Reactant Conversion Research Articles

Preparation of 4,4-bis(5-methylthiophen-2-yl)pentanoic acid from biomass-based functional molecules using solid acid catalysts

For the first time, the successful synthesis of 4,4-bis(5-methylthiophen-2-yl)pentanoic acid (bisthiophenic acid-methyl; BTA-M) and its alkyl esters (BTAE-M) from levulinic acid (LA) and its esters with 2-Methylthiophene (2-Met) has been achieved, utilizing solid acid catalysts (Amberlyst-15 and Indion-190). Notably, Indion-190, a cost-effective catalyst, demonstrated the formation of BTA-M and bisthiophenic methyl ester-methyl (BTME-M) with 96–98% selectivities and 99% conversion of LA and methyl levulinate under optimized, solvent-free reaction conditions. The recyclability of Indion-190 has been showcased, maintaining good recyclability for the preparation of BTA-M and BTME-M over three reaction cycles, with a slight decrease in the conversion of reactants.

Aerosol metal-organic framework-derived Ni–Zn–Al hybrid catalyst for efficient methane Bi-reforming

Bi-reforming of methane (BRM) has emerged as a promising advancement in hydrogen production via direct carbon utilization. To promote BRM, metal-organic framework (MOF)-derived Ni–ZnO–Al2O3 hybrid catalyst was developed via aerosol-assisted approach. The results demonstrated that the incorporation of Al2O3 nanoparticle cluster and ZnO with Ni alloy enhanced the catalytic activity. Superior conversions of reactants and operation stability of the MOF-derived Ni–ZnO–Al2O3 hybrid catalyst was observed, and a high turnover frequency (TOFCH4) of 2.86 s−1 at a moderate operating temperature (650 °C) was achieved. Further, the H2/CO ratio of 1.4–6.5 was attained through the proper adjustment of feed ratios (H2O/CH4, CO2/CH4) and reaction temperature (600–700 °C). Overall, the newly fabricated MOF-derived Ni–ZnO–Al2O3 hybrid catalyst via aerosol-assisted method, demonstrated significant improvements in reducing the required operating temperature of BRM, which is beneficial for simultaneous reduction of the CO2 generated from the methane reforming plus energy consumption, and advancing the development of low-carbon H2 production.

Transition metal modified hierarchical ZSM-5 nanosheet for catalytic cracking of n-pentane to light olefins

Catalytic cracking of naphtha is an effective way to produce light olefins, in which zeolite catalyst plays an important role. In this work, hierarchical ZSM-5 self-pillared nanosheet (NS) supporting Ca, Fe and Zr is prepared for catalytic cracking of n-pentane to produce ethylene and propylene. Hierarchical pores by self-pillared nanosheet zeolite aggregates delivers enhanced exposed surface, thus giving improved conversion of n-pentane and yield of olefins, in comparison with conventional microporous ones. Moreover, different metal sites intrigue various reaction pathways in cracking. The dehydrogenation-cracking of n-pentane is demonstrated by Ca/NS catalyst with enhanced conversion of reactant and selectivity of olefins. The introduction of Fe on NS (Fe/NS) sacrifices part of acidities and inhibits the hydrogen transfer reaction by monomolecular cracking pathway, leading to enhanced olefin selectivity and catalytic stability, but decreased conversion of n-pentane. Zr incorporation promotes utilization of Brønsted acid sites through bimolecular cracking routes. The interaction between reactants and Brønsted acid sites or olefins carbenium ions could be promoted by the introduced framework Zr, which improves the conversion of n-pentane, but leading to reduced olefin selectivity with relative low stability.

