Propylene Production Research Articles

High-Entropy Intermetallics Serve Ultrastable Single-Atom Pt for Propane Dehydrogenation.

Propane dehydrogenation has been a promising propylene production process that can compensate for the increasing global demand for propylene. However, Pt-based catalysts with high stability at ≥600 °C have barely been reported because the catalysts typically result in short catalyst life owing to side reactions and coke formation. Herein, we report a new class of heterogeneous catalysts using high-entropy intermetallics (HEIs). Pt-Pt ensembles, which cause side reactions, are entirely diluted by the component inert metals in PtGe-type HEIs. The resultant HEI (PtCoCu) (GeGaSn)/Ca-SiO2 exhibited an outstandingly high catalytic stability, even at 600 °C (kd-1 = τ = 4146 h = 173 d), and almost no deactivation of the catalyst was observed for 2 months for the first time. Detailed experimental studies and theoretical calculations demonstrated that the combination of the site-isolation and entropy effects upon multi-metallization of PtGe drastically enhanced the desorption of propylene and the thermal stability, eventually suppressing the side reactions even at high reaction temperatures.

Bioethanol Conversion into Propylene over Various Zeolite Catalysts: Reaction Optimization and Catalyst Deactivation.

Catalytic conversions of bioethanol to propylene were investigated over different zeolite catalysts. H-ZSM-5 (SiO2/Al2O3 = 80) was found to be the most effective for propylene production. Furthermore, H-ZSM-5 (SiO2/Al2O3 = 80) was investigated under different variables of catalytic reaction (calcination temperature, feed composition, reaction temperature, and time on stream) for the conversion of ethanol to propylene. The H-ZSM-5(80) catalysts calcined at 600 °C showed the highest propylene yield. The moderate acidic site on ZSM-5 is required for the production of propylene. The activity on ZSM-5 is independent of the ethanol feed composition. H-ZSM-5 catalyst deactivation was observed, owing to dealumination. The highest propylene yield was 23.4% obtained over HZSM-5(80). Propylene, butene, and ≥C5 olefins were formed by parallel reaction from ethylene. Olefins were converted to each paraffin by sequential hydrogenation reaction. HZSM-5(80) catalyst is a promising catalyst not only for ethanol but also for the conversion of bioethanol to light olefins.

Synthesis and catalytic properties of Al-ITQ-34

ITQ-34 zeolite is an interesting catalyst in FCC process due to its three-dimensional medium pore topology. Nowadays, the zeolite ITQ-34 is synthetized as germanosilicate with a zero acid capacity, low stability and sometimes its channels system are partial blocked by the formation of phosphate compounds during the calcination process. For these reasons, to develop a synthesis route to incorporate aluminum in its framework as well as avoid the described problems has a great interest. In the present work is described the possibility to synthesize the zeolite ITQ-34 rich in aluminum, with a low content of germanium and with the total elimination of the phosphate compounds. The zeolite Al-ITQ-34 shows a great catalytic capacity in the propylene production by FCC.

Regulating Ni–O–V bond in nickel doped vanadium catalysts for propane dehydrogenation

Supported vanadium catalysts are commonly investigated in industrial propane dehydrogenation (PDH) but still remain a great challenge to achieve high propylene selectivity and productivity. Here, Ni species were adopted to regulate the micro-structure of V2O5 supported by γ-Al2O3 via incipient wetness impregnation method. The Ni-doped vanadium catalyst exhibits an optimal propylene yield of 31.88% with a superior propylene selectivity of 85.91% compared to undoped catalyst with a propylene yield of 20.49% (propylene selectivity of 80.77%). Experimental characterizations (such as XPS, XAFS and Raman studies) and DFT calculations were combined to support that the Ni–O–V bonds are active sites for PDH and could promote the charge redistribution from Ni to V based in the Ni–O–V bonds, which greatly strengthens the adsorption of C3H8 over V sites. This endows the Ni-doped vanadium catalyst high propane conversion and superior propylene selectivity.

Quasi-Orthogonal Configuration of Propylene within a Scalable Metal-Organic Framework Enables Its Purification from Quinary Propane Dehydrogenation Byproducts.

