Among the different thermo-chemical recycling routes for plastic waste valorization, gasification is one of the most promising, converting plastic waste into syngas (H2+CO) and energy in the presence of an oxygen-rich gas. Plastic waste gasification is associated with many different complexities due to the multi-scale nature of the process, the feedstock complexity (mixed polyolefins with different contaminations), intricate reaction mechanisms, plastic properties (melting behavior and molecular weight distribution), and complex transport phenomena in a multi-phase flow system.
The gas–solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid’s kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics.
Predicting the impact of input process variables on chemical processes is key to assess their performance of the latter. Models explaining this impact through a mechanistic approach are rarely readily available, complex in nature and/or require long development time. With increased automation in industries and the availability of high-throughput experimental data, data-driven machine learning models are gaining popularity due to their simplicity and reduced computational effort.
Flexible plastic packaging is still one of the most difficult streams to recycle due to the presence of multilayers. With multilayers being very functional during their use phase, the delamination of multilayer structures is promising because it enables the recovery of the constituent polymer layers without any degradation and/or dissolution, thus creating economic and environmental benefits.
Hydrogenation into light olefins is an attractive strategy for CO2 fixation into chemicals. In this article, high throughput experimentation and extended characterization were employed to identify the most efficient promoters and to elucidate structure−performance correlations and reaction paths in the CO2 hydrogenation to light olefins over zirconia-supported iron catalysts. K, Cs, Ba, Ce, Nb, Mo, Mn, Cu, Zn, Ga, In, Sn, Sb, Bi, and V were added in the same molar concentrations to zirconiasupported iron catalyst and evaluated as promoters.
In cooperation between UCCS and Ghent University, an article on the PSYCHE project has recently been published in the scientific journal Actualité Chimique. The management of plastic waste is nowadays a major concern of society and requires new technological breakthroughs. This paper addresses development of a new and unique approach for valorization of plastic waste into olefins. This approach involves their pre-treatment, their gasification (using the latest Vortex reactor technology), the syngas purification, and finally the Fischer-Tropsch synthesis combined with kinetic modeling.
Heat management problems often prevail in reactors when highly exothermic chemical reactions occur. In these situations, fluidised bed reactors are often preferred due to their excellent heat transfer capabilities. However, the design, scale-up and operation of these reactors is still challenging due to the complex hydrodynamics. To gain a better understanding on the heat transport in these reactors, the degree of temperature non-uniformity for several fluidisation regimes in a pseudo-2D fluidised bed was quantified using Infra-Red Thermography.
Machine learning (ML) methods, such as artificial neural networks (ANNs), bring the data-driven design of chemical reactions within reach. Simultaneously with the verification of the absence of any bias in the machine learning model as compared to the microkinetic data, interpretation techniques such as permutation importance, SHAP values and partial dependence plots allow for a more systematic (model agnostic) analysis of these data.
Kinetic models constitute a useful tool to provide fundamental insights for catalyst development. Single-Event MicroKinetic modelling (SEMK) is a versatile strategy to assess complex reactions with a limited number of parameters. Particularly for Fischer–Tropsch synthesis SEMK modelling has focused on explaining the performances of individual catalysts within a wide range of operating conditions. In this work, we extend the capabilities of the SEMK modelling approach to investigate the influence of variation in catalyst properties i.e.
Metal nanoparticles on the surface of porous supports have found numerous applications in different areas of science. Fischer-Tropsch synthesis, which proceeds on the surface of cobalt metal nanoparticles, is an efficient way to convert renewables and fossil feedstocks into alternative fuels. The stability of cobalt catalysts is an essential and even crucial parameter and can be significantly improved by promotion.
Biomass fast pyrolysis has been considered one of the best alternatives for the thermal conversion of biomass into bio-oil. This work introduces a new reactor technology for biomass fast pyrolysis, the Gas-Solid Vortex Reactor (GSVR), to obtain high bio-oil yields. The GSVR was designed to decrease the residence time of the pyrolysis vapors; thus, the secondary cracking reactions are reduced, to enhance the segregation of the char and the unreacted biomass and to improve the heat transfer rate.
Kinetic models constitute a useful tool to provide fundamental insights for catalyst development. Single-Event MicroKinetic modelling (SEMK) is a versatile strategy to assess complex reactions with a limited number of parameters. Particularly for Fischer–Tropsch synthesis SEMK modelling has focused on explaining the performances of individual catalysts within a wide range of operating conditions. In this work, we extend the capabilities of the SEMK modelling approach to investigate the influence of variation in catalyst properties i.e.
Fischer-Tropsch synthesis provides an important opportunity for utilization of biomass and plastic waste. Iron catalysts are the catalysts of choice for light olefin synthesis using Fischer-Tropsch reaction. In this paper, we investigate strong promoting effects of antimony and tin on the catalytic performance of silica supported iron Fischer-Tropsch catalysts using a combination of advanced and in-situ techniques. The catalyst doping with these elements added via impregnation results in a major increase in the reaction rate and much better catalyst stability.
Fischer–Tropsch synthesis (FTS) is an essential approach to convert coal, biomass, and shale gas into fuels and chemicals, such as lower olefins, gasoline, diesel, and so on. In recent years, there has been increasing motivation to deploy FTS at commercial scales which has been boosting the discovery of high performance catalysts. In particular, the importance of support in modulating the activity of metals has been recognized and carbonaceous materials have attracted attention as supports for FTS.
