Scientific publications

Scientific peer-reviewed papers

All the open access scientific publications of FLEDGED project are available in the FLEDGED community on Zenodo.

Steam separation enhanced reactions: Review and outlook (van Kampen J., Boon J., van Berkel F.P.F. Vente J., van Sint Annaland M., Chemical Engineering Journal, Volume 374, 2019)
Enhancement by steam separation is a promising process intensification for many types of reactions in which water is formed as a byproduct. For this, two main technologies are reactive vapor permeation (membrane technology) and reactive adsorption. Both can achieve significant conversion enhancement of equilibrium limited reactions by in situ removal of the by-product steam, while additionally it may help protecting catalysts from steam-induced deactivation.
In general, reactive permeation or reactive adsorption would be preferable for distinctly different process conditions and requirements. However, although some advantages of reactive steam separation are readily apparent from a theoretical, thermodynamic point of view, the developments in several research lines make clear that the feasibility of in situ steam removal should be addressed case specifically and not only from a theoretical point of view. This includes the hydrothermal stability of the membranes and their permselectivity for reactive steam permeation, whereas high-temperature working capacities and heat management are crucial aspects for reactive steam adsorption. Together, these developments can accelerate further discovery, innovation and the rollout of steam separation enhanced reaction processes.
Reversible deactivation of γ-alumina by steam in the gas-phase dehydration of methanol to dimethyl ether (Boon J., van Kampen J., Hoogendoorn R., Tanase S., van Berkel F.P.F.,van Sint Annaland M., Catalysis Communications, Volume 119, 2019)
Acidic γ-Al2O3 is an active catalyst for the dehydration of methanol to dimethyl ether (DME). However, the produced steam reduces the activity. In this work, the influence of the exposure of γ-Al2O3 to steam on the catalytic activity for methanol dehydration has been determined. At 250 °C and increasing stream partial pressure the conversion of γ-Al2O3 into γ-AlO(OH) is observed at a p(H2O) of 13–14 bar. As a consequence, the catalytic activity decreases, reducing the rate of methanol dehydration to around 25%. However, this conversion is reversible and under reaction conditions γ-AlO(OH) converts back to γ-Al2O3, recovering its catalytic activity.

Conference abstracts

2017 - TMFB2017 - 5th International Conference on Tailor-Made Fuels from Biomass
A novel sorption enhanced dimethyl ether synthesis (SEDMES) process is presented using a solid adsorbent to remove produced water in situ. SEDMES experiments from feed mixtures of H2, CO, and CO2 have shown an increased yield of DME, an improved selectivity to DME over methanol, and a strongly reduced CO2 content in the product. Consequently, SEDMES will reduce the downstream separation effort and minimise the recycle streams. Within the European Horizon 2020 project FLEDGED, synthesis gas from biomass gasification will be used as feedstock for the separation enhanced DME-synthesis.

Other FLEDGED concept related publications

Flexible sorption enhanced gasification (SEG) of biomass for the production of synthetic natural gas (SNG) and liquid biofuels: Process assessment of stand-alone and power-to-gas plant schemes for SNG production (Martìnez I., Romano M., Energy, Volume 113, 2016)
A flexible sorption enhanced gasification (SEG) process is assessed in this work, where CaO-based material circulating between gasifier and combustor reactors is adjusted for fulfilling the syngas composition requirements according to the downstream fuel synthesis process. A case study of a synthetic natural gas (SNG) production plant based on this SEG process is presented, which has been analysed under different conditions of gasification temperature or solid circulation. A possible integration of this plant with an electrolysis system for power-to-gas application for balancing the electric grid is also proposed and assessed. SNG production efficiencies as high as 62% (LHV-based) have been found for the production of SNG with final CH4 content of 98%. Excess energy recovered from the process streams can be used for producing electricity in a steam turbine, covering the electric demand in the plant. If credits associated to electricity production are considered, equivalent SNG production efficiencies higher than 70% have been calculated. Efficiencies reported in this work are in the upper limit of the range found in the literature for non-SEG concepts, which require an intermediate conditioning step of WGS and CO2 removal. When coupled with an electrolyser, power-to-gas efficiencies of about 60% have been calculated, in line with stand-alone power to gas methanation systems.
Modelling of indirect steam gasification in circulating fluidized bed reactors (Kari Myöhänen, Juha Palonen, Timo Hyppänen, Fuel Processing Technology, Volume 171, 2018)
The indirect steam gasification in circulating fluidized bed reactors was studied by modelling. The object of study was a coupled 12 MWth gasifier-combustor system, which was fired by woody biomass. The heat for the steam-blown gasifier was produced in the air-blown combustor and transported by circulating solids between the interconnected reactors. The system was modelled by a semi-empirical three-dimensional model, which simulated the fluid dynamics, reactions, and heat transfer in the coupled process. The studied cases included different temperature levels, which were controlled by the amount of additional fuel feed to the combustor. The model concept can be later applied to study sorption enhanced gasification, which is a promising method for sustainable production of transport fuels to substitute fossil based fuels.