Evaluation of industrial aromatic oils as potential hydrogen carriers: Study of the hydrogenation step

Industrial organic streams (oils) with high concentration of aromatics compounds are present in different carbochemical and petrochemical processes. These aromatic compounds are potential hydrogen carriers through hydrogenation-dehydrogenation cycles. For this purpose, catalytic hydrogenation of three different aromatic oils using conventional hydrogenation catalysts is considered in this work. Two oil samples (petrochemical Oil A and carbochemical Oil B) enriched with polyaromatic compounds, along with a manufactured oil of petrochemical origin (SolvessoTM 200), were hydrogenated using Pt/γ-Al2O3 and Pd/γ-Al2O3 catalysts. The study aims to work under mild conditions to avoid secondary reactions and cracking, which is important for using these oils as potential LOHCs. The methodology involved using a stainless-steel autoclave reactor and analysing the composition of the oils and reaction products using gas chromatography and mass spectrometry. Diaromatic compounds were found to be the most reactive, reactant conversion depending on the catalyst and reaction temperature. However, the presence of tri and tetra-aromatic compounds hinder the reaction. Moreover, nitrogenated aromatic compounds are extremely reactive at these conditions. Comparison of SolvessoTM 200 with benzyltoluene, an established LOHC, resulted in promising results. Thus, both Oil A and B, after a purification step, would have interesting qualities to be used as LOHCs with the added advantage of its low price.

Using Enzymes to Understand and Control the Local Environment of Catalysis

Local environments within porous electrodes are an inherent, but often neglected component of catalysis as the local conversion of reactants to products means catalysis occurs in a very different environment to bulk solution. By understanding and modifying these local environments using a combination of experimental and computational techniques, we show how to improve the performance of electrocatalytic reactions to address the climate crisis by efficiently converting renewable energy to chemical fuels. The selectivity and activity of enzymes means they are ideal model catalysts that can guide the design of synthetic systems. However, they must be in an environment that is close to their optimal to operate efficiently, with small changes in properties such as pH drastically affecting their activity. By optimising their local environment, the rates of fuel formation can be drastically (>18×) increased.[1] We also demonstrate the crucial role of CO2 hydration kinetics on the local pH and CO2 concentration using the enzyme Carbonic Anhydrase co-immobilised with Formate Dehydrogenase.[2] Carbonic Anhydrase catalyses CO2 hydration, causing CO2 to act as a better buffer to mitigate changes in the local pH environment allowing the system to operate closer to its optimal and how this contrasts with heterogeneous CO2 reduction. (fig. 1a)We extend this approach to low CO2 concentrations, taking inspiration from the natural carboxysome to develop a system where Formate Dehydrogenase and Carbonic Anhydrase are co-immobilised in a nanoconfined structure to improve low CO2 concentration utilisation. (fig. 1b).[3] The electrolysis of dilute CO2 streams suffers from low concentrations of dissolved substrate and its rapid depletion at the electrolyte-electrocatalyst interface. These limitations require first energy-intensive CO2 capture and concentration, before electrolyzers can achieve acceptable performances. For direct electrocatalytic CO2 reduction from low-concentration sources, we introduce a strategy that mimics the carboxysome in cyanobacteria by utilizing microcompartments with nanoconfined enzymes in a porous electrode. Carbonic Anhydrase accelerates CO2 hydration kinetics and minimizes substrate depletion by making all dissolved carbon available for utilization, while a highly efficient formate dehydrogenase reduces CO2 cleanly to formate; down to even atmospheric concentrations of CO2. This bio-inspired concept demonstrates that the carboxysome provides a viable blueprint for the reduction of low-concentration CO2 streams to chemicals by using all forms of dissolved carbon.

