Reduction Of The Carbon Footprint In Ammonia Production Through Petrochemical Plant Integration In Qatar

Abstract

Abstract The gas industry in Qatar is experiencing a massive growth and its energy consumption leads to significant carbon emissions specifically Carbon Dioxide (CO2). All plant operators have been required to report carbon emissions to local authorities according to international standards. However, it is not clear how carbon will be managed in the future. In this work, a potentially attractive solution for carbon management will be put forward. This work involves a case study on Ammonia production facility and the carbon footprint of the Ammonia process. The sources of CO2 investigated were from the Ammonia process itself and its main support utilities (combustion in gas turbines, steam boilers and natural gas reformers). Refering to previous work done (on Ammonia process simulation using industry standard HYSYS and process calculation using a spreadsheet), an attempt was made to recover CO2 from the process to be utilize in Urea and Methanol manufacturing. This approach was based on the concept of plant integration where Ethylene, Ammonia, Urea, and Methanol production facilities would have a certain degree of mass integration. The work highlighted the importance of the Hydrogen balance from the Ethylene facility and the extent of CO2 recovery and capture from the Ammonia facility. The results indicated that it is possible to target around 45% of CO2 produced in Ammonia manufacturing and utilize it to produce high value products such as Urea and Methanol. It was found that when excess Hydrogen is utilizaed with part of CO2 produced from Ammonia manufacturing facility, excess Methanol that is equivalent to a half a train capacity can be produced (~1424 MTPD*). In addition to that it was found that utilizing another part of CO2 with Ammonia product - that is usually gets exported - almost one train of Urea can be produced (~3728 MTPD). The concept of plant integration was found very powerful and relevant in the context of carbon management since it is known that captured CO2 in Qatar and gulf area may not be stored underground in large quantities because the geology is mainly carbonate reservoirs. The work also indicated the need to purify both CO2 and hydrogen to qualities compatible with the applications indicated. A network of hydrogen and CO2 pipelines was also highlighted in the plant integration study. This plant integration of important petrochemical processes has shown that it is possible to reduce significantly carbon emission in Ammonia manufacturing.