Rafrinor S.L., the company responsible for the collection of used cooking oil in almost 80% of the municipalities in the Basque province of Bizkaia, has undertaken an R+D+i research project in collaboration with the Gaiker-IK4 technological centre, the aim being to optimise the recycling of the oil.
The oil we use in the kitchen is one the most contaminant wastes that we generate in our everyday domestic life. It is calculated, for example, that 1 litre of vegetable oil contaminates 1,000 litres of water, to the extent that its dumping in the aquifer network considerably increases the cost of treating the water we require to be reused. This problem is typical of Mediterranean countries such as Spain, Italy, Portugal or Greece — the largest consumers of edible oil — and where it is necessary to enhance awareness of the issue.
In the Autonomous Community of the Basque Country, it is local authority councils that decide how this waste should be managed. Rafrinor S.L., after collecting the cooking oil from nearly 80% of the municipalities in Bizkaia, treats it (humidity, acidity, sediments, and so on) and sells it for its subsequent use as a raw material in the production of biodiesel. With a growing volume of collected waste - currently about 400 tons annually -, and in the process of expanding its installation of containers, Rafrinor, S.L. began this R+D+i project in collaboration with Gaiker-IK4 in 2010 with a twin aim: to explore possible ways of recycling which enable obtaining enhanced value from the tons of plastic container bottles left over after the used oil is extracted; and to optimize the process of separation of oil from plastic at Rafrinor, S.L.
So, R+D+i experts in recycling and in the value enhancement of plastic materials at Gaiker-IK4 have been working to determine what the optimum recycling process is for oil container bottles, drawing the conclusion after trials for washing, extrusion and combustion, that the energy revaluation with the subsequent use of the material as an alternative fuel for boilers, furnaces, etc., turned out to be the ideal option in terms of technical viability. Other possible applications from linked recycling processes have been pointed to, such as in construction (insulating panels, etc.). Factors such as the heterogeneity of the plastic material collected or its extreme dirtiness were key in discarding other possible processes for recycling and value enhancement.
The challenge – improving the habits of the public
To come to such conclusions, representative samples were analysed from a total of 10 local authority associations – chosen using a methodology developed by Gaiker-IK4 within the remit of the above-mentioned R+D+i project. From these analyses, besides the conclusions mentioned, other results relevant for the second objective were drawn: to optimize the process of separation of oil from plastic at Rafrinor, S.L.
Amongst other conclusions, the samples chosen showed that the presence of inappropriate material in the oil container is sufficiently common to make the total automation of the separation process difficult. Highlighted amongst bad practices identified is the presence of glass jars or bottles, newspaper or clothes, which end up incorrectly in these containers; which is why Rafrinor S.L. proposes the need to continue working in dissemination tasks aimed at raising the awareness of the public as regards the importance, not just of recycling as such, but of doing it appropriately.