Liquid Fuels Research Articles

Catalytic Co-Pyrolysis of Oil Palm Frond and Plastic Waste into Liquid Fuel using Ni-CaO Catalyst

Catalytic Co-Pyrolysis of Oil Palm Frond and Plastic Waste into Liquid Fuel using Ni-CaO Catalyst

Microscopic insights into the ammonia-methanol blended combustion at high temperatures

Ammonia and methanol have a broad application prospect in the future as green renewable liquid fuels. Methanol has high reactivity and good solubility with ammonia, which is conducive to solving the dilemma of ammonia combustion. However, there are few studies on ammonia-methanol blended combustion, and the effect of blended combustion on the reaction pathways needs to be further investigated. Therefore, this study used the reaction molecular dynamics simulations to reveal the role of methanol on the ammonia combustion and emission process at the microscopic level, focusing on the effects of different fuel blending ratios and oxygen concentration in the air under stoichiometric conditions. The variation of oxidation pathways from ammonia to NO and methanol to CO under different conditions was analyzed in detail. It was found that the methanol accelerated ammonia combustion mainly through enhancing OH production, but methanol and its intermediates inhibited the initial oxidation of ammonia. When the fuel blending ratio was 0.75, the system had lower fuel-type NO production alongside a higher ammonia consumption rate under stoichiometric conditions. The crucial role of NH in the HNO formation at high-temperature ammonia oxidation conditions was revealed. The pathway of HNO + OH → NO + H2O dominated the conversion of HNO to NO in this study. Increasing the methanol content promoted the conversion of NH to HNO and the pyrolysis of HNO while inhibiting the reaction between HNO and O2. In addition, the finding indicated that the high O2 level in air can enhance the reactions between ammonia and OH radicals but inhibit the pyrolysis of CH2OH/CH3O significantly.

Green adsorption of quinoline as basic N-compounds from liquid fuel using mesoporous and Fe-functionalized walnut shell-activated carbon

Removing nitrogenous compounds from liquid fuels is essential, and adsorption de-nitrogenation is a new process for this goal. This work has the purpose of investigating quinoline adsorption using Iron functionalized Activated carbon (IFAC) mesoporous nanocomposite. The mesoporous nanocomposite was synthesized in a one-step process by chemical activation of the walnut shell using Iron chloride as the activation and modification agent. The IFAC mesoporous nanocomposite was utilized to remove quinoline from isooctane as the liquid fuel via a discontinuous (batch) process by examining the effect of initial concentration, contact time, and temperature. The effect of contact time on the adsorption ability of IFAC for quinoline was well described by the pseudo-second-order model. The Langmuir model described the equilibrium manner of the process well, and the adsorbent could retain 344.82 mg/g of quinoline (37.37 mg N/g). The thermodynamic parameters show the endothermic (ΔH°= +30.070 kJ/mol) and spontaneity of the adsorption process. The regeneration experiments indicated that functionalized AC’s adsorption ability for quinoline adsorption decreased by 23% after five cycles. The obtained data indicate that the functionalization of activated carbon surface with iron particles leads to improving its adsorption ability toward N-containing compounds from liquid fuels.

Assessing Particulate Emissions of Novel Synthetic Fuels and Fossil Fuels under Different Operating Conditions of a Marine Engine and the Impact of a Closed-Loop Scrubber

Particle emissions from marine activities next to gaseous emissions have attracted increasing attention in recent years, whether in the form of black carbon for its contribution to global warming or as fine particulate matter posing a threat to human health. Coastal areas are particularly affected by this. Hence, there is a great need for shipping to explore alternative fuels that both reduce greenhouse gas emissions, as anticipated through IMO, and also have the potential to reduce particle emissions significantly. This paper presents a comparative study of the particulate emissions of two novel synthetic/biofuels (GTL and HVO), which might, in part, substitute traditionally used distillate liquid fuels (e.g., MDO). HFO particulate emissions, in combination with an EGCS, formed the baseline. The main emphasis was laid on particle concentration (PN) and particulate matter (PM) emissions, combining gravimetric and particle number measurements. Measurements were conducted on a 0.72 MW research engine at different loads (25%, 50%, and 75%). The results show that novel fuels produce slightly fewer emissions than diesel fuel. Results also exhibit a clear trend that particle formation decreases as engine load increases. The EGCS only moderately reduces particle emissions for all complaint fuels, which is related to the formation of very fine particles, especially at high engine loads.

