Propane Ammoxidation Research Articles

Effects of Local Structural Changes of Orthorhombic Mo3VOx Induced by High-Temperature Heat Treatment on Catalytic Ammoxidation of Propane

Effects of Local Structural Changes of Orthorhombic Mo₃VO_<i>x</i> Induced by High-Temperature Heat Treatment on Catalytic Ammoxidation of Propane

Propene ammoxidation over an industrial bismuth molybdate-based catalyst using forced dynamic operation

Propene ammoxidation to acrylonitrile (ACN) over bismuth molybdate-based catalysts has been commercialized for more than 60 years. To meet forecasted growth, there is an opportunity for smaller-scale, decentralized ACN production. Forced dynamic operation (FDO), here referring to step changes in reactant inlet concentrations, has been used in low-volume production applications and has shown advantages in partial oxidation reactions. As a proof-of-concept study to evaluate FDO for acrylonitrile production, we applied periodic changes in inlet gas concentrations that varied between one phase containing all reactants and another that just contained O2, over an industrial bismuth molybdate-based catalyst. We varied the cycle period, duty cycle, and O2 concentration in the second phase and show that improved acrylonitrile yields can be obtained compared with those of steady-state operation under certain conditions. A correlation between lattice oxygen availability and FDO performance was observed.

Environmental Feasibility Analysis for the Acrylonitrile Production from Glycerol

AbstractAcrylonitrile is a monomer traded as a commodity on the global market with applications in several industrial sectors, produced from the ammoxidation of propylene. New technological alternatives are being studied, reducing the use of petroleum derivatives through renewable raw materials. This article proposes the application of the life cycle assessment technique for acrylonitrile production from glycerol, with the objective of evaluating the environmental impacts generated in the process. The results demonstrated that the use of glycerol from the state of Mato Grosso can reduce consumption of fossil fuel and water by 45 % and 31 %, respectively. The results about greenhouse gas (GHG) emissions were little significant when replacing the raw material.

A Review of the Catalysts Used in Propane Ammoxidation Reaction to Produce Acrylonitrile

Abstract: Background: Various catalysts were studied to synthesize acrylonitrile via propane ammoxidation. The catalysts used for this process can be categorized as antimony-based catalysts, molybdenum-based catalysts, zeolites, nitride material catalysts, and other catalysts. The catalyst which was proved to be an efficient catalyst among all other catalysts is the mixed metal oxide catalyst MoVNbTe due to its high selectivity and yield.

Light hydrocarbon conversion to acrylonitrile and acetonitrile - a review.

Nitriles, particularly acrylonitrile and acetonitrile, are versatile chemicals that are used in various fields, such as polymer synthesis and pharmaceutical production. For a long time, acrylonitrile has been produced via propylene ammoxidation with acetonitrile as a byproduct. The depletion of crude reservoirs and the production of unconventional hydrocarbon resources (e.g., shale gas) renders light alkanes (including propane, ethane, and methane) to be potential feedstocks in the syntheses of acrylonitrile and acetonitrile. In this review, the processes of transforming light hydrocarbons to nitriles are surveyed, the developments in nitrile synthesis from alkanes are discussed, and the existing challenges and plausible solutions are addressed.

Simulation and Optimization of Operating Conditions of a Packed Bed Reactor for Acrylonitrile Production from Propene Ammoxidation over $$\alpha$$-Bismuth Molybdate

Simulation and Optimization of Operating Conditions of a Packed Bed Reactor for Acrylonitrile Production from Propene Ammoxidation over $$\alpha$$-Bismuth Molybdate

Technical and Economic Analysis for the Production of Acrylonitrile from Crude Glycerol

AbstractGlycerol is the main by‐product of biodiesel plants, and new technological routes using it as a raw material are being developed due to the increased global production of biofuels. One possible application is in the production of acrylonitrile, a product with several industrial applications. Here, the production process of acrylonitrile using crude glycerol is proposed and analyzed. The process is shown to be economically viable, requiring an operating time of 5 years to achieve a net present value/investment ratio greater than 2 and an internal rate of return greater than 10 % per annum. The new process was found to be competitive compared to the current route (through propylene ammoxidation), supporting the development of new studies on this new route.

