Hydrocarbons Research Articles

Innovative research on waste tire recycling for sustainable biofuel production: Assessment of its usability on multi-cylinder diesel engine employing constant injection of oxyhydrogen and biogas through a premixing device

This study investigates the production of waste tire pyrolyzed oil on a laboratory scale and its potential use as a fuel along with biogas and hydrogen in a variable-speed transportation engine. The pyrolyzed oil, obtained from waste tire pieces through a lab-scale plant, undergoes distillation and is blended with diesel fuel in a 20% ratio. This blended fuel is supplied to a multi-cylinder variable-speed transportation engine, either alongside biogas or HHO separately or both combined, at fixed flow rates with air passage through a premixing device (venturi). This study aimed to assess engine combustion characteristics such as in-cylinder pressure and heat release rate; performance parameters, including brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC), as well as emissions of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). The results indicate that using pyrolyzed oil in unmodified diesel engines reduces combustion characteristics and performancewhile increasing HC and NOx emissions and decreasing CO emissions. In addition, supplying biogas and the fuel mixture further deteriorates combustion and performance, while increases HC and CO emissions, and reduces NOx emissions. The focus of the present research is to evaluate the impact of adding green hydrogen (HHO) gas to a pyrolyzed oil fuel mixture and a biogas-led fuel mixture in a compression ignition (CI) engine. The results indicate that the addition of hydrogen enhances combustion characteristics, engine performance and reduces emissions, except for NOx. Specifically, there is an increase in cylinder peak pressure and HRR by around 6–10% range, improvement in BTE by 16–20% and BSFC by 5–7%, along with a decrease in HC and CO emissions by 13–16% and 11–13%, respectively. However, there is an increase in NOx emissions of 6–9%. In essence, the addition of green hydrogen enhances engine performance and reduces emissions in waste tire-derived pyrolyzed oil and biogas blends, indicating a viable path for sustainable transportation fuel.

Catalytic hydrodeoxygenation of lignin-derived phenolic compounds with Ni-based aluminum phosphate catalyst

Lignin-derived products possess high carbon content and offer significant potential to be used as liquid fuels. However, they also contain high oxygen element and unstable functional groups. Hydrodeoxygenation (HDO) is an effective method for upgrading lignin-derived phenolic compounds to produce high-quality liquid biofuels. In this study, a series of Ni-based phosphate catalysts incorporating various metals (Al, Ce, La) were prepared and employed for the HDO of lignin-derived phenolic compounds. The results showed that Ni/AlPO4 had the most efficient HDO performance, with guaiacol conversion of 99.9 % and cyclohexane selectivity of 91.1 % at the reaction temperature of 250 °C. Various catalyst characterization measurements were conducted to assess the impact of metal phosphate species on the crystallography, morphology, physicochemical characteristics and surface properties. Results indicated that Ni/AlPO4 catalyst exhibited stronger acidity, smaller Ni particle sizes and larger specific surface area than other Ni-based phosphate catalysts. Based on the characterization results and experimental data, the corresponding HDO reaction pathways and mechanisms were also proposed. Ni/AlPO4 catalyst was also applied to the HDO of various lignin-derived phenol compounds and achieved a good HDO effect. Moreover, the catalytic upgrading of lignin-oil was also carried out, and a high proportion of hydrocarbon products that increased from 16.0 % to 88.6 % was obtained. This Ni/AlPO4 catalyst provides potential reference for the HDO application of lignin-derived phenolic compounds for the production of hydrocarbon liquid fuels.

Enhancing ammonia decomposition in ammonium hydroxide/diesel emulsion through hybrid nanocomposite and optimization for improved and greener combustion

