Connect with us

Biofuel

CTI-Maritec: Why accurate testing of energy content is essential for bio bunker fuels

Owing to the composition of bio-marine fuels, accurate measurement of NSE / Net Heat of Combustion to correctly gauge energy content of bio-marine fuels is key for efficient fuel management onboard ships.

Admin

Published

on

Louis Reed from Unsplash

Marine environmental services and fuel testing solutions company CTI-Maritec on Wednesday (8 January) shared on why one of the most important testing parameters or properties of bio-marine fuel is energy content.

Owing to the composition of bio-marine fuels, the accurate measurement of Net Specific Energy (NSE) / Net Heat of Combustion to correctly gauge energy content of bio-marine fuels is key for efficient fuel management onboard ships: 

Introduction

Bio-marine fuel is widely adopted as a drop-in fuel to achieve the current emission requirements in the shipping industry. ISO 8217:2024 specification allows bio-marine fuels to contain up to 100% fatty acid methyl ester (FAME). The major production route of FAME is transesterification of vegetable oils, animal fats or used cooking oils with methanol using alkaline catalysts. The ISO 8217:2024 version has included additional test parameters to measure FAME content, energy content and oxidation stability for bio-marine fuels.

Accurate Net Specific Energy (NSE) assists with efficient fuel consumption management

In this newsletter article, we review why one of the most important testing parameter or property of bio-marine fuel is Energy Content. Accurate measurement of NSE for energy content of bio-marine fuels is essential for efficient fuel management onboard ships with respect to:

  • Fuel consumption
  • Voyage planning
  • Operating cost
  • Machineries or equipment performance
  • Emission & environmental implications

Why accurate testing of Energy Content is an essential test parameter for Bio-marine fuel

Marine fuel containing FAME typically has lower energy content compared to conventional marine fuels.

The heating value of a fuel is the total energy released as heat when a fuel undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon reacting with oxygen to form carbon dioxide, water and heat as shown in the equation below:

Hydrocarbon + Oxygen à Carbon Dioxide + Water + Heat Released

Conventionally, NSE of marine fuels (which consist of predominantly hydrocarbons from petroleum sources) is calculated using a formula specified in Annex of ISO 8217 (Annex J of ISO 8217:2024) with acceptable accuracy. For marine fuels containing FAME, the NSE cannot be calculated using the formula specified in Annex J of ISO 8217:2024 and shall be measured using ASTM D240 method. FAME molecules contain the Carbonyl group and Ester bonds as shown in Figure 1 below and do not consist purely of carbon and hydrogen atoms.

Figure 1: An Ester of a Carboxylic Acid

Figure 1: An Ester of a Carboxylic Acid

The density of potential energy of a hydrocarbon is determined by the number of carbon to hydrogen bonds that can be replaced by oxygen to carbon (CO2) and oxygen to hydrogen bonds (H2O), in other words, the amount of energy released is dependent on the oxidation state of the carbons in the hydrocarbon. For marine fuel containing FAME, the FAME molecule itself contains oxygen atoms in the Carbonyl group and Ester bond. The Ester group of FAME has a carbon forming 3 bonds with oxygen atoms, this means esters are more oxidised than hydrocarbons and esters release less energy content when compared to hydrocarbon since higher oxidation reactions are needed for hydrocarbons.

The paragraphs above explain the reasons marine fuel containing FAME typically have lower energy content compared to conventional marine fuels, which consist of predominantly hydrocarbons and the calculated formula for NSE is not applicable to marine fuel containing FAME.

According to ASTM D240 test method, heat of combustion is determined by burning a weighed sample in an oxygen bomb calorimeter under controlled conditions. The heat of combustion is computed from temperature observations before, during, and after combustion, with proper allowance for thermochemical and heat transfer corrections. The average of gross specific energy (GSE) or gross heat of combustion, and NSE or net heat of combustion of MGO, VLSFO, HSFO and Bio-marine Fuels are tabulated in Table 1 below:

Why accurate testing of Energy Content (Net Heat of Combustion) is essential for Bio-Marine Fuels

Note: The average GSE and NSE for each of the fuel types was obtained from at least 50 samples.

Based on Table 1, bio-marine fuel B30 has 8% lower energy content when compared to MGO. The energy content of bio-marine fuel will become lower when the FAME content is higher.

Energy content of marine fuel containing FAME shall be determined by ASTM D240 method and cannot be calculated using the current NSE formula, which is commonly used for the conventional marine fuels.

Note: The full article by CTI-Maritec can be found here

 

Photo credit: Louis Reed from Unsplash
Published: 9 January, 2025

Continue Reading

Bunker Fuel

Alkagesta highlights key insights of Malta bunkering market in 2026

Darren Lee Axisa discusses the key trends influencing Malta’s bunkering market and the factors that will determine Malta’s long-term competitiveness as a regional bunkering hub.