Plasma-based dry reforming of CH4: Plasma effects vs. thermal conversion

In this work we evaluate the chemical kinetics of dry reforming of methane in warm plasmas (1000–4000 K) using modelling with a newly developed chemistry set, for a broad range of parameters (temperature, power density and CO2/CH4 ratio). We compare the model against thermodynamic equilibrium concentrations, serving as validation of the thermal chemical kinetics. Our model reveals that plasma-specific reactions (i.e., electron impact collisions) accelerate the kinetics compared to thermal conversion, rather than altering the overall kinetics pathways and intermediate products, for gas temperatures below 2000 K. For higher temperatures, the kinetics are dominated by heavy species collisions and are strictly thermal, with negligible influence of the electrons and ions on the overall kinetics. When studying the effects of different gas mixtures on the kinetics, we identify important intermediate species, side reactions and side products. The use of excess CO2 leads to H2O formation, at the expense of H2 formation, and the CO2 conversion itself is limited, only approaching full conversion near 4000 K. In contrast, full conversion of both reactants is only kinetically limited for mixtures with excess CH4, which also gives rise to the formation of C2H2, alongside syngas. Within the given parameter space, our model predicts the 30/70 ratio of CO2/CH4 to be the most optimal for syngas formation with a H2/CO ratio of 2.

Synthesis of Ethylene Carbonate by Urea Transesterification Using Zeolitic Imidazolate Framework Derived Fe-Doped ZnO Catalysts.

The development of environmentally friendly and efficient methods for the synthesis of ethylene carbonate (EC) is crucial for advancing carbon capture, utilization, and storage technologies. Herein, we present the synthesis of EC through the transesterification of urea with ethylene glycol (EG) using a zeolitic imidazolate framework (ZIF) derived Fe-doped ZnO catalyst (Fe;ZnO-ZIF). The Fe;ZnO-ZIF catalyst, prepared by incorporating Fe dopant atoms into a ZnO-ZIF template, demonstrates excellent catalytic activity, achieving high conversion of reactants and superior selectivity toward EC at 160 °C for 150 min under an applied vacuum (160 mmHg). Based on the thermogravimetric, X-ray spectroscopic, and temperature-programmed desorption analysis, the simultaneous presence of strong Lewis acidic and basic sites in Fe;ZnO-ZIF enables its excellent catalytic performance toward EC synthesis with high selectivity. Acidic sites activate the carbon center in urea, while basic sites facilitate the nucleophilic attack on urea by deprotonation of EG. This synergistic reaction pathway resulting from the interaction between the strong Lewis acidic and basic sites promotes nucleophilic attacks of EG on urea, leading to significantly higher conversion efficiency and selectivity, compared to the commercial benchmark ZnO. Although the establishment of a continuous reaction system which takes into account cyclability and stability of the catalysts is further required in the future, our research reported herein provides valuable insights into the design of synergistic, localized active sites for EC synthesis and contributes to the development of sustainable carbon utilization technologies for achievement of net-zero emissions.

Application of Fluorescent Carbon Dots as Catalysts for the Ring-Opening Reaction of Epoxides.

Considering the increased anthropogenic emissions of CO2 into the atmosphere, it is important to develop economic incentives for the use of CO2 capture methodologies. The conversion of CO2 into heterocyclic carbonates shows significant potential. However, there is a need for suitable organocatalysts to reach the required efficiency for these reactions. Given this, there has been an increasing focus on the development of organocatalytic systems consisting of a nucleophile and a hydrogen bond donor (HBD) so that CO2 conversion can occur in ambient conditions. In this work, we evaluated the potential of fluorescent carbon dots (CDs) as catalytic HBDs in the ring-opening reaction of epoxides, which is typically the rate-limiting step of CO2 conversion reactions into heterocyclic carbonates. The obtained results demonstrated that the CDs had a relevant catalytic effect on the studied model reaction, with a rate constant of 0.2361 ± 0.008 h-1, a percentage of reactant conversion of 70.8%, and a rate constant enhancement of 32.2%. These results were better than the studied alternative molecular HBDs. Thus, this study demonstrated that CDs have the potential to be used as HBDs and employed in organocatalyzed CO2 conversion into value-added products.

Conversion in a char bed reactor of tars and syngas from a wood gasifier

Cleaning syngas, particularly reforming tars, is still a major bottleneck to the development of gasification. In this work, syngas was simultaneously sampled and analysed downstream and upstream of a tar conversion reactor using a real syngas produced with a commercial gasifier.At 800 °C and 2 s residence time, tar conversion reached 51a% compared with only 11 % in an inert bed. The tar content in the syngas decreased from 8.1 to 4.2 g/Nm3. Almost all the tertiary tars were converted, and only benzene, toluene, and naphthalene persisted. The energy content of the syngas increased by 5 % thanks to simultaneously increase of the LHV and syngas flowrate. LHV's increase in mainly due to H2 production.

