最新刊期
卷 49 ， 期 4 ， 2024
-
摘要：Methane reforming is an endothermic reaction, typically requiring the combustion of methane for heating (accounting for approximately 30% of total methane consumption). This traditional approach not only results in heat losses from flue gas but also contributes to CO2 emissions, failing to meet the demand for clean hydrogen energy under the dual carbon goals. Electrified methane reforming technology introduces renewable electric energy into the methane reforming reactor through efficient electrical heating, significantly reducing CO2 emissions in the methane reforming process. It eliminates the heat losses from flue gas in traditional methane reforming and enhances the efficiency of hydrogen production from methane and renewable electric energy. Traditional methane reforming techniques, electrified methane reforming reactors (resistive heating, microwave heating, electromagnetic induction heating, and plasma heating), electrified methane reforming systems and electrified methane reforming catalysts were summarized. Electric heating not only effectively increases reactor power density and reduces reactor scale but also interacts with catalysts to improve catalytic activity and methane conversion rates. Electrified methane reforming technology provides a new pathway for China’s energy transition towards a green and low-carbon future.关键词：electrification;methane reforming;clean hydrogen energy;reactor;catalyst- 25
- |
- 0
- |
- 0
发布时间：2024-04-26 -
Research progress on influence of Pd-based catalyst supports on natural gas catalytic combustion AI导读
摘要：Natural gas is widely used in chemical synthesis and transportation. As the main component of natural gas, methane has a strong greenhouse effect, and its incomplete combustion will have adverse effects on the environment. Catalytic combustion technology is an effective method to solve the problem of incomplete methane combustion, in which palladium (Pd)-based catalysts are the core of the technology, and the supports are important factors affecting the catalytic activity of Pd-based catalyst for methane catalytic combustion. Firstly, the mechanism of methane catalytic combustion was described. Secondly, the research progress of Pd-based catalysts at home and abroad in recent years was summarized. For Pd-based catalysts with porous particle carrier, the researches focus on improving the dispersion of Pd, stability and heat resistance, so as to enhance catalytic activity and reduce Pd load, thus reducing cost. As for monolithic Pd-based catalysts, the researches focus on improving the effective specific surface area, heat and mass transfer efficiency and structural stability to adapt to large flux methane catalytic combustion. Finally, the future research development trends of Pd-based catalyst supports for methane catalytic combustion were prospected, including optimizing the coating process of the monolithic Pd-based catalyst skeleton supports to improve catalytic efficiency, using new materials instead of traditional support materials to prepare high-performance catalysts, and carrying out the support life cycle experiments to ensure the long-term stability of the catalysts.关键词：natural gas catalytic combustion;Pd-based catalysts;catalytic activity;supports- 30
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：SAPO-44 molecular sieve has the same CHA topological structure as SAPO-34 and has excellent catalytic performance in methanol conversion to light olefins (MTO) reaction. However, the single microporous pore structure of traditional SAPO-44 limits the molecular diffusion of reactants and products, and the mass transfer and diffusion performance of the molecular sieve needs to be further improved. SAPO-44 molecular sieve with special morphology was synthesized by adding ammonium chloride to the crystallization system by the hydrothermal method. XRD, SEM, N2 adsorption/desorption and NH3-TPD were used to study the effects of the amount of ammonium chloride added to the synthesis system on the crystal phase structure, morphology, pore structure and acid properties and other physical and chemical properties of SAPO-44 molecular sieve. The catalytic performance of SAPO-44 molecular sieve in MTO reaction was also investigated. The results show that pH value of molecular sieve crystallization system is reduced by adding ammonium chloride. The particle size of SAPO-44 molecular sieve synthesized without ammonium chloride is 14.79 μm, and