Propylene production via nonoxidative propane dehydrogenation (PDH) holds great promise in meeting growing global demand for propylene. Effective adsorptive purification of a low concentration of propylene from quinary PDH byproducts comprising methane (CH4), ethylene (C2H4), ethane (C2H6), propylene (C3H6), and propane (C3H8) has been an unsolved academic bottleneck. Herein, we now report an ultramicroporous zinc metal–organic framework (Zn-MOF, termed as 1) underlying a rigid one-dimensional channel, enabling trace C3H6 capture and effective separation from quinary PDH byproducts. Adsorption isotherms of 1 suggest a record-high C3H6 uptake of 34.0/92.4 cm3 cm–3 (0.01/0.1 bar) at 298 K. In situ spectroscopies, crystallographic experiments, and modeling have jointly elucidated that the outstanding propylene uptakes at lower pressure are dominated by multiple binding interactions and swift diffusion behavior, yielding quasi-orthogonal configuration of propylene in adaptive channels. Breakthrough tests demonstrate that 30.8 L of propylene with a serviceable purity of 95.0–99.4% can be accomplished from equimolar C3H6/C3H8 mixtures for 1 kg of activated 1. Such an excellent property is also validated by the breakthrough tests of quinary mixtures containing CH4/C2H4/C2H6/C3H6/C3H8 (3/5/6/42/44, v/v/v/v/v). Particularly, structurally stable 1 can be easily synthesized on the kilogram scale using cheap materials (only $167 for per kilogram of 1), which is important in industrial applications.

Reshaping the Role of CO2 in Propane Dehydrogenation: From Waste Gas to Platform Chemical

The valorization of CO2 appeals to the chemical industry due to the reduction in greenhouse gas emissions and the ability to offer more renewable products. Propylene production is the second largest process in the chemical industry, and it strongly depends on fossil fuel feedstocks. Coupling CO2 reduction with propane dehydrogenation boosts conversion and produces CO, a valuable platform chemical currently synthesized by fossil-methane reforming. In this work, (i) we demonstrate the environmental benefits of coupling CO2 with a life-cycle assessment under industrial conditions, potentially reducing emissions by 3 tCO2-eq per ton of propylene produced. (ii) We screen supported catalytic materials─both known and novel─with a focus on propane and CO2 reaction mechanisms under industrial reaction conditions of 400–700 °C and pressures of 1–6 barg (redox: V, Galinstan, In, Mo, Mn, Bi, Sb, Ta; nonredox: Cr, Ga, co, Al, Zn, Au, Zr, Ag, W, La, Cu; and some alloy combinations). We evaluate each material under the kinetic regime, and we quantify reaction, side reaction, and deactivation kinetics (coking, cracking, and dry-reforming), as well as the regeneration ability. We then classify them based on their dominant mechanisms (direct CO2 assistance or indirect with H2 via reverse water gas shift) and identify each catalyst’s strengths and weaknesses. Finally, (iii) we correlate our database of experimental results of 22 active metals/metal oxides with the Tamman temperature and density functional theory (DFT)-based oxygen vacancy formation energies. We discovered that oxygen mobility plays a crucial role in the kinetics of reoxidation with CO2 and the overall balance of active sites related to dehydrogenation and reoxidation.

Process optimization, exergy efficiency, and life cycle energy consumption-GHG emissions of the propane-to-propylene with/without hydrogen production process

Propylene is an extreme important intermediate chemical and it is traditionally produced by steam cracking and fluid catalytic cracking of light oil in petrochemical plants, which will be gradually limited by the increasingly scare oil resources. The propylene production from propane is promising and expected to significantly reduce oil consumption. The process modeling and system analysis methods are used to investigate the techno-environmental performance of the propane dehydrogenation processes with poly-generation of propylene and hydrogen. The propane dehydrogenation processes have great energetic and environmental competitiveness compared with the coal-to-propylene. The propane consumption and direct CO2 emissions are only 1.19 t/t C3H6 and 415 kg/t C3H6. The exergy efficiency of the propane dehydrogenation process with no H2 production is calculated to be 77.61%, while that are as high as 78.68% and 80.73% for the propane dehydrogenation process with H2 recovery rates of 90% and 95%. After subtracting the hydrogen production part, the life cycle energy consumption and GHG emissions of 1 t propylene for the process with H2 recovery rate of 95% are 2.72% and 3.97% lower than that the process with no hydrogen production. This study confirms that development of propane-based propylene and hydrogen production is energetic and environmentally competitive and is therefore promising in olefins industry.

