Sustainable and Flexible Production of Marine Biofuels


Danish shipowners own more than 10% of the world fleet (by tonnage) and because of this they consume vast amounts of fossil fuels. This is taken very seriously by shipowners such as DFDS who are working actively to find sustainable ways in which they can solve their core objective of transporting people and goods. An obvious way forward is to develop sustainable, maritime fuel products.

The Project

This project has received funding from the Energy Technology Development and Demonstration Program. Project no. 64019-0565.

The project, funded by the Energy Technology Development and Demonstration Program (EUDP), is aimed at conducting the necessary R&D to arrive at a hybrid solution able to produce sustainable “bio-bunker”, “bio-methanol”, electricity, thermal energy and biochar in a mix that reflects the market demand. We take point of departure on research results from DTU Chemical Engineering, which have been proven in lab scale. The goal of the project is to build a prototype pilot, which is close to full scale and which can be used to validate the scalability and interoperability of the aforementioned processes in a continuous production setup.

The purpose of the present project is to make a critical leap forward towards a cost effective and sustainable pipeline between the unutilised global biomass resources on one side and the demand for “green” fuel products on the other side – in this case, the Danish maritime sector.

In its interactions with global stakeholders in both the biomass and fuel markets, MASH has shown that there is a significant demand for sustainable fuel products. However, it is also clear that the current technological platforms do not offer the necessary flexibility in terms of biomass inputs and the fuel products being produced are not aligned with the requirements of the customer. In the case of the maritime sector, the bulk of the fuels consumed fall within the ISO 8217 standard (preferably low-sulphur), but this is rarely recognized by prospective bio-oil producers.

Because of the above shortcomings, no bio oil product has managed to gain a foothold in the maritime sector – due to compliance-, scalability- and pricing issues. MASH has shown that this triad of issues can be addressed by careful selection of feedstocks, technology and upgrading processes. Despite being a good point of departure and the basis for the recent investment by DFDS in MASH, it is clear that the underlying issue in achieving true proliferation of bio-fuels in this and other sectors is the lack of a flexible process that will produce oil outputs of predictable quality from a wide range of inputs. The good news is that efforts at DTU has shown that such a platform can be achieved through a combination of very promising research results. The purpose of this project is to arrive at the desired technological solution by developing a new process based on the research conducted at DTU and in MASH.

The demand for the outputs of the process is already a given and the commercial upside is clear: For DFDS and other shipowners, bio-bunker and bio-methanol constitute an attractive fuel product of which large amounts are needed. Indeed, we expect to be able to sell our sustainable fuel and electricity outputs at rates comparable to those in the (fossil fuel) commodity market for energy products. Indeed, we expect to sustain a high profit margin even when doing so.

Another important revenue stream comes from the “bi product” of the process, namely the biochar, which is produced. This biochar has a wide range of benefits if applied to farmland including reduced fertiliser- and irrigation needs, improved soil biodiversity, improved cation exchange etc. Also, the biochar is extremely stable, meaning that when put into the soil, it will stay there for hundreds if not thousands of years. The latter means that biochar provides an immensely attractive mechanism for carbon sequestration, which can be monetised in the form of carbon credits.

The project builds on a combination of state-of-the-art research conducted at DTU, but also within MASH Energy ApS. The technologies in question are:

  1. The TwoStage gasifier: The TwoStage process has long been known to hold various records in terms of process efficiency and quality of the synthetic gas produced. The latter is an important feature in terms of enabling various downstream upgrading processes, which take point of departure in e.g. hydrogen or carbon monoxide. It is due to this high syngas quality that the TwoStage process is used as an enabling technology in the present project application. In fact, our research shows that the biomass waste derived syngas poses a hugely attractive source of cheap H2 and CO. Furthermore, the system also has a very high tolerance to moisture content and has been shown to run on difficult feedstocks such as sewage sludge pellets. 
  2. Steam or pure oxygen as oxidation media for gasification: By using pure oxygen and CO2 nitrogen is eliminated from the syngas, leading to a higher energy density and the avoidance of an inert substance in downstream process steps such as catalytic production of methanol. Also, the removed nitrogen is useful in reducing NOx emissions. Steam can also be used to similar effects in conjunction with oxygen. This has the further potential of reducing the necessary maximum temperature in the process by around 200 deg C.
  3. The syngas to methanol synthesis process: The process has been shown to work in a test rig situated at DTU Risø (using syngas from the TwoStage process) and although modelling predicts good performance, several questions still remain to be answered in relation to how efficient the process will be when brought to a commercial context.
  4. Advanced condensation and de-oxygenation: The classical issue with pyrolysis derived fuel is high acidity, high oxygen content and – as a consequence of both – short shelf life and poor miscibility with other oils. Also, the calorific value of pyrolysis oils tends to be significantly lower than what is expected by industry. MASH Energy has addressed this by carefully selecting feedstocks for their pyrolysis processes and thereby ensuring that the outputs are appropriate (e.g. low oxygen content). However, this strategy means that only a small subset of the available biomass can be used. Luckily, research at DTU Chemical engineering has yielded several interesting strategies for reducing oxygen content in the pyrolysis oil and for improving the overall quality of the output.

