Diffusion coefficients, D, for ethanol in supercritical carbon dioxide (scCO2) were measured in the temperature range 306.15−331.15 K and along the 10.5 MPa isobar, using the Taylor dispersion technique. The obtained diffusivities ranged from 1.49 × 10−8 to 2.98 × 10−8 m2 s−1, an order of magnitude higher than in usual liquids. The dependence of D on temperature and solvent density was examined. Various correlation models based in the hydrodynamic theory were assessed to estimate the diffusion coefficients, with reasonable results obtained for the Wilke−Chang and Lai−Tan models.

Diesel engines play a very significant role in the automotive industry, but the total emissions of diesel engines are more than 1.8 times that of petrol engines. It is therefore important for diesel engines to control emissions. Theoretically, the Miller cycle can be used to achieve NOx reductions by changing the effective compression ratio, while it has become increasingly popular in recent years with the increasing maturity of current turbocharging technology. Based on Ricardo WAVE software, this paper analyses the NOx emissions and engine performance of diesel engines by modelling and simulating their operation under different loads with two types of Miller cycles (EIVC and LIVC) at different degrees. Simulation of engines operating under different loads allows a more comprehensive study of the effects of the Miller cycle on the engine, and a specific analysis in the context of the actual engine operating environment. The result is that both versions of the Miller cycle are most eff... [more]

This paper focuses on the investigation and optimisation of the Miller cycle, methanol, ethanol and turbocharging when applied to a high-performance gasoline engine. These technologies have been applied both individually and concurrently to test for potential compounding effects. Improvements have been targeted with regards to both emission output and performance. Also assessed is the capability of the engine to operate when exclusively powered by biofuels. This has been carried out numerically using the 1D gas dynamics tool ‘WAVE’, a 1D Navier−Stokes equation solver. These technologies have been implemented within the McLaren M838T 3.8L twin-turbo engine. The Miller cycle early intake valve close (EIVC) improved peak efficiency by 0.17% and increased power output at low and medium loads by 11%. Reductions of 6% for both NOx and CO were also found at rated speed. The biofuels achieved NOx and CO reductions of 60% and 96% respectively, alongside an efficiency increase of 2.5%. Exclusive... [more]

There are four main waste products produced during the harvesting and milling process of sugarcane: cane trash, molasses, bagasse and mill mud−boiler ash mixture. This study investigates the value proposition of different techniques currently not being adopted by the industry in the utilisation of these wastes. The study addresses the technical challenges and the environmental impact associated with these wastes and comes up with some recommendations based on the recent findings in the literature. All the biomass wastes such as bagasse, trash (tops) and trash (leaves) have shown great potential in generating higher revenue by converting them to renewable energy than burning them (wet or dry). However, the energy content in the products from all the utilisation methods is less than the energy content of the raw product. This study has found that the most profitable and challenging choice is producing ethanol or ethanol/biogas from these wastes. The authors recommend conducting more rese... [more]

Since both ethanol and acetone are the main components in many alternative fuels, research on the burning characteristics of ethanol-acetone blends is important to understand the combustion phenomena of these alternative fuels. In the present study, the burning characteristics of ethanol-acetone fuel blends are investigated at a temperature of 358 K and pressure of 0.1 MPa with equivalence ratios ranging from 0.7 to 1.4. Ethanol at 100% vol., 25% vol. ethanol/75% vol. acetone, 50% vol. ethanol/50% vol. acetone, 75% vol. ethanol/25% vol. acetone, and 100% vol. acetone are studied by the constant volume combustion chamber (CVCC) method. The results show that the laminar burning velocities of the fuel blends are between that of 100% vol. acetone and 100% vol. ethanol. As the ethanol content increases, the laminar burning velocities of the mixed fuels increase. Furthermore, a detailed chemical kinetic mechanism (AramcoMech 3.0) is used for simulating the burning characteristics of the mixt... [more]

