In Thailand, there are only (10) thinks in the Civil Commercial Code (CCC) that a Thai court can grant a divorce.
(1) of which is Infidelity by either party; another abandonment my either party for (1) year, yet another, is abused; and also separated for (3) years.
I think in any country, Infidelity & Abused are the most difficult to prove and trashed out in any court on this planet.
Under Thai law there is no clause for Alimony.
It would be advisable to retain a "Divorce Lawyer", many chaps kicking around this town calling themselves lawyers and do not have a clue about Thai divorce laws.
The cost of a Thai divorce Lawyer depends on your location, can start from 10,000 THB into the hundreds of thousands.
Goes without saying, have a very very good English / Thai interpreter friend.
To use the abandonment clause, you cannot be seen in photos, parties, dinner, sleeping over etc. together. I think you may have to bring a witness or two, stating that you and your wife have not been living together for such and such period.
If there is property involved, the key is " What date" was your name or her name placed on that ownership document at the land office. Before marriage or after marriage, is all the divorce court looks at.
Another point; any think you want stated in your divorce filing, ensure it is written in Thai then that same clause written in English.
Also if in Thailand on a marriage visa, upon divorce you will have to go to the immigration and have your visa canceled. They would give you I think (7) days to pack up and leave Thailand, unless you switch to another visa before the divorce.
Best of luck.