Title: Improving ammonia reactor performances through exergy analysis

Authors: Sri Haryati; Andriadoris Maharanti; Anthony Hamzah; Muhammad Djoni Bustan

Addresses: Chemical Engineering Graduate Program, Sriwijaya University, Jalan Padang Selasa No. 542 Bukit Besar, Palembang, 30139, Indonesia ' Chemical Engineering Graduate Program, Sriwijaya University, Jalan Padang Selasa No. 542 Bukit Besar, Palembang, 30139, Indonesia ' Chemical Engineering Graduate Program, Sriwijaya University, Jalan Padang Selasa No. 542 Bukit Besar, Palembang, 30139, Indonesia ' Chemical Engineering Graduate Program, Sriwijaya University, Jalan Padang Selasa No. 542 Bukit Besar, Palembang, 30139, Indonesia

Abstract: Exergetic performance assessment based on intrinsic kinetic of ammonia synthesis reaction is applied to improve an ammonia synthesis reactor (ASR) in Indonesia. The molar balance calculation obtained from intrinsic kinetic is subsequently used to compute exergy parameters. The original configuration consists of an ammonia cooler interchanger (ACI) and four beds, with four quench streams. The reactor employs Fe-based catalyst in all four beds. It is clear that the main problems are the chemical exergy destruction in Bed 2-4 and external loss as N₂ and H₂ exergies. To alleviate the problems, we switch the catalyst to Ru-based catalyst. Simplification of ASR configuration is conducted by diminishing bed number to three, while a quench stream is replaced by an intercooler. The modification attains significant improvements on conversion as well as exergetic efficiency. High-activity Ru-based catalyst is effective at decreasing external loss and chemical exergy destruction rates, therefore increasing exergy efficiency.

Keywords: ASR; ammonia synthesis reactors; chemical exergy destruction; exergy analysis; iron catalyst; ruthenium catalyst; reactor performance; kinetics; Indonesia; intercoolers; exergy efficiency.

DOI: 10.1504/IJEX.2016.080071

International Journal of Exergy, 2016 Vol.21 No.4, pp.383 - 404

Received: 18 Sep 2015
Accepted: 27 Jun 2016
Published online: 31 Oct 2016 *

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