Wet Ethanol Research Articles

Experimental and Theoretical Study of the Energy Savings from Wet Ethanol Production and Utilization

AbstractAs a result of the energy crisis in recent decades, biofuels have gained importance as an option to diminish the oil dependence of automotive industry. Ethanol is one of these biofuels for which demand around the world has increased in recent years. However, to be used as a fuel, the ethanol must be dehydrated to avoid problems in actual engines, and this step has a high energy cost. To overcome this drawback, some studies have demonstrated the use of wet ethanol in homogeneous charge compression ignition (HCCI) engines. In this work, the production of wet ethanol, using conventional distillation, was studied using rigorous simulation studies and experimental tests in a distillation column. The simulation analysis and experimental validation of the energy requirements to obtain wet ethanol were achieved. The results showed that wet ethanol can be produced by using a distillation column with a small number of stages and low reflux ratios, which results in energy savings. Also, the results indicated that for low purities of the distilled ethanol (wet ethanol), the ratios between the energy required during the distillation process and the energy produced by ethanol during the combustion were low. This result implies that the use of wet ethanol can be considered as realistic option in HCCI engines.

Upright or Flat Orientations of the Ethanol Molecules on a Surface with Charge Dipoles and the Implication for Wetting Behavior

Using molecular dynamics simulations, we have found that the charge dipole length has a large effect on surface–ethanol adsorption behavior, particularly the orientations of the ethanol molecules of the first ethanol layer and subsequently the wetting behavior. At surfaces with large charge dipole length, an ordered ethanol monolayer forms with upright orientations of the ethanol molecules and an ethanol droplet forms on this ordered monolayer, which can be termed as “ordered ethanol monolayer does not completely wet ethanol”. The upright orientations, with the OH groups buried beneath the monolayer, exclude the possibility of forming hydrogen bonds between the ordered ethanol monolayer and ethanol molecules in contact with the monolayer, leading to a phenomenon wherein the ordered ethanol monolayer does not completely wet ethanol. The strong binding mainly occurs between the negative charges of the surface and the OH group of the ethanol molecules while the hydrophobic ethyl tails point away from the sur...

Production of Ethyl Esters from Jatropha Oil using Wet Ethanol

Ethanol based biodiesel prepared from plant oils is environment friendly. Ethyl esters were prepared from Jatropha curcas L. oil using wet ethanol (170, 180 and 190 proof ethanol) as reactant. The crude oil had free fatty acid contents of 6.3% and acid value of 11.2. In the present study, two methods were employed for the preparation of biodiesel. The first method involved pre-treatment of crude oil with acid catalyst, followed by base-catalysed transesterification. The second method involved acid catalysed esterification/trans-esterification of crude oil, followed by base-catalysed trans-esterification reaction. The highest recovery and per cent conversion of oil into ethyl ester was achieved with acid catalyst pre-treatment for 1h using 190 proof ethanol as reactant, followed by base catalysed reaction using anhydrous ethanol (199.8 proof) .The concentration of KOH used as catalyst was 2.5% (w/v of oil). The recovery and conversion of oil into ethyl ester were 55.1 and 90%, respectively. The cost of ethyl esters (biodiesel), thus prepared, was estimated to be slightly lower as compared to the conventional process used for preparation of ethyl esters.

Optimal operating conditions for wet ethanol in a HCCI engine using exhaust gas heat recovery

This study explores optimal operating conditions for power generation from wet ethanol in a HCCI engine using exhaust gas heat recovery. Wet ethanol is a difficult fuel to ignite as it requires high compressed gas temperatures to achieve ignition causing the requirement for substantial intake charge heating. A heat exchanger is retrofitted to a HCCI engine in this study to recover excess heat from the exhaust gases to provide the energy input for intake charge heating. This study builds on prior experimental research by focusing on optimal operating conditions for wet ethanol in HCCI with exhaust gas heat recovery. Operating points include intake pressures of 1.8 and 2.0bar absolute, equivalence ratios of 0.50 and 0.55, combustion timings from just before TDC to misfire, and fuel mixtures from 70% to 100% ethanol (with water being the balance).The results suggest that the best operating conditions for the HCCI engine and heat exchanger system in terms of high power output, low ringing, and low nitrogen oxide emissions occur with high intake pressures, high equivalence ratios and highly delayed combustion timing. With a 2bar absolute intake pressure, an equivalence ratio of 0.55, and a combustion timing near 8 CAD ATDC, 70% ethanol produced a power output of nearly 7.25bar gross IMEP with low ringing and low nitrogen oxide emissions. This operating point was sustained by using heat transfer from hot exhaust gases into the intake charge, and thus no external heat addition was required – a substantial improvement over prior studies.