Catalytic pyrolysis of polypropylene waste for liquid fuels production using Ni/Al-MOF-derived catalysts

Waste plastics pose significant environmental risks due to their non-biodegradable nature and accumulation in the environment. The pandemic has exacerbated this issue by increasing the production of plastic medical waste such as surgical masks. This study developed Ni/Al-MOF-derived catalysts for pyrolysis, an effective plastic waste utilization technology. By optimizing conditions, the study successfully converted waste surgical masks, made primarily of polypropylene, into gasoline or diesel range chemicals. The oil yield from polypropylene waste reached 72.8 % using Ni/Al-MOF-derived catalysts with 5 % Ni loading at 450°C, while surgical masks yielded 58.9 % oil under the same conditions. Catalyst characterization revealed a high surface area and evenly distributed Ni particles in MOF-derived Al2O3, maximizing catalytic performance. This catalyst provides a promising solution for converting waste surgical masks into liquid fuels, reducing the environmental impact of plastic products, and promoting plastic waste recycling.

Aquatic toxicity, bioaccumulation potential, and human estrogen/androgen activity of three oxo-Liquid Organic Hydrogen Carrier (oxo-LOHC) systems

The Liquid Organic Hydrogen Carrier (LOHC) technology offers a technically attractive way for hydrogen storage. If LOHC systems were to fully replace liquid fossil fuels, they would need to be handled at the multi-million tonne scale. To date, LOHC systems on the market based on toluene or benzyltoluene still offer potential for improvements. Thus, it is of great interest to investigate potential LOHCs that promise better performance and environmental/human hazard profiles. In this context, we investigated the acute aquatic toxicity of oxygen-containing LOHC (oxo-LOHC) systems. Toxic Ratio (TR) values of oxo-LOHC compounds classify them baseline toxicants (0.1 < TR < 10). Additionally, the mixture toxicity test conducted with D. magna suggests that the overall toxicity of a benzophenone-based system can be accurately predicted using a concentration addition model. The estimation of bioconcentration factors (BCF) through the use of the membrane-water partition coefficient indicates that oxo-LOHCs are unlikely to be bioaccumulative (BCF < 2000). None of the oxo-LOHC compounds exhibited hormonal disrupting activities at the tested concentration of 2 mg/L in yeast-based reporter gene assays. Therefore, the oxo-LOHC systems seem to pose a low level of hazard and deserve more attention in ongoing studies searching for the best hydrogen storage technologies.

Potential of Growing Energy Crops and Then Producing Liquid Fuels in Marginal Land: A China Scenario

To explore the potential of growing energy crops and then producing liquid fuels in marginal land in China, in this paper, the status quo of existing biomass resources and marginal land utilization in China have been first analyzed and the development process of biomass liquid fuels has then been reviewed. Secondly, using ethyl levulinate (EL) as our research subject, the production capacity of growing energy crops in marginal land and their potential to prepare liquid fuels have been explored. Finally, the problems in developing marginal land have been summarized, and proposed policy recommendations for marginal land development, energy crop cultivation, and liquid fuel development suitable for Chinese conditions. The results showed that the potential of sweet sorghum, cassava, jatropha curcas, and switchgrass cultivation in China in producing is 75.76 million tonnes, 1.52 million tonnes, 4.57 million tonnes, and 5.16 million tonnes, respectively. Among these crops, sweet sorghum and switch grass have a higher production capacity and are more suitable to be planted on marginal land and used to produce liquid fuels. The planting of these two crops has absorbed about a 111.11 million tonnes and 7.57 million tonnes of carbon dioxide (CO2), respectively, presenting significant carbon sequestration and oxygen-producing effects, which provides a theoretical basis for the analysis of land use change.

Study of circulating liquid fuel in a 1D critical system with thermal feedback

This research focuses on the description and modeling of a one-dimensional molten salt reactor (MSR), in the presence of thermal feedback. Following the example of previous works, a simple one-dimensional system is proposed, describing a molten salt reactor with a main neutron-multiplying zone called core and a recirculation loop where the salt cools down. Specific attention is paid to the precursors’ drift by modifying the neutron balance equation. Liquid nuclear fuels are characterized by a high volumetric expansion coefficient in comparison to customary solid fuels. Therefore, a strong coupling between neutronics and thermal-hydraulics is expected. As a consequence, a highly negative density coefficient characterizes the thermal feedback on the neutron reactivity. The precursor equation is here inverted analytically and combined with the neutron balance equation to obtain a generalized eigenvalue problem with the neutron flux distribution as the unknown. The balance equations are derived by finite volume integration over a discretized mesh, and the coupling between the two physical models is treated by Picard iterations. The numerical solution is finally extended to time-dependent calculations and compared to an analytical work for a one-dimensional circulating fuel reactor already existing in the literature.

