Design of a core-shell catalyst : an effective strategy for suppressing side reactions in syngas for direct selective conversion to light olefins

An elegant catalyst is designedviathe encapsulation of metallic oxide Zn-Cr inside of zeolite SAPO34 as a core-shell structure (Zn-Cr@SAPO) to realize the coupling of methanol-synthesis and methanol-to-olefin reactions. It can not only break through the limitation of the Anderson-Schulz-Flory distribution but can also overcome the disadvantages of physical mixture catalysts, such as excessive CO2formation. The confinement effect, hierarchical structure and extremely short distance between the two active components result in the Zn-Cr@SAPO capsule catalyst having better mass transfer and diffusion with a boosted synergistic effect. Due to the difference between the adsorption energies of the Zn-Cr metallic oxide/SAPO zeolite physical mixture and capsule catalysts, the produced water and light olefins are easily removed from the Zn-Cr@SAPO capsule catalyst after formation, suppressing the side reactions. The light olefin space time yield (STY) of the capsule catalyst is more than twice that of the typical physical mixture catalyst. The designed capsule catalyst has superior potential for scale-up in industrial applications while simultaneously extending the capabilities of hybrid catalysts for other tandem catalysis reactions through this strategy. © The Royal Society of Chemistry 2020

Coal and biomass co-pyrolysis in a fluidized-bed reactor: Numerical assessment of fuel type and blending conditions

Co-pyrolysis is one of the most promising options for using coal and biomass because coal is low in hydrogen and biomass can supplement the hydrogen content to make a more valuable and reactive product gas. The mixture of coal and biomass is prepared, with the mass ratio of biomass varying between 0 and 100%. Due to limitations in experimental methods, the data points measured in these studies are coarse and therefore, insufficient for kinetic energy analysis and model comparison. Therefore, a mathematical model has been proposed to combine a study of the influence of experimental parameters with different materials to understand better the effect of these parameters on pyrolysis with the rigorous control of experimental conditions in terms of precision and repeatability. The advantages of mathematical modelling co-pyrolysis make it possible to design a reaction scheme capable of describing this phenomenon and extracting kinetic parameters, making it possible to compare fuels, which can be used for the simulation of this process in thermal power plants. The experimental analysis of measured co-pyrolysis data was taken from literature work to validate the proposed model. The numerical model results are in good agreement with the experimental data for co-pyrolysis. The most significant degree of synergetic effects on the product yields was observed at 600 °C and a biomass blending ratio of 70 wt%. Furthermore, the improvement of char reactivity also identifies the synergies in co-pyrolysis

Evaluation of the effect of pressure and heat transfer on the efficiency of a batch fuel reactor, using Iron-based Oxygen Carrier with a CFD model

19 figures, 4 tables.Coupling a Chemical Looping Combustor fed with biofuels with a turbo expander is a promising Negative Emissions Technology (NET) to realize climate neutral targets in China and Europe. This is also an example of Bioenergy with Carbon Capture and Storage (BECCS) technology. To realize it, we need a Pressurized Chemical Looping Combustion process (PCLC). In this work, a Eulerian-Lagrangian hybrid model is developed in Barracuda-VRTM software, incorporating chemical reactions to predict the performance of a Fuel Reactor using Fe2O3 as oxygen carrier and syngas as fuel, under different pressures, ranging from 1 bar to 20 bars. The model predicted the conversion efficiency of syngas reduction using an iron-based oxygen carrier (Fe2O3/Al2O3). The results show, that the increase in pressure promotes the conversion of CO and inhibits the conversion of H2. When the two gases are considered together, the increase in pressure promotes the reaction between syngas and Fe2O3 and reduces the demand for Fe2O3 oxygen carrier per unit of syngas Lower Heating Value and so also the inventory of the reactor. Increasing temperatures promotes both the reaction of H2 and CO with Fe2O3. Dealing with CO conversion, this is more affected by pressure changes and temperature changes than H2. This represents important information for Fuel Reactor design, scale up and optimization. Further validation is neded in batch and continuous pressurised plants.This work has been funded by the GTCLC-NEG project that has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 101018756.Peer reviewe

Bioenergy with Carbon Capture and Storage (BECCS) developed by coupling a Pressurised Chemical Looping combustor with a turbo expander: How to optimize plant efficiency

18 figures, 6 tables.-- Supplementary information available.Carbon Capture and Storage is a technology of paramount importance for the fulfillment of the Sustainable Development Goal 7 (Affordable and Clean Energy) and the Sustainable Development Goal 5 (Climate Action). The European Union is moving rapidly towards low carbon technologies, for instance via the Energy Union Strategy. Coupling biofuels and carbon capture and storage to decarbonize the power and the industrial sector can be done through the development of BECCS (Bioenergy with Carbon Capture and Storage). Chemical Looping combustion is one of the cheapest way to capture CO2. A Chemical Looping Combustion (CLC) plant can be coupled with a turbo expander to convert energy to power, but it has to work in pressurised conditions. The effect of pressure on the chemical reactions and on fluidised bed hydrodynamics, at the moment, is not completely clear. The aim of this review is to summarize the most important highlights in this field and also provide an original method to optimize power plant efficiency. The main objective of our research is that to design a pressurised Chemical Looping Combustion plant which can be coupled to a turbo expander. To achieve this we need to start from the characteristics of the turbo expander itself (eg. the Turbine Inlet Temperature and the compression ratio) and then design the chemical looping combustor with a top down approach. Once the air and the fuel reactor have been dimensioned and the oxygen carrier inventory and circulation rate have been identified, the paper proposes a final optimization procedure based on two energy balances applied to the two reactors. The results of this work propose an optimization methodology and guidelines to be used for the design of pressurised chemical looping reactors to be coupled with turbo expanders for the production of power with carbon negative emissions.This work has been funded by the GTCLC-NEG project that has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement No. 101018756.Peer reviewe

Bimetallic carbon nanotube encapsulated Fe-Ni catalysts from fast pyrolysis of waste plastics and their oxygen reduction properties

Carbon-based bimetallic electrocatalysts were obtained by catalytic pyrolysis of waste plastics with Fe-Ni-based catalysts and were used as efficient oxygen reduction reaction (ORR) catalysts in this study. The prepared iron-nickel alloy nanoparticles encapsulated in oxidized carbon nanotubes (FeNi-OCNTs) are solid products with a unique structure. Moreover, the chemical composition and structural features of FeNi-OCNTs were determined. The iron-nickel alloy nanoparticles were wrapped in carbon layers, and the carbon nanotubes had an outer diameter of 20–50 nm and micron-scale lengths. FeNi-OCNT with a Fe/Ni ratio of 1:2 (FeNi-OCNT12) exhibited remarkable electrochemical performance as an ORR catalyst with a positive onset potential of 1.01 V (vs. RHE) and a half-wave potential of 0.87 V (vs. RHE), which were comparable to those of a commercial 20% Pt/C catalyst. Furthermore, FeNi-OCNT12 exhibited promising long‐term stability and higher tolerance to methanol than the commercial 20% Pt/C catalyst in an alkaline medium. These properties were attributable to the protective OCNT coating of the iron-nickel alloy nanoparticles

Space advanced technology demonstration satellite

The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of similar to 500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance