Abstract:

In response to the ammonia recovery difficulties in ammonia refrigeration system in the recontacting section of continuous catalytic reforming units, this study proposes two new ammonia-free refrigeration processes, i.e., the recontacting absorber combined with lithium bromide refrigeration and the direct application of low-temperature lithium bromide refrigeration. The energy consumption, CO? emissions, investment and technical-economic performance of the two new processes were evaluated. The results show that, compared to the conventional process, both the two new processes can maintain the hydrogen purity after the recontacting while effectively utilizing the low-temperature waste heat from the unit. The electricity consumption and energy consumption of the unit can be reduced by around 40% and 2%, respectively. Remarkable saving energy and carbon reduction effect can be achieved. The static investment of project can be recovered in 1 to 3 years, indicating significant economic benefits.

Key words: continuous catalytic reforming, recontacting, low temperature heat, new process, lithium bromide refrigeration, absorber, energy saving and carbon reduction