“ How quickly a person metabolizes alcohol depends on:
sex (male or female)
weight
age
metabolism speed
how much food eaten
type of alcohol
how quickly alcohol was consumed
if there are other substances involved
liver problems
On average the body can eliminate 0.015% BAC per hour, so depending on the person and type of alcohol, they may have a BAC of 0.02% – 0.03% at a rate of 1 drink per hour. That means, the body can take 1 – 2 hours to metabolize the alcohol consumed in that hour. If you have two glasses of wine with dinner, it could take up to 6 hours for you to fully break down the alcohol, depending on the variables listed above.
For a person with alcoholism who may consume closer to 10 glasses of wine (about 2 bottles) in a day or binge, it could take up to 15 hours or more for the body to fully metabolize and eliminate the alcohol consumed from the bloodstream. That means the person binge drinking 2 bottles of wine will not start to be “sober” until 15 hours after drinking.
HOW LONG DOES ALCOHOL STAY IN THE SYSTEM?
Even after the effects of alcohol wear off, it can remain in the body for long periods of time. Depending on the body system, alcohol can last different lengths of time. For example, alcohol is traceable in the saliva and breath for up to 24 hours after drinking, while it can be detected in the blood stream for up to 12 hours and in urine for up to five days, depending on the test used. Most surprising of all, alcohol can be found in hair strands for as long as 90 days after the last drink.”
https://dreamliferecovery.com/how-long-does-it-take-for-alcohol-to-leave-your-system/
He may have a big tolerance to alcohol if he is a chronic drinker.
If he had a high enough alcohol contact it can take many more than 8 hours to completely eliminate alcohol from his system. Also as his liver is already damaged it will take his body that much longer to eliminate alcohol from his blood stream as his liver is not fully functioning and able to do its job.
That being said he has liver cirrhosis and if he wants to live he needs to stop ALL alcohol consumption. If he doesn’t stop drinking immediately he is slowly killing himself. He will continue to destroy his liver and could possibly develop liver cancer. If he does not stop drinking when he goes into liver failure or develops liver cancer he will not be eligible for the a liver transplant.