(272a) TEA of the Production of Advanced Marine Biofuels through HTL of Sewage Sludge

The rapid growth of the marine sector and the increasingly stringent environmental legislation have raised the demand of sustainable marine fuels that meet the quality and specifications required. Particularly in the North Sea, maritime transportation is a sector with a high influence due to its major contribution to the region’s economy and its high environmental impact caused by its dependency on fossil fuels. According to a study by the International Energy Agency (IEA) published in 2017, current marine fuels consumption is estimated to be around 330 million tons/year, and demand is predicted to double by 2030 as global trade increases. Due to the challenges in the implementation of other technological options, advanced drop-in biofuels are considered the most feasible option for the decarbonization of the shipping sector in the short-medium term as its implementation do not require significant changes in the existing infrastructure.

Being sewage sludge a residual and relatively high available waste feedstock, it has the potential to overcome the scalability issues of currently available biofuels in the marine market such as HVO and FAME. Sewage sludge valorization through HTL for the production of biofuels has been proved and recently realized with the development of several demonstration projects in USA and Canada, being interesting to study its implementation in the marine sector in which fuel specifications are typically less demanding to accomplish compared to aviation and road.
In this context, the process proposed in this work is a case study that comprises a distributed configuration of HTL regional plants with centralized upgrading in the Port of Rotterdam in The Netherlands. This location is considered strategic due to the infrastructure for utilities and hydrogen supply in connection with the existing refinery, the direct access for biofuel bunkering in the Port, and the relatively short distances in the Netherlands that decrease the transportation costs in the distributed scheme evaluated.

The process is modeled based solely on experimental data available for the HTL and upgraded fuels, contrasting key properties with the marine fuel specifications, and using Aspen Plus V9® to evaluate the technical and economic performance of the process and estimate the minimum fuel selling price (MFSP).