the shape is traditional cube. The SAPO-44 molecular sieve synthesized adding ammonium chloride shows a new special shape morphology structure, and the particle size is reduced. When n(NH4Cl):n(Al2O3) = 0.25, SAPO-44 molecular sieve has a particle size of 7.58 μm and a flying saucer-shaped structure. When n(NH4Cl):n(Al2O3) = 0.50, the size of SAPO-44 molecular sieve is 9.41 μm, which shows similar spherical structure. The novel morphology is deposited in the molecular sieve to form mesoporous, constructs the micro-mesoporous structure, the specific surface area and pore volume are both increase, and the acid strength and acid content are also increase. In the MTO reaction, the reduction of micro-mesoporous structure and particle size generated by SAPO-44 molecular sieve with special morphology synthesized by adding ammonium chloride is conducive to enhancing the molecular diffusion efficiency and increasing the reaction stability by more than 1.4 times. Meanwhile, the enhancement of acidity forms more catalytic active centers. Moreover, the joint action of micro-mesoporous structure and small size particle can increase the selectivity of light olefins (ethylene + propylene) by more than 3.00%.关键词：SAPO-44 molecular sieve;ammonium chloride;novel morphology;methanol;light olefins- 26
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：Fischer-Tropsch synthesis reaction has the characteristics of complex product types, wide distribution of carbon numbers and long collection process. The qualitative and quantitative analysis of product components involves multiple steps, laborious spectrum peak identification and data processing, which is time-consuming, labor-intensive and easy to produce human errors. Combined with the latest analytical technology, a combination analysis method was designed and verified for the analysis of tail gas, water phase and oil phase low-carbon product components by one-dimensional gas chromatography, oil phase and wax phase products (C≤30) components by two-dimensional gas chromatography with backflushing device, wax phase products (C31~C100) components by high temperature simulated distillation, and C100+ product components by theoretical extrapolation. By using the data processing function of Python language, detailed product analysis and data automatic processing strategies of Fischer-Tropsch synthesis were proposed. Through in-depth analysis of product spectral peak data characteristics, corresponding quantitative calculation methods were proposed for different product flows, and an efficient and accurate automatic processing scheme for total product distribution of Fischer-Tropsch synthesis was finally formed. The accuracy of product distribution calculation under various operating conditions was verified. It is found that under the reaction conditions of Fischer-Tropsch synthesis with high chain growth factor (temperature of 275 ℃, pressure of 3 MPa, syngas space velocity of 35 L/(g·h) and n(H2):n(CO) = 1), the maximum carbon number of products determined by this method can reach 164.关键词：Fischer-Trosch synthesis;product distribution;chromatography;simulated distillation;retention time- 19
- |
- 0
- |
- 0
发布时间：2024-04-26 -
Research progress on modification of Cu-based catalysts in methyl acetate hydrogenation to ethanol AI导读
摘要：Methyl acetate hydrogenation to ethanol is an important step in the indirect synthesis route of ethanol from syngas. Catalyst development is the key and Cu-based catalysts are mainly used in industry. The catalytic performances of Cu-based catalysts are closely related to their microstructure. The structure modulation of catalysts can effectively adjust their catalytic performances. The research progress of Cu-based catalysts in methyl acetate hydrogenation to ethanol was reviewed, and the effects of modulation strategies on the catalytic performance were summarized, including introducing additives, modifying carriers, optimizing preparation methods and designing special structures. On this basis, developing efficient and stable Cu-based catalysts for methyl acetate hydrogenation to ethanol at low temperature and low hydrogen/ester mole ratio was prospected.关键词：methyl acetate;hydrogenation;ethanol;Cu-based catalysts;property modification- 22
