Techno-economic assessment of an integrated GTL facility for urea production

Decarbonising industrial processes remains a critical challenge, particularly in gas-to-liquid (GTL) and chemical manufacturing sectors. This study conducts a comprehensive techno-economic assessment of an integrated GTL-urea facility that leverages hydrogen from Fischer-Tropsch (FT) tail gas and green hydrogen via proton exchange membrane (PEM) electrolysis. Using ASPEN Plus simulations, process synergies, emission reductions, and profitability are analysed across multiple configurations. Key findings indicate that utilising internally generated hydrogen is more cost-effective, achieving a 4 % reduction in equipment costs, lowering total equipment cost from $2.58 billion in the base case to $2.47 billion. This results in a total annualised cost saving of $225 million and a 32 % increase in profitability, raising annual profits from $412 million in the base case to $543 million. The integration efficiently repurposes CO₂ emissions and nitrogen-rich waste streams to produce urea, demonstrating strong potential for promoting circularity . It enhances carbon efficiency to 84 % reducing overall emission from 180 tonnes CO 2 e/h in the business-as-usual case to 135 tonnes CO 2 e/h while PEM-based hydrogen reduces emissions by 14 tonnes CO 2 e/h compared to internally generated hydrogen. The high capital and operational costs due to electricity demands for PEM-based hydrogen process limit its viability. The study identifies the 9 tonnes/h internally generated hydrogen configuration as the optimal solution, offering significant emission reductions and financial benefits. These findings highlight the importance of process integration, renewable energy, and advanced hydrogen strategies for industrial decarbonisation, providing a sustainable pathway for GTL and urea production in line with global net-zero goals. • Integration with internally generated hydrogen increased profit by 32 % and reduced CO₂ emissions by 20 %. • Process synergies improved carbon efficiency to 84 % by reuse of FT tail gas and ASU nitrogen. • PEM-based green hydrogen lowered emissions further but was limited by high capital and electricity costs. • Profitability varied by 3–10 % with feed gas and hydrogen cost changes, as shown in sensitivity analysis. • The integrated GTL–urea system offers a viable route for industrial decarbonization and CO₂ utilization.