Light Olefins Research Articles

Hydrogenation of Simulated Bio-Syngas in the Presence of GdBO3 (B = Fe, Co, Mn) Perovskite-Type Oxides

Direct light olefin synthesis from bio-syngas hydrogenation is a promising pathway to decarbonize the chemical industry. The present study is devoted to the investigation of co-hydrogenation of carbon oxides in the presence of complex systems with the perovskite structure GdBO3 (B = Fe, Mn, Co). The catalyst samples were synthesized by sol-gel technology and characterized by XRD, XPS, BET and TPR. It was found that the Fe/Mn-containing samples exhibited efficient catalysis of the hydrogenation of simulated bio-syngas to light hydrocarbons. The GdMnO3 catalyst exhibits selectivity for C2–C3 light olefins of up to 37% among C1+ hydrocarbons, with a maximum olefin/paraffin ratio. GdMnO3 also exhibits high conversion of CO and CO2, reaching up to 70–75% at 723 K. However, the GdFeO3 catalyst shows a lower selectivity of (C2−3= = 22%, while it exhibits a higher conversion of CO2, up to 95%, at the same temperature. Herein, we established a catalyst structure–performance relationship as a function of chemical composition. Oxygen mobilities and ratios of surface (Os) to lattice (Ol) oxygen, forms of hydrogen adsorption, formation of -CHx- radicals and their subsequent recombination to olefins are influenced by the nature of the element in the B position. This work provides valuable insights for the rational design of bimetallic catalysts for bio-syngas hydrogenation.

Conversion of Polypropylene to Light Olefins by HMFI Catalysts below Pyrolytic Temperature: Catalytic, Spectroscopic, and Theoretical Studies

Conversion of Polypropylene to Light Olefins by HMFI Catalysts below Pyrolytic Temperature: Catalytic, Spectroscopic, and Theoretical Studies

Bio-methanol conversion into light olefins catalyzed by zeolites: Influence of pore structure and acid Properties

Bio-methanol conversion into light olefins catalyzed by zeolites: Influence of pore structure and acid Properties

CO2 hydrogenation to light olefins over Fe–Co/K–Al2O3 catalysts prepared via microwave calcination

Microwave calcination optimizes the Fe–C/Fe3O4 ratio to 0.34, enhancing CO2 conversion and light olefin yield.

Design and analysis of a CO2-to-olefins process, using renewable energy

This paper presents a light olefins production plant that hydrogenates carbon dioxide to C2-C4 using green hydrogen and electricity produced from solar and wind energy resources. In this regard, combining Fischer-Tropsch and methanol-mediated pathways on a large scale is analyzed as a new method to increase light olefins production. Additionally, an optimized hybrid renewable energy system comprised of solar panels, wind turbines, electrolyzers, batteries, converters, and so on is designed to supply the necessary utilities for the plant. The simulation results indicate that 590.9, 744.8, and 522.9 kg/h of ethylene, propylene, and butylene can be produced by processing 10% of carbon dioxide emitted from a cement factory, resulting in the negative emission of 2.14 kg CO2/kg C2-C4. This plant needs 1420 kg/h of hydrogen to convert carbon dioxide into light olefins and 32 MW of electricity to meet hot, cold, and electric utility requirements, all powered by renewable energy. The optimization results demonstrate that the initial capital and net present costs of the renewable energy system are $1.15B and $1.38B, respectively, leading to the levelized costs of hydrogen and electricity of 3.56 $/kg and 0.12 $/kWh, respectively.

Forecasting Methanol-to-olefins Product Yields based on Relevance Vector Machine with Hybrid Kernel and Rolling-windows

Light olefins (ethylene and propylene) have become prominent in chemical industries. Forecasting of the yields of light olefins plays a crucial role in monitoring and optimizing the Methanol-to-olefins (MTO) process. In this work, we introduce an approach for forecasting the yields of ethylene and propylene in the MTO process with the Relevance Vector Machine (RVM) model, which is uniquely enhanced with hybrid kernels and a rolling window methodology. Through an in-depth analysis of 32 independent variables and their pairwise differences, our research pinpoints temperature and pressure as the most critical factors influencing the yields of ethylene and propylene, respectively. The model showcases satisfactory predictive accuracy and reasonable interpretability compared with the traditional statistical and popular machine learning models, marking a step forward in the predictive modeling of chemical engineering processes.