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：The preparation of caprolactam (CPL) by cyclohexanone oxime (CHO) gas-phase Beckmann rearrangement is a green and environmentally friendly production process, but the performance of gas-phase rearrangement catalysts has always restricted the industrial application of this process. In order to enhance the reaction performance of gas-phase Beckmann rearrangement, ethyleneamine with different molecular sizes were used to modify pure silicalite molecular sieves. Characterization of the modified pure silicalite molecular sieves was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and N2 adsorption/desorption tests, and the catalytic performance of the catalysts for CHO gas-phase Beckmann rearrangement was evaluated. The results indicate that the pure silicalite molecular sieves maintain their original MFI topology after ethyleneamine-modification, and the Brunner-Emmet-Teller (BET) specific surface area decreases to 354.1 m2/g, and the CPL selectivity increases to 97.00%. The effects of reaction temperature, weight hourly space velocity and mass fraction of CHO on gas-phase Beckmann rearrangement were investigated. The optimal reaction processes are as follows: reaction temperature 370 ℃, weight hourly space velocity of CHO 1.0 h-1 and mass fraction of CHO 30%. Under the optimal reaction processes, the CHO conversion rate of S-1-B catalysts is ≥ 99.90%, and the CPL selectivity of S-1-B catalyst is ≥ 97.00%. The S-1-B catalyst has single-pass life of 1200 hours and stable regeneration performance, which has good industrial application prospect.关键词：caprolactam;gas-phase rearrangement;molecular sieve modification;cyclohexanone oxime- 14
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：In the process of methanol to olefins, a large number of C4+ mixed hydrocarbons are generated as by-product. Using C4+ mixed hydrocarbons to efficiently produce and improve the yield of ethylene and propylene has become an important research direction in the coal-to-olefin industry. Nano-sized HZSM-5 molecular sieve was synthesized by hydrothermal method. P modified HZSM-5 molecular sieve catalyst (P/HZSM-5) and P-Mg composite modified HZSM-5 molecular sieve catalyst (P-Mg/HZSM-5) were prepared based on nano-sized HZSM-5 molecular sieve respectively. The prepared molecular sieve and corresponding catalysts were characterized by XRD, SEM and N2 absorption/desorption. The experiment of C4+ mixed hydrocarbons to produce light olefins catalyzed by nano-sized HZSM-5 molecular sieve and molecular sieve catalysts respectively, was carried out in a small fixd-bed reactor. The results show that the yield of ethylene and propylene of P-Mg/HZSM-5 can reach 46.2% with the best overall performance (the coversion rate of ethylene is 28.6% and the coversion rate of propylene is 60.8%) at the condition of temperature of 520 ℃, pressure of 0.2 MPa , steam space velocity of 1000 h-1 and raw mixed gas volume space velocity of 100 h-1 for 8 h.关键词：mixed hydrocarbon;molecular sieve;light olefins;ethylene;propylene- 15
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：Biomass pyrolysis is an effective method to convert lignocellulosic biomass into bio-oil, but the crude bio-oil has high oxygen content and low calorific value. The catalytic cracking of biomass pyrolysis volatiles using Ga-loaded HZSM-5 catalysts can promote the selective deoxygenation and aromatization of bio-oil, realizing the upgrading of bio-oil. Two Ga-loaded HZSM-5 catalysts (Ga-H5-E and Ga-H5-H) were prepared by ion exchange and hydrothermal methods, respectively. Catalytic cracking experiments of peanut straw pyrolysis volatiles were conducted in a two-stage fixed-bed reactor. The peanut straw was heated from room temperature to 700 °C at a heating rate of 10 ℃/min in the lower part of the reactor, and the evolved volatiles were catalytically cracked by the upper catalyst layer maintained at 600 ℃. The results show that compared to the unloaded HZSM-5, Ga-H5-E and Ga-H5-H increase the BTX (benzene, toluene and xylene) yield by 77% and 93%, respectively, with a significant increase in the production of toluene and xylene. The catalysts were characterized by thermogravimetric analysis, inductively coupled plasma emission spectrometry, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, surface area analyzer, and chemisorption analyzer. The results indicate that the carbon deposition yield on both Ga-loaded catalysts is significantly lower than that on HZSM-5. Ga loading increases the strong acid sites on the catalyst, favoring the catalytic active centers for deoxygenation reactions. Compared to Ga-H5-E, Ga-H5-H has larger mesopores with smaller average pore diameter, and more Ga impregnation into the particle interior, which may promote the aromatization of ethylene and propylene within mesopores, thereby increasing the yield of monocyclic aromatic hydrocarbons.关键词：biomass;volatiles catalytic cracking;bio-oil upgrading;Ga-loaded HZSM-5;monocyclic aromatics- 19
