If your acid chloride is expected to have high volatility "a reasonable boiling point i.e. < 100 oC", then you can react the carboxylic acid with excess benzoyl chloride "to avoid formation of anhydride" applying simple distillation to isolate the acid chloride which will go to the receiving flask. The equation shows that the side product is benzoic acid which will stay in the distillation flask so no problem to the environment. But the experiment is better done in the hood with due care.

R-COOH + Cl-CO-Ph → R-CO-Cl + HOOC-Ph

If your acid chloride has high boiling point, then oxalyl chloride is to be tried as what has been suggested by a Research Gate colleague 2 years ago:

https://www.researchgate.net/post/How_to_achieve_chlorination_of_carboxylic_acid_to_convert_into_acid_chloride

Thank you so much for your response

https://www.chemguide.co.uk/organicprops/acids/pcl5.html