Thermodynamic analysis and utilisation of wet ethanol in homogeneous charge compression ignition engine

In this study, our objective is to computationally analyse the wet ethanol operated homogeneous charge compression ignition (HCCI) engine to evaluate its first and second law efficiency and observe these results by varying effectiveness of regenerator. The paper concludes that the first and second law efficiency decreases due to the increase in the effectiveness of regenerator. This increase in effectiveness leads to an increase in the temperature of air coming out of the regenerator. It further results in increase of the fuel air mixture intake temperature which finally reduces the work output and efficiency of the engine. Furthermore, the method of exergy analysis has been applied and evaluated. This study indicates that due to domination of chemical exergy destruction in combustion reaction in these systems, maximum exergy is destroyed in HCCI engine and to a lesser extent in catalytic converter. These findings will help in the design of such system for optimum result.

Pressurised gasification of wet ethanol fermentation residue for synthesis gas production

Pressurised steam gasification of wet biomass in a fixed-bed downdraft gasifier was implemented to identify reaction conditions yielding the highest synthesis gas concentration and efficiency, and to examine the generation of sulphur compounds. The gasification of lignin-rich fermentation residue derived from a bench-plant for bioethanol production from woody biomass was investigated at p=0.99MPa and T=750–900°C for steam to biomass ratios (S/B) of 3.4–17 and equivalence ratios (φ) of 3.3–∞. The results showed that the highest concentration of around 70mol% was obtained at T⩾850°C, φ=13 and S/B=3.4, the highest efficiency of 0.26 was obtained at T=900°C, φ=3.3 and S/B=3.4, and sulphur compounds were H2S and COS. For the production of BTL synthesis gas, pressurised gasification has the potential to convert the wet residue below 77.3wt.% moisture contents.

Synthesis of functionalized 2-pyridones via Michael addition and cyclization reaction of amines, alkynes and dialkyl acetylene dicarboxylates

The Michael addition and three-component cyclization reaction of amines, alkynes and dialkyl acetylene dicarboxylates to form pyridones has been developed. Aliphatic amines and aromatic amines could selectively be converted into N-alkyl-disubstituted 2-pyridones and N-aryl-trisubstituted 2-pyridones with good yields in the presence of wet ethanol, which means a suitable amount of water is required for this reaction. The Michael addition and cyclization reaction process was confirmed through deuterium-labeling experiments, intermediates isolation and control experiments.

Wet ethanol in HCCI engines with exhaust heat recovery to improve the energy balance of ethanol fuels

This study explores the use of wet ethanol as a fuel for HCCI engines while using exhaust heat recovery to provide the high input energy required for igniting wet ethanol. Experiments were conducted on a 4-cylinder Volkswagen engine modified for HCCI operation and retrofitted with an exhaust gas heat exchanger connected to one cylinder. Tested fuel blends ranged from 100% ethanol to 80% ethanol by volume, with the balance being water. These blends are directly formed in the process of ethanol production from biomass. Comprehensive data was collected for operating conditions ranging from intake pressures of 1.4–2.0bar and equivalence ratios from 0.25 to 0.55. The heat exchanger was used to preheat the intake air allowing HCCI combustion without electrical air heating. The results suggest that the best operating conditions for the HCCI engine and heat exchanger system in terms of high power output, low ringing, and low nitrogen oxide emissions occur with high intake pressures, high equivalence ratios, and highly delayed combustion timings.Removing the final 20% of water from ethanol is a major energy sink. The results of this study show that HCCI engines can use ethanol fuels with up to 20% water while maintaining favorable operating conditions. This can remove the need for the most energy-intensive portion of the water removal process.

