Wageningen researchers are developing a sustainable and vegetable alternative for paraffin candles.
Paraffin wax is obtained from petroleum, explains Rolf Blaauw, Project Leader at Wageningen Food & Biobased Research. ‘Refineries have been producing decreasing amounts of paraffin wax, for various reasons, which caused the price of the wax to increase. On top of that, there has been an increased demand for sustainable raw materials.’ That is why Wageningen researchers are working on a sustainable and affordable alternative for paraffin wax based on vegetable oil. To achieve this, they are collaborating with Cargill Global Edible Oil Solutions, one of world’s largest vegetable oil producers.
To convert vegetable oil into candle wax, it first must be ‘hardened’ by hydrogenation – a process used extensively in the food industry. In this process, liquid oil, such as palm or rapeseed oil, is treated with hydrogen gas, which creates saturated fatty acids with a higher melting point.
This material is very suitable for encased candles, such as tealights. But according to Blaauw, before this hardened oil can be used in the production of free standing candles, several challenges have to be overcome. One example is that the hardened oil can solidify in various crystalline forms, which may cause the candle to look less attractive. Blaauw: ‘It is comparable to what happens when you melt chocolate and put it in the cooler: it gets and entirely different structure. What is more: the current processes have been developed to produce paraffin candles. The hardened oil is too brittle and therefore harder to process in the same way as paraffin wax.’
Preliminary results look promising
By smartly combining hardened oil with softer fats, the researchers have already developed a vegetable wax that does solidify normally. That means the first challenge has been overcome. The preliminary results look very promising, according to Blaauw. ‘We are currently mainly working on a way to make the material more flexible, less brittle in other words. This is not only important for the processing, but also for the transport, as the candles will otherwise easily break. We have made good progress in this as well.’
The project was started in early 2015 and will run until the end of 2017. Blaauw expects that they will be able to produce free standing candles based on vegetable oils in a sustainable and affordable way before that time. He also sees possibilities for other applications. ‘As these vegetable waxes are harmless, they could also safely be used in the packaging industry, such as in water repelling coatings that can come into direct contact with a food product.’ ’