Renewable Fuels Research Articles

Fueling the future of clean energy with self‐supported layered double hydroxides‐based electrocatalysts: A step toward sustainability

AbstractAmid the ongoing transition toward renewable fuels, the self‐supported layered double hydroxides (LDHs) are envisioned as propitious electrocatalysts for reinvigorating the electrocatalysis realm, thereby facilitating environmental remediation and bolstering sustainable global energy security. Exploiting appealing attributes such as unique lamellar structure, abundant active sites, tunable intercalation spacing and compositional flexibility, LDHs boast remarkable activity, selectivity and stability across diverse energy‐related applications. By virtue of addressing the technological and time prominence of excavating their renaissance, this review first encompasses the facile state‐of‐the‐art synthetic approaches alongside intriguing modification strategies, toward deciphering the authentic structure–performance correlations for advancing more robust and precise catalyst design. Aside from this, heterostructure engineering employing diversified ranges of coupling materials is highlighted, to construct ground‐breaking binder‐free LDHs‐based heterostructures endowing with unprecedented activity and stability. Subsequently, the milestone gained from experimental research and theoretical modeling of this frontier in multifarious electrocatalytic applications, including HER, OER, UOR, AOR, seawater splitting and other fundamental conversion reactions is rigorously unveiled. As a final note, a brief conclusion is presented with an outline of future prospects. Essentially, this review aspires to offer enlightenment and incite wise inspiration for the future evolution of innovative and resilient next‐generation catalysts.image

Efficient Production of Platform Chemicals from Lignocellulosic Biomass by Using Nanocatalysts: A Review

This paper discusses significant advancements in using lignocellulosic biomass for the sustainable production of biofuels and chemicals. As fossil-based resources decline and environmental concerns rise, the paper emphasizes the role of integrated biorefineries in producing renewable liquid fuels and high-value chemicals from biomass. It highlights exploring various green pathways for biomass conversion, with a particular focus on nanocatalysis. Due to their large surface area-to-volume ratio, nanocatalysts provide enhanced catalytic activity and efficiency in biomass transformation processes. The review delves into the synthesis of value-added and furfural platform chemicals alongside the hydrogenolysis of 5-hydroxymethylfurfural (5-HMF) into biofuels like 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF). The paper ultimately underscores the importance of nanotechnology in achieving high yield and selectivity in the biomass conversion process, positioning it as a promising approach for future sustainable energy and chemical production.

Synthesis and Properties of Nickel Copper Phosphorus (NixCuyPz) Catalyst

Nowadays, scientists around the world are paying more attention to renewable hydrogen fuels. There is a growing need for precious metal catalysts to calculate the cost of obtaining renewable energy, an efficient method of producing H2 by electrolysis of water, as well as to facilitate the decomposition of water into its elemental parts. Today, due to the increase in the problem of the shortage of energy resources and the growing of CO2 emissions into the atmosphere, attention is being paid to hydrogen energy. However, the production of H2 requires low-cost, efficient catalysts that facilitate hydrogen/oxygen separation reactions in the water splitting. For this purpose, intermediate metal phosphides (Fe, Co, Ni, Cu, Mo, W) were used as effective electrocatalysts for water decomposition. The catalytic activity of intermediate metal phosphides to form hydrogen is largely dependent on the phosphorus content, but the P atoms play an important role in increasing efficiency. The production of hydrogen by electrolysis of water on the basis of bifunctional catalysts has good prospects for use in the energy industry. In the article, the one-step hydrothermal synthesis method and physico-chemical (electronic structure and conductivity, structure morphology) of double metal phosphide with NixCuyPz composition were studied.