The electronic interaction of encapsulating graphene layers with FeCo alloy promotes efficient CO2 Hydrogenation to light olefins

The electronic interaction of encapsulating graphene layers with FeCo alloy promotes efficient CO2 Hydrogenation to light olefins

Selective light olefin synthesis with high ethylene abundance via CO2 hydrogenation over (Ga-In)2O3/SSZ-13 catalysts

Selective light olefin synthesis with high ethylene abundance via CO2 hydrogenation over (Ga-In)2O3/SSZ-13 catalysts

Electronic interaction promoting CO2 hydrogenation to light olefins over ZnZrOx/SAPO-34 catalyst

Electronic interaction promoting CO2 hydrogenation to light olefins over ZnZrOx/SAPO-34 catalyst

Hierarchical ZSM-5 nanosheets for production of light olefins and aromatics by catalytic cracking of oleic acid

The bolaform surfactant C6H13-N+(CH3)2-C6H12-N+(CH3)2-C6H12-O-C6H4-C6H4-O-C6H12-N+(CH3)2-C6H12-N+(CH3)2-C6H13 (BCPH-6-6-6) was synthesized and used to guide the synthesis of hierarchical ZSM-5 nanosheets (HZN) for use as zeolite catalysts.

Maximizing Ethylene Production Yield by Modifying the Methanol to Olefin Process with the Addition of a Distillation Tower

Ethylene is a feedstock that produces polyethene and other industrial chemicals such as ethylene oxide. The methanol-to-olefins process is a technology designed to transform methanol into light olefins like ethylene and propylene, which are crucial raw materials in the petrochemical industry. The first reaction involves the production of dimethyl ether and water from methanol. The second reaction consists of the conversion of dimethyl ether to ethylene and water. This paper will explain how to maximize ethylene production yield by modifying the methanol to olefin process. The process modification was carried out by adding a distillation tower. Based on process modifications increased the ethylene quantity from 21,070 tons/year to 179,400 tons/year. The case study results indicate an increasing yield of the product exiting. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Propane Activation on Pt Electrodes at Room Temperature: Quantification of Adsorbate Identity and Coverage

C—H bond activation is the first step in manufacturing chemical products from readily available light alkane feedstock and typically proceeds via carbon‐intensive thermal processes. The ongoing emphasis on decarbonization via electrification motivates low‐temperature electrochemical alternatives that could lead to sustainable chemicals production. Platinum (Pt) electrocatalysts have shown activity towards reacting alkanes; however, little is known about propane electrocatalytic activation and conditions suitable for enabling selective oxidation to valuable products. Herein, we utilize a combination of electrochemical mass spectrometry (ECMS) and density functional theory (DFT) calculations to elucidate the potential dependence of propane activation on Pt electrocatalysts. Results show a strong dependence of adsorption on the applied potential in room‐temperature aqueous acidic electrolyte, with a maximum coverage of propane‐derived adsorbates at 0.30 V vs RHE. Using charge deconvolution and deuterated experiments, the mechanism of adsorption was elucidated, and C3H2* was determined as the average dehydrogenated propane‐derived adsorbate species. DFT calculations further corroborate these results, showing that the formation of deeply dehydrogenated species is energetically accessible at room temperature. The combined theoretical and experimental findings yield insights for selective activation of paraffinic C—H bonds at room temperature, aqueous conditions – a critical step towards decarbonized chemical manufacturing.

Propane Activation on Pt Electrodes at Room Temperature: Quantification of Adsorbate Identity and Coverage.