Second Law Assessment of a Wet Ethanol Fuelled HCCI Engine Combined With Organic Rankine Cycle

In this study, first and second law analyses of a new combined power cycle based on wet ethanol fuelled homogeneous charge compression ignition (HCCI) engine and an organic Rankine cycle are presented. A computational analysis is performed to evaluate first and second law efficiencies, with the latter providing good guidance for performance improvement. The effect of changing turbocharger pressure ratio, organic Rankine cycle (ORC) evaporator pinch point temperature, turbocharger compressor efficiency, and ambient temperature have been observed on cycle’s first law efficiency, second law efficiency, and exergy destruction in each of its component. A first law efficiency of 41.5% and second law efficiency of 36.9% were obtained for the operating conditions (T0 = 300 K, rp = 3, ηT = 80%). The first law efficiency and second law efficiency of the combined power cycle significantly vary with the change in the turbocharger pressure ratio, but the change in pinch point temperature, turbocharger efficiency, and ambient temperature shows small variations in these efficiencies. Second law analysis demonstrates well how the fuel exergy is used, lost, and reused in all of the cycle components. It was found that 78.9% of the total input exergy is lost: 2.0% to the environment in the flue and 76.9% due to irreversibilities in the components. The biggest exergy loss occurs in the HCCI engine which is 68.7%, and the second largest exergy loss occurs in catalytic converter, i.e., nearly 3.13%. Results clearly show that performance evaluation based on first law analysis alone is not adequate, and hence more meaningful evaluation must include second law analysis.

Future Testing Opportunities to Ensure Sustainability of the Biofuels Industry

For the soil and plant analysis community, development and expansion of biofuels will create many opportunities to provide a wide variety of analytical services. Our objective is to explore potential areas where those services could be marketed to support sustainable development of biofuels. One of the first is to provide soil fertility and plant nutrition information for sustainable feedstock production. Chemical, physical, and biological indicators of soil quality should also be monitored and interpreted using tools such as the soil management assessment framework (SMAF) to ensure soil resources can continue to meet global food, feed, and fiber demands as well as the new demands for biofuels. Feedstock sugar profile information will be needed to help manage conversion processes, calculate economic drivers such as the minimum ethanol selling price (MESP), and determine suitability for other bioproducts. There will also be an increasing need to evaluate a variety of coproducts created by corn (Zea mays) milling, soybean (Glycine max Merr.) processing, and the fledgling lignocellulosic conversion processes. For coproducts produced from wet or dry corn milling and dry grind ethanol production, accurate and efficient analysis and digestibility of fiber components [neutral detergent fiber (NDF), acid detergent fiber (ADF), and total dietary fiber (TDF)], amino acids (lysine, trypotophan, and methionine), fatty acids, and minerals (phosphorus and sulfur) will be needed. In addition, a capacity to accurately and rapidly detect contamination by mycotoxins such as aflatoxin, zearalenone, and fumonisisn or the presence of antibiotics such as penicillin or virginiamycin could potentially be important. For the biodiesel industry, methanol concentrations in crude glycerin must be reduced to meet Food and Drug Administration guidelines and quantified to ensure this coproduct is safe for use in livestock feeds. Finally, monitoring for several processes and coproducts associated with pyrolysis, a thermochemical platform for biomass conversion to bio-oils, biochar, and other products will be needed. We conclude that sustainable development of biofuel industries will have many positive benefits for soils, plant, and animal production systems and the analysts who will provide analytical services for monitoring all aspects of the biofuels industry.

Thermal Imaging of Solid Oxide Fuel Cell Anode Degradation with Dry and Wet Ethanol Fuel Flows

Near-infrared thermal imaging has been used to study the effects of humidifying ethanol fuel flows on the surface temperature of SOFC anodes. Temperatures were monitored for SOFCs operating with dry and wet ethanol fuel flows at 800 ºC. The results indicate a dramatic decrease in the amount of carbon that is formed when ethanol flows are humidified. Humidifying the fuel stream reduces both the cooling observed under ethanol fuel flow conditions and the heating observed under post-fuel flow electrochemical oxidation conditions. The spatial variation of the temperature is also reduced. Thermal imaging is capable of detecting fatigue in functioning cells because temperature variations observed in situ provide early signs of SOFC failure, therefore thermal imaging is a viable system diagnostic.