- |
- 0
- |
- 0
发布时间：2024-04-26 -
Study on conversion performance of encapsulated Ni-based catalysts for coal tar model compounds AI导读
摘要：In order to increase the content of light fractions in coal pyrolysis tar and regulate tar cracking products in a targeted manner, Ni-based catalysts (xNi@HZSM-5, x is Ni content, mass fraction) were prepared by in situ encapsulation, and their catalytic conversion effects on tar model compounds: fluoranthene and pyrene were investigated. The results show that the difference of the xNi@HZSM-5 conversion rates of two model compounds under N2 atmosphere is relatively small. Under H2 atmosphere, 2.0Ni@HZSM-5 has the maximum conversion rates of fluoranthene and pyrene, which are 51.91% and 46.21%, respectively. And 2.0Ni@HZSM-5 has higher stability than 2.0Ni/HZSM-5 (Ni mass fraction is 2.0%) prepared by impregnation method. The catalysts were analyzed and characterized by characterization methods such as X-ray diffraction (XRD), transmission electron microscope (TEM) and N2 adsorption/desorption, etc. The results show that 2.0Ni@HZSM-5 has larger specific surface area and pore volume than 2.0Ni/HZSM-5, and Ni is located inside the molecular sieve pores, which has higher activity and stability. The reaction paths of fluoranthene and pyrene during catalytic conversion were deduced by analyzing the conversion products of model compounds under different atmospheres.关键词：encapsulated catalysts;HZSM-5 molecular sieve;model compounds;reaction mechanism- 18
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：Oilfield enterprises are major energy consumers in the energy industry. Using clean energy to replace fossil fuels consumed in oil fields and reducing carbon emissions in oil fields can effectively help achieve China’s carbon peaking and carbon neutrality goals. Based on the characteristics of energy consumption structure and resource conditions in oil fields, the application conditions, construction investment, operating costs, and carbon emissions of clean alternative process for oil fields were analyzed, such as high-temperature produced fluid utilization, heat pump process, liquefied natural gas (LNG) process, solar energy utilization, and wind power generation, using different types of projects as examples. The results show that under the same energy consumption, the comprehensive cost per Kilowatt of the water source heat pump process is 0.17 × 104 CNY/kW and LNG process is 0.40 × 104 CNY/kW, both have lower construction investment compared to other processes. Wind power generation and photovoltaic power generation do not generate carbon emissions. The operating costs of solar thermal, photovoltaic, and wind power generation range from 0.018 × 104 to 0.040×104 CNY/(kW·a), with carbon emission intensity ranging from 0 to 0.45 t/(kW·a). The three processes have lower operating costs and carbon emission intensity compared to other processes. When conditions such as high-temperature produced liquid, oilfield associated gas, and electricity are available, priority should be given to using the high-temperature produced liquid utilization and water source heat pump process with the lowest present value of cost, which are 1.20 × 104 CNY/kW and 1.29 × 104 CNY/kW, respectively. When conditions such as high-temperature production fluid and oilfield associated gas are not available, priority should be given to using LNG process and large wind turbines for power generation. Compared with small wind turbines, the economic benefits of large wind turbines for power generation are more significant, while the economic benefits of photovoltaic power generation are between large and small wind turbines. In the construction of zero carbon oil fields, priority should be given to using high-temperature produced liquid utilization and water source heat pump process to provide heat, and using large wind turbines or photovoltaics to provide electricity.关键词：carbon peaking and carbon neutrality goals;clean energy;high temperature produced fluid;heat pump;solar energy- 13
