A method to produce a halogen-depleted gas. The method provides a gas derived from and/or including a source of biogas, mixing the gas with a source of hydrogen to produce a processed gas mixture including an acid, and separating the acid from the processed gas mixture. Sulfur, oxygen, carbon dioxide removal processes are integrated into the method. Production of secondary products, and removal thereof, are included. Pre and post processing may be integrated. Also, production of products from the processed gas.