Catalytic evaluation of Pd-promoted Ni-Co/Al2O3 catalyst for glycerol dry reforming: Assessing hydrogen-rich syngas production, kinetics and mechanisms

The Pd-promoted Ni-Co bimetallic catalysts were prepared using ultrasonic-assisted impregnation, and their performance was subsequently assessed in a fixed-bed reactor. The catalyst's performance was evaluated in glycerol dry reforming (GDR) over a range of temperatures, from 873 K to 1173 K and reactant partial pressures ranging from 10 kPa to 40 kPa. The results indicated that as the temperature was raised from 873 K to 1073 K, there was a noticeable rise in both reactant conversion and product yield. However, beyond 1173 K, catalytic performance declined due to glycerol thermal cracking and sintering of the support at high temperatures, resulting in increased carbon formation. The presence of excessive CO2 was found to suppress glycerol adsorption on the catalyst surface, causing a decline in catalytic activity with a CO2 partial pressure of more than 20 kPa, regardless of reaction temperature. Additionally, excess CO2 were found to enhance the side reaction, particularly reverse water-gas shift (RWGS) that related to produce intermediate H2O. Similarly, the glycerol partial pressure was found to impact catalytic performance, with a decrease in performance beyond 20 kPa due to competing reactants between glycerol and CO2. According to the Langmuir-Hinshelwood kinetic mechanism, a dual molecular adsorption site for glycerol and CO2 was appropriate for this GDR reaction, with an associated activation energy of 47.3 kJ mol−1. The GDR reaction was identified as a kinetically controlled process due to its high activation energy, more than 25 kJ mol−1. The plausible mechanism of GDR over Pd-Ni-Co/Al2O3 occurred through the dissociative-type of adsorption of on active metallic sites of the catalysts for both reactant (glycerol and CO2). This was further facilitated by the bifunctional mechanisms based on H2 generated from dissociative adsorption involving both catalyst's basic sites and metallic active sites. This was ascribed to the highly dispersed and strong interaction between metal-support in Pd-promoted Ni-Co bimetallic catalysts.

Prebiotic synthesis on meteorite parent bodies: Insights from hydrogen and carbon isotope models

Several mechanisms could produce the biorelevant organic compounds contained in carbonaceous meteorites. The ratio of heavy-to-light stable isotopes can constrain a compound's formation history because substrates, mechanisms, and physiochemical conditions impact isotope ratios of a reaction's products. Prior stable isotope studies of meteoritic organic compounds have interpreted data via qualitative or semi-quantitative models. Here we create quantitative models (i.e., explicitly fit to measurements) for hydrogen and carbon isotope compositions of organic compounds in primitive carbonaceous meteorite and use these models to reach broader conclusions regarding the environments, substrates, and chemical processes that contributed to their synthesis.The hydrogen isotope model gathers previous molecular-average δD measurements, sorts them into compounds classes (e.g., amines, carboxylic acids), and fits the measurements in each class as linear combinations of the non-exchangeable hydrogen moieties, which are determined by their chemical environment (e.g., R-CH3, R-CH(NH2)(COOH)). In the chondrites studied, methyl hydrogens are the most deuterium-enriched moiety (up to 5000 ‰) and hydrogens attached to α‑carbons are the least. Deuterium enrichment is inversely related to a moiety's acidity and a meteorite sample's degree of aqueous alteration and terrestrial weathering, which suggests that ISM-sourced compounds reacted to form deuterium-enriched organic molecules before parent body accretion or during parent body evolution and that those D enrichments were variably attenuated through exchange with water during aqueous alteration on the parent body and subsequent terrestrial processing.The carbon isotope model tests five potential chemical reaction networks by taking δ13C of reactants for each network and applying isotope effects to determine a range of product δ13C from minimal to complete reactant conversion. The model that fits compounds in the Murchison meteorite most accurately (70% of previous measurements fall within the values predicted by model ±5‰) with the lowest average residuals (6‰) uses an integrated aldehyde network (oxidation, reductive amination, and Strecker synthesis acting on an initial pool of aldehydes and ketones) to produce straight-chain compounds, which then react with aldehydes to create branched-chain compounds. The addition of aldehydes provides a parsimonious fit the carbon isotope contents of compounds that span over 100‰ in δ13C, making it an attractive working hypothesis.

