A new study brings promising advancements for cleaner power generation on offshore platforms, exploring the transition from natural gas to low-carbon fuels like hydrogen, ammonia, and methanol. Conducted by researchers at SINTEF Energy Research in Norway [63.4°N,10.4°E], the study highlights how this fuel switch could significantly reduce greenhouse gas emissions while maintaining power efficiency.
The Challenge: Reducing Offshore Emissions
Offshore oil and gas platforms heavily rely on natural gas-powered turbines for energy, making them major contributors to CO₂ emissions. Traditional natural gas combustion not only releases CO₂ but also faces limitations in thermal efficiency. Although bottoming cycles—systems that capture exhaust heat for additional power generation—can improve efficiency, space and weight constraints offshore make implementing these systems challenging.
The Solution: Compact and Efficient Combined Cycles
Researchers have tested an optimised Once-Through Steam Generator (OTSG), designed specifically for offshore use. This system uses low-carbon fuel mixtures, generating steam from the exhaust heat of gas turbines without requiring bulky equipment. Fuels like ammonia and hydrogen were particularly effective; hydrogen, when combusted, produces only water, while ammonia generates nitrogen and water, dramatically lowering CO₂ emissions.
The Results: Fuel Savings and Lower Emissions
In scenarios using ammonia or hydrogen as fuel, the study found that the optimised combined cycle could cut fuel consumption by up to 462 tonnes per day compared to traditional natural gas systems. This efficiency gain translates directly into lower emissions, with ammonia and hydrogen scenarios reducing greenhouse gases by 85–90%. Even bio-methanol, a renewable fuel, showed reductions of up to 70% under certain conditions.
Transformative Potential for Offshore Sustainability
These findings underscore the potential for fuel flexibility in offshore energy, proving that retrofitting existing gas turbines with compact bottoming cycles could support a significant transition to low-carbon fuels without major design overhauls. The study marks a step forward in offshore decarbonisation, making it possible to meet energy demands sustainably while advancing the global drive toward net-zero.
Source
Effect of Use of Zero-Carbon and Low-Carbon Fuels on the Performance of Compact Combined Cycles for Power Generation, SSRN, 2024-10-26
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