Acrylonitrile Process Enhancement through Waste Minimization: Effect of Reaction Conditions and Degree of Backmixing

Waste minimization in reactor design is an effective approach for pollution control, when compared to the traditional practice of the end-of-pipe treatment. Reactor degree of backmixing and operating conditions are important factors that determine the performance of chemical process, including environmental impact. For the purpose of waste minimization, two modeling methods were used for simulating the performance of the acrylonitrile production reactor, based on the ammoxidation of propylene. The effect of residence time, temperature, degree of backmixing on the steady-state propylene conversion, and production of waste were determined. The tanks-in-series model and the axial dispersion model were used to account for the degree of backmixing. The two main by-products in the acrylonitrile process are acetonitrile and hydrogen cyanide, which are both highly toxic waste. Extensive reactor backmixing reduces propylene conversion, especially at high temperature and residence time. Minimum acetonitrile production is favored by low residence time, high to moderate temperature, and no backmixing. Minimum hydrogen cyanide production is favored by low residence time, low temperature, and no backmixing. At 450 °C, the percentage of increase in the selectivity of acrylonitrile, with respect to hydrogen cyanide at plug-flow reactor conditions, as compared to a continuous stirred tank reactor, is 87.1, 74.3, 50.9, 30.4, and 12.4% at a residence time of 1, 2, 4, 6, and 8 s, respectively. The reactor degree of backmixing and operating conditions are important factors that affect the environmental friendliness of the acrylonitrile production process.

Simultaneous production of hydrogen and acrylonitrile in a new bifunctional micro-reactor, mathematical modeling and optimization study

In the last decade, there have been numerous investigations toward enhancing the efficiency of hydrogen production methods, as well as improving their operational variables. In this work, hydrogen and acrylonitrile are produced in a bench-scale concept by steam reforming of glycerol and ammoxidation of propane, respectively. Based on the present micro-reactor configuration, the needed heat, which is vital for the advancement of the endothermic glycerol steam reforming process in the outer tube, is supplied with the produced heat in the propane ammoxidation reactions in the inner tube. Consequently, in spite of the conventional steam reforming and ammoxidation process, the cooler and furnace are not required. As a result, appropriate energy-saving has been made, along with the reduction of the emission of hazardous greenhouse gases. Adequate improvement can be noticed in the performance of the reactor in which the glycerol conversion has improved from 53.32% to 87.11%. Also, to investigate the impact of the operating condition on the behavior of the proposed reactor configuration, a sensitivity analysis in the case of inlet flow rate, inlet feed composition, and inlet temperature is implemented. It is worth highlighting that the optimization scheme is applied in order for governing the best solution for the suggested configuration within the defined ranges. Optimization outputs established 3.97%, 1.41%, 4.93%, and 3.01% augmentation in the glycerol conversion, hydrogen yield, propane conversion, and acrylonitrile yield, respectively.

Rapid scan FTIR reveals propane (am)oxidation mechanisms over vanadium based catalysts

Rapid scan FTIR coupled with Mass Spectrometry (MS) has been used to determine the role of spectroscopically observed species in the reaction media during propane dehydrogenation over a V/Al catalyst, and propane ammoxidation on a Sb-V-O sample. During the propane dehydrogenation reaction, it was shown that oxygenates are not formed during the first minutes and propylene is formed directly from propane via dehydrogenation on a V-O site. Oxygenates may form though secondary reactions due to further propylene oxidation. Propane dehydrogenation is the first step during the propane ammoxidation reaction. This is followed by the transformation of propylene into acrylonitrile, which is the rate limiting step. Rapid scan FTIR/MS is shown to be a useful technique for monitoring chemical reactions in order to identify or eliminate observed surface species as potential reaction intermediates. Understanding of the reaction mechanism is necessary in order to improve the chemical process design and the catalytic material.

Clariant, TechnipFMC test acrylo catalysts

Clariant and the engineering firm TechnipFMC will work together to commercialize Clariant’s AcryloMax propylene ammoxidation catalysts, which are used for making acrylonitrile. Clariant says its ne...

