Global bunker supplier Vitol Bunkers and agricultural firm Olam Agri have completed a bio-bunkering operation in Singapore using VLSFO co-processed with cashew nutshell liquid (CNSL), demonstrating the fuel's performance across a full commercial voyage. Vitol Bunkers described the operation as the world's first bio-bunkering using co-processed VLSFO.

The operation involved the MV Scion Mathilda, which received around 247 mt of co-processed VLSFO at the Port of Singapore. The stem comprised 212 mt of conventional VLSFO and approximately 35 mt of VLSFO co-processed with CNSL.

Vitol Bunkers supplied the fuel, which was procured by Olam Agri's ocean freight business. The vessel subsequently consumed the fuel on a voyage carrying cargo from Caofeidian in China to Rotterdam in the Netherlands, followed by a ballast leg from Rotterdam to Barcarena in Brazil. According to Vitol Bunkers, the voyage was completed without any operational issues, demonstrating the fuel's performance under real-world conditions.

"This operation proves that co-processed VLSFO can be delivered and consumed at sea without any compromise to vessel performance or operational routine," Vitol Bunkers' trading manager Sherman Yeo said.

The co-processed VLSFO has a GHG intensity of 2.02 gCO2eq/MJ and delivered emission savings of at least 120 mt CO2eq compared with conventional VLSFO on an equivalent basis, Vitol Bunkers said. The fuel required no additional onboard handling or fuel treatment. Such emission performance carries growing commercial weight for ship operators, with the International Maritime Organization's revised greenhouse gas strategy targeting net-zero emissions by or around 2050, and EU measures including the Emissions Trading System and FuelEU Maritime increasingly pricing or limiting the GHG intensity of fuels used on voyages touching European ports — a relevance underscored by the Rotterdam legs of this voyage.

A different approach to biofuel production

Vitol launched its CNSL co-processed VLSFO in June last year at its 100,000 b/d refinery in Fujairah. CNSL is a byproduct of cashew nut processing rather than a food or feed crop, one of the characteristics that has drawn interest in it as a marine biofuel feedstock.

The process differs from conventional biofuel blending, in which bio components are added to marine fuel after the refining stage. Instead, CNSL is introduced directly into the refinery stream and processed alongside conventional crude oil. Most biofuel stems delivered in Singapore, the world's largest bunkering port, have involved such post-refining blends of fatty acid methyl esters (FAME), including the standard B24 grade, which can require tank segregation and flushing procedures when switching between bio and conventional fuels.

CNSL has historically presented challenges when blended directly into marine fuels, including material compatibility and handling issues, and direct CNSL blending has traditionally been viewed by the marine fuel industry as impractical for these reasons. Vitol's co-processing approach is designed to overcome these limitations by passing a small quantity of CNSL through the refinery's distillation and cracking units alongside a much larger volume of crude oil.

According to Vitol, the resulting fuel is chemically identical to conventional VLSFO. This means it retains the full energy content and does not require engine modifications, additional approvals or special charterparty clauses, the company previously told ENGINE.

By co-processing the bio component within the refinery stream, CNSL could instead offer a commercially viable route to contribute to shipping's GHG reductions. Open questions for wider adoption include how certification schemes attribute the bio-derived fraction of a fuel whose feedstock is processed with crude rather than blended afterwards, and whether volumes scale beyond the roughly 35 mt of co-processed fuel involved in this stem.

Source: By Tuhin Roy, ENGINE,