In this study, a hybrid nanocomposite was synthesized and characterized to intensify ammonia decomposition in ammonium hydroxide (AH) emulsified diesel fuel. The optimal concentrations of AH and zinc oxide/carbon nanotube (ZnO/CNT) nanocomposite in diesel fuel were evaluated using response surface methodology for effectual and greener combustion. The range of AH concentration was varied from 10 % to 30 %, and ZnO/CNT nanocomposite concentration ranged from 50 ppm to 150 ppm in diesel fuel. Validation experiments were performed to confirm the optimized parameters’ competence compared to regular diesel fuel (RDF). Fourier Transform Infrared and X-ray Diffraction analyses verified successful ZnO/CNT nanocomposite synthesis with desired structural and chemical properties. Optimization results indicated that an 17.2 % volume concentration of AH and 82.3 ppm of ZnO/CNT nanocomposite in RDF yielded efficient combustion with reduced emissions. Validation results showed that the inclusion of 17 % AH in RDF decreased engine brake thermal efficiency (BTE) by 11.1 % and increased brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) emissions by 11.3 %, 9.1 %, 9.9 %, and 3 %, respectively. Furthermore, the presence of the nanocomposite (82.3 ppm) enhanced BTE by 10.1 % and reduced BSFC, HC, CO, and NOx emissions by 6.9 %, 6.2 %, 6.9 %, and 5.9 %, respectively. The advancements in fuel additives, such as ZnO/CNT nanocomposites in AH emulsified diesel fuel, have the potential to create more fuel-efficient and cleaner diesel engines. These improvements can significantly contribute to sustainable energy solutions.

Evaluation of heavy hydrocarbon liquid in the Eastern Dahomey Basin, Southwestern Nigeria (case study of Agbabu Bitumen in Ondo State)

Solvent-aided dilution processes are often employed to recover bitumen by reducing its viscosity. In this study, methanol, toluene, and xylene were investigated as potential hydrocarbon solvents for solvent-aided hydrocarbon recovery of Agbabu bitumen. To achieve this, the solubility of the sample in the solvents was determined with a solubility test, its viscosity was measured with the Saybolt Furol Viscometer using the ASTM D88 method, and its SARA analysis was conducted using high-performance liquid chromatography. Agbabu bitumen was found to have a high content of saturates and aromatics. Viscosity decreases as pressure increases, while solubility reduces as temperature increases. The sample was most soluble in toluene, and its viscosity was reduced most in it, followed by xylene. Methanol reduced the saturates content and significantly raised the asphaltene content, keeping the mixture viscosity high. In terms of asphaltene stability of the mixtures, the bitumen-methanol system with the lowest colloidal instability index of 0.874 will give a mild asphaltene deposit issues compared with others that are unstable. This approach of combining multiple tests with the CII can accurately predict the behavior of Agbabu bitumen in solvents and enhance decision on the choice of bitumen recovery technology.

(Invited) Plasma Reforming of Liquid Hydrocarbons

Engineering systems that more sustainably use our natural resources is central to both reducing the risks associated with CO2 emissions and making the long-term transition to a more circular, sustainable, and electrified economy. In particular, developing electrically driven technologies to leverage the energy density of liquids to produce clean fuels, e.g., H2, without making CO2, could be game changing. Here, we investigate the potential of directly exciting plasmas in liquid hydrocarbons to create multi-phase reaction environments, i.e., environments where plasma (ionized gas), H2, gaseous and liquid hydrocarbons, and solid carbon are all present simultaneously, to produce H2, unsaturated C2s, and carbon. The ultimate target is direct transformation of liquid hydrocarbons to gaseous H2 and solid, easy-to-separate carbon using electricity that can be provided from any source and/or points of use.This talk will focus on our recent experiments to strike and sustain low and high frequency plasma discharges in liquid hydrocarbon jets to simultaneously generate gaseous H2, C2s, and solid carbon at high rates. Preliminary experiments show that (i) input energy is not wasted in simply vaporizing the liquid - so the system’s specific energy input preferentially drives hydrocarbon cracking; (ii) discharge drive frequency and plasma space time have a big effect on the H2 specific energy requirement (SER) and H2 generation rate, respectively; (iii) feedstock chemistry affects the H2 and C2 products observed; (iv) carbon particulates rapidly form in the liquid hydrocarbon, but they can be separated easily; and (v) the SER for H2 production is 25-30 kWhr/kg, roughly two times less than water electrolysis in practice (60 kWhr/kg). Hydrocarbon conversion, reaction rates, and characterization of the plasma (OES, high speed imaging), gas (MS), liquid (GC/MS), and solid phase (SEM, Raman) products as a function of plasma operating conditions (high and low AC drive frequency; liquid-plasma contact time) and hydrocarbon source will be discussed.

