Highly selective homogeneous ethylene epoxidation in gas (ethylene)-expanded liquid: Transport and kinetic studies

CO2-Free Ethylene Oxide Production via Liquid-Phase Epoxidation with Fe2O3/MSM Catalyst

In this study, we present an approach for ethylene oxide (EO) production that addresses environmental concerns by eliminating greenhouse gas emissions. Our catalyst, Fe2O3/MSM, was synthesized using a hydrothermal method, incorporating Fe2O3 nanoparticles into a well-structured mesoporous silica matrix (MSM). We selected peracetic acid as the oxidant, enabling CO2-free EO production while yielding valuable by-products such as acetic acid, monoethylene glycol, and diethylene glycol. X-ray diffraction (XRD), X- ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyses confirmed the heteroatom structure of the catalysts and porosity, while Transmission electron microscopy (TEM) analysis provided insights into its morphology. Then, the synthesized catalyst was used in the liquid-phase epoxidation of ethylene for EO production. Our systematic experiments involved varying critical parameters such as temperature, ethylene to oxidant ratio, catalyst dosage, and solvent to optimize EO selectivity and ethylene conversion. The results of this study demonstrated an 80.2 % ethylene conversion to EO with an EO selectivity of 87.6 %. The production process yielded valuable by-products without CO2 emissions, highlighting its environmental friendliness.

Plant-Wide Modeling and Economic Analysis of Monoethylene Glycol Production

Monoethylene glycol (MEG) is used to produce polyester fibers and polyethylene terephthalate resins. It is also utilized in antifreeze, pharmaceuticals, and cosmetics applications. In this research, we consider the development of a novel process plant that produces MEG from ethylene. The proposed ethylene-to-ethylene oxide (EO) plant is integrated with an EO-to-MEG plant to reduce utility costs and recover high-value products. Energy-saving opportunities are analyzed via heat integration tools. Furthermore, a multitube glycol reactor is used in conjunction with a novel MTO catalyst in the ethylene-to-EO reactor. Our results demonstrate that the integrated EO/EG plant produces ethylene glycols with that same purity and product recovery as conventional designs. A comparative economic assessment based on a 200,000 t/y plant indicates that process integration techniques can reduce costs significantly.

Insight into essential channel effect of pore structures and hydrogen bonds on the solvent extraction of oily sludge

In this study, solvent extraction experiments were conducted to investigate the channel effect of pore structures and hydrogen bonds by analyzing the desorption behavior of oil components. The highest oil recovery efficiency was 87.9 % under optimum conditions. Pore structure of oily sludge was analyzed by N₂ adsorption-desorption analysis and scanning electron microscope (SEM) measurements. Mesopores of sludge inhibited the desorption of oil molecules by analyzing the pore width and cumulative pore volume of residual sludge in desorption process. In addition, saturates and aromatics were easily extracted from sludge, while the desorption rate and desorption efficiency of oily sludge were limited by resins and asphaltenes respectively through component analysis and kinetic analysis. Furthermore, channel effect of pore structures and hydrogen bonds was investigated in the desorption process of oily sludge, which also provided a guidance to selectively extract light components from oily sludge with high efficiency in industry processing.

Enhanced hydroformylation of 1-octene in n-butane expanded solvents with Co-based complexes

The use of n-butane expanded liquids (BXLs) as reaction media to enhance Co-catalyzed hydroformylation of 1-octene has been successfully demonstrated.

Epoxidation of Ethylene by Whole Cell Suspension of Methylosinus trichosporium IMV 3011

Methane monooxygenase (MMO) has been found in methanotrophic bacteria, which catalyzes the epoxidation of gaseous alkenes to their corresponding epoxides. The whole cell suspension of Methylosinus trichosporium IMV 3011 was used to produce epoxyethane from ethylene. The optimal reaction time and initial ethylene concentration for ethylene epoxidation have been described. The product epoxyethane is not further metabolized and accumulates extracellularly. Thus, exhaustion of reductant and the inhibition of toxic products make it difficult to accumulate epoxyethane continuously. In order to settle these problems, regeneration of cofactor NADH was performed in batch experiments with methane and methanol. The amount of epoxyethane formed before cosubstrate regeneration was between 0.8 and 1.0 nmol/50 mg cells in approximately 8 h. Combining data from 7 batch experiments, the total production of epoxyethane was 2.2 nmol. Production of epoxyethane was improved (4.6 nmol) in 10% gas phase methane since methane acts as an abundant reductant for epoxidation. It was found that the maximum production of epoxyethane (6.6 nmol) occurs with 3 mmol/L methanol. The passive effect of epoxyethane accumulation on epoxyethane production capacity of Methylosinus trichosporium IMV 3011 in batch experiments was studied. Removal of product was suggested to overcome the inhibition of epoxyethane production.

Towards highly selective ethylene epoxidation catalysts using hydrogen peroxide and tungsten- or niobium-incorporated mesoporous silicate (KIT-6)

Nb- and W-KIT-6 materials display significant ethylene epoxidation activity with H₂O₂ as the oxidant at mild temperatures that eliminate substrate burning.