Admin

Published

on

By

Alkagesta highlights key insights of Malta bunkering market in 2026

In an article published on Alkagesta Market Insights, Darren Lee Axisa, Malta Country Manager of Alkagesta, on Monday (20 July) discussed the key trends influencing Malta’s bunkering market and the factors that will determine Malta’s long-term competitiveness as a regional bunkering hub: 

Malta’s bunkering and energy market is moving through a period of structural adjustment. The disruptions that defined the first half of 2026 have accelerated shifts in product demand, terminal strategy, and the competitive dynamics of one of the Mediterranean’s most strategically positioned bunkering hubs. For Alkagesta, whose storage footprint on the island approaches 300,000 cubic metres, the period has tested operational flexibility while reinforcing the value of diversified infrastructure access.

A Market Shifting in Two Directions

Malta’s broader economy has remained resilient — GDP growth reached 3.9% in Q1 2026 — but the bunkering market has undergone a significant product mix shift, the roots of which predate the current geopolitical disruption.

The Mediterranean Emission Control Area, which came into force on 1 May 2025, triggered an immediate and measurable realignment in fuel demand across the region. VPS data covering the first six months post-ECA implementation shows that across the top ten Mediterranean bunkering ports, VLSFO volumes fell 23%, MGO more than doubled, ULSFO quadrupled, and biofuels increased fivefold. In Valletta specifically, the shift was even more pronounced: VLSFO dropped 57% from 111,641 mt to 47,732 mt, while MGO volumes more than tripled from 33,299 mt to 103,445 mt, and ULSFO rose from 2,821 mt to 34,535 mt over the same period.

This structural rotation has been further accelerated by the broader regulatory environment. FuelEU Maritime and EU ETS requirements are pushing shipowners toward cleaner, verifiable fuel options at every port call — a direction Alkagesta had already positioned itself ahead of, having been among the first movers in the Mediterranean to support the transition to 0.1% sulphur fuel oil following the ECA’s introduction.

Layered on top of this regulatory shift has been a period of reduced terminal capacity affecting bunkering market availability across the island. Fuel oil volumes dropped roughly 35% year-on-year between January and May 2026, falling from approximately 382,000 mt in 2025 to 247,000 mt. DMA demand moved sharply in the opposite direction, rising from around 150,000 mt in January to April 2025 to 247,000 mt over the same period in 2026 — a trend consistent with both the ECA-driven product mix shift and the disruption to heavier fuel availability during the constrained period.

Note: The full article can be read here

 

Photo credit: Alkagesta
Published: 22 July, 2026

Continue Reading

Alternative Fuels

ENGINE on Fuel Switch Snapshot: LSMGO surges to greater premium over biofuel

B100 discount to LSMGO widens to $541/mt in Rotterdam; Singapore’s B100 drops to $106/mt below LSMGO; Rotterdam LBM at $639-833/mt discounts to LSMGO.

Admin

Published

on

By

ENGINE on Fuel Switch Snapshot: LSMGO surges to greater premium over biofuel

Once a week, bunker intelligence platform ENGINE will publish a snapshot of alternative and conventional bunker fuel prices in the world’s two biggest bunkering hubs. The following is the latest snapshot:

20 July 2026

  • B100 discount to LSMGO widens to $541/mt in Rotterdam
  • Singapore’s B100 drops to $106/mt below LSMGO
  • Rotterdam LBM at $639-833/mt discounts to LSMGO

B100’s premium over HSFO in Rotterdam has narrowed by $50/mt over the past week to $64/mt, while its discount to VLSFO has widened by $83/mt to $105/mt.

B100 has become far more competitive against LSMGO in Rotterdam, with its discount widening by $180/mt over the past week to $541/mt, as a surge in conventional fuel prices left B100 broadly unchanged by comparison.

B100’s price has risen by $109/mt in Singapore, but its discount to LSMGO has still widened by $102/mt to $106/mt, as LSMGO surged by an even greater $211/mt.

Rotterdam’s LNG premium over VLSFO has widened by $35/mt to $201/mt for vessels with Otto medium speed (Otto MS) engines. For vessels with diesel slow speed (diesel SS) engines, LNG has flipped to a $15/mt premium over VLSFO, from a $22/mt discount the prior week.

Liquefied biomethane (LBM) discounts to VLSFO in Rotterdam have narrowed by $50-52/mt to $203-396/mt over the past week. Against LSMGO, LBM discounts have widened by $45-47/mt to $639-833/mt, depending on engine type.

In Singapore, LNG is now $42/mt cheaper than LSMGO for vessels with Otto MS engines, and $134/mt cheaper for vessels with diesel SS engines.

