Preliminary B50 trial finds mining equipment performance unchanged, fuel use higher

By Pandu Setiadi

Preliminary trials of Indonesia's B50 biodiesel blend on mining equipment showed no significant impact on engine performance compared with the current B40 blend, although fuel consumption increased by up to 3.3% and water accumulation during storage rose slightly, an Energy Ministry official said.

Herbert Wibert, coordinator for bioenergy engineering and environmental affairs at the Energy and Mineral Resources Ministry's Directorate General of New, Renewable Energy and Energy Conservation (EBTKE), said preliminary tests conducted by the Lemigas oil and gas research institute found that B50 delivered comparable power, torque and specific fuel consumption (SFC) performance to B40.

"Based on the preliminary results, B50 does not have a significant impact compared with B40 in terms of power, torque and specific fuel consumption. For the storage stability test, there is indeed a slight increase in the rate of water content," Herbert said during a webinar on Wednesday.

The preliminary storage stability test showed the average rate of water content increased by 1.9 parts per million (ppm) per day in a 4,300-litre storage tank and 1.8 ppm per day in a 1,300-litre tank.

A 1,000-hour durability test found valves and cylinder walls remained in good condition, while fuel filter replacement intervals were unchanged from B40. No fuel system malfunctions or warning signals were detected during the trial.

Herbert said carbon deposits accumulated more quickly on pistons than with B40 but remained within normal and acceptable limits. Under field operating conditions, fuel consumption increased by up to 3.3% compared with B40.

The B50 testing programme for mining equipment is scheduled to run from January to August 2026. As of July 13, limited performance testing had been completed on two units, while testing on one additional unit was awaiting confirmation. The storage stability test had run for 165 days, and the 1,000-hour durability test had been completed on three of the four planned units.

Indonesia is evaluating B50 biodiesel as the next step in increasing the biofuel content of diesel after introducing the mandatory B40 blend earlier this year.

Editing by Alexander Ginting