LISBON, Dec 19 (Reuters) - Portugal's Galp Energia anticipates to begin producing biodiesel and biojet fuel from waste in an industrial-scale unit it is building at its Sines refinery in 2026, the company, which is mostly an oil producer and refiner, said on Thursday.

Last year Galp participated in a 75%-25% joint endeavor with Japan's Mitsui to invest 400 million euros ($415 million) in the Hydrogenated Grease (HVO) plant, which will have a production capacity of 270,000 metric tons per year.

It will change waste materials, such as utilized cooking oils, into sustainable biodiesel and biojet fuel, likewise referred to as sustainable aviation fuel (SAF), utilizing green hydrogen produced by an electrolyser powered by wind or solar power.

Galp stated in a statement it got on Wednesday the 3 reactors to process biofuels, which will permit the HVO unit to "produce SAF and biodiesel in 2026 ... placing Galp at the leading edge of establishing low-carbon solutions important for the energy transition".

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;-RRB-