(Invited) Nanosecond Electrical Discharges in Liquids: Applications in the Synthesis of Nanoparticles, Including Nanoalloys

In recent decades, the field of nanotechnology has witnessed rapid growth, fueled by the exceptional physical, chemical, mechanical, and electrical properties of nanoscale materials. Nanomaterials have found applications across various domains, including catalysis, drug delivery, microelectronics, and more. Notably, plasma-based methods have emerged as promising avenues for nanomaterial synthesis, offering versatile approaches through both bottom-up and top-down techniques.One particularly innovative area of research is the plasma-liquid system, which has demonstrated remarkable efficiency in nanomaterial synthesis. This system involves the generation of plasma in a gas phase in contact with a liquid or directly within the liquid, sometimes aided by the introduction of bubbles. This communication has two goals: 1) present an overview of the physics of different discharge mechanisms, with a particular focus on the intriguing phenomena occurring at the interfaces, and 2) show different cases where nanomaterials of interest are produced. For instance, we will show that in-liquid spark discharges prouce nanoparticles through electrode erosion, and notably, the properties of these materials are highly sensitive to both the nature of the electrode and the composition of the liquid. In the second part, we introduce an innovative plasma-liquid system where a discharge can be produced at or close the interface of two immiscible liquids. In specific cases where the system is composed of a conductive solution (e.g. salty water) and a hydrocarbon liquid, spark discharges can be generated between a pin in liquid hydrocarbon and the surface of the conductive solution. This unique configuration facilitates therefore an interaction between a high-density plasma (generated in liquid) and a solution containing metal ions. At this stage, many reactions may occur and lead to the reduction of ions to produce nanomaterials. We found that the particles collected from hydrocarbon liquid are different from those collected from the solution, in terms of composition and size distribution. This finding suggests the triggering of different chemical reactions in each liquid, involving thus species with short- as well as long-lifetime species. Consequently, we adopted this approach to synthesize metal nanoparticles as well as binary and ternary nanoalloys, expanding the scope of possibilities in nanomaterial synthesis.

(Invited) Nanowire Catalysts and Adsorbents

The unique properties of nanowire materials like fast charge transport, short diffusion length, controlled surface sites and single crystal nature make them ideal for designing high performance catalysts, adsorbents and electrocatalysts by design. To realize any of these applications, one would need either large quantities of nanowire powders or nanowire arrays on large areas. In this presentation, we will highlight our group’s efforts with scalable methods for continuous manufacturing of nanowire powders and arrays for oxides1 and III-nitride materials.2 The process for producing metal oxide nanowires has been scaled up to ton-scale. The resulting nanowire powders can be used to formulate unique catalyst and adsorbent products.Zinc oxide nanowires alloyed with catalytically active metals and have been formulated into ultra-deep desulfurization catalytic adsorbents.3,4 These materials exhibited ultra-deep desulfurization with sulfur removal down to 1 ppm or below for liquid hydrocarbons (diesel, gasoline and naphthalene) and to less than 1 ppb for natural gas. The desulfurization mechanism does not involve formation of H2S species unlike that typically observed with hydro-desulfurization process involving sulfided catalysts.Titania nanowires supported with nickel and molybdenum clusters have also shown to exhibit high activity and durability as hydro-desulfurization catalysts for removal of sulfur from hydrocarbons by forming H2S.5 The synergistic activity with MoS2 and titania are expected to contribute to enhanced activity with desulfurization.Alloying of nanowires with other elements is also studied to produce compound and alloyed nanowires. Fundamental studies have shown that alloying process occurs at much lower temperatures than decomposition temperatures for precursors used. Alloying studies have clearly shown that the solubility in nanowires to be much more than that expected for bulk materials systems. This presentation will provide several examples in which nanowires were alloyed with elements at compositions more than that expected for thermodynamic solubility.In the case of CO2 sorbents, alkali metal oxide nanowires have shown high capacity for CO2 sorption as high as 75% by wt. The alkali metal oxide nanowires have been alloyed with alkali hydroxides to produce alkali metal oxide compound nanowires. These solid sorbents showed selective CO2 sorption from a variety of streams including air, exhausts containing CO2 at various concentrations. Nanowire geometry for these nanowires allow for non-sinterability, and smaller length scales for rapid diffusion of alkali ions allow for fast kinetics and regenerability. 6,7 Acknowledgements: Authors also acknowledge contributions from Drs. Juan He, Sivakumar Vasireddy, Vivekanand Kumar, Veerendra Atla and Tu Nguyen. Partial support from National Science Foundation (NSF) and US Department of Energy (DOE) EPSCOR programs and full support from NSF and DOE SBIR programs and Kentucky Cabinet for Economic Development for Advanced Energy Materials, LLC are highly appreciated.