FISH PRODUCTION AND THE POTENTIAL OF TILAPIA PRODUCTION IN BRAZIL AND IN THE WORLD: A SYSTEMATIC REVIEW OF ITS USE AS ENERGY AND FOOD

The need for new sources of renewable energy is something that is widely studied today. In several countries, the search for new sources of raw materials for biodiesel production is being evaluated and used. Among these sources is the use of animal fat waste. In this context, the use of fish waste is being evaluated and applied as an intensive source in the production of biodiesel. However, the development of technologies that can make the extraction of these fats viable is still a determining factor in the full use of these wastes. This study presents a review of the production of Nile Tilapia, farmed in captivity, as well as its use in the production of and application in the biodiesel production chain. This work, because it is a review of the potential for the use of waste, used a systematic assessment of the collection of studies, market assessments, and government agencies, which made it possible to obtain data on production and waste generation. For this purpose, searches were carried out on journal platforms and websites that involve the fish production chain. Thus, the verification of this new source of biomass in energy generation becomes viable for the development of new technologies that can add value to waste and reduce the environmental impacts caused by fish farming. The study indicates that there is a significant opportunity in the use of fish waste for the production of renewable fuels, specifically those that have a high lipid content, and their use for the production of biodiesel is possible.

Effect of dilution and Lewis number of the fuel in the fuel-air mixture on the heat flux during flame wall interaction (FWI)

Most combustion systems where flame is bounded by walls encounter Flame-wall interactions (FWI). Heat losses during FWI are in the magnitude of MW/m2 leading to concern about inefficiency, and thermal stresses. Hence, FWI is a topic of significant interest. With the goals of climate change pushing us toward renewable fuels with least carbon emissions, it is imperative to understand the FWI of renewable fuels like hydrogen-air mixture. In this study, FWI in a head-on-quenching configuration is carried out in a constant volume chamber. High-speed surface temperature measurement is carried out to compute instantaneous wall heat flux. Adding inert diluents to methane-air mixtures, the effect of dilution on the peak of heat flux during FWI is studied. Dilution affects the peak of heat flux predominantly by changing the adiabatic flame power of the fuel-air mixture. Furthermore, a large variation in flame power is carried out by changing the dilution fraction in the methane-air mixture to quantify its effect. It is found that the peak of heat flux and non-dimensional heat flux follows a nonlinear decrease with an increase in flame power. Knowing this effect, FWI of three different fuels, that is, methane, hydrogen, and a mixture of acetylene and hydrogen, having different Lewis numbers ( Le) of fuel in a fuel-oxidizer mixture are studied at equivalent flame power. This comparison shows that FWI of hydrogen-air mixtures in HOQ configuration have a lower peak of heat flux compared to other fuels which may be due to the preferential diffusion of hydrogen-air mixture.

Comparative Analysis of Performance and Exhaust Emissions from Jet A1 Blends with Various Aviation Biofuels

The aviation industry is a significant contributor to greenhouse gas emissions. Given the growing demand for air travel and the unsustainable use of fossil fuels, it is crucial to develop and commercialize renewable fuels to reduce these emissions. Conventional jet fuels like Jet A1 release harmful pollutants such as carbon monoxide (CO) and nitrogen oxides (NOx) into the atmosphere. In contrast, biofuels offer a renewable, biodegradable, and non-toxic alternative that emits fewer pollutants, excluding NOx, and is easier to treat than fossil fuels. Due to their eco-friendly characteristics, biofuels have garnered attention in recent years. This study focuses on producing biofuels from jatropha oil and waste cooking oil. Jatropha oil, aside from its medicinal benefits such as antimicrobial and anticancer properties, can be effectively used in industrial applications, particularly for biofuel production. The production of biofuels from jatropha and waste cooking oil is of growing interest due to their environmental and economic benefits. The study investigates the production of these biofuels using appropriate catalysts under controlled experimental conditions, followed by blending the biofuels with Jet A1 fuel to achieve similar engine performance while mitigating the environmental impact of greenhouse gases from petroleum-based fuels.