A conceptual comparison between potential configurations in the thermal coupling of naphtha reforming with propane ammoxidation

Abstract In order to achieve a proper temperature profile and consequently a higher production rate, the conventional catalytic naphtha reforming process (CNR) was coupled thermally with the propane ammoxidation process as a heat source through a novel bifunctional reactor. Propane ammoxidation is a highly exothermic process that occurs on the reactor tube side to supply the required heat for naphtha reforming reactions on the shell side. In this study, the performance of the novel reactor with different types of feeding has been investigated. Two possible counter-current configurations of Series-Naphtha-Parallel-Ammoxidation (SNPA) and Parallel-Naphtha-Parallel-Ammoxidation (PNPA) have been compared with four possible co-current configurations of SNPA, PNPA, Series-Naphtha-Series-Ammoxidation (SNSA), and Parallel-Naphtha-Series-Ammoxidation (PNSA). Among the co-currents, PNPA showed the highest production. The counter series feeding of propane ammoxidation (SNSA and PNSA) was not possible due to the exothermic side's temperature runaway. The results showed that the counter-current SNPA arrangement significantly boosts the heat transfer between the endothermic and the exothermic sides, improving the product yields more than other arrangements and CNR. For counter-current SNPA 42% yield of aromatics was achieved, which is 5% and 7% more than the co-current PNPA and CNR, respectively. In addition, co-current and counter-current configurations were investigated in terms of temperature uniformity. The best configurations in co-current and counter-current were co-SNSA and count-SNPA, respectively. Also, optimization of counter-current SNPA was examined and its results compared with non-optimized results. It was observed that in optimized reactors, the yield of aromatics and the overall yield of acrylonitrile (ACN) were increased to 45% and 41%, respectively.

Thermally Induced Transformation of Sb-Containing Trigonal Mo3VOx to Orthorhombic Mo3VOx and Its Effect on the Catalytic Ammoxidation of Propane

Crystalline orthorhombic Mo3VOx and trigonal Mo3VOx (Orth-MoVO and Tri-MoVO) are structurally analogous, both being constituted by pentagonal {Mo6O21}6– units and {MO6} (M = Mo, V) octahedra to for...

Technical and economic analysis of acrylonitrile production from polypropylene

In this research, we investigate the propylene ammoxidation process, which is under the license of Sohio Company, as well as its supply and demand, production method, and economical analysis of acrylonitrile production process. Acrylonitrile is a key material in textile, plastic, and packaging industries as well as automobile manufacturing. This research studies the economic aspects of its production process. Over time, the need for this product has become more sensible due to the enhancement of production and autarky. We do not have any acrylonitrile production unit in Iran at this time. Some acrylonitrile process simulations and its economic analysis have been carried out with HYSYS and Icarus software, respectively, then we compared the results with those obtained from COMFAR software in the Persian Gulf Petrochemical Holding. Results indicated that this process is economically feasible only in large scale production. It is very important to take precautions since hazardous precursors are used in this process. Hydrogen cyanate is an extremely hazardous material that is produced as a by-product in this process. There is not any solution for disposal or any usage for this byproduct in Iran. Results obtained from Icarus software were more precious and promising compared to desk calculations. Comparison of these two production units, with different production capacities, has indicated that reduction in production rate of return was lower in the large unit and it is better to establish a smaller unit for acrylonitrile production.

Modeling and optimization of thermally coupled reactors of naphtha reforming and propane ammoxidation with different feed distributions

In this paper, the thermal coupling of naphtha reforming with propane ammoxidation was simulated using a one-dimensional homogenous model for two processes. By this technique, the required heat for the endothermic naphtha reforming process is provided by the exothermic propane ammoxidation which caused the related furnaces to be removed. The propane ammoxidation takes place in the tube side while the naphtha reforming occurs in the shell side of thermally coupled reactors. Depending on the feed distribution, four configurations including (1) series naphtha-series ammoxidation, (2) series naphtha-parallel ammoxidation, (3) parallel naphtha-parallel ammoxidation, and (4) parallel naphtha-series ammoxidation were investigated to select the best configuration which yields the highest efficiency. The modeling results showed that the first configuration is the best configuration in which produces the aromatics 4 kmol h−1 greater than the conventional naphtha reforming (CNR). Hence the optimization of the first configuration with the genetic algorithm method was done to obtain the optimal value of its key variables. The molar flow rate of aromatics was achieved to 141.9 kmol h−1 at optimized input temperature of naphtha reforming (776.94 K), input temperature of propane ammoxidation (779.9 K) and the number of tubes (395).