The Influence of Natural Bayah Zeolite on the Pyrolysis Process of Liquid Fuel Based on HDPE and PP Plastic Waste

The Influence of Natural Bayah Zeolite on the Pyrolysis Process of Liquid Fuel Based on HDPE and PP Plastic Waste

The Food, Energy, and Water Nexus through the Lens of Electric Vehicle Adoption and Ethanol Consumption in the United States

The US produces a large share of global biofuels but is unique in using a relatively inefficient biofuel pathway involving corn (maize) for ethanol production. The Renewable Fuel Standards that enshrine this feedstock were intended as a greenhouse gas emissions reduction measure but have had the effect of coupling the food, energy, and, to a lesser extent, water systems. This paper looks at the food–energy–water (FEW) nexus as exemplified by the growth in corn agriculture for internal combustion engine vehicle fuel and how that will likely change as vehicle electrification proceeds and accelerates. Starting with scenarios in which there is a rapid uptake in electric vehicles by 2030 and beyond, we examine the implications for the switch from liquid fuels for transportation in the United States toward electric vehicles (EVs). We find that scenarios in which EV penetration grows rapidly will clearly decrease demand for corn ethanol. Our analysis shows that, with judicious planning, the decrease in corn ethanol demand can have potential positive co-benefits. These co-benefits include reducing stressors on depleting aquifers and nutrient runoff to waterways. Substituting a small fraction of displaced industrial corn–ethanol cropland with large-scale solar photovoltaic (PV) capacity can supply a large fraction of the additional electricity needed for EVs. Finally, solar PV generation can ameliorate or even increase income and create more jobs than those lost to the decreased ethanol demand.

Direct Liquid Fuel Cell Using Cyclohexanol as Regenerative Fuel for Emission-Free Energy Generation

Direct Liquid Fuel Cell Using Cyclohexanol as Regenerative Fuel for Emission-Free Energy Generation

SIMULATION OF LIQUID FUEL SPRAY FORMATION AND DISTRIBUTION IN A REACTING TURBULENT FLOW

The paper presentsthe computational experiments of the liquid fuels spray and its droplets distribution in a turbulent reacting flow. Primary and secondary atomization of two types of liquid fuel droplets (isooctane and dodecane) in the presence of combustion was described by the equations of continuity, momentum, internal energy, concentration of components of reacting substances and a two-parameter model for calculating turbulent flow. The study results of the spray, dispersion and combustion of droplets of hydrocarbon liquid fuels in a model combustion chamber when changing the injector injection angle were obtained. The injection angle values varied from 2 to 10 degrees. Based on the computational experiment temperature profiles and concentration characteristics of combustion products and gas in the combustion chamber at various times were obtained. Numerical calculations of the droplets’ Sauter mean diameter distributions have the same dispersion pattern for dodecane. This suggests that the accuracy and adequacy of developed complex model of the formation and distribution of spray in a reacting flow has been confirmed by its strong correlation and good agreement of the modeling results with experimental data from other researchers. This kind of modeling methods and the obtained computational experiments results from them are widely used not only in traditional thermal power engineering, but also in the study of technological processes in the new generation engines chambers, combustion of alternative types of fuels and optimization of their combustion.

Recent Progress in the Conversion of Methylfuran into Value-Added Chemicals and Fuels.

2-methylfuran is a significant organic chemical raw material which can be produced by hydrolysis, dehydration, and selective hydrogenation of biomass hemicellulose. 2-methylfuran can be converted into value-added chemicals and liquid fuels. This article reviews the latest progress in the synthesis of liquid fuel precursors through hydroxyalkylation/alkylation reactions of 2-methylfuran and biomass-derived carbonyl compounds in recent years. 2-methylfuran reacts with olefins through Diels-Alder reactions to produce chemicals, and 2-methylfuran reacts with anhydrides (or carboxylic acids) to produce acylated products. In the future application of 2-methylfuran, developing high value-added chemicals and high-density liquid fuels are two good research directions.