C-H bond activation is the first step in manufacturing chemical products from readily available light alkane feedstock and typically proceeds via carbon-intensive thermal processes. The ongoing emphasis on decarbonization via electrification motivates low-temperature electrochemical alternatives that could lead to sustainable chemicals production. Platinum (Pt) electrocatalysts have shown activity towards reacting alkanes; however, little is known about propane electrocatalytic activation and conditions suitable for enabling selective oxidation to valuable products. Herein, we utilize a combination of electrochemical mass spectrometry (ECMS) and density functional theory (DFT) calculations to elucidate the potential dependence of propane activation on Pt electrocatalysts. Results show a strong dependence of adsorption on the applied potential in room-temperature aqueous acidic electrolyte, with a maximum coverage of propane-derived adsorbates at 0.30 V vs RHE. Using charge deconvolution and deuterated experiments, the mechanism of adsorption was elucidated, and C3H2 * was determined as the average dehydrogenated propane-derived adsorbate species. DFT calculations further corroborate these results, showing that the formation of deeply dehydrogenated species is energetically accessible at room temperature. The combined theoretical and experimental findings yield insights for selective activation of paraffinic C-H bonds at room temperature, aqueous conditions-a critical step towards decarbonized chemical manufacturing.

Pt-ZnOx Interfacial Effect on the Performance of Propane Dehydrogenation and Mechanism Study.

Bimetallic Pt-based catalysts, for example, PtZn and PtSn catalysts, have gained significant attention for addressing the poor stability and low selectivity of pristine Pt catalysts over propane dehydrogenation (PDH). However, the structures of the active sites and the corresponding catalytic mechanism of PDH are still elusive. Here, we demonstrate a spatially confined Pt-ZnmOx@RUB-15 catalyst (where "m" is the mole ratio of Zn/Pt and RUB-15 is a layered silica), which exhibited high catalytic activity, ultrahigh selectivity (>99%), and resistance to coking at 550 °C for PDH. Significantly different from the preliminary studies over the PtZn catalysts, through the assistance of quasi-in situ X-ray photoelectron spectroscopy (XPS), in situ Fourier transform infrared spectroscopy (CO-FTIR), in situ X-ray absorption spectroscopy (XAS), and CO titration, we discovered that the active sites for PDH were the Pt-ZnOx interfaces, characterized by a structure of Ptδ+-Zn2+-O-Si. Density functional theory (DFT) calculations showed that Pt atoms positioned at Pt-ZnOx interfaces with coordinatively unsaturated ZnOx sites facilitate the C-H bond breaking of propane while concurrently suppressing deep dehydrogenation processes. This study suggests that engineering the interfaces of Pt-metal oxides under spatially confined conditions holds promise for developing highly efficient Pt-based catalysts for light alkane dehydrogenation.

Highly Porous Scandium(III) Tetrafluoroisophthalate Framework for Adsorptive Separation of Light Alkanes.

The separation of light alkanes is one of the most important tasks for modern industry due to the widespread use of ethane and propane as chemical feedstocks. Their extraction from natural gas is a challenging task and is now carried out by cryogenic distillation at a limited number of plants around the world. The development of new materials for adsorption separation is therefore important. Among the different types of adsorbents, metal-organic frameworks (MOFs) are one of the most interesting due to their infinite design possibilities. Here we present a highly porous perfluorinated MOF [Sc(OH)(1,3-tFbdc)] (1,1,3-tFbdc2-─1,3-C6F4(COO)22- tetrafluoroisophthalate linker) with a BET surface area greater than 1000 m·g-1 and its ability to separate light alkanes was investigated. The ability of 1 to separate light hydrocarbons at 0 and 25 °C is demonstrated by IAST calculation of selectivity factors as well as by dynamic breakthrough experiments. The role of fluorine substituents within the organic linker of MOF 1 in gas adsorption is revealed by quantum chemical calculations.