ENGINE on Fuel Switch Snapshot: LSMGO surges to greater premium over biofuel

Liquid fuels

HSFO and VLSFO prices in Rotterdam have jumped by $66/mt and $99/mt respectively over the past week, while LSMGO has surged by an even steeper $196/mt. A $9.69/bbl ($71/mt) rise in front-month ICE Brent futures, to $87.94/bbl ($645/mt), drove bunker prices sharply higher across the board.

Bunker fuel availability is tight for prompt delivery dates in the ARA ports, with buyers advised to enquire about stems between 5-7 days ahead to get good coverage, a trader said.

Rotterdam’s B100 price has risen by $16/mt over the past week. Dutch ZRE A ticket prices were unchanged at €107.50/mtCO2e.

Singapore’s HSFO and VLSFO prices have risen by $130/mt and $132/mt respectively, while its LSMGO price has gained an even steeper $211/mt over the past week.

VLSFO availability in Singapore has been tight, with several suppliers reporting low stock levels. Recommended lead times have widened from 13–17 days last week to 14–19 days now.

Liquid gases

Rotterdam’s LNG prices have surged by $134-136/mt over the past week, while its LBM prices have climbed by $149-151/mt.

LBM discounts to LNG in Rotterdam have narrowed by $15/mt to $404-411/mt.

Singapore’s LNG bunker benchmarks have surged by $196-197/mt over the past week.

By Erik Hoffmann

 

Photo credit and source: ENGINE
Published: 21 July, 2026

Continue Reading

Alternative Fuels

Repsol and Maersk wrap up first bioethanol bunkering operation in Port of Barcelona

Repsol supplied 2,800 mt of bioethanol to a Maersk container vessel, “Antonia Maersk”, in the first bunkering operation of its kind in the Port of Barcelona and one of the first in the Mediterranean.

Admin

Published

on

By

Repsol and Maersk wrap up first bioethanol bunkering operation in Port of Barcelona

Spanish energy company Repsol and shipping giant A.P. Moller – Maersk (Maersk) completed the first bioethanol bunkering operation in the Port of Barcelona, according to the port authority on Wednesday (15 July). 

Repsol successfully supplied 2,800 metric tonnes (mt) of bioethanol to a Maersk container vessel, Antonia Maersk, in the first bunkering operation of its kind in the Port of Barcelona and one of the first in the Mediterranean. 

The operation demonstrates growing demand for alcohol-based marine fuels, as well as the readiness of the infrastructure, logistics, and operational capabilities required to support their deployment at commercial scale. 

Juan Abascal, Repsol’s Executive Managing Director of Industrial Transformation and Circular Economy, said: “With this supply, we reaffirm our commitment to the decarbonization of maritime transport through solutions that are available today and ready to scale in the future. 

“At Repsol, we provide shipping companies with a reliable supply chain and a multi-energy strategy that combines different renewable fuels to support the sector in a safe, competitive, and sustainable transition.”

The supply took place in the Port of Barcelona under fully commercial conditions, bringing together key players across the maritime value chain and demonstrating how collaboration can accelerate the adoption of lower-emission solutions in shipping. 

The delivery was carried out by Bahía Candela, Repsol’s newest bunker vessel, operated by Mureloil and designed to supply both conventional marine fuels and next-generation energy products. 

During the bunkering operation, Bahía Candela operated using its battery system, enabling the fuel transfer to be completed with zero local emissions, and further reducing the environmental footprint of the operation. 

Prior to the bunkering, Maersk tested ethanol on one of its smaller vessels, the 1,800 TEU feeder vessel Laura Maersk, which in 2023 became the world’s first dual-fuel container vessel able to operate on methanol. Today, Maersk has 23 dual-fuel container vessels designed to operate on methanol; however, the company continues to explore ethanol as an alternative fuel for its methanol-enabled vessels. Laura Maersk has performed sailings on 100% ethanol as well as blends of ethanol and methanol. 

Emma Mazhari, Vice President Energy Markets at Maersk, said: “Following the successful ethanol trials conducted on Laura Maersk, this latest bunkering of Antonia Maersk marks another important step in our efforts to explore scalable low-emission fuel solutions. 

“As the first ethanol trial on one of our large dual-fuel vessels, with a capacity of 16,000 TEU, it allows us to deepen our understanding of ethanol’s operational potential at scale. 

“Building on the experience we have gained with methanol, we are working closely with port authorities and industry partners to develop the infrastructure and procedures needed to support ethanol bunkering. Ethanol is one of several pathways we are pursuing to diversify our future fuel portfolio and help accelerate the development of new, viable liquid marine fuel markets.”

 

Photo credit: Port of Barcelona
Published: 20 July, 2026

Continue Reading

Trending