Experimental Investigation on Performance and Emission Characteristics of Low Heat Rejection Diesel Engine with Ethanol as Fuel

Problem statement: Depleting petroleum reserves on the earth and increasing concerns about the environment leads to the question for fuels which are eco-friendly safer for human beings. The objective of present work was to investigate the effect of coating on piston, cylinder head and valves of a Diesel engine on the performance and emission characteristics of exhaust gases using wet ethanol (5% water) as a fuel. Approach: In this study the effect of Zirconia coating on the performance and emission characteristics of diesel engine was investigated using ethanol as sole fuel. For this purpose the cylinder head, valve and piston of the test engine were coated with a partially stabilized Zirconia of 0.5 mm thick by the plasma spray coating method. For comparing the performance of the engine with coated components with the base engine, readings were taken before and after coating. To make the diesel engine to work with ethanol a modification was done. Results: The engine’s performance was studied for both wet ethanol and diesel with and without Zirconia coating. Also the emissions values are recorded to study the engine’s behavior on emissions. Satisfactory performance was obtained with Zirconia coating compared with a standard diesel engine. The brake thermal efficiency was increased up to 1.64% for ethanol with coating and there was a significant reduction in the specific fuel consumption. The NOx, CO and HC emissions in the engine exhaust decreases with coating. Conclusion: Using ethanol as sole fuel for a LHR diesel engine causes an improvement in the performance characteristics and significant reduction in exhaust emissions.

Thermal Imaging of Solid Oxide Fuel Cell Anode Degradation with Dry and Wet Ethanol Fuel Flows

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Investigation of a wet ethanol operated HCCI engine based on first and second law analyses

Abstract In this paper, a conceptual wet ethanol operated homogeneous charge compression ignition (HCCI) engine is proposed to shift the energy balance in favor of ethanol. The investigated option, HCCI engine is a relatively new type of engine that has some fundamental differences with respect to other prime movers. Combined first and second law of thermodynamic approach is applied for a HCCI engine operating on wet ethanol and computational analysis is performed to investigate the effects of turbocharger compressor ratio, ambient temperature, and compressor adiabatic efficiency on first law efficiency, second law efficiency, and exergy destruction in each component. First law and second law efficiencies are found to be an increasing function of the turbocharger pressure ratio, while they are found to be a decreasing function of the ambient temperature. The effect of turbocharger pressure ratio on exergy destruction is found to be more significant than compressor efficiency and ambient temperature. Exergy analysis indicates that maximum exergy is destroyed in HCCI engine which represents about 90.09% of the total exergy destruction in the overall system. Around 4.39% exergy is destroyed by the process of heat transfer in fuel vaporizer and heat exchanger. Catalytic converter contributes about 4.08% of the total exergy destruction. This will provide some original information on the role of operating variables and will be quite useful in obtaining the optimum design of ethanol fuelled HCCI engines.

Crystal structure versus solution for two new lutetium thiocyanato complexes

The comparative study of chemical reactivity between trivalent late actinides (An) and the lanthanides (Ln) has always been a challenging issue. For that purpose, soft donor ligands (containing for example sulfur atoms or more borderline N atoms) are known to have a relative tendency for higher interaction with the An(III) than with the Ln(III) metal cations. Consequently, thiocyanates have been envisioned as possible ligands for the selective complexation of heavy actinides (namely, Am and Cm) over lanthanides. This paper is an illustration of this approach and reports on the thiocyanate chemistry of lutetium. Three new complexes, 1, [n-(C4H9)4N]3[Lu(NCS)4(NO3)2], 2, K4[Lu(NCS)4(H2O)4](NCS)3(H2O)2 and for comparison 3, K4[Nd(NCS)4(H2O)4](NCS)3(H2O)2 have been characterized by X-ray single crystal diffraction. In addition, dissolution of the nitrato lutetium adduct (1) in wet ethanol solvent brings some valuable information about the structure of the cation coordination sphere in solution compared to the solid crystalline state. Another point of comparison comes from the dissolution of lutetium nitrate also in wet ethanol. In both cases, the cation's coordination sphere has been probed by IR and EXAFS at the Lu L3 edge. Additional comparison with molecular dynamic simulations of the lutetium-nitrate–ethanol (wet) system has been performed and coupled to the EXAFS data fitting. Upon dissolution of 1 as well as of lutetium nitrate, a decrease of the number of nitrate ligands has been observed. In the case of 1, a clear decrease of the number of thiocyanate ligand coordination has also been observed, leading to a strong rearrangement of the cation polyhedron from solid state to solution.