Enhancing biodiesel engine performance and emission reduction using Fe and Zn coated zeolite catalytic converters

ABSTRACT This study evaluates the performance and emission characteristics of diesel, fish biodiesel (comprising 20% fish oil and 80% diesel), and fish biodiesel using Fe and Zn-coated zeolite catalytic converters. The research aims to mitigate environmental challenges associated with diesel engines by exploring the efficacy of metal-doped zeolite catalysts in reducing harmful emissions. Fish biodiesel was derived from fish waste via transesterification and tested in a single-cylinder diesel engine. Key performance metrics, including Brake Specific Fuel Consumption, Brake Thermal Efficiency, Exhaust Gas Temperature, cylinder pressure, Heat Release Rate, and ignition delay, were measured. Emission characteristics such as carbon monoxide, hydrocarbon, nitrogen oxide, and smoke opacity were also analyzed. Results showed diesel had the lowest Specific fuel consumption, ranging from 730 g/kWh at 25% load to 320 g/kWh at full load. Fish biodiesel exhibited higher Specific fuel consumption, from 770 g/kWh to 350 g/kWh. Regarding emissions, the NOx of the biodiesel increased significantly compared to diesel; the use of a catalytic converter has reduced the NOx emission to a maximum extent of 37.5% at full load for a Fe-coated converter. The Zn-coated converter also improved emissions by up to 33% for NO but was slightly less effective than the Fe-coated converter. The study concludes that Fe-coated zeolite catalytic converters significantly enhance biodiesel-fueled diesel engines’ performance and emission characteristics. Both catalytic converters reduced the smoke emission significantly. These findings highlight the potential for developing more efficient and eco-friendly emission control technologies and promoting using renewable transportation fuels.

Synthetic natural gas (SNG) production by biomass gasification with CO2 capture: Techno-economic and life cycle analysis (LCA)

The integration of renewables with CCUS technologies has the promising potential to deliver energy applications with overall negative CO2 emissions which would significantly contribute to the climate neutrality. Moreover, the renewable-based synthetic fuels are predicted to replace the conventional fossil fuels. The current work evaluates key techno-economic and environmental indicators for the SNG production from various renewable fuels (e.g., sawdust, residual wood, organic wastes, agricultural and urban wastes etc.) through gasification process fitted with decarbonization capability. The investigated plant capacity was set to 500 MWth SNG with 60 % CO2 capture rate of primary fuel (biomass). The overall concept was evaluated using various process engineering approaches e.g., reactor & process modelling and simulation, model validation, heat and power analysis, techno-economic assessment combined with detailed environmental impact by Life Cycle Analysis (LCA). The investigated design shows promising performance indicators such as high cumulative energy efficiency (69 %) and carbon conversion to SNG, almost zero plant specific CO2 emissions (3 kg/MWh) and overall negative carbon emissions (−457 kg/MWh) from the whole biomass chain. The SNG production cost is not yet fully competitive versus the EU natural gas prices (53 vs. 30–35 €/MWh) but it shows promising potential considering the trends of increasing fossil prices and CO2 emission tax.

Interface Synergy of Exposed Oxygen Vacancy and Pd Lewis Acid Sites Enabling Superior Cooperative Photoredox Synthesis.

Photo-driven cross-coupling of o-arylenediamines and alcohols has emerged as an alternative for the synthesis of bio-active benzimidazoles. However, tackling the key problem related to efficient adsorption and activation of both coupling partners over photocatalysts towards activity enhancement remains a challenge. Here, we demonstrate an efficient interface synergy strategy by coupling exposed oxygen vacancies (VO) and Pd Lewis acid sites for benzimidazole and hydrogen (H2) coproduction over Pd-loaded TiO2 nanospheres with the highest photoredox activity compared to previous works so far. The results show that the introduction of VO optimizes the energy band structure and supplies coordinatively unsaturated sites for adsorbing and activating ethanol molecules, affording acetaldehyde active intermediates. Pd acts as a Lewis acid site, enhancing the adsorption of alkaline amine molecules via Lewis acid-base pair interactions and driving the condensation process. Furthermore, VO and Pd synergistically promote interfacial charge transfer and separation. This work offers new insightful guidance for the rational design of semiconductor-based photocatalysts with interface synergy at the molecular level towards the high-performance coproduction of renewable fuels and value-added feedstocks.

