Techno-economic and environmental assessment of HFO, LNG, and ammonia under the red sea crisis and IMO carbon pricing: an OPEX-based multi-scenario analysis of Suez Canal and Cape of Good Hope routing

Abstract

The maritime shipping industry faces increasing pressure to decarbonise, with alternative fuels emerging as key pathways to reduce greenhouse gas emissions. This study develops an operational expenditure -based multi-scenario framework to evaluate the techno-economic and environmental performance of alternative marine fuels for a 15,000 TEU containership operating on the Rotterdam–Singapore route. The analysis compares Heavy Fuel Oil (HFO), Liquefied Natural Gas (LNG), and ammonia across Suez Canal (SC) and Cape of Good Hope (COGH) routing options under normal market conditions and Red Sea crisis conditions, incorporating fuel costs, tank-to-wake CO2 emission costs, and SC transit tolls under alternative pricing and rebate schemes. The results demonstrate that the Red Sea crisis substantially increases total operating costs across all fuel pathways on the COGH route. Compared with normal market conditions, total operating costs increase by approximately 155% for HFO, 118% for LNG, and 58% for ammonia. While ammonia remains the highest-cost option in absolute terms, it exhibits the smallest relative cost escalation under crisis conditions, indicating greater resilience to fuel price and carbon cost shocks. LNG emerges as the most cost-competitive option across most scenarios, whereas HFO loses relative competitiveness due to its higher exposure to fuel and carbon costs. The diversion of vessels from the SC to the COGH increases voyage distance from 8288 to 11,755 nm, resulting in higher fuel consumption, emissions, and carbon costs. Consequently, CO2 emissions increase from 4114 to 5,481 tons on the SC route to 5797–7723 tons on the COGH route, highlighting the critical influence of route choice on both environmental and economic performance. The findings further suggest that emerging IMO carbon pricing measures are likely to strengthen the competitiveness of low- and zero-emission fuels, particularly under conditions of geopolitical disruption. Overall, the study provides a comparative benchmark for evaluating alternative fuel pathways and routing strategies, contributing to the understanding of the interactions between maritime decarbonization, route selection, and geopolitical risk in global container shipping.