Utilization of hydrogen as clean energy resource in chlor-alkali process

Abstract

Hydrogen produced from chlor-alkali plants in Jordan is typically wasted and vented to the atmosphere. If it is recovered and utilized then it can viably play a significant role for process heat on site. This study demonstrates how cleaner production can be applied to the chlor-alkali industry, with focus on utilization of hydrogen as energy resource. A chlor-alkali based on membrane cell process, in northern part of Jordan, was examined as a case of reusing excess hydrogen produced. In the baseline scenario, 47% of produced hydrogen was used in HCl production, 10% in controlling pressure difference, and the remainder was not used (i.e. 43% of hydrogen was vented into the atmosphere). The proposed cleaner production option was to install a hydrogen boiler next to the existing fuel boiler and utilize the hydrogen to generate steam for on-site process heating purposes. The effectiveness of this cleaner production option was discussed in relation to its technical and environmental feasibility. On-site utilization of hydrogen was found to provide 34% of the total steam needed at the full capacity. This in return yields a saving percentage of around 33.37% and a payback period of 0.947 year. From environmental perspective, theoretically, carbon dioxide emission reductions can be up to 1810 tons based on the chlor-alkali productions pattern for 24 consecutive months.