Hello my kids have not seen, heard, or had any support from their father in a year and a half. Can I file to revoke his rights? He was abusive to the kids, and I left him. I do have proof of this also.

Read the stickie posts at the top of the Family Law category, especially about what abandonment DOESN'T mean.
You need to go to Family Court to get custody, court ordered child support, and to present your evidence of abuse. Even if he is nowhere to be found, the support will accumulate and he will always owe it.
You don't say if you were married to him at the time of each birth, or if he is on the birth certificate, or if DNA tests proved paternity.
All this will be factored in.
Start with the phone book to find out where to go to fill out forms and get a hearing.

Never married to him and he is on the birth certificate there is a child support order which hasn't been paid since 2002 and I have sole custody of one and the other child we didn't do a custody order but the child support is for both of them

Read the stickie posts at the top of the Family Law category, especially about what abandonment DOESN'T mean.
You need to go to Family Court to get custody, court ordered child support, and to present your evidence of abuse. Even if he is nowhere to be found, the support will accumulate and he will always owe it.
You don't say if you were married to him at the time of each birth, or if he is on the birth certificate, or if DNA tests proved paternity.
All this will be factored in.
Start with the phone book to find out where to go to fill out forms and get a hearing.

Never married to him and he is on the birth certificate there is a child support order which hasn't been paid since 2002 and I have sole custody of one and the other child we didn't do a custody order but the child support is for both of them

There isn't much more to do other than track him down and have his income garnished. It's not easy to hide these days unless he left the country or is homeless and without any income, not even welfare. They can't garnish welfare. Again, read about abandonment under Family law.