HYBRID TANDEM CATALYTIC CONVERSION PROCESS TOWARDS HIGHER OXYGENATE E-FUELS

Project Information

E-TANDEM

Grant agreement ID: 101083700

DOI

10.3030/101083700

Project closed

EC signature date 21 October 2022

Start date 1 November 2022

End date 30 April 2026

Funded under

• Climate, Energy and Mobility

Total cost

€ 3 334 885,00

EU contribution

€ 3 334 885,00

Coordinated by

AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS
Spain

Periodic Reporting for period 2 - E-TANDEM (HYBRID TANDEM CATALYTIC CONVERSION PROCESS TOWARDS HIGHER OXYGENATE E-FUELS)

Reporting period: 2024-01-01 to 2025-04-30

Summary of the context and overall objectives of the project

The EU target for 2050 to achieve a net-zero greenhouse gas (GHG) emissions economy is crucial to cease global warming and its consequences on climate. While electrification is the blueprint for passenger vehicles, the de-fossilization of other transport sectors such as heavy-duty and long-haul ground, shipping and aviation transport relies on the availability of carbon-neutral fuels with much higher volumetric energy densities than state-of-the-art batteries.
Synthetic liquid hydrocarbons and light oxygenate (methanol, DME) renewable fuels stand as the current options. Higher (with 5 or more carbon atoms in their chemical formula) oxygenate compounds, such as aliphatic alcohols and ethers, could prove a highly preferred alternative, due to their exceptional capacity to reduce tailpipe volatile organics and soot emissions compared to paraffinic fuels (owing to their mildly oxygenated chemical formula) and their advantageous logistics and compatibility with current-fleet infrastructures (fuel distribution networks and internal combustion engines) compared to lighter oxygenate compounds with greater oxygen contents.

The E-TANDEM project ambitions to unlock an efficient and direct production of a new higher-oxygenate diesel-like e-fuels which can replace fossil diesel in the marine and heavy-duty transport sectors. Said oxygenated fuel is directly produced from waste CO2 (from industrial exhaust streams or direct capture from the air) as the sole carbon source, and renewable power as the sole energy input, in a once-through hybrid catalytic process which integrates three major catalysis branches: electrocatalysis, solid thermocatalysis and molecular chemocatalysis.
E-TANDEM advances on breakthrough findings made by consortium partners with catalyst materials which, owing to their unconventional performance, enable for the first time the integration of reductive polymerization and oxo-functionalization reactions from renewable syngas (CO+H2) in a single-step process with greater carbon and energy efficiency than conventional multi-step conversion schemes, alongside essentially no CO2 side-production. The project will demonstrate the new e-fuel production concept in continuous mode at bench-scale (< 1L/h) validating the technology at technology readiness level (TRL) 4. Emphasis will be placed on assessing and optimizing the process dynamic response to stationary and daily fluctuations which are inherent to renewable hybrid wind-solar power inputs. Moreover, fuel benchmarking, techno-economic and life-cycle analyses will assess the soundness of current fleet-compatibility, sustainability and societal aspects of the newly proposed higher oxygenate e-fuel and its production concept.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the second reporting period, significant progress has been made towards the project objectives. Current main achievements include:

- Successful development of co-electrolysis anodes based on low-Ni content LSFNT infiltrated with Ni/GDC allowing for (i) optimized for downstream outlet composition H2:CO=2.5 (ii) degradation rates <3%/kh at 1 bar, and finally (iii) tolerance to alcohol impurities in steam feed.

- New formulations have been discovered for (i) multimodally porous and surface hydrophobic cobalt-based FT catalysts, and (ii) molecular metal carbonyl reductive hydroformylation catalysts bearing monodentate phosphine ligands. These catalysts lead to high alcohol selectivity (45-50 %) and productivity (240 mg gmetal-1 h-1 ), surpassing the performance objective of the project.

- Several characterization tests of the HOEF e-fuels in the higher alcohol as well as in the higher ether realizations, and their MGO blends has been executed, and their compliance to the ISO 8217 (marine gasoil) DMA Limit and EN 590 (automotive diesel) norms has been assessed.

- Recycling of the (i) FT-solid catalyst, and (ii) molecular RHF catalyst were achieved at the level of a bench-scale semi-continuous stirred tank reactor, jointly reaching metal retention rate of 99.92%. Now, the reactor will be tested for continuous operation, implementing both recovery strategies at the same time.

- Concept for water purification for recycling of process water into the steam feed was developed based on experimental process water contamination profiles.

- Developed the in-silico design of a complete e-fuel production process for a site of 1MW capacity.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

- Optimized CO2-H2O solid oxide co-electrolysis (co-SOE) anodes with excellent stability, essentially null methanation side-production, low carbon buildup and tolerance for trace alcohol impurities in steam feed, enabling process water recirculation. IMPACT: Enhanced integrability of co-SOE process step into continuous e-fuel production concepts.

- An optimized 2D-GC-ToFMS analytical procedure has been developed, enabling unprecedented quantitative characterization of complex product mixtures, potentially including paraffins, olefins, linear and branched higher alcohols, and both symmetric and asymmetric higher ethers. IMPACT: Informed process optimization in e-fuel production targeting oxygenated compounds.

- All HOEF realizations can be blended with marine gas oil (MGO) and, in the studied compositions, the physico-chemical properties of the stable blends are compliant with the relevant current standards for MGO fuels (ISO8217). The use of blends, instead of pure HOEF e-fuels, is already more sustainable than traditional fuels. IMPACT: solid grounds for drop-in acceptance of new HOEF e-fuel for immediate de-fossilization of the hard-to-electrify waterborne transport sector.

- Machine-learning-guided development of Organic Solvent Nanofiltration (OSN) as a low energy-demand, and catalyst-preserving process step for recovery of soluble catalysts from reaction liquors in continuous mode. IMPACT: new process design tool with long-reach implications in chemical process deplying molecular catalysts in solution.

- A multi-step water conditioning concept has been developed which enables the purification of process water, side-product recovered from the tandem syngas conversion process, to achieve suitable parameters for its recycle into a co-SOE unit. IMPACT: Enhanced process intensification for continuous e-fuel production concepts based on co-SOE as the entry process step.

- The overall process pathway was developed, and an in-silico model replica was established. These models were calibrated using experimental data provided by project partners. This work serves as the basis for further analysis and optimization. IMPACT: accelerated process optimization (in silico) and solid assessment of techno-economics and environmental impact of HOEF production concept.

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