Comprehensive study of alkali lignin pyrolysis catalyzed by composite metal-modified molecular sieves for the preparation of hydrocarbon liquid fuels

Catalytic lignin pyrolysis for hydrocarbon liquid fuel production offers a viable alternative to fossil fuels. This study investigated the effects of transition metal (Fe, Co, Ni, Cu) modified composite molecular sieve catalysts on the pyrolysis product distribution and behavior of alkali lignin (AL). AL pyrolysis achieved the highest liquid product yield of 24.50 % at 600 °C, with high temperatures favoring hydrocarbon product formation. Volatile gaseous products from AL pyrolysis included H2, CO, CO2, phenolic compounds, heteroatomic compounds, and hydrocarbons. Molecular sieve catalyst additions were all favorable to the increase in hydrocarbon content. Compared with ZSM-5 and SBA-15, catalysts processed through acid etching and metal modification exhibited optimized pore structure, acid site distribution, and catalytic performance. Metal-modified composite molecular sieve catalysts (FeZS, CoZS, NiZS, and CuZS) generated more liquid products and promoted hydrocarbon formation. Notably, Cu-modified ZS catalysts exhibited superior acid site distribution and specific surface area, considerably reducing oxygenated compounds in the products. A higher catalyst-to-feedstock ratio increased the number of catalytically active sites, facilitating the cracking and deoxygenation of oxygenated components and generating more hydrocarbon products. The highest hydrocarbon yield for AL with a catalyst-to-biomass ratio of 10:1 under CuZS was 92.25 %, with 66.07 % being monocyclic aromatic hydrocarbons (MAHs) and 61.72 % benzene, toluene, ethylbenzene, and xylenes (BTEX). Additionally, kinetic and thermodynamic analyses revealed a substantial decrease in the average activation energy (Eα) of AL and a reduction in entropy value with the CuZS catalyst, indicating enhanced pyrolytic reactivity of AL. Therefore, the proposed method is highly effective for producing highly selective hydrocarbons through catalytic pyrolysis of AL.

The Biosynthesis of Liquid Fuels and Other Value-Added Products Based on Waste Glycerol—A Comprehensive Review and Bibliometric Analysis

The Biosynthesis of Liquid Fuels and Other Value-Added Products Based on Waste Glycerol—A Comprehensive Review and Bibliometric Analysis

Lattice distortion and elemental synergy in platinum-based high-entropy alloy boosts liquid fuels electrooxidation

Addressing the pivotal challenge of lattice distortion and electronic structure modulation in High-Entropy Alloys (HEAs) for electrochemical catalysis, this investigation presents the synthesis of a novel PtRhNiCoFeGaW HEA in a three-dimensional nanoflower configuration. This design strategically combines enhanced morphological features and a synergistic metallic interaction, propelling the catalytic efficiency forward in methanol and formic acid oxidation reactions (MOR and FAOR). The synthesized HEA nanoflowers exhibit superior mass and specific activities of up to 1.34 mA μgPt−1 and 4.43 mA cm−2 for MOR, alongside 0.52 mA μgPt−1 and 1.74 mA cm−2 for FAOR, markedly surpassing those of conventional Pt/C and PtRhNi NFs. This leap in performance is primarily attributed to the intricate elemental synergy within the HEAs, which effectively minimizes CO poisoning (a notorious catalyst deactivator) by improving CO* resistance. Furthermore, the study delineates how the unique nanoflower morphology contributes to exposing a plethora of active sites, thereby maximizing catalytic action. This research not only navigates through the complexities of crafting multi-elemental catalytic systems but also establishes a foundational strategy for developing next-generation HEA-based electrocatalysts, poised to significantly impact future advancements in energy conversion technologies.