Cost‐Effective Synthesis of Fe5C2 Catalyst From Nanosized Zero‐Valent Iron to Achieve Efficient Photothermocatalytic CO Hydrogenation to Light Olefins

AbstractFe‐based catalysts are commonly applied in the process of Fischer−Tropsch synthesis (FTS) to olefins, with Hägg iron carbide (Fe5C2) recognized as the primary active phase. However, iron carbonyls, the raw materials for wet chemical synthesis of Fe5C2, are expensive and toxic, which limits large‐scale preparation. Here, a cost‐effective and versatile method is proposed for the synthesis of Fe5C2 nanoparticles (NPs) with nanosized zero‐valent iron (abbreviated as NZVI, prepared by reducing iron salts or ball‐milling iron powder) instead of iron carbonyls, achieving a cost reduction of 76.8%. Experimental characterizations revealed that NZVI obtained from the reduction of iron salts can catalyze the cracking of octadecylamine to form a carbonized atmosphere, thus realizing the phase transition of Fe into Fe5C2. The optimized Fe5C2 catalyst is employed in the photothermocatalytic FTS process, achieving a light olefins selectivity of 54.2% in hydrocarbons, with a CO conversion of 24.3%. Furthermore, it is proved that the particle size and surface oxide state of NZVI can impact the synthesis of Fe5C2. This study demonstrates a cost‐effective method for the large‐scale preparation of the Fe5C2 catalyst.

Catalytic pyrolysis of low-density waste polyethylene into light olefins and hydrogen over manganese-supported alumina

Catalytic pyrolysis of low-density waste polyethylene into light olefins and hydrogen over manganese-supported alumina

Synergy induced by physical mixing m-ZrO2 and α-Ga2O3 for effective conversion of syngas to light olefins

Synergy induced by physical mixing m-ZrO2 and α-Ga2O3 for effective conversion of syngas to light olefins

Boron-containing MFI zeolite: Microstructure control and its performance of propane oxidative dehydrogenation

Boron-containing zeolites can catalyze the oxidative dehydrogenation of propane (ODHP) to produce propylene. Enhancing the quantity of active boron-oxygen species and regulating the positioning of these species within the zeolite are the main challenges in developing efficient boron-based catalysts. In this study, a boron-containing zeolite catalyst with exposed (010) crystal facets, referred to as the MFI-type boron-containing zeolite (BMFI), was synthesized using a urea-assisted hydrothermal method. The research indicates that the addition of an appropriate amount of urea can regulate the morphology of the zeolite, with its short-axis flake-like structure enhancing the accessibility of active boron sites and anchoring a higher content of active boron-oxygen species through hydrogen bonding, which significantly improves the ODHP activity and olefin selectivity of the catalyst. The propane conversion rate reached 20 ​%, with a propylene selectivity of 62.3 ​% and a total olefin selectivity of 81.3 ​% at 520 ​°C. Compared to the ellipsoidal boron-containing catalyst formed without urea, the flake-like BMFI catalyst exhibited nearly a 20-fold increase in the reaction rate of propane. The flake-like BMFI possesses a greater number of framework tetrahedrally coordinated boron (B[4]) and defective boron species (B[3]a and B[3]b), and active boron structural evolution occurred during the reaction process, with B[3]a and B[3]b being the active sites for the catalytic reaction. This study provides a reference for the structural design and regulation of boron-based catalysts for the oxidative dehydrogenation of light alkanes.

Tuning the Selectivity in the Nonoxidative Alkane Dehydrogenation Reaction by Potassium-Promoted Zeolite-Encapsulated Pt Catalysts.

The significance of the nonoxidative dehydrogenation of middle-chain alkanes into corresponding alkenes is increasing in the context of the world's declining demands on transportation fuels and the growing demand for chemicals and materials. The middle-chain alkenes derived from the dehydrogenation reaction can be transformed into value-added chemicals in downstream processes. Due to the presence of multiple potential reaction sites, the reaction mechanism of the dehydrogenation of middle-chain alkanes is more complicated than that in the dehydrogenation of light alkanes, and there are few prior studies on elucidating their detailed structure-reactivity relationship. In this work, we have employed Pt catalysts encapsulated in pure-silica MFI zeolite crystallites as model catalysts and studied how the catalytic performances for dehydrogenation of n-pentane can be modulated by the K+ promotor in the Pt-MFI catalyst. A combination of comprehensive structural characterizations by aberration-corrected electron microscopy, X-ray absorption spectroscopy, in situ CO-IR, X-ray photoelectron spectroscopy, and kinetic studies shows that K+ promoter can not only influence the particle size but also modify the electronic properties of Pt species, which further affect the activity and selectivity in the dehydrogenation of n-pentane.