The primary objective of this paper is to identify the possibilities of using sugar beet pulp as feedstock to produce a variety of added-value products. Such an application of the sugar production byproducts contributes to implementing circular bio-economy, which is a source of many economic, social, and environmental benefits. Specific objectives of this paper are: (1) Presenting the concept and meaning of circular bio-economy. (2) Characterizing properties of the sugar beet pulp from the perspective of using them as feedstock. (3) Determining the volume of production of the sugar beet pulp and the current methods of using them. (4) Determining the methods of obtaining attractive bioproducts and renewable energy from sugar beet pulp. Special attention was given to the amount of sugar beet pulp produced in Polish sugar refineries. Poland is among the European countries in which the volume of produced sugar is especially high. Therefore, the problem of appropriate waste management in th... [more]

Xylose is the second most abundant monomeric sugar on earth. Nevertheless, metabolizing xylose into ethanol is a complex process due to several biochemical reactions. Some microorganisms of the genus Mucor are suitable for this bioprocess. Using metal ions, such as zinc and calcium, allows some fungal species to increase their ethanol yield. In this work, the wild strain Mucor spp. (C1502) was molecularly identified via internal transcribed spacer (ITS) sequencing. Secondly, an optimization using response surface methodology (RSM) with a central composite experimental design (CCD) was carried out. The independent variables (X) were ZnSO4·7H2O (X1, 0.0−1.5 g/L) and CaCl2 (X2, 0.0−2.5 g/L) concentration in the fermentation broth in order to demonstrate the effect of these ions, xylose was used as the only carbon source. The dependent variables (Y) measured were ethanol yield (Y1, g ethanol/g xylose) and xylitol yield (Y2, g xylitol/g xylose). The identified strain, Mucor circinelloides,... [more]

The growth in the number of vehicles circulating has led to a proportional increase in polluting gas emissions. Bioenergy can be used to help meet these increasing energy demands and mitigate environmental impacts. This work verified the effect of the content of ethanol on the exergy and exergoenvironmental analyses of a spark-ignition engine. Different gasoline−ethanol mixtures were tested along with hydrous ethanol (4.6% water by volume). The thermodynamic data refer to wide-open throttle conditions and variable engine speeds. The life cycle assessment methodology quantified the environmental impacts associated with equipment and fuel using the Eco-indicator 99 method. Pollutants emitted during combustion were measured and included in the environmental assessment (nitrogen oxides, carbon monoxide, and dioxide). Hydrous ethanol at 1500 rpm presented the highest energy efficiency. The effects of the environmental impact rate of pollutant formation and exergy efficiency were significant... [more]

The growth in the number of vehicles circulating has led to a proportional increase in polluting gas emissions. Bioenergy can be used to help meet these increasing energy demands and mitigate environmental impacts. This work verified the effect of the content of ethanol on the exergy and exergoenvironmental analyses of a spark-ignition engine. Different gasoline−ethanol mixtures were tested along with hydrous ethanol (4.6% water by volume). The thermodynamic data refer to wide-open throttle conditions and variable engine speeds. The life cycle assessment methodology quantified the environmental impacts associated with equipment and fuel using the Eco-indicator 99 method. Pollutants emitted during combustion were measured and included in the environmental assessment (nitrogen oxides, carbon monoxide, and dioxide). Hydrous ethanol at 1500 rpm presented the highest energy efficiency. The effects of the environmental impact rate of pollutant formation and exergy efficiency were significant... [more]

This study focuses on the measurement of sub-23 nm particles emitted from a small DI/PFI spark ignition engine through conventional techniques and innovative systems. Measurements were performed with well-known systems, such as the EEPS coupled to a PMP-compliant sample conditioning device. Moreover, a novel instrument developed within the European project Sureal-23, the advanced HM-DMA, capable of operating with a simplified conditioning setup was used. The engine was fueled with ethanol, both pure and in blend at 30% v/v. The effects of fuel on the particle emissions were analyzed at different operating conditions. The results highlighted that a larger fraction of emissions consists of particles smaller than 23 nm, and their number changes according to the fuel, injection strategy and operating condition. A significant effect of the sampling system conditions was observed reveling the inception of nucleation mode particles or the condensation of the volatiles onto existing particles... [more]