(Invited) Electrochemical Reduction of Carbon Dioxide to Oxygenates and Hydrocarbons

Currently, more than 80% of the world’s energy needs are met by burning fossil fuels. Supplies of these fuels are intrinsically limited and will eventually run out. Combustion of fossil fuels also generates carbon dioxide, whose rapidly increasing atmospheric concentration contributes to global warming. One solution for mitigating atmospheric concentrations of CO2 is to electrochemically reduce these molecules into chemicals and fuels. If the energy used for these processes is generated from renewable sources such as solar and wind, we can envisage a chemical production cycle that is closed-loop with net zero carbon emission.In this talk, we share our recent works related to the development of catalysts for the selective electroreduction of CO2 to oxygenates and hydrocarbons. We shall show the pathway by which CO2 could be converted to 1-butanol, a C4 alcohol. Through a series of control experiments and density functional theory (DFT) calculations, we pinpoint that its C4 backbone was formed from a surface-mediated aldol condensation of acetaldehyde formed from CO2 reduction, rather through the coupling of four CO intermediates. We also discuss how CO2 could be reduced to methanol through a tandem process - CO2 was first reduced to formic acid, and the latter can be reduced to methanol using anodized titanium. For the latter step, experiments and DFT calculations identify Ti3+ and oxygen vacancies (TOV) as the active sites in a vacancy-filling pathway mediated by *H2COOH. We also give screening rules based on the *HCOOH and *H2COOH binding energies alongside TOV formation energies. These can facilitate the high-throughput automated design of catalysts for CH3OH synthesis from tandem CO2 electrolysis. In the last part of our talk, we show how molecules not commonly observed during CO2 reduction such as propylene and other C4-C6 products could be formed.

Synergistic effect of Zn with Ni on ZSM-5 as propane aromatization catalyst: effect of temperature and feed flowrate

This work shows how propane was catalytically converted to aromatic compounds over Zn-Ni/HZSM-5 to investigate the synergistic role of nickel as a zinc stabilizer and promoter in propane aromatization. Co-impregnation method was employed for Zn-Ni/ZSM-5 synthesis fixed 2 wt% of zinc and 1, 2 and 3 wt% of nickel. Modified catalysts’ were fully characterized. Catalysts crystallinity, structure and microporosity were retained from the analysis results. The propane aromatization process was conducted at 540 °C, 1200 ml/g-h gas hourly space velocity and atmospheric pressure. The presence of Ni with Zn improved catalytic performance for all Ni loading. Aromatic selectivity and propane conversion were improved, with the best performance to be Zn-Ni/ZSM-5 with 2 wt% Zn, 2 wt% Ni on ZSM-5 averaging 88 and 60% for twelve hours’ time on stream. Aromatic selectivity on Zn-Ni/ZSM-5 is eight times better than the parent HZSM-5 and one and half times better than the Zn/ZSM-5 catalyst. The electronic interaction of zinc and nickel resulting from equality of oxidation state of +1 and +2 and metal-binding energy change synergistically improved the catalytic performance of the bimetallic Zn-Ni/ZSM-5 over the HZSM-5 and Zn/ZSM-5. Flowrate increase from 6 to 35 ml min−1 decreased propane conversion from 80–40% with increased aromatic selectivity from 55–80%. Temperature increase from 500–580 °C favours both propane conversion and aromatic selectivity increase from 50–68 and 55–92% respectively. The metallic interactions from H2-TPR and XPS analysis revealed a big improvement in propane conversion, aromatic selectivity and product distribution.

