The generator matrix

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

generates a code of length 18 over Z2[X]/(X^2) who´s minimum homogenous weight is 16.

Homogenous weight enumerator: w(x)=1x^0+153x^16+72x^20+30x^24

The gray image is a linear code over GF(2) with n=36, k=8 and d=16.
As d=16 is an upper bound for linear (36,8,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 8.
This code was found by Heurico 1.16 in 0.00397 seconds.