To understand the effect of hydrogen addition on the laminar burning velocity (LBV) of ethanol−air mixtures, experiments were conducted in a constant volume combustion chamber with the high-speed schlieren photography technique. The experiments were carried out under the equivalence ratios (ERs) of 0.7−1.4, an initial temperature of 400 K, an initial pressure of 0.1 MPa, and hydrogen fractions of 30% and 90% by volume, respectively. The effects of ER, initial temperature, initial pressure, and hydrogen fractions on the LBV were investigated. Moreover, adiabatic flame temperature (AFT), heat release rate (HRR), flow rate sensitivity analysis, and ROP (rate of production) analysis were also performed. Results showed that LBV increased with increasing hydrogen addition and temperature but decreased with increasing pressure. The hydrogen addition significantly increased the HRR of ethanol−hydrogen−air flames. The sensitivity analysis showed that R5 (O2 + H = O + OH) significantly influence... [more]

The present work describes highly efficient hydrogen production from ethanol in a plasma-catalytic reactor depending on the discharge power and catalyst bed temperature. Hydrogen production increased as the power increased from 15 to 25 W. A further power increase to 35 W did not increase hydrogen production. The catalyst was already active at a temperature of 250 °C, and its activity increased with increasing temperature to 450 °C. The further temperature increase did not increase the activity of the cobalt catalyst. The most important advantage of using the catalyst was the increased ethanol conversion to CO2 instead of CO production. As a result, the hydrogen yield was very high and reached 4.1 mol(H2)/mol(C2H5OH). This result was obtained with a stoichiometric molar ratio of water to ethanol of 3.

With the world’s energy resources decreasing, ethanol/acetone/ethyl acetate mixed fuel has the potential as a fossil fuel alternative or oxygenated fuel additive. In this work, the burning characteristics of ethanol/acetone/ethyl acetate mixed fuels including 3 pure fuels, 9 binary fuels, and 7 ternary fuels were studied at a temperature of 358 K, the pressure of 1 bar, and the equivalence ratios of 0.7 to 1.4 in the constant volume combustion chamber (CVCC). The burning velocities of the ternary fuels were compared at ϕ = 0.8, 1.0, and 1.4. The results show that the laminar burning velocities of the mixed fuels are affected by the contents of ethanol, acetone, and ethyl acetate. The Markstein length, Markstein number, and burning flux were also analyzed in this paper. Furthermore, a detailed chemical mechanism comprising 506 species and 2809 reactions was reduced to a skeletal mechanism including 98 species and 642 reactions, using the directed relation graph with error propagation (D... [more]

Many countries have adopted the addition of biodiesel to diesel as a way of inserting renewable content into mineral fuel and making a contribution to the environment. The addition of ethanol to the diesel/biodiesel blend to increase the renewable content of the added fuel blend and reduce the percentage of biodiesel could be a strategysince the demand for biodiesel production is high, and this fuel has a high production cost when compared to ethanol. Thus, this study evaluated the performance and the content of NOx, CO and CO2 exhaust gases from a diesel engine fueled with blends of diesel/biodiesel/ethanol: pure B7, B7E3 (B7 with 3% ethanol) and B7E10 (B7 with 10% ethanol). Emissions of fuel blends were evaluated using the engine speed variation and tested at a speed of 1500 rpm under constant load (185 Nm). Assays were performed at engine speeds of 1000, 1100, 1250, 1500 and 1750 rpm and with loads of 10, 25, 50, 75 and 100% of the maximum torque. Through the performance curves, the... [more]

Wet ethanol is a biofuel that can be rapidly integrated into the existing transportation sector infrastructure and have an immediate impact on decarbonization. Compared to conventional hydrocarbon fuels, wet ethanol has unique fuel properties (e.g., short carbon chain, oxygenated, high heat of vaporization, no cool-flame reactivity), which can actually improve the efficiency and engine-out emissions of internal combustion engines while decarbonizing. In this work, wet ethanol 80 (80% ethanol, 20% water by mass) was experimentally studied at high loads under boosted conditions in compression ignition to study the tradeoffs in efficiency and emissions based on boosting and injection strategies. Specifically, this work explores the potential of adding a third, mixing-controlled injection at high loads. The results indicate that adding a third, mixing-controlled injection results in combustion stabilization at high loads, where the peak pressure limit of the engine is a constraint that req... [more]

