The Waste to Fuel technology produces biofuels from the Organic Fraction of Municipal Solid Waste (OFMSW), made up of leftover kitchen waste. At Eni's Research Centre in Novara it was designed, developed and patented the first of its type in the world. A continuous pilot plant was built at the end of 2018 at the Gela biorefinery and was managed by Eni Rewind until April 2022, in compliance with the authorisation granted for research facilities. The Waste to Fuel process produces a bio-oil that can be used for sea transport, due to its low sulphur content, or refined into high performance advanced biofuels. The process also releases up to 60% of water, which, once purified, can be reused in production cycles. Other than waste, Waste to Fuel can treat sewage sludge, plant waste, waste from the agri-food industry and large-scale distribution.
Italy collects about 30 million tonnes of waste every year, of which 18 million tonnes is correctly separated. Of this, about 7 million tonnes is OFMSW. By promoting the increased and more accurate separation of kitchen waste, this figure could reach 10 million tonnes of OFMSW. Currently, it's mainly used to produce compost for agriculture and, to a lesser extent, biogas. An increasingly important sector, but with a rising cost for the community. By combining a well-managed separated waste collection and more Waste to Fuel plants across Italy, we could in theory obtain about a billion litres of bio-oil annually, equivalent to about 6 million barrels of crude oil per year. It would be like discovering a small oil deposit without having to drill a well, and, above all, without emitting additional CO2 into the environment. With a single operation, we could make a major contribution to Italy's energy security and, at the same time, reduce the quantity of waste and greenhouse gas emissions.
FUTURA#2 – From Waste to Fuel
With Waste to Fuel, in two or three hours, we simulate the natural process by which nature took hundreds of millions of years to generate hydrocarbons from prehistoric organisms. At the core of this technology is hydrothermal liquefaction, a thermochemical process in aqueous solution that transforms the initial biomass into a sort of “biological petrol”, or bio-oil. At this stage, nearly all the energy contained in the initial organic material is recovered and concentrated, retaining the precious hydrogen-carbon component and separating out the water. Each step is studied to reduce losses and obtain a product with a high calorific value (35 MJ/Kg) and low sulphur content. The main advantage of hydrothermal liquefaction over other waste treatment processes is that the water doesn't have to be eliminated. Indeed, all other processes evaporate off the water by heating the biomass, with an obvious energy cost. In this case, however, the water is used in the reaction itself, harnessing its properties that occur at high temperatures. Furthermore, lower temperatures are used: 250-310°C rather than 400-500°C for pyrolysis and 800-1000°C for gasification. The energy yield of hydrothermal liquefaction, reaching 80%, is also good. But Waste to Fuel's most persuasive advantage is the transformation of waste into bio-oil – waste that would have a disposal cost – thus making it a useful raw material as per circular economy principles.
PEOPLE#1 - Meet Valerio
Testing and development
After the first small-scale pilot built at the Eni Research Centre in Novara, a new and larger Waste-to-Fuel continuous operating pilot plant was built in an area of the Gela bio-refinery and fed with wet municipal waste (up to 100 kg/day) from the municipalities in the Ragusa area. The testing was carried out between January 2019 and April 2022 with more than 1,000 total hours of production tests. The analysis of plant performance with various batches and of the resulting products made it possible to gather useful information for the further improvement and industrial-scale development of the technology.
Municipal waste becomes a resource - OFMSW | Eni Video Channel
Waste to fuel energy recovery is virtually carbon neutral, since, by using the bio-oil obtained to power heat engines, the carbon dioxide already present in the initial biomass is generated, in turn captured from the atmosphere by plants and fixed in organic matter during photosynthesis. There is thus no need to add additional carbon derived from fossil fuels to this virtuous cycle. In other words, instead of being released into the atmosphere, the carbon is stored in the bio-oil and biofuel and reused, so helping to reach the targets set by the EU's Renewable Energy Directive for transport (RED II). Solid residue, on the other hand, is made inert by recovering the remaining energy within the process itself, while the water is used in the production of biogas and biomethane and then purified for subsequent reuse in agriculture. In addition, if adopted in countries or places with economies where agriculture predominates, the system could provide an industrial outlet for the large amounts of waste biomass, and contribute to the supply of fuels for local markets.
The features of the process
Data, performance and results.
bio oil obtained from incoming organic waste
up to 60 %
recovered water available for new industrial uses
bio-oil calorific value
up to 80 %
energy efficiency of Waste to fuel technology
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