Non-equilibrium thermodynamics and stoichiography in studying solid-phase preparation processes of functional materials

The application of the general principles of the non-equilibrium thermodynamics and stoichiography allows obtaining novel information on the solid-phase transformations happening in multielement and heterophase substances and materials. Without the solid-phase standards, the use of stoichiography allows detecting, identifying and quantitative determining known and unknown crystalline and amorphous phases being of constant or variable composition. For the first time, reliable results concerning evolution of solid products during preparation of the Mo-V-Te-Nb-O catalyst of propane ammoxidation are presented.

Some history on the new ways of synthesis of nitriles

In this note discuss the papers I wrote together with Robert Grasselli in the field of ammoxidation. Together, we have investigated the ammoxidation of propylene, essentially on the role of Te as promoter, the ammoxidation of propane to acrylonitrile, the ammoxidation of alkyl aromatics to nitriles and we have analyzed from data in the literature the possibility to produce acrylonitrile from biomass. In the field of ammoxidation of propane we have investigated catalysts based on Sb/V/Al mixed oxides with some promoters. In the field of ammoxidation of alkyl aromatics we have investigated V/Ti mixed oxides and V/Sb/Al mixed oxides.

A novel reactor concept for thermal integration of naphtha reforming with propane ammoxidation

In this study, propane ammoxidation as an exothermic process is thermally coupled with the endothermic naphtha reforming process which resulted in the elimination of the naphtha reforming furnaces. Both processes are available in petrochemical plants. Naphtha reforming produces aromatics (BTX, Toluene, Ethylbenzene) as well as hydrogen, while propane ammoxidation reactions on V-Sb-Al oxide catalyst produce acrylonitrile (ACN) as the main product which is a known intermediate for the production of various polymers and polyamides. In addition to energy saving, the aromatics production in the proposed scheme increased by 10% compared to conventional naphtha reforming (CNR). Furthermore, the effect of operating temperature, the number of tubes of the reactors, and the inlet molar flow rate of propane on the hydrogen production and aromatics yield in the naphtha reforming process have been investigated.

Nonequilibrium Thermodynamics and Stoichiography in Studying Solid-Phase Processes of Fabrication of Functional Materials

The application of general principles of nonequilibrium thermodynamics and stoichiography allows obtaining novel information on the solid-phase transformations of multielement and heterophase substances and materials. Without solid-phase standards, the use of stoichiography makes it possible to detect, identify, and quantify known and unknown crystalline and amorphous phases of constant or variable composition. For the first time, reliable results are presented concerning the evolution of solid products in the course of preparation of the Mo–V–Te–Nb–O catalyst of propane ammoxidation.

Propane ammoxidation over MoVTeNb oxide catalyst in a microchannel reactor

Propane ammoxidation (PAO) is a promising way to produce acrylonitrile from propane instead of propylene. It is found that the catalytic performances of MoVTeNb oxide catalyst for PAO including product selectivity and catalyst stability are very sensitive to the reaction temperature, requiring a narrow temperature window of 440–450 °C to maintain low selectivity to COx. Owing to the large heat transfer surface area and short heat transfer distance, the temperature gradient in a microchannel reactor (0.5 × 12.7 × 80 mm) can be maintained at less than 0.5 °C as opposed to 43.2 °C in a conventional fixed bed tubular reactor with an inner diameter of 4 mm at a reactor wall temperature of 440 °C. Therefore, PAO reaction can be operated in a microchannel reactor under much harsher reaction conditions to achieve a higher productivity (189.9 kmol/m3·h) while still maintaining a low COx selectivity and high catalyst stability. © 2018 American Institute of Chemical Engineers AIChE J, 64: 4002–4008, 2018