Plantwide Simulation and Operation of a Methanol to Propylene (MTP) Process

BackgroundMethanol to propylene (MTP) process is considered as one of the most important methods for propylene production. The MTP process consists of four sections: conversion of reactants to products, cooling, compression and products separation. In this process, is utilized from multi-stage fixed bed reactors. Due to high exothermicity of the MTP reactors, and existence of recycle loops, a plant-wide control structure is required to be designed for stable, safe and maximum production of propylene. MethodModeling and simulation of the heterogeneous fixed bed MTP reactors with interphase and intra-particle mass and heat transfer were carried out in Aspen Custom Modeler. Steady-state simulations of the MTP process were carried out in Aspen Plus. A simple control strategy was proposed to achieve maximum propylene production with temperature control of the MTP multi-stage reactors by splitting the cold oxygenate feed and the recycled hydrocarbons among the reactor beds. The performance of the proposed control strategy was tested against several disturbances including change in flowrate and composition of feed, using dynamic simulations by Aspen Plus Dynamics. Significant findingDynamic simulation results revealed that simultaneous control of the split range for the 5th and 6th reactor beds and cascade temperature of other reactor beds, could be a suitable temperature control strategy for the reaction section of the MTP process.

Environmental performance of nonthermal plasma dry and conventional steam reforming of methane for hydrogen production: Application of life cycle assessment methodology

The environmental performance of nonthermal plasma assisted dry reforming of methane (NTP-DRM) for hydrogen production from methane rich natural gas is investigated and compared with the current state of the art steam reforming technology through a cradle-to-gate life cycle assessment (LCA). The NTP-DRM technologies studied in this analysis include dielectric barrier, microwave, and pulsed plasma discharges. Due to the level of technology the study is considered as the prospective LCA of selected types of NTP-DRMs for hydrogen production. Of these, the NTP-DRM using microwave and pulsed plasma presented better environmental performance. The impact categories include midpoints levels applying TRACI 2.1 and AWARE for the water scarcity, using ecoinvent 3.8 and US NETL databases. The scenario analysis regarding carbon dioxide, electricity, and natural gas sources, revealed the highly dependency of NTP-DRMs technologies environmental performance to the energy efficiency of the processes. In terms of steam reforming of methane (SRM) despite the main contribution of steam use in the technology environmental performance, the uncertainty analysis showed higher sensitivity to natural gas input. Investigation showed that using renewable energy sources can have significant improvement regarding NTP-DRMs environmental performance and specifically global warming potential. Accordingly, at their current reactant conversion and product selectivity reaching the energy use of eV per molecule of reactant equal or less than 2, can be a proper target for the studied best case NTP-DRM to make their environmental behavior competitive with the state-of-the-art SRM technologies.

