A group of researchers from Kuwait’s Public Administration for Applied Education and Training has proposed using waste motor oil as supplementary fuel for large thermal power plants. According to their calculations, for Kuwait alone this could generate about 1.1 TWh of electricity annually by 2035, save nearly $100 million in fuel costs, and simultaneously reduce hazardous waste volumes.


Waste motor oil is one of the most hazardous waste types: during engine operation it accumulates metal wear particles, soot, sulfur compounds, and other contaminants. Improper disposal can lead to soil and water contamination. At the same time, the motor oil retains a high calorific value – about 40 MJ/kg – comparable to that of fuel oil and crude oil. It has to be cleaned of water, mechanical impurities, and sediment prior to usage; otherwise, contaminants can cause nozzle clogging, ash deposits, equipment corrosion, and unstable combustion.

Kuwait’s vehicle fleet is growing rapidly, and due to the country’s hot climate, motor oil must be changed more frequently than in many other regions. This for its part generates ever-increasing volumes of waste oil, which is currently treated primarily as hazardous waste. In 2024, the volume in question reached 181,800 tons. At the same time, the country’s thermal power plants burn millions of tons of crude oil and fuel oil annually. The researchers set out to determine whether these two problems could be linked, turning waste oil into an additional fuel source for the power sector.


With a view to this effect, they analyzed vehicle registration statistics from 2011 onward, estimated the annual volume of waste oil generated, and forecast its quantity through 2035. They then compared this available resource with the needs of one of the country’s largest power plants, specifically the East Doha Power Station, which supplies Kuwaiti residents with both electricity and desalinated water.


Calculations showed that by 2035, Kuwait will generate about 303,000 tons of waste motor oil per year. After purification, this volume will contain approximately 12,100 TJ of thermal energy. With a power plant efficiency of 33%, this amount of thermal energy would be sufficient to generate roughly 1.1 TWh of electricity, which totals nearly one-third of the East Doha Power Station’s average annual generation. This would be enough to replace about 311,000 tons of fuel oil or 287,000 tons of crude oil annually, corresponding to 58% and 64% of the station’s average consumption of these fuels in 2013–2021, respectively.


Even after accounting for collection, transportation, and pretreatment costs, net savings could reach $98 million per year. The researchers note that these estimates do not include potential reductions in remediation costs from illegal waste oil dumping or other environmental expenditures, so the actual benefit could be even higher.


According to previously published studies, purified waste oil can emit less carbon dioxide and nitrogen oxides than fuel oil when combusted. The researchers’ calculations indicate that CO₂ emissions could be about 19% lower, and NOₓ emissions nearly 46% lower.


The researchers also tested the robustness of their results under various development scenarios. Even with relatively low waste oil collection efficiency and less favorable power plant operating conditions, its use could still provide over 2,200 TJ of electricity per year. In the most optimistic scenario, this figure nearly triples up to 6,400 TJ. This corresponds to annual electricity generation of roughly 0.6 to 1.8 TWh.

It should be noted that the Kuwaiti researchers’ work represents a feasibility assessment of the technology rather than a ready-made implementation project. The next stage would require testing purified waste oil at operational power plants, as well as evaluating the long-term effects of such fuel on equipment. If these challenges can be addressed, waste motor oil could become a viable supplementary energy source.


Source: Global Energy Association