GREEN PATHWAYS TO PRODUCE CARBAMIDE

Abstract

Urea is an organic compound with a very high demand among fertilizers. It has been produced industrially for many decades; however, since toxic ammonia is required for its production, new green methods need to be implemented with respect to the environment and new stricter environmental legislation. This report offers a rigorous design of an industrial urea plant operating through Stamicarbon technology located in Kazakhstan. Apart from the synthesis process, the operation includes wastewater treatment and carbon dioxide recovery. In comparison with other available technologies, this method implements low-pressure recovery of carbon dioxide, resulting in an energy-efficient and more environmentally friendly process. Throughout this report, the work on significant equipment design has been done using a variety of methods, including shortcut and Kern methods for heat exchanger units such as scrubber, stripper, and film condenser, rules of thumb for a reactor, and the application of principles of fluid mechanics and transport phenomena for the prilling tower. The general minor equipment design was prepared using the values from the process simulation in ASPEN PLUS V14. The plant's location was decided to be in a special economic zone ”Aktau Seaport”, next to the "KazAzot" JSC, after analyzing economic, environmental, geographical, and other site considerations. An analysis of the environment and waste streams was conducted to ensure the ecological safety of our process in accordance with the Environmental Code of the Republic of Kazakhstan. The plant's operation and construction proved to be profitable through the estimation of purchased equipment costs, production costs, and revenues using APEA computer tools, cost escalation, historical data, and other techniques. The proposed design for an industrial urea plant in Kazakhstan, utilizing Stamicarbon technology and incorporating efficient waste management and carbon dioxide recovery, underscores the feasibility of achieving both ecological safety and profitability in fertilizer production.