Well-Designed morphology regulated ZIF-67 derived 0D/1D Co3O4@TiO2 NWs integrated with in-situ grown Ni/Co-Active metals for Low-Temperature driven CO2 methanation

Well-designed morphology regulated MOF-templated Co3O4 over titanium dioxide nanowires (TiO2 NWs) boasting intimate interfacial contact for highly efficient CO2 methanation was synthesized via a facile in-situ grown approach. The synergistic effect of 0D Co3O4 with reducible 1D TiO2 NWs and the role of Ni/Co-active metals were systematically investigated for CO2 methanation. The performance comparison of the Ni dispersed in-situ grown Co3O4 on TiO2 NWs (Insitu-10N7CT) and its mechanically assembled counterpart (M−10N7CT) was further explored. The in-situ grown ZIF-67 acts as a sacrificial template to produce Co3O4 with high dispersion of Ni active sites to enhance CH4 production. By regulating the morphology, 0D Co3O4 promoted a superior methanation performance for Insitu-10N7CT (XCO2 = 97.42 %, SCH4 = 99.29 %) compared to M−10N7CT (XCO2 = 91.45 %, SCH4 = 98.42) due to intimate interfacial contact between the Ni, Co, and Ti species. Comparatively, the MOF-derived composites displayed much higher CH4 yield than uncalcined MOF nanocomposites. This is because the high reaction temperature caused a rapid collapse of the ZIF-67 dodecahedral structure, leading to a lower methanation performance. Insitu-10N7CT exhibited higher reducibility, generating low valence oxidation/metallic states of Ni-Co-Ti, leading to the high density of oxygen vacancies (Ov). An optimal reaction temperature of 350 °C and gas hourly space velocity of 9,400 mL gcat-1h−1 was revealed, suggesting an efficient reactant contact and CO2 conversion into CH4. The Insitu-10N7CT composite exhibited durability up to 100-hour time-on-stream due to the gradual reduction of Co3O4. Thus, the novel MOF-templated ternary nanocomposite revealed a facile method for regulating the structure of MOF derivatives while boosting strong interfacial interactions for efficient renewable fuel production.

Probing reaction channels via reinforcement learning

Chemical reactions are dynamical processes involving the correlated reorganization of atomic configurations, driving the conversion of an initial reactant into a result product. By virtue of the metastability of both the reactants and products, chemical reactions are rare events, proceeding fleetingly. Reaction pathways can be modelled probabilistically by using the notion of reactive density in the phase space of the molecular system. Such density is related to a function known as the committor function, which describes the likelihood of a configuration evolving to one of the nearby metastable regions. In theory, the committor function can be obtained by solving the backward Kolmogorov equation (BKE), which is a partial differential equation (PDE) defined in the full dimensional phase space. However, using traditional methods to solve this problem is not practical for high dimensional systems. In this work, we propose a reinforcement learning based method to identify important configurations that connect reactant and product states along chemical reaction paths. By shooting multiple trajectories from these configurations, we can generate an ensemble of states that concentrate on the transition path ensemble. This configuration ensemble can be effectively employed in a neural network-based PDE solver to obtain an approximation solution of a restricted BKE, even when the dimension of the problem is very high. The resulting solution provides an approximation for the committor function that encodes mechanistic information for the reaction, paving a new way for understanding of complex chemical reactions and evaluation of reaction rates.

Cyclo-addition of carbon dioxide to epoxides employing hierarchical silicoaluminophosphates molecular sieves

Hierarchical silicoaluminophosphates comprising dual micro/meso pore structures have been explored, and proven to be effective, robust, and recyclable materials for the production of cyclic carbonates in the absence of co-catalyst. Upon activation at the temperature range of 80–100 °C, treated SAPOs have been examined as catalysts for the reaction. The crystalline structures of the hierarchical SAPO were checked by P-XRD. FE-SEM images confirmed the morphology and TEM measurement showed the periodicity of the framework. The BET analysis revealed the surface modification. In the cycloaddition of CO2 to epoxide (cyclohexene oxide, and styrene oxide), the hierarchical silicoaluminophosphate materials were explored where the activity of post-synthetic treated materials as catalyst was discovered to be superior. 100 % and 93 % reactant conversion were found for treated SAPO-34 and SAPO-5 catalyst, respectively.

