LISBON, Dec 19 (Reuters) - Portugal's Galp Energia expects to begin producing biodiesel and biojet fuel from waste in an industrial-scale system it is constructing at its Sines refinery in 2026, the business, which is primarily an oil producer and refiner, stated on Thursday.

Last year Galp got in into a 75%-25% joint venture with Japan's Mitsui to invest 400 million euros ($415 million) in the Hydrogenated Vegetable Oil (HVO) plant, which will have a production capability of 270,000 metric heaps per year.

It will change waste products, such as used cooking oils, into and biojet fuel, likewise called sustainable air travel fuel (SAF), utilizing green hydrogen produced by an electrolyser powered by wind or solar power.

Galp said in a statement it received on Wednesday the 3 reactors to process biofuels, which will allow the HVO unit to "produce SAF and biodiesel in 2026 ... positioning Galp at the forefront of establishing low-carbon services essential for the energy shift".

Galp is also investing 250 million euros in a 100 megawatt (MW) electrolyser unit to produce green hydrogen to power the refinery in Sines. ($1 = 0.9637 euros) (Reporting by Sergio Goncalves