The brown Tunisian seaweed Halopteris scoparia was used as a feedstock for producing renewable bioethanol, biogas, and biodiesel to demonstrate the proof of concept for the North African energy sector. A quantitative and qualitative quantification of H. scoparia composition using different colorimetric methods was completed to highlight its bioconversion potential. These substrate inputs were subjected to anaerobic fermentation by Saccharomyces cerevisiae to produce bioethanol. The materials were also used to generate bio-hydrogen and volatile fatty acids during dark fermentation by a bacterial consortium and using the oleaginous yeast Yarrowia lipolytica. The lipids were extracted and trans-esterified to Fatty Acid Methyl Esters (FAMEs), and their profiles were then analyzed with gas chromatography (GC). A significant ratio of the bioethanol, e.g., 0.35 g ethanol/g DW substrate, was produced without pretreatment, consistent with the theoretical Gay-Lussac yield. The production of the... [more]

This article presents a method for quantification of methanol and ethanol integrated in the same gas-chromatographic run with a quantification of gases dissolved in mineral oil, making it an integrated tool in transformer diagnostics. The results of aging experiments at 120 °C and 60 °C of Kraft paper, copper, barrier, and pressboard immersed in mineral oil, as well as the aging of thermal upgrade paper in mineral and natural ester oil at 140 °C are presented, in order to investigate correlations between different aging markers and to evaluate their partitioning between oil and cellulose at defined conditions. The results of partitioning experiments at 60 °C showed that re-absorption of methanol from oil to the cellulose materials is faster than the re-absorption of furans. This means that methanol is a paper-degradation marker that can be used in diagnostics over shorter equilibrium times and for the detection of developing faults at broader temperature ranges. Furthermore, a statisti... [more]

The constantly growing number of vehicles sold and operated has resulted in greater contribution of automobiles to global pollution. One way to reduce emissions of carbon dioxide (CO2) and toxic compounds, including the particulates and nitrogen oxides (NOx) contained in exhaust gases, is to use alternative fuels. Within this group of fuels, those of plant origin, mainly alcohols, are attracting more and more attention because of their high oxygen content (around 35%), low viscosity, and good atomisation. However, alternative fuels have different physicochemical properties than diesel fuel, and these may affect the formation of the fuel spray, which, in turn, impacts the operation of the internal combustion engine, operating parameters, and the purity of the exhaust gases emitted into the environment. To make sure this type of fuel can be used in compression ignition engines, it is necessary to gain a thorough understanding of the phenomena and relationships occurring during fuel injec... [more]

The objective of this review is to provide a deep overview of liquid biofuels produced from sugarcane bagasse and to address the economic challenges of an ethanol and acetone-butanol-ethanol blend in commercial processes. The chemistry of sugarcane bagasse is presented. Pretreatment technologies such as physical, chemical pretreatment, biological, and combination pretreatments used in the fermentation process are also provided and summarised. Different types of anaerobic bacteria Clostridia (yeast) are discussed to identify the ingredient best suited for sugarcane bagasse, which can assist the industry in commercializing ethanol and acetone-butanol-ethanol biofuel from biomass sugarcane. The use of an acetone-butanol-ethanol mixture and ethanol blend in internal combustion engines is also discussed. The literature then supports the proposal of the best operating conditions for fermentation to enhance ethanol and acetone-butanol-ethanol plant efficiency in the sugar waste industry and i... [more]

The growing level of modern environmental problems and the need to ensure energy security creates new challenges for the development of the energy sector. Nowadays, countries must balance their international competitiveness and progress in achievement the Sustainable Development Goals. This provides a necessity for the development of alternative energy technologies. Modern trends in the development of alternative energy indicate a gradual increase in the relevance of biofuel production. At the same time, the development of clean energy technologies needs significant investments, and their commercial implementation is a long process. Moreover, energy industry transformations require significant changes in the functioning of complementary spheres. That makes necessary the use of additional incentives for the development of the bioenergy sector. Thus, an assessment of the impact of environmental taxes on biofuel production and consumption becomes crucial. This research is aimed at the ide... [more]