Revolutionizing waste from household plastics to eco-friendly diesel alternatives through catalytic degradation with biogas utilization

The study tackled the pressing environmental issue of managing both biodegradable and non-biodegradable household plastic waste, aiming to convert this waste into valuable hydrocarbons, thus addressing critical concerns over plastic pollution and the quest for renewable energy sources. In the context of escalating environmental degradation and the urgent need for sustainable alternatives to fossil fuels, the ability to transform various forms of waste into energy presents a significant stride towards ecological and energy sustainability. Utilizing an innovative methodology, the research employed catalytic degradation of mixed plastic waste, leveraging fly ash as a catalyst and biogas produced from a combination of cow dung and kitchen waste as a renewable and sustainable heat source. This process was fine-tuned across several catalyst-to-polymer (cat/pol) ratios, specifically 0.10, 0.15, and 0.20, with detailed documentation of the degradation temperatures and yields of liquid and gaseous hydrocarbons for each 1 kg batch of plastic waste. Notably, at a cat/pol ratio of 0.20, a remarkable 100% conversion rate was achieved, highlighting the efficiency of this method. Following this, the resultant oil was segmented based on boiling points for further analysis and evaluation of its utility as a diesel fuel substitute. Significant findings include the highest liquid hydrocarbon yield of 65.1% at 378 °C, achieved with the 0.20 cat/pol ratio. Moreover, fractions boiling above 100 °C were identified to possess superior heating values and cetane numbers compared to conventional diesel, particularly the fraction boiling at 100 °C–150 °C (C2), which demonstrated optimal performance and combustion qualities. This fraction achieved a maximum brake thermal efficiency of 32.92%, exhibited low smoke density and hydrocarbon emissions of 48 HSU and 32ppm, but it also resulted in a significant increase in NOx emission. Among all the fractions, diesel C2 was observed to be the best in terms of performance & combustion and was lower in emission. The conclusions drawn underscore the method’s potential to mitigate plastic pollution and reduce fossil fuel reliance by converting both biodegradable and non-biodegradable waste into useful energy. This study’s novelty lies in its comprehensive approach to waste management and energy recovery, significantly advancing over previous literature by achieving a 100% conversion rate at a specific cat/pol ratio and optimizing the output for use as a diesel alternative. It stands out by producing a fraction with both high efficiency and lower emissions, offering a scalable, sustainable solution to waste management challenges and paving the way for future innovations in sustainable energy production.

On the Influence of Engine Compression Ratio on Diesel Engine Performance and Emission Fueled with Biodiesel Extracted from Waste Cooking Oil

Despite the extensive research on biodiesels, further investigation is warranted on the impact of compression ratios on emissions and engine performance. This study addresses this gap by evaluating the effects of increasing the engine’s compression ratio on engine performance metrics—brake-specific fuel consumption (BSFC), power, torque, and exhaust gas temperature—and emissions—unburnt hydrocarbons (HCs), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2)—when fueled with a 20% blend of waste cooking oil biodiesel (WCB20) and petroleum diesel (PD) under various operating conditions. The viscosity of the prepared fuels was measured at 25 °C and 40 °C. Experiments were conducted on a single-cylinder diesel engine under wide-open throttle conditions at three different speeds (1400 rpm, 2000 rpm, and 2600 rpm) and two compression ratios (16:1 and 18:1). The results revealed that at a lower compression ratio, both WCB20 and petroleum diesel exhibited reduced BSFC compared to higher compression ratios. However, increasing the compression ratio from 16:1 to 18:1 significantly decreased HC emissions but increased CO2 and NOx emissions. Engine power increased with engine speed for both fuels and compression ratios, with WCB20 initially producing less power than diesel but surpassing it at higher compression ratios. WCB20 demonstrated improved combustion quality with lower unburnt hydrocarbons and carbon monoxide emissions due to its higher oxygen content, promoting complete combustion. This study provides critical insights into optimizing engine performance and emission characteristics by manipulating compression ratios and utilizing biodiesel blends, paving the way for more efficient and environmentally friendly diesel engine operations.

