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Sustainable Drop-In Transport fuels from Hydrothermal Liquefaction of Low Value Urban Feedstocks

Periodic Reporting for period 1 - NextGenRoadFuels (Sustainable Drop-In Transport fuels from Hydrothermal Liquefaction of Low Value Urban Feedstocks)

Reporting period: 2018-11-01 to 2020-04-30

Europe is facing major challenges in balancing its future energy needs and reaching the targets of 10 % renewables in transport fuels by 2020, and a total of 27 % penetration across energy sectors by 2030. At the same time, increasing residual mass flows from society are challenging Europe’s ability to design sustainable and circular approaches for valorization of organic as well as inorganic components. Increasing the use of bio-based products in the European economy is a strong focus, and an important aspect is the conversion of biomass into ‘advanced biofuels’ that significantly contribute to reducing the greenhouse gases (GHG) by more than 60 % as required by the RED II. The transport sector is especially challenged in the European Energy Roadmap 2050, by an 80 % reduction of GHG emissions compared to 1990.

The overall objective of the NextGenRoadFuels project is to prove the HTL technology pathway as a viable, sustainable and efficient route for production of liquid drop-in fuels for road transportation from urban organic residuals. The outstanding feedstock flexibility of advanced HTL technology and state-of-the-art, low-H2 upgrading techniques will be applied to low value, aggregated urban wastes, in order to obtain cost competitive, high volume, sustainable drop-in quality synthetic gasoline and diesel fuels. From a validated baseline HTL process chain for lignocellulosics, new innovative process steps will be designed and existing steps optimized to address the additional challenges encompassed by such feedstocks, with the objective to demonstrate all main process steps at >TRL5.
The focus of the first part of the project has been to establish HTL production capacity targeting high yields and to deliver a first batch of HTL biocrude and aqueous product to project partners produced from sewage sludge, as well as preparing to address stability and high quality data for process modelling and scenario development. At the M18 marker, several tons of sewage sludge has been analyzed, prepared and processed at the CBS1 continuous HTL plant, in order to establish process conditions and gain experience with the feedstock. The other major feedstock, organic fraction of municipal solid waste, has been investigated in batch HTL, prior to being used in the continuous plant. Significant effort has gone into product separation, in order to identify necessary process steps to deliver an upgradable biocrude for hydrotreatment, as well as to extract and isolate important non-organic compounds from the aqueous and solid byproducts, specifically phosphates (reaching >95 % as apatite) and nitrogen (>50 % as ammonia).

Furthermore, to establish whether protein extraction from the waste feedstocks, primarily sewage sludge, is technically feasible as a means to add value to the overall process by producing valuable non-fuel “side products”, as well as by removing nitrogen from the feedstock and thereby alleviating downstream heteroatom removal issues. This has been demonstrated as feasible, although further work needs to be done in identifying recovered proteins and amino acids in order to establish overall process economics of this. Activities on the feedstocks have been supported by extensive characterization campaigns aimed at developing a European database on feedstock variability as well as establishing analysis protocols and carrying out an internal “round robin” test for reproducibility of data at the different partner labs.

At the downstream side, initial work has been carried out to establish hydrotreating conditions, based on model compounds as well as the actual biocrude from the first delivery from the HTL campaign. As a novel process design, early stage electro-catalysis is being investigated as an internal source of hydrogen at low external energy input. Combining the entire process, flow sheets have been developed, comprising all stages and unit operations from protein extraction, feedstock preparation, through HTL, product separation and biocrude conditioning, to upgrading and fractionationation into relevant fuel fractions. These are now ready to receive high quality experimental data, which is the focus of the next stage of the project, in order to develop realistic implementation scenarios to establish financial and environmental benefits of the process.

Aiding this part, a road-to-market study has been carried out, identifying potential countries for initial deployment as well as critical implementation aspects such as legislation and competing technologies.
At this stage of the project, all HTL process stages from feedstock preparation to biocrude separation and conditioning have been identified at relevant stages, and initial testing has been performed to ensure that the delivery of 100 kg of upgradable HTL biocrude at M24 is can be carried out as planned. This also includes the production of high quality data and mass balances, that will establish at reproducible conditions the conversion parameters that will contribute to establish credible deployment scenarios including financial and environmental aspects as well as scalability and EU-wide deployment. Once the biocrude is available, similar data will be developed on the upgrading stages and also fed to the scenario development. All in all, the project will deliver scalable, reproducible scenarios for deployment, which can be used for actual implementation. In the near term, leading to M24, the project will deliver what is probably the first long term stability demonstration of HTL on high-ash feedstocks such as sewage sludge; once published, it is expected that this will be a reference publication for future work in this field.
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