Prediction of the influence of pressure on flash points of liquid fuels at sub-atmospheric pressure

Aircraft fuel tanks experience sub-atmospheric pressure during flight, and so do fuels during storage and transportation at high altitudes. Additionally, chemical processes commonly operate at non-atmospheric pressure. Flash points measured at sub-atmospheric pressure are lower than those measured at the standard atmospheric pressure of 101.3 kPa, signifying that ignitable liquids at sub-atmospheric pressure are more hazardous than those at 101.3 kPa. This study developed a model for predicting the influence of pressure on flash points on the basis of basic thermodynamic characteristics; this model was validated against experimental data obtained from the literature for six single-component and multiple-component liquid fuels at sub-atmospheric pressure. The proposed model effectively predicts closed-cup flash points, with small deviations in the range 0.18 °C–1.25 °C. However, because the model's assumption of vapor–liquid equilibrium was violated in the experiments, the predicted open-cup flash points did not agree well with their experimental counterparts, with the deviations in the range 1.11 °C–12.55 °C. Nevertheless, the trends predicted by the model agreed with those in the experimental data. Furthermore, standard flash point test method (such as ASTM D56-22, ASTMD93-20, and ASTMD7094-17) are based on a linear formula for correcting flash points measured at pressures other than 101.3 kPa. When the ambient pressure is approximately 101.3 kPa during flash point testing, the slope value of the correction formula should be changed from 0.25 to 0.20.

Comparative Study of Thermodynamic Performances: Ammonia vs. Methanol SOFC for Marine Vessels

AbstractIn response to escalating environmental concerns and the imperative to institute effective energy management strategies, the pursuit of alternative fuels has emerged as a pivotal endeavor for realizing sustainable energy solutions. Methanol and ammonia have surfaced as particularly promising and environmentally friendly liquid fuels, holding significant potential for aiding in the attainment of decarbonization objectives and addressing global energy requirements. This research proposes and scrutinizes a sophisticated cogeneration system integrating solid oxide fuel cells (SOFCs), gas turbine (GT), steam Rankine cycle, and organic Rankine cycle. Direct utilization of ammonia and methanol as fuel in this intricate system is examined, with the design and modeling facilitated through the utilization of Aspen HYSYS V.12.1. The thermodynamic performance of the proposed system is rigorously assessed by employing the foundational principles of the first and second laws of thermodynamics. The direct SOFCs fueled by ammonia and methanol exhibit notable energy efficiencies of 64.25 % and 58.42 %, respectively. Remarkably, the amalgamated systems showcase heightened energy efficiencies, witnessing a commendable increase of 12.64 % and 10.66 % when powered by ammonia and methanol, respectively, as compared to individual SOFC systems. Examination of exergy destruction reveals the SOFC as the principal contributor, with electrochemical and chemical processes constituting the primary sources of irreversibility. Additionally, explicit values for exergy destruction in the GT, afterburner, and heat exchanger components are provided. A comprehensive parametric study underscores the pivotal role of the fuel utilization factor (Uf), identifying a value of 0.85 as optimal and significantly augmenting the thermodynamic efficiency of the system. This analysis not only substantiates the potential of ammonia and methanol as effective carriers for hydrogen but also underscores the efficacy of waste heat recovery as a viable strategy for enhancing the overall thermodynamic performance of an SOFC system. The findings presented herein contribute valuable insights, paving the way for the strategic utilization of alternative fuels and cogeneration systems in the broader context of sustainable and environmentally conscious energy solutions.

Descriptors-based machine-learning prediction of cetane number using quantitative structure–property relationship

The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.

The impact of a zero-flaring system on gas plants, environment, and health

Continuous natural gas flaring wastes significant energy resources and increases greenhouse gas emissions, contributing to global warming. Our work provides an overview of a technique to recover flare gas and reduce CO2 emissions to a minimum level. There are two methods to recover flare gas: the recovery of natural gas liquids and sales gas production by existing LPG unit and the production of liquid fuels by mini-GTL unit (gas to liquid). This study was conducted using real data from the field. All cases were simulated using Aspen HYSYS software. The mini-GTL unit is modeled using an autothermal reforming method. CO2 emissions will be reduced by 107.68 tonne/day in both methods. Economic analyses revealed that the NGL and sales gas product has a net present value (NPV) of 77.03 MMUSD, while the mini-GTL product has an NPV of 73.7 MMUSD. The study showed that we could extract natural gas liquids (NGLs), including propane, LPG, and sales gas, from the flare gas or convert it to liquid products, including gasoline and diesel. The expected internal rate of return (IRR) and payout time (POT) for NGL and sales gas method are 150.73% and 0.27 years, respectively. The mini-GTL method is recommended due to Egypt’s petroleum fuel shortage and the best solution without an entry point to the Egyptian national gas grid in the plant. However, the IRR and POT for the mini-GTL method are 30.09% and 1.19 years, respectively, and it needs more CAPEX than the NGL and sales gas method.Graphical