Exploratory study on low-GWP working fluid mixtures for industrial high temperature heat pump with 200 °C supply temperature

The development of an industrial high temperature heat pump (HTHP) using a subcritical vapor-compression cycle (VCC) for process heat delivery at 200 °C faces significant challenges due to the scarcity of suitable single-component working fluids. These challenges are further compounded by safety, environmental concerns, material and lubrication oil compatibility and cost considerations. In response, this study investigates the potential of various fluid mixtures to meet these stringent criteria. Using the REFPROP and Cantera software libraries, a Python code was developed to simulate a simplified HTHP VCC with an advanced cycle architecture and assess the flammability risks of the proposed mixtures. Ten single-component fluids of two different families of compounds, hydrocarbons (HCs) and hydro(chloro)fluoroolefins (H(C)FOs), were pre-selected as promising candidates as mixture components. From these, over 460,000 binary, ternary, and quaternary mixtures were generated and evaluated for cycle performance. Although no mixture perfectly met all the predefined criteria, a binary blend of cyclopentane and R1336mzz(Z) in a mole fraction of 0.68 and 0.32, respectively, emerged as the most promising candidate. This mixture demonstrated the best balance of performance and safety under the imposed constraints and is selected for further experimental investigation and validation in a specially designed test rig.

Impact of Oil Viscosity on Emissions and Fuel Efficiency at High Altitudes: A Response Surface Methodology Analysis

This study investigates the effect of oil viscosity on pollutant emissions and fuel consumption of an internal combustion engine (ICE) at high altitudes using a response surface methodology (RSM). A Chevrolet Corsa Evolution 1.5 SOHC gasoline engine was used in Cuenca, Ecuador (2560 m above sea level), testing three lubricating oils with kinematic viscosities of 9.66, 14.08, and 18.5 mm2/s, measured at a temperature of 100 °C under various engine speeds and loads. Key findings include the following: hydrocarbon (HC) emissions were minimized from 150.22 ppm at the maximum load to 7.25 ppm with low viscosity and load; carbon dioxide (CO2) emissions peaked at 15.2% vol with high viscosity and load; carbon monoxide (CO) ranged from 0.04% to 3.74% depending on viscosity and load; nitrogen oxides (NOx) were significantly influenced by viscosity, RPM, and load, indicating a need for model refinement; and fuel consumption was significantly affected by load and viscosity. RSM-based optimization identified optimal operational conditions with a viscosity of 13 mm2/s, 1473 rpm, and a load of 78%, resulting in 52.35 ppm of HC, 13.97% vol of CO2, 1.2% vol of CO, 0 ppm of NOx, and a fuel consumption of 6.66 L/h. These conditions demonstrate the ability to adjust operational variables to maximize fuel efficiency and minimize emissions. This study underscores the critical role of optimizing lubricant viscosity and operational conditions to mitigate environmental impact and enhance engine performance in high-altitude environments.

Enhancing diesel engine performance and emission reduction through hydrogen enrichment in algal biodiesel blends.

