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FLExible Dimethyl ether production from biomass Gasification with sorption-enhancED processes

Periodic Reporting for period 3 - FLEDGED (FLExible Dimethyl ether production from biomass Gasification with sorption-enhancED processes)

Reporting period: 2019-07-01 to 2020-10-31

The FLEDGED project delivered a process for Bio-based dimethyl Ether (DME) production from biomass. The FLEDGED project combined a flexible sorption enhanced gasification (SEG) process and a novel sorption enhanced DME synthesis (SEDMES) process to produce DME from biomass with a process intensified and flexible process.

The primary aim of FLEDGED was to develop a highly intensified and flexible process for DME production from biomass and validate it in industrially relevant environments. This objective has been accomplished by:
- Experimental validation of the flexible SEG and SEDMES processes at TRL5.
- Evaluation of the full biofuel production chain from energy, environmental, economic, socio-economic and risk point of view.
- Preparation of the future exploitation of the results of the project beyond FLEDGED.

By combining the SEG and the SEDMES processes, the FLEDGED project validated a plant concept that:
- is highly process intensified: sorption of CO2 in the gasifier and of water in the DME reactor allows designing an overall process for DME production with with reduced number of process units
- allows operating with a wide range of biomass feedstocks
- is competitive with other bio-DME production processes, thanks to the reduced number of components, the avoidance or significant reduction of recycles and the avoidance of energy consuming and costly air separation and CO2 separation units
- is capable of producing syngas with tailored composition by adapting the SEG process parameters, which allows coupling with an electrolysis system for converting excess intermittent renewable electricity into a high value liquid fuel
Development of SEG process:
Different feedstocks (wood pellets, pine wood, straw, grape seeds, different samples of municipal solid waste from Econward plant) have been characterised and tested in the 30 kW bubbling fluidized bed gasifier at CSIC.
TRL5 validation tests have been carried out in the 200 kW pilot facility at the University of Stuttgart with wood pellets and municipal solid waste derived pellets. Operational flexibility of the SEG process was demonstrated, by showing the capability of controlling the syngas composition by modifying the solids circulation rate. To reach the target syngas M-module (M=(H2-CO2)/(CO+CO2)) of 2, a gasification temperature of approximately 720-740°C is needed. Higher gasification temperatures lead to lower M, allowing mixing of hydrogen from electrolysis.

Development of SEDMES process:
SEDMES process has been tested in different facilities from TRL3 to TRL5, that allowed to test different materials, including catalysts developed by CSIC, and conditions representative of different cycles. During the TRL5 experimental campaign at TNO in a multi-column PSA facility, more than 500 full cycles have been measured. All SEDMES objectives, demonstrated at TRL3 and TRL4, have been confirmed at TRL5. The process has demonstrated a more than halved single passage remaining CO+CO2 content compared to the conventional process. The formation of CO2 can be suppressed, with carbon selectivity to CO2 of less than 5%. Furthermore, SEDMES is highly flexible with respect to the CO/CO2-ratio in the feed, where the conversion of CO2 to DME performs similarly to the conversion of CO.

Process modelling and techno-economic analysis:
The complete FLEDGED process that combines the SEG and the SEDMES processes has been assessed through process simulation study at POLIMI, exploiting SEG models developed by LUT and SEDMES models developed by TNO. The economic analysis has been carried out with the support of the industrial partners FRES, SFW and Econward.
Different FLEDGED cases have been assessed, namely: F1: baseline case; F2: case with CO2 capture and storage (bio-CCS); F3: case with enhanced production thanks to the integration with the electrolyzer. The obtained technical performance are in line with the targets. The baseline FLEDGED case (F1 ) reached overall fuel efficiency of 58.5%, increasing to 65.7% in enhanced operations with hydrogen addition (F3). The economic analysis resuklted in a cost of DME of about 20 €/GJ for the baseline case F1, excluding the biomass cost.

Risk and Sustainability Analysis:
Risk assessment of the different process units of the FLEDGED biomass to DME value chains has been carried out by INERIS. The main risk scenarios were identified, the cause and the consequences were identified followed by the proposition of the risk mitigation measures. A WTW analysis has been performed by QUANTIS. Net WTW CO2 emissions <10 gCO2/km for the baseline FLEDGED case (F1). When in a bio-CCS configuration (case F2), the FLEDGED process can achieve negative emissions estimated equal to -190 gCO2/km. The socio-economic analysis (SEA) of the FLEDGED concept has been carried out by INERIS using monetary estimates of induced environmental and health impacts identified in LCA and modelling air quality and health impacts in EU28 of different DME use scenarios.

Exploitation study:
Commercial exploitation study with business model have been developed by Econward, FRES and Sumitomo FW with reference to: (i) small-scale plant for the conversion of MSW into DME, for subsequent use in garbage diesel trucks and other heavy vehicles and (ii) large-scale plant (100 MWth) for conversion of forestry biomass or lignin into DME.
Combination of conditions needed to make the commercial deployment of FLEDGED processes economically feasible have been identified.
Significant progress beyond the state-of-the-art has been achieved in FLEDGED, especially in relation to: (i) unprecedented tests of SEG process with several types of biomass; (ii) the validation at TRL5 the SEG flexibility on the syngas composition and the possible integration with electrolysis unit; (iii) the validation of the sorption enhanced DME synthesis reactor at TRL5; (iv) the development of novel catalysts specifically designed for the SEDMES process; (v) the development of a novel overall biomass to DME process characterized by better energy and economic performance, with high flexibility and the possibility of integration of bio-CCS.

The expected impact of FLEDGED project is summarized in the following list:
- Technical-scientific impact: two novel complementary processes have been developed that will create new knowledge, new methods and new technology.
- Technical-industrial impact: a new process-intensified, efficient, compact and flexible DME synthesis route has been developed.
- Societal impact: FLEDGED process can favour the spread of electric intermittent renewables by supporting power to liquid fuels conversion, leading to specific societal impacts: i) improve EU energy security due to a reduction in the reliance of fuel imports to the EU; ii) contribute reducing the emissions of CO2 and other classical pollutants from the EU energy sector by increasing the share of electric renewables in the European energy mix; iii) allow for negative WTW CO2 emissions by CO2 capture and storage.
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