Have a friend coughing up blood after stopping alcohol consumption, is this normal?

Normal=No. Blood should never be coughed up whether associated with alcohol intake or not. Blood signifies torn tissues and active blood loss. The source of the blood would require a thorough exam and testing.

Please see your physician or the Emergency room, if moderate amount or rapid bleeding. The liver function may be affected and liver function tests are indicated. An imaging study is useful but for small bleeds may be normal. Consider infection and upper airway sources.

Any abnormal bleeding, and coughing up blood is an abnormal bleeding, warrants evaluation by a doctor. The sooner your friend sees a doctor, the better.

This could evolve into a critical situation, and an immediate ER visit is warranted. You describe an upper GI hemorrhage, which needs critical evaluation. Do not hesitate.