Low-temperature selective production of propylene from non-oxidative dehydrogenation of propane over unconventional Zr/ZK-5 catalysts

The supply-side abundance of inexpensive propane and ethane from shale gas and stranded gas are drivers for technologies for the on-demand production of light olefins, propylene and ethylene. However, existing catalysts exhibit relatively poor stability and deactivate rapidly at the high temperature required for dehydrogenation. This indicates an opportunity for new catalyst systems which can activate propane at a relatively lower temperature. Small pore zeolites, ZK-5 with improved acidity, notably monodispersed zirconia ZK-5 catalyst, are explored for low-temperature dehydrogenation of propane to propylene. Zeolite supports help to stabilise the metal particles and improve metal-support synergy. This paper demonstrates a Pt-free metal impregnated zeolite catalyst for propane dehydrogenation while maintaining good stability and activity. The Zr/ZK-5 catalyst exhibits 40.3% conversion with 45.2% propylene selectivity at 500 °C for 24 h. The combination of Zr and ZK-5 effectively activates the CH bond, inhibits side reactions, reduces coke formation, and improves selectivity as well as stability.

Highly efficient propane dehydrogenation promoted by reverse water–gas shift reaction on Pt-Zn alloy surfaces

CO2-assisted propane dehydrogenation has been developed in propylene production technology to deal with thermodynamic equilibrium limitations. However, the rational design of catalysts is a crucial challenge in achieving high catalytic performances. Herein, we report the successful fabrication of highly dispersed PtZn alloy on hierarchical zeolites for CO2-assisted propane dehydrogenation through the reverse water–gas shift reaction (RWGS). Compared with monometallic Pt, the synergistic effect of PtZn plays a crucial role in both direct propane dehydrogenation and RWGS, resulting in an outstanding catalytic performance with a high turnover frequency (TOF) of 1.82 × 104h−1. From the catalytic point of view, Pt-Zn alloy surfaces facilitate the equilibrium shift in propane conversion by consuming produced H2 through RWGS with weakening CO-metal surface interaction revealed by operando studies and DFT calculations. These findings illustrate the conceptual design of alloy catalysts and allow insights into the mechanistic details of CO2-assisted alkane dehydrogenation.

Increasing the propylene production in the MTP process through thermal coupling with naphtha reforming process

• Thermal coupling of naphtha reforming and methanol to propylene (MTP) process. • Using the MTP process as a heat source instead of naphtha reforming furnaces. • Enhancement in propylene production in the MTP process. • Mathematical modeling of MTP process. This paper presents the thermal coupling of the naphtha reforming process with methanol to propylene (MTP) process. In this integrated configuration, the required heat of the endothermic naphtha reforming process is provided by MTP which is an exothermic process. Therefore, intermediate heaters of conventional naphtha reforming (CNR), which were used to adjust the feed temperature of the reactors, were eliminated. The temperature of the MTP reactor increases slightly by transferring its heat to the naphtha reforming reactor; hence, the produced heat in the MTP reactor is controlled to prevent hotspot formation on catalysts. Furthermore, the MTP process is cooled inherently without extra equipment. MTP and naphtha reforming processes were considered to occur in fixed-bed reactors with axial co-current feed streams. The MTP reactor feed streams are parallel while the naphtha reforming feed streams are in series. Results show that in the MTP process, produced propylene and consumed methyl ether in the three parallel reactors are 878 kmol/h and 0.034 kmol/h, respectively. Also, the molar flow rate of aromatics in naphtha reforming is 112 kmol/h. The propylene yield in thermally coupled reactors is 10% more than the conventional one.

A novel microwave-assisted methanol-to-hydrocarbons process with a structured ZSM-5/SiC foam catalyst: Proof-of-concept and environmental impacts

This study presents a novel combination of microwave irradiation and structured zeolite/SiC foam catalyst to improve the methanol-to-hydrocarbons (MTH) process as well as its environmental sustainability. Accordingly, ZSM-5/SiC foam was studied under microwave irradiation at various reaction temperatures (400–550 °C) and space velocities (8 and 12 h−1) and compared to conventional ZSM-5 pellets. ZSM-5/SiC foam promoted higher selectivity towards C1−C5 hydrocarbons (∼95%) and particularly propylene (∼40% at 400 °C and 8 h−1) compared to ZSM-5 pellets (∼40% and 6–9%, respectively) due to the enhanced mass and heat transfers. The microwave-assisted MTH process with both the structured catalyst and pellets was also assessed on the environmental sustainability via life cycle assessment in comparison with the conventionally-heat process with the structured catalyst. The results showed that the microwave-based process with the structured catalyst could reduce the environmental impacts of propylene production by 22–30% compared to the conventionally-heated process with the same catalyst.

