Economic Recovery of Hydrogen from Purge Gas

Abstract

Synthesis of Urea fertilizer requires production of Ammonia first. In the Ammonia synthesis, conversion is low, about 20-30%. So, after product separation, the stream is recycled. But, this closed loop synthesis causes accumulation of inerts. Hence, for optimum conversion, it is required to purge a certain amount of this recycled gas. It is economically feasible to recover valuable gases rather than burning them. Therefore, important components including Hydrogen gas are recovered. After recovery, it is sent back into the synthesis loop which decreases the amount of Natural Gas required as raw material and enhances the production efficiency. The most economical process for Hydrogen recovery is proposed in this project. As per the industrial directive, two processes are studied in depth; Linde’s Technology (Cryogenic Separation) and Prism Technology (Membrane Separation). A detailed study has been carried out on each process’s Material & Energy Balance, Equipment Design, Simulation, Instrumentation & Process Control and ultimately the Economic Analysis, which is the main objective of the project. Finally, an optimized and economically feasible option for the industry for installation has been proposed