Numerical Modeling of the Fluids Petroleum Flow Through the Supersonic Separator

In the context of increasing concerns regarding the amplification of the thermal effects of climate change, the Council of the European Union has proposed the reduction (up to the elimination) of the use of fossil fuels. For this purpose, the implementation of new ecological (renewable) fuels is being analyzed to reduce the carbon dioxide footprint, natural gas being the transition fuel. Also, in the next period, an increase in the demand for methane, the exploitation of condensate deposits, those with natural gas mixed with acid gases (containing hydrogen sulfide, carbon dioxide, and nitrogen), as well as oil deposits with associated natural gas, which will require their treatment (to eliminate saline or non-saline water, mechanical impurities, of condensate and acid gases). At the same time, the exploitation of offshore deposits in deep waters will be emphasized, which will lead to the location of treatment equipment on the seabed. The present work discusses the simulation of natural gas treatment processes, focusing on the separation from methane (in the supersonic field) of water, condensate, and acid gases.

Effects of Diesel Pre-Injection Time on Combustion Process and Emission Characteristics of Diesel/Methanol Dual Fuel Engine

ABSTRACT The traditional diesel engine not only causes the reduction of nonrenewable energy but also aggravates environmental pollution. The utilization of renewable fuels in engine can not only effectively reduce the dependence on oil sources but also effectively reduce emissions. As a renewable oxygen-containing fuel with low production cost and widely sourced, methanol holds vast potential for application in engine. The dual-fuel combustion of diesel and methanol has emerged as an important research issue in the internal combustion engine industry. This paper conducted a study on the combustion and emission characteristics of the diesel/methanol dual fuel based on the optical engine test platform and 3D numerical simulation software. The results show that the change in cylinder pressure is relatively small and the heat release rate increases with the advance of diesel pre-injection time. The pre-injection time of diesel mainly affects the mixture distribution of pre-injection diesel, and the mixture is more evenly mixed with the advance of the pre-injection time. The degree of premixed combustion becomes higher, premixed combustion will lead to more rapid combustion, so the peak heat release rate shows an increasing trend. The pre-injection time of diesel is advanced, resulting in a leaner mixture in the early stage, and the fuel is not easy to burn, so CA10 and CA50 are delayed. The soot formation decreases as the mixture becomes more uniform, and the number of pixels of KL factor in each range also decreases. The average temperature in the cylinder is reduced and the NOX shows a decreasing trend with the advance of the pre-injection time. The change in CO generation is relatively small with the advance of pre-injection time.

The Toxic Effects of Petroleum Diesel, Biodiesel, and Renewable Diesel Exhaust Particles on Human Alveolar Epithelial Cells.

The use of alternative diesel fuels has increased due to the demand for renewable energy sources. There is limited knowledge regarding the potential health effects caused by exhaust emissions from biodiesel- and renewable diesel-fueled engines. This study investigates the toxic effects of particulate matter (PM) emissions from a diesel engine powered by conventional petroleum diesel fuel (SD10) and two biodiesel and renewable diesel fuels in vitro. The fuels used were rapeseed methyl ester (RME), soy methyl ester (SME), and Hydrogenated Vegetable Oil (HVO), either pure or as 50% blends with SD10. Additionally, a 5% RME blend was also used. The highest concentration of polycyclic aromatic hydrocarbon emissions and elemental carbon (EC) was found in conventional diesel and the 5% RME blend. HVO PM samples also exhibited a high amount of EC. A dose-dependent genotoxic response was detected with PM from SD10, pure SME, and RME as well as their blends. Reactive oxygen species levels were several times higher in cells exposed to PM from SD10, pure HVO, and especially the 5% RME blend. Apoptotic cell death was observed in cells exposed to PM from SD10, 5% RME blend, the 50% SME blend, and HVO samples. In conclusion, all diesel PM samples, including biodiesel and renewable diesel fuels, exhibited toxicity.

