The generator matrix

 1  0  0  0  1  1  1  1  1  0  1  1  1  X  1  1  1  1  1  X  1  X  1  X
 0  1  0  0  X  1  1  X X+1  1  X X+1  X  X  1  1 X+1  0  0  1 X+1  1  0  0
 0  0  1  0  0  0  X  1 X+1  1 X+1  1  X  1  X X+1  1  1  0  1  X  0 X+1  X
 0  0  0  1  1 X+1  0  0  X  1 X+1 X+1  1  X  X  1  X  0  X X+1  1  0 X+1  1

generates a code of length 24 over Z2[X]/(X^2) who´s minimum homogenous weight is 22.

Homogenous weight enumerator: w(x)=1x^0+144x^22+60x^24+48x^30+3x^32

The gray image is a linear code over GF(2) with n=48, k=8 and d=22.
As d=22 is an upper bound for linear (48,8,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 8.
This code was found by Heurico 1.16 in 8.41 seconds.