Adsorption heat storage is the most feasible technology for heating decarbonization, which can store large quantities of waste and renewable heat for an exceptionally long time. However, utilizing adsorption heat storage in geographical locations with sub-zero ambient conditions is challenging. Therefore, this paper experimentally investigates the use of ethanol as a working fluid paired with silica gel for adsorption heat storage and utilizes sub-zero ambient as the heat source. The heat storage characteristics, heat charging/discharging cyclic performance, and energy conversion performance via exergy analysis were determined under realistic operating conditions and benchmarked against the widely investigated silica gel/water. Ethanol adsorbate was successfully utilized as a working fluid to employ the evaporators operating under sub-zero ambient conditions. Silica gel/ethanol showed the most significant net cyclic uptake, twice that of silica gel/water. However, the physical characte... [more]

This study aims to provide a review of the state-of-the-art literature regarding the impacts and contributions of corn ethanol on retail gasoline prices in the US. For this, a systematic literature review following PRISMA statement was carried out, seeking to answer four research questions: (1) What are the main characteristics of the literature regarding the impact and contributions of ethanol on US retail gasoline prices? (2) What are the main article clusters identified in the evaluated literature? (3) What was the numerical impact of the Volumetric Ethanol Excise Tax Credit/Renewable Fuel Standard (VEETC/RFS) mandate on the price of gasoline and what are the main methods used for calculation in the literature? (4) What are the main trends and possibly new research directions for this literature? As a result of the characterization of the sample, driving themes, such as energy policy, costs, price dynamics, trade and energy market, were identified. Furthermore, three main clusters w... [more]

The emissions from direct injection (DI) diesel engines remain a serious setback from the viewpoint of environmental pollution, especially for those who have been persuaded to use biofuel as an alternative fuel. The main drawbacks of using biofuels and their mixtures in DI diesel engines are increased emissions and decreased brake thermal efficiency (BTE) compared to using neat diesel fuel. The current study analyses the biodiesel made from cashew nut shell liquid (CNSL) using a single-cylinder, direct-injection diesel engine to validate the engine’s performance and discharge characteristics. In addition to the improved CNSL and a twin-fuel engine that runs on hydrogen, ethanol was added to the fuel at rates of 5%, 10%, and 15%. The investigation was conducted using a single-cylinder direct injection diesel engine at steady-state settings, above the sustained engine speed (1500 RPM). Several performance parameters and pollutant emissions, such as hydrocarbons (HC), carbon monoxide (CO)... [more]

Laser technology is being widely studied for controlled energy deposition for a range of applications, including flow control, ignition, combustion, and diagnostics. The absorption and scattering of laser radiation by liquid droplets in aerosols affects propagation of the laser beam in the atmosphere, while the ignition and combustion characteristics in combustion chambers are influenced by the evaporation rate of the sprayed fuel. In this work, we present a mathematical model built on OpenFOAM for laser heating and evaporation of a single droplet in the diffusion-dominated regime taking into account absorption of the laser radiation, evaporation process, and vapor flow dynamics. The developed solver is validated against available experimental and numerical data for heating and evaporation of ethanol and water droplets. The two main regimes—continuous and pulsed laser heating—are explored. For continuous laser heating, the peak temperature is higher for larger droplets. For pulsed lase... [more]

Algae are regarded among the most favorable feedstocks for producing sustainable biodiesel and utilizing it in diesel engines. Additionally, ethanol addition further enhanced the performance and reduce greenhouse emission. Algae biodiesel was produced, and an experimental study was performed to understand the diesel engine performance and emissions characteristics using different fuel blends by varying the ratio of diesel, biodiesel, and ethanol, such as D100, B10, B20, B5E5, and B10E10 (where number shows the percentage of the respective fuel). It was found that brake thermal efficiency was reduced by 0.49% and 1.29% for B10 and B20 blends, while the addition of ethanol enhanced the BTE by 0.37% and 1.60% respectively. However, SFC increases by 1.45%, 2.14%, 3.18%, and 3.78% respectively for B10, B20, B5E5, and B10E10 with respect to diesel fuel. Combustion characteristics were increased with increasing concentration of biodiesel and ethanol addition. Particulate matter, smoke emissio... [more]