All of the above are interesting technologies in their own rights. However, by combining them, we arrive at something truly interesting; an efficient hybrid system, which can continuously shift its output between different ratios of bio-bunker, bio-methanol and electricity, depending on what is required – perhaps even in real time using smart algorithms such as machine learning. 

The graphic below shows the proposed system along with its different components.

A flexible platform for production of liquid fuels

Using this modular system MASH Energy will as a point of departure use sewage sludge from wastewater treatment plants (WWTPs) and produce a biofuel compliant with ISO 8217 standard and meeting the environmental regulations for marine fuels, as required by DFDS. Practical development of the technology in an intelligent grid system is the core objective of DTU BGG and MASH Energy ApS. The project will also be reducing the environmental impact of the sewage sludge and transforming it into valuable resources – biofuels and biochar.

The Consortium


MASH was founded in 2015 as a spinout from the Technical University of Denmark (further on DTU), with the aim to commercialise the DTU-developed thermochemical technologies in biomass processing. Currently, we sell a unique, modular pyrolysis and gasification solutions, which can transform a variety of feedstock (nut shells, agro-waste, river and ocean debris), into commodities as electricity, fuel biooil and fertilisers. Thanks to our unique approach to supply chain establishment and technology development, we also commercialise these commodities, offering them at a similar price than their unsustainable competitors. 

With strong connection to the shipping industry, MASH has recognised its need for an affordable marine fuel, which complies with the increasingly stricter global shipping regulations on sulphur and greenhouse gases.

Role in the project: MASH is the project leader and its tasks involve working in close coordination with DTU on the implementation and testing of learnings and models from the lab-scale setup. Based on this, MASH Energy will design, develop and test a pilot scale HES.


DTU Chemical Engineering’s Biomass Gasification Group (now part of DTU CHEC), is the Academic partner in this application. The BGG focuses on the development of thermochemical technologies for utilization of Biomass/waste. The research goal is to develop highly efficient technological solutions for optimal utilization of biomass resources. The research includes: optimization of pyrolysis + gasification TwoStage processes, fundamental understanding of tar formation and decomposition, low temperature residue waste and characterization of producer gas properties. The group is internationally recognized as a leader and has wide ongoing collaboration with industry (Ørsted, Haldor Topsoe, Wattenfall, Weiss, TI) as well international universities and research institutions. The Project will primarily be led by Jesper Ahrenfeldt and Ulrik Birk Henriksen. 

Senior Scientist Jesper Ahrenfeldt has 19 years of research experience focusing thermochemical processes like gasification of biomass and end-uses of biomass producer gas/syngas (with 3000+ international research/book citations). 

Senior Scientist Ulrik Birk Henriksen has 30 years of research experience focusing in DTU on development of TwoStage gasification process, with extensive research work on its optimization (with citation: 2340, h-index: 27.). The designs and concepts have been used by multiple companies to produce large-scale gasification plants (e.g. WEISS 400KW gasification unit). 

The research conducted over the last 3 decades broadly consistent of pyrolysis, gasification and methanol production technology. DTU Risø has developed and optimized the process by extensive research and was subsequently patented (WO2019072350, WO2019072351). The Viking TwoStage (pyrolysis + gasifier) system has been operated with digested sewage sludge from Bjergmarken Renseanlæg.

Role in the project: Being the academic partner in the project, DTU CHEC is tasked with integration of the technologies mentioned in the portfolio – and perform modeling, testing and optimization on the lab-scale HES.


DFDS is a Danish international shipping and logistics company. It is the busiest shipping company of its kind in in Europe. The company’s name is an abbreviation of Det Forenede Dampskibs-Selskab (literally The United Steamship Company). DFDS was founded in 1866, when C.F. Tietgen merged the three biggest Danish steamship companies of that day.

Today, DFDS operates a network of 25 routes with over 50 freight and passenger ships in the North Sea, Baltic Sea and the English Channel under the name DFDS Seaways. The rail and land-based haulage and container activities are operated by DFDS Logistics.

Role in the project: DFDS is primarily involved in the project as an off-taker of the bio-bunker and bio-methanol produced for in-land engine trials. These trials will validate the quality, usability and storage characteristics of the oil product. Pending the viability and success of the trials, DFDS has stated an intention to procure the marine biofuel(s) for their vessels.


Please note this page is continuously updated for outputs and results from the ongoing project. If you’re interested to know more please contact us at