A comparative study on combustion characteristics of PPC and RCCI combustion modes in an optical engine with renewable fuels

Application of renewable fuels in compression ignition engines provides one solution to reduce greenhouse gas emission in heavy-duty transportation sector. However, it is a big challenge to find a single alternative fuel to replace the traditional diesel under full load conditions. In this study, the combustion characteristics of two kinds of renewable fuels with different reactivity, namely methanol and hydrogenated catalytic biodiesel (HCB), were investigated in an optical engine under partially premixed combustion (PPC) and reactivity-controlled compression ignition (RCCI) modes, respectively. A two-color (2C) method was employed to quantify the in-flame soot formation. Meanwhile, the flame oscillation phenomenon was captured and evaluated. The results indicate that the RCCI mode exhibits reduced peak cylinder pressure, resulting in smoother and more stable combustion compared to that of the PPC mode. Moreover, the more uniform fuel distribution in the RCCI mode further decreases soot formation from the blended fuel. Additionally, with increasing methanol proportion, the rise in oxygen content within the blended fuel significantly reduces soot formation. The flame oscillations are primarily related to the rate of cylinder pressure variation. Under PPC mode, multi-point autoignition causes a rapid increase in cylinder pressure, leading to larger oscillation amplitudes (M15: 0.268, M25: 0.772). Conversely, under the RCCI mode, the heat release process is more stable, resulting in weaken oscillations (M15: 0.161, M25: 0.064) compared to that of PPC.

Thermal and emission analysis of waste plastic and microalgae biodiesel as a potential power source for diesel engines: A sustainable approach.

The future of diesel engines is greatly influenced by ongoing research on alternative fuels. Renewable fuels have been researched and adopted by several nations to encourage the production and use of biodiesel. This study examines the energy conversion of waste plastic biodiesel and Spirulina microalgae biodiesel at a 20% blending ratio to analyze the behavior of a one-cylinder, 4-stroke diesel engine running at 1500rpm with a compression ratio of 17.5. The authors evaluated, analyzed, and compared the engine's combustion, performance, and emission at an incremental engine load of 25% from 25 to 100%. The findings demonstrated that the biodiesel fuel samples generated somewhat poorer efficiency but reduced emissions from the engine. At 100% load, the percentage differences between the diesel and blended fuel samplesranged from 2.4 to 7.3% for BTE, 2.9 to 16.5% for BSFC, and 1.0 to 4.62% for BSEC; however, the PM, SO2, and CO2 emissions were reduced by 1.6-28.8% except for NOx emissions, which are increased by up to 9.4%. Pure diesel exhibits the best performance characteristics; however, pure biodiesel exhibits the best emission characteristics. The 20% blended fuels showed promising results, as they exhibited comparable or slightly improved BTE values compared to their respective pure biodiesel fuels. The findings indicate that Spirulina microalgae biodiesel and waste plastic biodiesel have the potential to be utilized as substitute fuels for diesel engines; however, for the greatest performance and lowest emissions, their blending ratios and engine operating conditions must be optimized.

Application of acetylene in multi-cylinder low heat rejection diesel engine fueled with ternary blend

The depletion of fossil fuels and environmental degradation have driven researchers worldwide to seek suitable alternative fuels for diesel engines. Internal combustion engines typically emit carbon monoxide (CO), hydrocarbon (HC), and smoke, contributing to environmental pollution. To address this issue, petroleum fuels can be substituted with alternative options like acetylene gas, hydrogen, CNG, or LPG. One effective strategy is to incorporate renewable fuels into diesel engines by partially or fully replacing diesel in a dual fuel mode (DFM). This research focuses on alternative renewable fuels for diesel engines like biodiesel and alcohol and its blends. The current research investigates the engine characteristics of diesel engines fueled with ternary blend (TB) fuel and different flow rates of acetylene in DFM. TB fuel was prepared using 70 % diesel, 20 % waste cooking oil biodiesel (WCOB), and 10 % methanol by volume. The induction of acetylene at different flow rates, such as 2, 4, and 6 lpm. Waste cooking oil is used to prepare biodiesel by transesterification. Partially stabilized zirconia (PSZ) is used to coat the cylinder head, piston crown, inlet, and exhaust valves with a thickness of 0.5 mm. The HC, CO, and smoke emissions are decreased by about 35.7 %, 29.8 %, and 21.6 %, respectively, for TB fuel with acetylene at 6 lpm at full load condition. The high calorific value of acetylene gas raised the in-cylinder temperature, significantly accelerating the combustion process. The heat release rate (HRR) and cylinder pressure are increased by 9.8 % and 6.8 %, respectively, at TB fuel with 6 lpm of acetylene induction. Acetylene induces rapid fuel combustion, resulting in increased energy transfer. The brake thermal efficiency (BTE) is improved by about 10.3 % for TB fuel with acetylene at 6 lpm and exhaust gas temperature (EGT) increased to 461oC at full load condition.