The introduction of hydrogen into the engine could enhance its combustion efficiency and emission characteristics. The current study examines the attributes of compression ignition (CI) engines by introducing hydrogen into a biodiesel blend derived from algae. The improved thermal properties of hydrogen, when combined with algae biodiesel, significantly affect the performance, combustion, and emissions of dual-fuel engines. A study was conducted to evaluate the impact of hydrogen enrichment levels of 5%, 10%, 15%, and 20% of the nozzle volume on a biodiesel blend fuel. In comparison to diesel, algal biodiesel reduces emissions of unburned hydrocarbons (HC), carbon monoxide (CO), and oxygen (O2) by 5.19%, 3.61%, and 2.83%, respectively, while increasing nitrogen oxide (NO) emissions by 4.73%. In contrast to biodiesel, diesel demonstrated superior brake thermal efficiency (BTE) and lower specific energy consumption (SEC). Injecting hydrogen into A20 blend fuel at volumes of 5%, 10%, 15%, and 20% results in a respective increase in brake thermal efficiency of 2.65%, 2.97%, 3.50%, and 4.15%. The addition of hydrogen gas to biodiesel blends further enhances their combustion qualities, leading to elevated peak cylinder pressure, temperature, and heat release rate. The results indicate that A20H5, A20H10, A20H15, and A20H20 fuel reduced CO emissions by 3.75%, 8.75%, 12.5%, and 16.25%, respectively, compared to the A20 blend. In the same vein, HC emissions decreased by 5.76%, 10.29%, 15.52%, and 18.98%, respectively, as compared to A20 fuel. However, NO emissions rose by 5.36%, 10.20%, 15.28%, and 23.23%, respectively, for A20H5, A20H10, A20H15, and A20H20 test fuels. Ultimately, the utilization of algal biodiesel and hydrogen enrichment in diesel engines was proven to substantially reduce pollutants while increasing efficiency. This study contributes valuable insights into the intersection of renewable fuels, hydrogen enrichment, and engine technology, with the potential to drive significant advancements in sustainable transportation and environmental conservation.

Investigation on the effect of ship emissions on the air quality, A case study in Hainan Island, China

This paper presents an air quality simulation model that incorporates shipping activities and weather conditions, with a case study of Hainan Island to examine the impact of ship emissions on air quality. The findings reveal that the density of automatic identification system (AIS) signals is particularly high in the southern coastal regions. The results showed that the annual ship emissions recorded the highest density of 896.7 tons/0.01°, 49.8 tons/0.01°, 1139.7 tons/0.01°, and 122000 tons/0.01° for sulfur oxides (SOx), particulate matter (PM), nitrogen oxides (NOx), and carbon dioxide (CO2), respectively. Furthermore, the partial distributions of these emissions were not significantly affected by the seasons. Ships within twelve nautical miles of Hainan coastlines emit approximately 2817.7 tons of SOx, 14686.4 tons of NOx, 630.4 tons of PM2.5, and 416.9 tons of hydrocarbons (HC) annually. These emissions are primarily concentrated in the sea areas surrounding the ports of Haikou, Yangpu, Basuo, and Sanya. Ships manufactured between 2000 and 2010 have contributed significantly to air pollution, with SOx and HC emissions accounting for approximately 51% and 56% of total emissions, respectively. However, for ships manufactured after 2016, these proportions have dropped to approximately 10%. In terms of air pollutants from ship emissions in Hainan Island, the spatial distribution of their contributions is significantly uneven. The impact of PM2.5 differs significantly depending on the season, with the concentrations being substantially higher during Spring. However, the proportions of O3 and other pollutants do not vary significantly, except during Spring.

Pengaruh Modifikasi Permukaan Piston terhadap Emisi Gas Buang Motor Bakar Kapasitas 100 cc

Technological advances in motorized transportation are progressing rapidly, making motorized vehicles the main mode of transportation. The increasing number of motorized vehicles in society results in a significant increase in exhaust emissions. Combustion in vehicle engines is not always perfect, producing exhaust gases containing compounds harmful to human health, such as carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), and nitrogen oxides (NOx). This study investigates the effect of variations in piston dome shape on exhaust emissions in a 100cc internal combustion engine using RON 90 fuel. The goal is to find the optimal compression ratio to produce cleaner exhaust emissions. The research data are presented in tabular form and analyzed using one-way ANOVA and graphs. The results showed a significant reduction in CO and HC emissions at all engine speeds (1000, 2000, 4000, and 5000 rpm) with variations in piston dome shape. The reduction in CO emissions ranged from 55.07% to 85.73%, while the reduction in HC emissions ranged from 54.14% to 86.10%. These results suggest that variations in piston dome shape can be an effective solution to minimize harmful exhaust emissions in internal combustion engines.