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：The catalytic reduction of p-nitrophenol, a common pollutant in industrial wastewater, to p-aminophenol with higher added value is of great significance for the development of green chemistry and chemical industry. Although noble metal catalysts (Au, Pd, etc.) show excellent catalytic performance for this reaction, high cost limits their industrial application. In contrast, Ni-based catalysts have attracted wide attention due to their advantages of low cost and high activity but traditional synthesis methods usually have disadvantages such as large size of Ni nanoparticles and easy agglomeration. Firstly, the SiO2-MHMs support was synthesized by aerosol technology combined with surfactant cetyltrimethyl ammonium bromide (CTAB) using solvent evaporation self-assembly strategy. And then using nickel nitrate as Ni source, a series of Ni/SiO2-MHMs catalysts with different Ni loadings (mass fraction) were obtained by using impregnation and NaBH4 reduction strategy. The analysis results of X-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform spectroscopy (FT-IR) and N2 physical adsorption/desorption and other characterization methods show that the SiO2-MHMs support has abundant ordered mesopore structure with concave hollow microsphere morphology, and Brunanuer-Emmett-Teller (BET) specific surface area and total pore volume are 1421 m2/g and 0.92 cm3/g, respectively. In the 5-Ni/SiO2-MHMs catalyst obtained by impregnation-reduction of the support, Ni nanoparticles are highly dispersed on the surface of the support and in the mesoporous channels, resulting in a decrease in the BET specific surface area (854 m2/g) and total pore volume (0.47 cm3/g). The obtained catalyst was applied to the reduction reaction of p-nitrophenol. The results show that the catalyst with 5% Ni loading shows the best catalytic performance (complete conversion within 4 min), and the catalytic performance does not decrease significantly after 4 cycles, which is better than other reported Ni-based supported catalysts.关键词：aerosol technology;mesoporous material;catalytic reduction;hollow structure- 18
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：In order to reduce the adverse impact on the atmosphere and marine environment and meet the environmental protection regulations, the shipping industry actively explores and adopts various ship exhaust purification technologies. The research progress and application of desulfurization, denitrification and carbon reduction technologies in this field were reviewed, including dry desulfurization, wet desulfurization, selective non catalytic reduction (SNCR), selective catalytic reduction (SCR), desulfurization and denitrification integration, and carbon capture, utilization and storage (CCUS). The principles, uses, characteristics, implementation obstacles and prospects of different technologies were summarized in order to provide reference for ship exhaust purification.关键词：ship exhaust;desulfurization;denitrification;CCUS technology- 16
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：The coal to methanol unit of CHN Energy Yulin Chemical Co., Ltd. uses coal as raw material and adopts coal water slurry gasification technology to produce crude gas. The crude gas undergoes sulfur tolerant shift to adjust the hydrogen carbon ratio, rectisol process to remove impurities and acidic gases, fine desulfurization in the fine desulfurization unit, and finally enters the methanol synthesis system to produce crude methanol products. In order to avoid deactivation of methanol synthesis catalysts and ensure normal production operation, the refined desulfurization unit uses domestically produced deep purification desulfurizer CNTS-11 for desulfurization under harsh conditions. The specific application of CNTS-11 desulfurizer was introduced, including loading, industrial operation data, strength after use, and sulfur capacity. After desulfurization, no sulfur-containing substances are detected in the syngas. The sulfur capacity of desulfurizer reaches 13.00%, which is 40% higher than similar domestic products, and there are no by-products produced during the process.关键词：methanol;desulfurizer;deep purification;low-temperature desulfurization- 14