Integrating environmental remediation with biodiesel production from toxic non-edible oil seeds (Croton bonplandianus) using a sustainable phyto-nano catalyst

In the current situation of the environmental uprising toxicology, rising global temperature, and energy-depleting urges to explore and discover more renewable and greener ecological-benefiting energy resources. Biobased renewable fuels generated by using waste products can help in waste management, climate change mitigation, and a low-carbon future. The main objective of this research is to produce environment-friendly and cost-effective biofuel. The potentiality of the novel, toxic, waste, and inedible feedstock Croton bonplandianus was evaluated for biodiesel synthesis through transesterification utilizing a Phyto-nano catalyst of potassium oxide prepared by Croton bonplandianus floral stalk's aqueous extract focusing on waste management. Phyto-nano catalyst characterization was done through innovative tools such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Zeta Potential (ZP), X-Ray Diffraction (XRD), Fourier Transformed Infrared spectroscopy (FTIR), and Diffuse Reflectance Spectroscopy (DRS). The characterization results revealed that the potassium oxide phyto-nanocatalyst possesses an average nanoparticle size of 44.5 nm. This size is optimal for enhanced catalytic activity, indicating significant potential for efficient catalysis. The highest yield (94 %) of biodiesel was secured at optimized reaction conditions of catalyst quantity (0.50 wt%), reaction time (180 min), methanol: oil ratio (9:1), and reaction thermal point (70 °C). Transformation of triglycerides to methyl esters was confirmed by GC/MS, NMR, and FTIR techniques. A total of 21 methyl esters were observed in Croton bonplandianus biodiesel confirmed via GC/MS results. Evaluation of fuel properties was done and matched with international fuel standards. The conclusive remarks for the conducted research are that Croton bonplandianus has a high potential for biodiesel production by applying Phyto-nanocatalysts of potassium oxide while dealing with hazardous environmental conditions and waste management. Phyto nanocatalyst of potassium oxide can be reused and gives the same yield after several cycles of reusability, this reusability of heterogenous Phyto nanocatalyst can reduce to total cost of biodiesel production and can contribute towards circular economy.

One techno-economic analysis to rule them all: Instant prediction of hydrothermal liquefaction economic performance with a machine learned analytic equation

Hydrothermal liquefaction (HTL) has remarkable potential for efficient conversion of abundant, decentralized organic wastes into renewable fuels. Because waste is a highly distributed resource with context-dependent economic viability, selection of optimal deployment sites is slowed by the need to develop detailed techno-economic analyses (TEA) for the thousands of potential deployment locations, each with their own unique combinates of scale, proximity to infrastructure/markets, and feedstock properties. An economic modeling framework that requires only easily obtainable inputs for assessing economic performance would therefore allow multiplexed analysis of many thousands of cases, whereas traditional TEA would not be possible for more than a handful of cases. Within such a context, the present study uses machine learning to guide development of a TEA and modeling framework which provides accurate cost predictions using three key inputs – feedstock cost, biocrude yield, and process scale – to estimate the minimum fuel selling price (MFSP) that an HTL process can achieve. The structure of the proposed framework is informed and based on empirical observations of cost projections made by a detailed TEA over a wide range of feedstock costs, biocrude yields, and process scales. A machine learning guided process was used to identify, train, and test a series of models using auto-generated data for training and independently reported data for testing. The most accurate model consists of three terms and requires 6 adjustable parameters to predict independently published values of MFSP (N = 28) to within an average value of ± 20.4%. It is demonstrated that the reduced-order model’s predictions fall within 40% of the corresponding published values 95% of the time, and in the worst case, the associated discrepancy is 45.9%, suggesting that the accuracy of the machine learned model is indeed comparable to the TEAs that were used to build it. Moreover, the terms in the model are physically interpretable, conferring greater reliability to the use of its predictions. The model can be used to predict the dependence of MSFP on biocrude yield, scale, and feedstock cost; interestingly, MFSP is insensitive to biocrude yield and/or scale under many situations of interest and identifying the critical value for a given application is crucial to optimizing economic performance. The proposed model can be also extended to evaluate economic performance of newly developed HTL-based processes, including catalytic HTL, and the methodological framework used in this study is deemed appropriate for the development of machine learned TEA models in cases of other similar waste-to-energy technologies.