ZSM-5-Based Catalyst Structure Design and Selectivity Control for Liquid Hydrocarbon Formation: A Mini Review

The selectivity limitation has long posed a significant challenge in the conversion of CO or CO2 into liquid hydrocarbon-based sustainable fuels via Fischer–Tropsch synthesis (FTS) and other related processing pathways due to the Anderson–Schulz–Flory (ASF) distribution. The unique pore structure, thermal stability, and acidic sites of ZSM-5 have enabled its widespread applications in various catalytic processes of value-added chemicals and sustainable fuels. In the reaction pathways from CO/CO2 to liquid HCs of interest, incorporating ZSM-5 into metal catalysts provides new opportunities to enhance product selectivity and catalytic activity, and even lower the reaction energetics. This review highlights recent advancements over the past five years in the structural design of ZSM-5-based catalysts aimed at improving the conversion selectivity of advanced liquid biofuels such as renewable diesel and sustainable aviation fuel. It explores innovative strategies for optimizing catalyst composition, the acidity, mesoporosity, and structures of ZSM-5 to design more efficient, selective, and robust catalysts. Additionally, the review addresses the direct hydrogenation of CO and CO2 into C5+ liquid hydrocarbons, focusing on catalyst selection, acidic site optimization, and the structural configuration of ZSM-5. The mechanisms involved in these processes are also surveyed.

STUDYING HOW DIESEL ENGINE ADDITIVES USING SILVER OXIDE (Ag2O) NANOPARTICLES AFFECT THE ENVIRONMENT

Abstract: Biodiesel has been defined as an alternative fuel that has the potential to be used instead of diesel fuel for years. In case of complete combustion reaction in engines, the products released do not directly threaten human health. Compared to diesel fuel, biodiesel has worse combustion performance due to some fuel properties. Therefore, incomplete combustion products such as hydrocarbon (HC), carbon monoxide (CO), nitrogen oxide (NOx), smoke emission and complete combustion products such as CO2 are thrown into the atmosphere. In this study, the changes in exhaust emissions of 50 ppm and 75 ppm Ag2O NPs were experimentally examined to improve the adverse combustion performance and emission characteristics of cottonseed oil methyl ester. In experiments, nano additive improved the thermal conductivity, mass dissipation and heat transfer of the test fuels, and resulted in reducing of CO emissions as it provided a higher oxidation rate of hydrocarbon molecules. Due to the improvement in the combustion reaction, CO2 emission increased with product of complete combustion. The increase in CO2 emissions was 3.17% and 3.97% for CAg-50 and CAg-75 fuels, respectively, when compared to C0 fuel at 40 Nm load. The NPs additive increased the lower calorific value of the fuel and cylinder temperature. This situation caused increase of NOx emissions by 3.69% and 7.47% CAg-50 and CAg-75 fuels 40 Nm load. Adding of NPs in base fuel reduced to viscosity and density provided better atomization. So a reduction in smoke emission was obtained with NPs addition by 35.09% and 47.32% in CAg-50 and CAg-75 fuels, respectively, compared to C0 fuel at 10 Nm load, while 7.45% and 19.43% at 40 Nm load.

Evaluation of Aluminum Oxide Nanoparticle Blended with Alcohol Based Biodiesel at Variable Compression Ratios

This paper highlights the use of aluminum oxide nanoparticles as an additive in diesel-butanol blends to show its effect on fuel consumption, emissions and performance. In the present experiment, different concentrations of aluminium oxide nanoadditives (30, 50, and 70 ppm) are used in alcohol-based biodiesel. Butanol has been used in concentrations of 5 and 10 % in diesel and therefore all blends are termed as B5 and B10 in addition to nanoparticle concentration to avoid complexity. These different blends (B5+30, B5+50, B5+70, B10+30, B10+50, B10+70) are tested for various engine loads at a constant speed of 1500 rpm. The experiment was performed on a Variable compression ratio (VCR) engine at varying compression ratios of 16, 17, and 18. Engine characteristics at different compositions of the blend at different compression ratios were provided by the interfaced computer through the software. The enhanced performance effects can be easily seen from the outcomes in the increment in brake thermal efficiency of the blends as compared to neat diesel. Considerable decrement can be observed in carbon monoxide (CO) and unburnt hydrocarbon (HC) values with an increase in compression ratio. Moderate reduction can be observed in NOx at higher loads in contrast to neat diesel.

