Using bromine to make renewable hydrogen from biowaste

A process that produces renewable hydrogen from organic biowaste and reduces the economic and environmental burden of wastewater treatment is being developed by Chemergy, Inc. (Miami Fla.; www.chemergy.com). Introduced at last month’s AIChE Spring Meeting (April 22–26; Orlando, Fla.), Chemergy’s HyBrTec technology offers an alternative method for processing sewage, manure, wood and agricultural residues, paper, plastics and municipal solid waste. Depending on the feedstock, the process can recover up to 420 lb of H2 per dry ton of biowaste, says CEO Robin Parker. HyBrTec utilizes two established steps (diagram) that are scalable to tons per minute with commercially available equipment, says Parker. First, cellulosic biowaste and wastewater are oxidized with bromine to produce HBr, CO2 and heat. The HBr reacts with unreacted water, forming concentrated hydrobromic acid (HBraq). The HBraq is then electrolyzed into H2 and recyclable Br2 reagent. renewable hydrogen[/caption] The heat released in the bromination step is recovered and used to concentrate the water content of the feedstock to 50 vol.%. Electro-osmotic water transfer from the Br2 anode to the H2 cathode produces 4–6 gal of potable water per kilogram of H2 and increases…