The generator matrix

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

generates a code of length 24 over Z2[X]/(X^2) who´s minimum homogenous weight is 20.

Homogenous weight enumerator: w(x)=1x^0+106x^20+124x^22+114x^24+40x^26+86x^28+28x^30+13x^32

The gray image is a linear code over GF(2) with n=48, k=9 and d=20.
As d=20 is an upper bound for linear (48,9,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 9.
This code was found by Heurico 1.16 in 6.87e-008 seconds.