabular}
end{table}


end{document}