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

Last year Galp entered into a 75%-25% joint venture 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 lots per year.

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

Galp said in a statement it got on Wednesday the 3 reactors to process biofuels, which will enable the HVO system to "produce SAF and biodiesel in 2026 ... positioning Galp at the leading edge of developing low-carbon options necessary for the energy shift".

Galp is likewise 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-