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：As oil and gas exploration continues to expand into deepwater areas, the low temperature and high pressure transmission environment during multiphase mixed flow in deepwater pipelines is highly prone to causing problems such as hydrate and wax deposition and pipeline blockage. Especially when wax and hydrate coexist, the gathering and transmission pipelines will face higher risks of pipeline blockage. To this end, the rheological properties of cyclopentane hydrate formation and hydrate slurry rheology in oil-water systems containing wax and surfactant (Span 80) were investigated using a rheometer. The effects of factors such as wax content(mass fraction, the same below) and surfactant concentration (mass fraction, the same below) on the critical time and shear dilution of wax-hydrate coexistence systems were clarified. The results show that when Span 80 concentration is 1.0%, the wax content increases from 0.00% to 1.00% and the critical time of hydrate formation increases from 25.8 min to 49.8 min, an increase of about 93%. When the concentration of Span 80 is 1.5%, 2.0% and 3.0%, the critical time of hydrate formation also increases with the increase of wax content by 113%, 93% and 241%, respectively. For the low-to-medium wax content systems (≤ 0.75%), the critical time of hydrate formation shortens with the increase of Span 80 concentration. For the high wax content systems (≥ 1.00%), the critical time of hydrate formation fluctuates with the increase of Span 80 concentration. In addition, with the hydrate formation, the viscosity of both wax-containing and wax-free systems first increases sharply, then gradually decreases and tends to be stable. Both the peak viscosity and final equilibrium viscosity of wax-containing hydrate slurry are significantly higher than those of the wax-free system. By comparing the consistency coefficient and flow characteristic index, it is found that the value of characteristic index for wax-containing hydrate slurry increases with the increase of wax content and Span 80 concentration. The wax-containing oil-water emulsion, hydrate slurry and wax-containing hydrate slurry systems all exhibit shear-thinning behavior, and the wax-containing hydrate slurry exhibits a stronger shear-thinning behavior.关键词：wax crystal;surfactant;hydrate slurry;critical time;shear-thinning behavior- 12
- |
- 0
- |
- 0
发布时间：2024-04-26 -
摘要：The use of hydrate-based technology for CO2 sequestration in permafrost layers is a promising and potential CO2 sequestration technique. In order to investigate the influence of formation properties on CO2 sequestration, CO2 hydrate synthesis experiments were conducted under the conditions of initial pressure of 5.5 MPa and temperature of 1.27 ℃ and the influence of different mineral compositions and particle size ratio of fine-grained. The pressure-temperature changes, CO2 hydrate average synthesis rates, CO2 consumptions, and phase saturations during the CO2 hydrate formation process were analyzed during the experiment. The results show that the CO2 hydrate average synthesis rate is the smallest when the ratio of fine-grained sand to coarse-grained sand particle sizes (mass ratio of each component, the same below) is 1.0:2.0, which is 12.60 mmol/min. With the increase of coarse sand proportion, the CO2 hydrate average synthesis rate decelerateds due to the reduction of specific surface area. Montmorillonite clay is not conducive to CO2 hydrate formation, and the CO2 hydrate average synthesis rate of the silty sand group (contains fine-grained sand and coarse-grained sand) is higher than that of the silty clay group (contains fine-grained sand and montmorillonite clay). And the experiments in the silty sand group are more likely to achieve high hydrate saturation and CO2 consumption, making it more suitable for CO2 sequestration in areas with mineral compositions containing fine-grained sand and coarse-grained sand. The CO2 consumption rates for the ratio of fine-grained sand to coarse-grained sand or clay mineral particle sizes of 1.0:0.5 are 0.86 mol and 0.77 mol, respectively. With the increase of the proportion of coarse-grained sand and clay minerals, both the hydrate saturation and CO2 consumption gradually decrease. The ratio of fine-grained sand to coarse-grained sand or clay mineral particle sizes of 1.0:0.5 is suitable for CO2 sequestration using the hydrate-based method.关键词：CO2;hydrate;carbon sequestration;clyey-silt;particle size ratio- 20
- |
- 0
- |
- 0
发布时间：2024-04-26
- Postal code：610225
- Tel：028-85964717 Email：dthxyhg@swchem.com
- Technical support is provided by Beijing Founder electronics co., LTD 蜀ICP备12008600号-10
蜀公网安备51012202001533 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：73733 Visits Today：124
0