Mesoporous Silica SBA-15 Supported Pt–Ga Nanoalloys as an Active and Stable Catalyst for Propane Dehydrogenation

Propane dehydrogenation is one of the most admired technologies for propylene production. However, the development of an active and stable catalyst presents a significant challenge. In this study, Pt–Ga/SBA-15 catalysts were prepared via coimpregnation, followed by H2 reduction, and applied in propane dehydrogenation. The Pt–Ga/SBA-15 catalyst with a Ga/Pt molar ratio of 1 exhibited a high propane conversion of up to 60% and high selectivity toward propylene of 98.2% at 550 °C for 10 min, with a propane conversion of 51.6% and propylene selectivity of 99.5% after reaction for 25 h. The physicochemical properties characterized using N2 physisorption, XRD, TEM, XPS, CO chemisorption, and in situ CO–DRIFT spectroscopy reveal that the Pt–Ga alloy nanoparticles were formed on the SBA-15 support after direct reduction with H2. The study of coke formation via temperature-programmed oxidation showed that a large amount of coke was deposited over the support of spent Pt–Ga/SBA-15 catalyst, indicating coke mobility from the active sites to the supports and its contribution to catalyst stability. The activities of spent catalysts could be almost completely recovered via reduction regeneration, during which Pt–Ga alloy retains the original geometrical and electronic structure well. The dilution of Pt ensembles due to the addition of Ga, e.g., Pt–Ga alloy formation, plays an important role in enhancing the catalytic performance for propane dehydrogenation.

Highly dispersed atomic layer deposited CrOx on SiO2 catalyst with enhanced yield of propylene for CO2 –mediated oxidative dehydrogenation of propane

The increasing worldwide demand for propylene and the necessity of CO2 mitigation attracted the attention of scientists to focus on CO2-oxidative dehydrogenation of propane (CO2-ODHP). In this regard, CrOx/SiO2 catalyst is an important and conventional option. Herein, we studied the atomic layer deposition (ALD) of CrOx on silica to increase the propylene production by increasing the dispersion of the catalyst. For ALD synthesis of CrOx/SiO2 catalyst, Cr(acac)3 and synthetic air were used as metal precursor and oxidant. The catalysts were examined in the CO2-ODHP reaction and their characteristics were compared to their impregnation counterparts using UV–Vis DRS, Raman, XANES, HRTEM and STEM-EDS mapping, H2-TPR, NH3-TPD and TPO. The ALD catalysts have shown up to 2 times higher acidity and enhanced reducibility compared to the impregnation catalysts. The presence of mainly Cr(VI) with a pre-edge peak at 5.994 keV in both series of catalysts was confirmed by XANES. UV–Vis DRS and Raman spectroscopy revealed the higher contents of active polymeric Cr(VI) species in the ALD ones. The dark field HRTEM and STEM-EDS mapping represented higher dispersion of chromium oxide particles in ALD catalysts. In CO2-ODHP, the ALD catalysts showed up to 18 and 15% promotion in propane conversion and propylene yield.

An integrated approach to the key parameters in methanol-to-olefins reaction catalyzed by MFI/MEL zeolite materials

Identification of the catalyst characteristics correlating with the key performance parameters including selectivity and stability is key to the rational catalyst design. Herein we focused on the identification of property-performance relationships in the methanol-to-olefin (MTO) process by studying in detail the catalytic behaviour of MFI, MEL and their respective intergrowth zeolites. The detailed material characterization reveals that both the high production of propylene and butylenes and the large MeOH conversion capacity correlate with the enrichment of lattice Al sites in the channels of the pentasil structure as identified by 27Al MAS NMR and 3-methylpentane cracking results. The lack of correlation between MTO performance and other catalyst characteristics, such as crystal size, presence of external Brønsted acid sites and Al pairing suggests their less pronounced role in defining the propylene selectivity. Our analysis reveals that catalyst deactivation is rather complex and is strongly affected by the enrichment of lattice Al in the intersections, the overall Al-content, and crystal size. The intergrowth of MFI and MEL phases accelerates the catalyst deactivation rate.

