Wärtsilä, a leading supplier of flexible power plants for the decentralised power generation market, has successfully performed a number of tests that demonstrate the ability of its engines to run on a range of vegetable and animal-based oils. This enables a wider range of renewable fuel options for the Wärtsilä engines, while at the same time enabling further CO2 emission reductions.
In the tests, conducted between February and April of this year at the VTT technical research centre in Espoo, Finland, a Wärtsilä Vasa 4R32 engine successfully operated on jatropha oil, fish oil and chicken oil.
The first tests with engines running on a liquid biofuel were carried out in 1995, when Wärtsilä began testing with rapeseed oil. Since 2003, Wärtsilä engine power plants have been in commercial operation using palm oil as the fuel source. Wärtsilä has, as an example, a market share of more than 95% in Italy for power generation from liquid biofuels. The aim of these recent tests has been to assess the capability of engines to operate on renewable fuels that do not compete with agricultural uses.
Commenting on the future market for power plants running on liquid biofuels, Vesa Riihimäki, vice president of Power Plant Technology, said: “Liquid biofuels represent an emerging market. We see that fuel supply infrastructures for crude vegetable oils are being developed at an increasing pace, suggesting that the availability of such fuels will be vastly extended during the next five to ten years. We provide technology that can use these new fuels and we have demonstrated that the chain from fuel to electricity exists. In addition to commodity fuels, we see a significant potential in industry process side streams, such as, fish and chicken oils, which can be used for generating renewable energy.”
Jatropha oil holds great promise
The first engine test with straight jatropha oil was performed in January 2009, with the engine being operated successfully on a batch of oil delivered from India. Jatropha oil is extracted from the seeds of the jatropha plant. The seeds are a non-edible, high-energy fruit grown on semi-arid or marginal land in Asia, Africa and Latin America. The fact that jatropha oil cannot be used in the food industry makes it extremely promising as a future fuel source.
An additional test will be conducted later this summer on a further batch of jatropha oil imported from Tanzania.
In April last year, Wärtsilä secured an order for an engine-based power plant that will run on jatropha oil at the Koekhoven combined heat and power plant in Merksplas, Belgium. This plant, which is expected to start operation this autumn, will be the first commercial installation of an engine running on the fuel.
Good results on animal oil
Fish oil was tested in February 2009. Fish contains 10-30% oil or fat, depending on the species. The global production of fish oil in 2007 was 1.1 million tonnes, exceeding the amount needed for food supplements.
Tests showed that the engine performed in much the same way as when running on vegetable-based oils and no further testing will be necessary for evaluation purposes at this stage.
Chicken oil, a by-product of the rendering process of chicken, was tested in April 2009. During the test, the engine performed as expected.
From these tests, it can be concluded that most animal fats are similar to conventional diesel fuels in terms of energy content, and ignition and combustion properties. The main differences are the melting point, the level of impurities, and the degree of acidity.
The main aim of the tests was to gain some experience with alternative fuels, and to verify that the engines would behave as expected in terms of performance and exhaust gas emissions.
Niklas Haga, chief development engineer at Wärtsilä Power Plants, said: “We have successfully tested and operated our engines using various vegetable-based oils in the past, now we are in the process of looking at animal-based oils. As a result of these tests, we are confident that we can operate our current engines on these renewables.”
Mr Riihimäki continued: “In the future, we will pursue further opportunities in the fuels arena, with a target to provide even more fuel flexibility to our customers.”