Experimental study of combustion characteristics fuelled with biodiesel/diesel blends in high-pressure common rail electronically controlled diesel engines

Abstract Under the pressure of petroleum shortage and more stringent vehicle emission regulations at present, finding green and renewable alternative fuels has become an important research direction for the internal combustion engine. Due to the increment in oil imports, it is urgent to find a clean alternative fuel that will meet the diesel power and economic performance requirements. Biodiesel, with its renewable characteristics and wide resources, was considered, applied, and promoted extensively. The biodiesel studied in this paper is acidified oil biodiesel. The composition and ratio of acidified oil biodiesel were detected. The physicochemical indexes of acidified oil biodiesel/diesel fuel blends were measured and compared. In the electronically controlled high-pressure common rail diesel engine on different blending ratios of biodiesel/diesel fuel blends for a bench test, we analyze the combustion and characteristics. The results indicate that with the increasing biodiesel proportion, the peak of the premixed combustion and diffusion combustion in the cylinder increase, the combustion start point advances, the combustion duration shortens, and the maximum combustion temperature rises.

Comparative techno-economic assessment of renewable diesel production integrated with alternative hydrogen supply

The hydrodeoxygenation of triglycerides and fatty acids (HEFA) represents a well-established technological pathway for producing renewable drop-in fuels, such as renewable diesel, aviation fuel, or renewable light ends, like naphtha and LPG. A hydrogen supply is required, and the conventional method involves steam methane reforming (SMR) from natural gas. Both HEFA and SMR processes have been investigated in the literature separately. In this context, the goal of this work is to assess the hydrodeoxygenation process (HDO) of triglycerides/fatty acids integrated with hydrogen production. Two scenarios are compared by process simulation, equipment sizing, and economic analysis: one with traditional SMR (SC-A) and another with electrified SMR (SC–B), which is a recent alternative for hydrogen production with no natural gas. The HDO capacity was 6220 BPSD (38000 kg/h) of soybean oil, and the average yields for renewable diesel, naphtha, and LPG were 71.23 %-wt, 1.80 %-wt, and 5.87 %-wt, accordingly. Both scenarios were technical feasible and may be economically attractive. However, the grey hydrogen source was more profitable per its plant simplicity — although the CO2 taxation may impact its profitability.

Photocarrier relay modulating solar CO2-to-Syngas conversion

Solar-driven syngas generation by CO2 reduction provides a sustainable strategy to produce renewable fossil fuels. Nevertheless, this promising approach often suffers from tough CO2 activation, sluggish reaction kinetics and complex selectivity. Herein, we exquisitely constructed spatially directional charge transport channel over two-dimensional transition metal chalcogenide (TMC)-based heterostructure via a facile and universal electrostatic self-assembly method. Tailor-made positively charged non-conjugated insulating polymer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) and negatively charged graphene oxide (GO) precursor as building blocks are controllably anchored on the TMC substrate, by which ultrathin PDDA layer is intercalated at the interface of GO and TMC. We ascertain that, in this customized sandwiched heterostructures, PDDA interim layer functions as an electron-relaying mediator, whilst graphene (GR) obtained from in-situ GO reduction during the photocatalytic reaction serves as a terminal electron-trapping reservoir, synergistically facilitating the spatially vectorial charge separation/migration over TMC, thus endowing the TMC/PDDA/GR heterostructures with conspicuously enhanced visible-light-driven photoactivity toward CO2-to-syngas conversion. Our work would inspire judicious ideas for finely modulating charge transfer over polymer-mediated photosystems and benefit our fundamental understanding of solar CO2 conversion.