Chemical Engineering Research and Design 1 5 8 ( 2 0 2 0 ) 177–192 Contents lists available at ScienceDirect Chemical Engineering Research and Design j ourna l h omepage: www.elsevier.com/locate/cherd The influence of raw material availability and utility power consumption on the sustainability of the ammonia process Sherard Sadeek a , Thérèse Lee Chan a , Rukam Ramdath a , Aqueel Rajkumar a , Miao Guo b,c,* , Keeran Ward a,* a Department of Chemical Engineering, University of the West Indies, St. Augustine, Trinidad and Tobago b Department of Chemical Engineering, Imperial College London, South Kensington, United Kingdom c Department of Engineering, King’s College London, Strand Campus, WC2R 2LS, United Kingdom a r t i c l e i n f o Article history: Received 5 October 2019 Received in revised form 8 February 2020 Accepted 17 March 2020 Available online 3 April 2020 Keywords: Ammonia process Sustainability Life cycle assessment Carbon capture utilization KBR Process design a b s t r a c t Trinidad and Tobago, one of the largest exporters of ammonia globally, has seen recent declines in natural gas availability making cutbacks in productivity necessary. This paper investigates, for the first time, effects of natural gas availability on environmental burden and operational profit across the ammonia process. Utilizing Aspen ® Plus, a model ammo- nia plant was designed and validated against current plant operations. The results indicated that as gas charge decreases, the specific energy demand increases, due to increased steam demand for CO 2 removal. The findings also showed that below a threshold of 98% gas charge, there was a direct loss in profit of US$10.3 million/year with increase in specific energy demand of up to 10%. Furthermore, a Life Cycle Assessment (LCA) indicated, through the utilization of CO 2 , greenhouse gas (GHG) reductions by 64.84% while fuel combustion was the main “hotspot”, contributing up to 91% across all impact categories. Insights into decreas- ing the environmental impacts were also considered with results showing that an increase in productivity (US$79,000/year) increases environmental burden. Moreover, useful power generation provides environmental benefits by 6% across all impact categories. Thus, spe- cific energy demand along with CO 2 utilization should be carefully considered for a more sustainable ammonia process. © 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. 1. Introduction Ammonia is one of the largest globally produced synthetic chemicals, with approximately 85% of the world consumption used as a fertil- izer synthesized from hydrogen and nitrogen (Appl, 1999). The world’s population is projected to reach 9.4 billion by 2050 (World Bank, 2019), which would increase the need for fertilizers and by extension ammo- nia. Alternatively, ammonia is being investigated as a potential energy carrier due to its high hydrogen content and it ease of storage and trans- portation as a liquid (Demirhan et al., 2018). Thus, the use of ammonia as both a fertilizer and energy carrier is expected to increase its global demand, with a projected global increase from 154 million tonnes in ∗ Corresponding authors. E-mail addresses: miao.guo@kcl.ac.uk (M. Guo), keeran.ward@sta.uwi.edu (K. Ward). 2015 to 170 million tonnes in 2020 (Food and Agriculture Organization of the United Nations, 2020). Ammonia synthesis utilizes a catalytic process developed by Fritz Haber and Carl Bosch, using a promoted iron catalyst discovered by Alwin Mittasch, at temperatures within 400-500 ◦ C and pressures of over 100bars (Appl, 2012a). Generally, single pass conversion rates are often low and hence, to achieve higher conversions unconverted syn- thesis gas is recycled after separation. The first commercial ammonia plant was built in Germany in 1913 utilizing the Haber-Bosch Process with a production capacity of 30 metric tonnes per day. Since then, sev- eral new technologies have surfaced, applicable to higher production rates as the global demand for ammonia increases. Once such tech- https://doi.org/10.1016/j.cherd.2020.03.020 0263-8762/© 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.