Promoting Propane Dehydrogenation with CO2 over the PtFe Bimetallic Catalyst by Eliminating the Non-selective Fe(0) Phase

Fine tuning the structure of bimetallic nanoparticles is critical toward understanding structure–activity relationships and further improving the catalytic performance in propane dehydrogenation (PDH). Excessive Fe species in the PtFe bimetallic catalysts promote carbon deposition leading to low propylene selectivity, and it remains challenging to synthesize well-defined PtFe catalysts while selectively eliminating the excessive Fe. Herein, we show that the formation of coke can be significantly inhibited by introducing CO2 into the PDH over PtFe catalysts, where CO2 effectively eliminates the active Fe(0) coking sites without changing the catalytic surface structure of the PtFe alloy. With a CO2/C3H8 feeding ratio of 0.20, the Pt1Fe7/S-1 catalyst shows the highest propylene production rate and decreased amount of coke from 18.8 to 1.0 wt % compared with dehydrogenation without CO2. X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and 57Fe Mössbauer results indicate that it is the oxidation of excessive unalloyed Fe species during the CO2-PDH reaction, instead of the reverse Boudouard reaction (CO2 + C = 2CO), that significantly inhibits the carbon deposition. This work provides a promising strategy for tuning the structure of PtFe bimetallic catalysts under reaction conditions and improving the performance of the PDH reaction.

Analysis Factors and Decision Strategies Dealing with Ongoing Project Delay in RDMP Balikpapan Project

The business activity in oil & gas sector may include accounting and financing, research and development, manufacturing, marketing, sales, safety, and supply chain processes including include in PT. Pertamina Kilang Balikpapan (PT. KPB) as well. In related manufacturing, currently PT. KPB was assigned the task of running and supervising the Balikpapan RDMP megaproject, a national strategic project for national energy independence and security through an increase in capacity of 100 MBSD, and an increase in diesel fuel of 30 MBSD. In addition, it will also produce new propylene products of 230 thousand tons per year, at the end all the production will decrease the import number quantity of fuel. Unfortunately, these figures are inverse to the overall progress of the current project, which is around 40%, of which 12% is the under-construction component, and large project delays are more than 50% higher than the baseline. The focus of this research is to understand the key factors that have a significant impact on project delays. To find the root cause of problems in project delays, the author tries to elaborate on technical data analysis from internal data, non-technical analysis, and qualitative data from expertise. Based on the available alternative business solution items for each root cause factor, the author establishes proposed initiatives and solutions to overcome and anticipate delays in the ongoing project RDMP Balikpapan.

The structural decoration of Ru catalysts by boron for enhanced propane dehydrogenation

Propane dehydrogenation (PDH) is an efficient technology for the direct production of propylene. Nevertheless, current PDH catalysts mainly rely on precious Pt or toxic Cr and especially undergo severe coke deposition. Herein, we report a Ru catalyst decorated by boron species (Ru-3B/Al2O3), which exhibits high catalytic performance for PDH. HAADF-STEM, EELS, and CO-FTIR characterization are used to identify the surface structure of the Ru active component, which shows that the high-energy unsaturated coordination sites, including corners, edges and step atoms for Ru-3B/Al2O3, are appropriately modified by BOx species. The encapsulation of high-energy active sites prone to CC cracking and deep dehydrogenation leads to higher propylene selectivity (> 95%) and strong carbon resistance (kd 0.0007 min) over Ru-3B/Al2O3. The XPS and H2-TPR results show that the migration of B species is driven by the reduction of B2O3 to B2O2 and that the coating degree of Ru particles is controlled by the chemical valance of Ru species.

Techno-Economic Analysis of a Hybrid Process for Propylene and Ammonia Production

Techno-Economic Analysis of a Hybrid Process for Propylene and Ammonia Production