An Energy, and Emission Assessment of Diesel Engines Powered with Shorea Robusta Biodiesel and Blends

The present investigation examines the exergy, energy, and pollutants of a diesel-powered engine fuelled with a blend of Shorea Robusta Biodiesel (SRB) and normal diesel. The impact of engine power, speed, and fuel mix on emissions and operating characteristics are investigated. The use of blended fuels including SRB reduces a number of performance metrics, including BTE, exergy efficiency, and the sustainability index. Furthermore, CO (carbon monoxide), smoke, and HC (hydrocarbon) emissions are reduced when compared to utilising pure diesel fuel. SRB20 has the lowest HC emissions among the mixes SRB. At an engine speed of 1500 rpm and a power output of 5.5kW, SRB10, SRB20, and SRB30 blends lower HC emissions by 8.92%, 10.71%, and 7.14%, respectively. Similarly, when compared to conventional diesel fuel, SRB10, SRB20, and SRB30 blends reduce CO emissions by 1.25%, 5%, and 6.25%, respectively.

Modeling the impact of plastic oil obtained from xlpe cable wastes on diesel engine performance and combustion parameters with the response surface method

The world's expanding population requires alternative energy sources to meet its energy needs. One such alternative is the efficient recovery of plastic waste through pyrolysis. The liquid produced from waste plastics via pyrolysis is a valuable commodity that may serve as fuel substituted for internal combustion engines. In this study, waste plastic oil (WPO) and diesel fuel (D100) blends (10%, 20%, 30%, 40% and 50% by volume) obtained by pyrolysis of waste XLPE cables were experimentally investigated and analyzed using response surface methodology (RSM) to determine their effects on the combustion parameters of a four-stroke, single cylinder diesel engine at different engine loads (750, 1500, 2250, 3000, 3750 and 4500 W). A response surface model was constructed using a two-factor central composite complete design and analysis of variance based on the experimental results obtained. The model determined the optimum values of WPO ratio and engine load that correspond to one of the finest brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NOx), and smoke emission levels. The study's optimization findings indicated that the optimal WPO ratio is 19.6%, and the optimal engine load is 2600 W. The BTE, BSFC, CO, HC, NOx, and smoke were found to be 22.3%, 332.3 g/kWh, 0.033%, 31.5 ppm, 397.9 ppm, and 1.63%, respectively, at the optimal WPO ratio and engine load. The R2 (correlation coefficient) values for BTE, BSFC, CO, HC, NOx, and smoke emissions were determined to be 99.95%, 97.76%, 98.10%, 99.74%, 99.74%, 99.79%, and 95.67%, respectively. The mean error rates, ranging from 0.64% to 4.27%, were deemed satisfactory when comparing the replies to the experimental data. The findings of this study demonstrated that the response surface method is a very efficient approach for forecasting and enhancing a diesel engine's performance and emission characteristics by using waste plastic oil.

Environmental Exhaust Emissions reduction and Performance Improvement Analysis of biodiesel operated Diesel Engine Performance Using Operating Parameters

<p style="margin-top:3px; margin-bottom:3px; text-align:justify; text-indent:31.5pt">The present investigation aims to study the performance and emission characteristics of a CI DI diesel engine using biodiesel blends derived from Jatropha seed feedstock. Four blends, namely B25, B50, B75, and B100, are employed as fuels to run the diesel engine at a rated speed of 1500 rpm, and their performance and emission characteristics are determined under different operating conditions in the first phase. The blend B25 of JME is found to be the optimum blend, and the optimum compression ratio is found to be 18.5.The optimum blend exhibits better performance in terms of brake specific fuel consumption (BSFC) and brake thermal efficiency (BTHE), along with a decline in the emissions of carbon monoxide (CO) and hydrocarbons (HC), except for the emission of nitrogen oxides (NOX) at the optimum compression ratio of 18.5. At maximum load, with a compression ratio of 18.5, the optimum blend results in better BSFC and BTHE, which are 0.255 kg/kW-hr and 31.87%, respectively.</p>