Recycling multilayer plastic packaging is challenging due to their intrinsic compositional heterogeneity. A promising route to increase recycling rates for these materials is delamination which allows recycling the polymers separately. Yet, this process is not well fundamentally understood. This study aims to obtain first principles-based insights of the delamination mechanism of multilayer flexible packaging film (MFPF) with carboxylic acids.
The UCCS partners have recently published a widely accessible article in the French press on the PSYCHE project and the recycling and valorization of plastic waste in general. The article, which gives an overview of the global plastic waste production and treatment numbers, current recycling technologies for plastic waste and the specific technologies developed in the PSYCHE project, was first published by the online press agency ‘The Conversation’ under the title “Recyclage et valorization des déchets plastiques: comment ça marche?”.
The UGent partners have recently published an article in the Dutch NPT process technology journal on the development, use and benefits of the Gas Solid Vortex Reactor which is currently also evaluated for the gasification process in the PSYCHE project. The reactor set-up has been designed and developed at Ghent University during the past 20 years. The current aim is to make the Gas Solid Vortex Reactor applicable for the process industry.
The full article can be find at NPT process technologie.
The vast increase in the generation of post-consumer PET plastic waste, as well as fast increasing pledges of brand owners around the world to include recycled content have resulted in a pressing need for efficient recycling processes, such as chemical depolymerization. Although recycling rates of PET bottles are high, those of PET trays and films are still significantly lower due to the broad range of colours and multilayer structures, as well as due to a much poorer collection.
In this work, 29 elements were evaluated as promoters for silica supported iron catalysts for high temperature Fischer-Tropsch synthesis using a high-throughput experimentation unit. The selected promoters include alkali/alkaline metals, transition metals, precious metals and lanthanides. Several general selectivity trends were observed and discussed. The selectivity enhancement to light olefins requires maintaining low selectivity to methane and light paraffins and at the same time, slowing the chain growth to the C5+ hydrocarbons.
Liquid metals are a new emerging and rapidly growing class of materials and can be considered as efficient promoters and active phases for heterogeneous catalysts for sustainable processes. Because of low cost, high selectivity and flexibility, iron-based catalysts are the catalysts of choice for light olefin synthesis via Fischer–Tropsch reaction. Promotion of iron catalysts supported by carbon nanotubes with bismuth, which is liquid under the reaction conditions, results in a several fold increase in the reaction rate and in a much higher light olefin selectivity.
Alan Barrios (CNRS) has presented his work on the Fischer-Tropsch synthesis towards light olefins at the The Netherlands’ Catalysis and Chemistry Conference (NCCC) in Groningen (The Netherlands). This conference is widely renowned in Northern Europe in the field of catalysis. Light olefins are important platform molecules in the chemical industry which can be produced via Fischer-Tropsch synthesis from syngas in the presence of a catalyst.
Additives are ubiquitously used in plastics to improve their functionality. However, they are not always desirable in their ‘second life’ and are a major bottleneck for chemical recycling. Although research on extraction techniques for efficient removal of additives is increasing, it resembles much like uncharted territory due to the broad variety of additives, plastics and removal techniques. Today solvent-based additive extraction techniques, solid-liquid extraction and dissolution-precipitation, are considered to be the most promising techniques to remove additives.
Alan Barrios (CNRS) has presented his work on the Fischer-Tropsch synthesis towards light olefins at the 2nd Chemical Research in Flanders conference in Blankenberge (Belgium). Light olefins are important platform molecules in the chemical industry which can be produced via Fischer-Tropsch synthesis from syngas in the presence of a catalyst. Research at CNRS recently demonstrated that promotion of iron catalysts with soldering metals (bismuth and lead) led to an exceptional increase in the Fischer-Tropsch reaction performance and selectivity towards light olefins.
On September 25th 2019, the PSYCHE kick-off meeting with the advisory board took place at Ghent University. The PSYCHE partners are happy to welcome the following companies in the advisory board: AVGI, Comet Traitements, Dow, Engie, Ematco, Galloo, Indaver, Ostend Basic Chemicals, Recticel, Suez, Total Feluy, Unilin and Vanheede. The PSYCHE advisory board will assemble every six months and next to the company members, also the the PSYCHE associated partners (Catalisti, Greenwin and Matikem) will be invited.
Sibel Ugduler (UGent) has presented her work on solvent pretreatment at the 23rd ACS Annual Green Chemistry & Engineering Conference in Reston, Virginia (USA). This international conference is world-wide renowned in the field of green chemistry and sustainability. At the conference, Sibel presented solvent-based techniques for the pretreatment of plastic waste and the challenges encountered with the removal of additives from plastic waste. Preliminary results on both the technical as economic and environmental aspects have been included.
The PSYCHE project on the conversion of plastic waste to base chemicals via gasification and subsequent Fischer-Tropsch synthesis has received European funding via the Interreg France-Wallonie-Vlaanderen program (total budget 2.6 million euro). The project, started on July 1st 2018, is a collaboration between Ghent University, Université Catholique de Louvain (UCL), Ecole National Supérieure de Chimie de Lille (ENSCL)-Centre Nationale de la Recherche (CNRS) and CERTECH. The coordination of the project will be performed by Ghent University. Co-funding is provided by the province of East-Flanders, the province of West-Flanders, the Walloon Region and by the Direction Générale Opérationelle de l’Economie, de l’Emploi et de la Recherche (DGO 6, Walloon Region).