Yes, Jehovah’s Witnesses recognise marriage between Witnesses and non-Witnesses. However, for a divorced Jehovah’s Witness man to remarry he must have divorced his wife on the grounds of her adultery. He may have a legal document granting him a divorce, but the Bible says the only basis for divorce is adultery. Here are a couple of quotes from the official Jehovah’s Witness web site:
Insight on the Scriptures, Volume 1, pages 639-643 – Divorce: What is the only Scriptural basis for divorce among Christians? Jesus said: “I say to you that whoever divorces his wife, except on the ground of fornication, and marries another commits adultery.” (Mt 19:8, 9) Today, generally, distinction is made between “fornicators” and “adulterers.” According to modern usage, those guilty of fornication are unmarried persons who willingly have sexual relations with someone of the opposite sex. Adulterers are married persons who willingly have sexual relations with a member of the opposite sex who is not their legal marriage mate. As shown in the article FORNICATION, however, the term “fornication” is a rendering of the Greek word por·neiʹa and includes all forms of illicit sexual relations outside of Scriptural marriage. Hence, Jesus’ words at Matthew 5:32 and 19:9 mean that the only divorce ground that actually severs the marriage bond is por·neiʹa on the part of one’s marriage mate. The follower of Christ may avail himself of that divorce provision if that is his desire, and such a divorce would free him to marry an eligible Christian.—1Co 7:39.
Nor does the Bible grant Christians the right to divorce their marriage mates because of difference in religion; it shows instead that by remaining with an unbelieving mate the Christian may win that individual over to the true faith. https://wol.jw.org/en/wol/d/r1/lp-e/1200001202
Honor “What God Has Yoked Together” Watchtower (Study) 2018 - The Only Scriptural Grounds: On two occasions, Jesus indicated that the only grounds for a divorce that would free an innocent mate to remarry is por·neiʹa. What does that Greek term mean? Por·neiʹa applies to illicit sexual relations outside Scriptural marriage. It includes adultery, prostitution, and sex relations between unmarried individuals as well as oral and anal sex and the sexual manipulation of the genitals of an individual to whom one is not married. https://wol.jw.org/en/wol/d/r1/lp-e/2018683
I have no idea what you mean by saying this man is “divorced from his wife after 22 years of sub- standard wife treatment” and all I can suggest is that you get him to explain exactly what the grounds for the divorce were.