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 Renewable Energy and Environmental R&D 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% 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 14 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 any new CO2. 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 imitate 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 the acidic 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 is also good: 80% for hydrothermal liquefaction, compared to 50-60% for biogas and 10-30% for incineration. 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
After a first small-scale pilot project carried out in the Research Centre for Renewable Energy and the Environment in Novara, a new and larger continuous Waste to Fuel pilot plant was set up in an area of the Gela biorefinery. It was fed by organic waste collected from Sicilian municipalities dell’area di Ragusa. Thanks to more than 1,000 hours of long production tests and to the analysis of products and plant sections, the experimentation allowed us to gather useful information for the refinement and industrial-scale development of this technology, a goal that will also be pursued through public-private partnerships.
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 same amount of carbon dioxide is generated that was present in the initial biomass, 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, 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 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
recovered water available for new industrial uses
bio-oil calorific value
energy efficiency of Waste to fuel technology
Our official communications.
Read more about circular economy
Selected contents on this issue.