CFD modeling of hydrogen production from glycerol steam reforming in Tesla microchannel reactor

Hydrogen produced by glycerol steam reforming (GSR) is considered a renewable fuel as glycerol can be produced from bio-resources. In this study, a Tesla microchannel reactor for GSR was modified using computational fluid dynamics (CFD). The research presents a novel approach to glycerol steam reforming using a Tesla and modified Tesla microchannel reactor and also a statistical model was developed using Response Surface Method (RSM) for predicting H2 yield in the Tesla microchannel reactor for the first time. In Tesla geometry, most of the fluid passes through the central path, and small amounts of fluid pass through the upper and lower loops. For this reason, Tesla geometry was modified by adding barriers in the central path using inclined walls. At the temperature of 773 K and steam/carbon ratio of 4 and feed inlet mass flow rate of 2 × 10−5 kg/s, the results show that glycerol conversion in the microchannel reactor by changing the geometry from Tesla to Modified Tesla was enhanced from 20.89 to 78.33% due to the passing of fluid through the two upper and lower loops and increasing the contact surface of the reactants with the wall-coated catalyst.

Study of the influence of operational parameters on biomass conversion in a pyrolysis reactor via CFD

Study of the influence of operational parameters on biomass conversion in a pyrolysis reactor via CFD

Techno-economic evaluation of simultaneous methanol and hydrogen production via autothermal reforming of natural gas

The demand for clean energy and efficient resource utilization needs the existing processes to be modified for optimal performance. The study investigates the production of high purity methanol through the autothermal reforming (ATR) process technology. Two cases were developed: Case I, where only methanol is produced from syngas via natural gas reforming, and Case II, where co-production of high-purity hydrogen and methanol was made possible. In Case II, the adjustment of the module number was used to optimize the conversion in the methanol synthesis reactor by manipulating the recycle split ratio. Results show that by adjusting the split ratio, approximately 21.12 t/h of high purity H2 can be produced along with 101.99 t/h of AA-grade methanol. However, the co-production of hydrogen is made at the expense of decreased methanol production. The proposed co-production route offers process flexibility to produce hydrogen and methanol as per customer demand. The study also examined the process efficiency and found that the proposed Case II consumes less energy in the methanol synthesis and methanol purification sections compared to Case I. The process efficiency is 55 % and 57.5 % for Case I and Case II respectively, on the other hand, Case I requires 13.05 GJ, while Case II requires 17.55 GJ for fuel production. A sensitivity analysis has been performed to study the effect of varying split ratio on the module number, and the results show that as the split ratio increases, methanol production decreases, which reduces the total energy requirement of the process. Finally, a detailed economic comparison has been conducted to ascertain the production of dual fuel versus single fuel, and the results show that Case II is more profitable than Case I over the project lifetime.

Highly selective and efficient hydrogenation of fatty acids to alcohols using NiMo@C catalyst

Selective hydrodeoxygenation is the central challenge in converting bio-derived fatty acids into fatty alcohols under mild conditions. Herein, an effective and highly selective carbon-supported NiMo catalyst (NiMo@C) was developed by the thermolysis Ni-based metal–organic frameworks (MOF) impregnated Mo species. At a low temperature of 160 °C, the stearic acid can be efficiently converted into corresponding stearic alcohols over the NiMo@C with about 97% selectivity at 100% reactant conversion, which is superior to the most reported catalysts containing noble catalysts. The excellent catalytic performance of NiMo@C catalyst was mainly attributed to the ordered arrangement of Ni in the MOF and the uniform loading of molybdenum salt, which leads to an ideal distribution of Ni and Mo after pyrolysis of the MOF. The carbon support also prevents the aggregation of metal particles, which promotes the dissociation of hydrogen and enhances the synergy between Ni and Mo sites. More importantly, the synthesized NiMo@C catalyst showed excellent reusability with no loss of activity after 15 consecutive runs due to the stability of the catalyst structure. This provides a useful and simple method for synthesizing highly efficiency and stable NiMo@C bimetallic catalysts, which can facilely and selectively hydrogenate the bio-derived fatty acids to corresponding alcohols under mild conditions.