ChemInform Abstract: From Beer to Ethylbenzene in One-Step (Alkylation of Aromatics with Wet Ethanol)

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Conversion of wet ethanol to syngas via filtration combustion: An experimental and computational investigation

Ethanol is often promoted as the biofuel of the future, yet its acceptance as a fuel for combustion devices is limited by the cost of production. Since most combustion engines cannot tolerate high concentrations of water, the ethanol must be distilled and dehydrated, requiring large amounts of energy. Ethanol also has great potential as a feedstock for syngas consisting of hydrogen, carbon monoxide, and other species. The conversion, called reforming, of ethanol to syngas does not necessarily require dehydration or distillation, thus eliminating or reducing the costs associated with those processes. In addition, there is potential for obtaining additional hydrogen from the water in the mixture. In this paper, we investigate the conversion of wet ethanol, or ethanol that has not been fully distilled or dehydrated, to syngas in an inert porous reactor. Experimental and computational results over a range of equivalence ratios, inlet velocities, and water fractions are presented. The results indicate that wet ethanol is a promising biological source for hydrogen.

Effect of filler composition and crosslinker concentration on the tribological behavior of spent germ particle-based polymeric composites

Thermosetting composites have been prepared by the use of a biobased resin and spent germ filler, which is a byproduct from a wet ethanol production plant. Microscale tribological measurements were performed on samples with different concentrations of the filler as well as the crosslinker using a ball-on-flat reciprocating microtribometer. Microscale friction and wear behavior during dry sliding were evaluated using a spherical silicon nitride probe (radius 1.2mm) and a conical diamond (radius 100μm, cone angle 90°) probe to impose different contact conditions. Finally, a pin-on-disc tribometer was used to study the macroscale wear properties at high loads against an alumina pin. Scanning electron microscopy (SEM) images of wear tracks on the samples were obtained to elucidate deformation mechanisms. All samples showed evidence of abrasive wear in both micro- and macro-scales. It was found that an increase in the concentration of the filler resulted in higher friction coefficients against Si3N4, while an increase in the concentration of the crosslinker lowered the abrasive wear depth. These results provide some insight into the effectiveness of using biobased spent germ–tung oil polymer composites as potential tribomaterials.

Demonstrating direct use of wet ethanol in a homogeneous charge compression ignition (HCCI) engine

Abstract Homogeneous charge compression ignition (HCCI) engines are amenable to a large variety of fuels as long as the fuel can be fully vaporized, mixed with air, and receive sufficient heat during the compression stroke to reach the autoignition conditions. This study investigates an HCCI engine fueled with ethanol-in-water mixtures, or “wet ethanol”. The motivation for using wet ethanol fuel is that significant energy is required for distillation and dehydration of fermented ethanol (from biosources, not from petroleum), thus direct use of wet ethanol could improve the associated energy balance. Recent modeling studies have predicted that an HCCI engine can operate using fuel containing as little as 35% ethanol-in-water with surprisingly good performance and emissions. With the previous modeling study suggesting feasibility of wet ethanol use in HCCI engines, this paper focuses on experimental operation of a 4-cylinder 1.9-L engine running in HCCI mode fueled with wet ethanol. This paper investigates the effect of the ethanol-water fraction on the engine's operating limits, intake temperatures, heat release rates, and exhaust emissions for the engine operating with 100%, 90%, 80%, 60%, and 40% ethanol-in-water mixtures.

Improving Ethanol Life Cycle Energy Efficiency by Direct Utilization of Wet Ethanol in HCCI Engines

Homogeneous charge compression ignition (HCCI) is a new engine technology with fundamental differences over conventional engines. HCCI engines are intrinsically fuel flexible and can run on low-grade fuels as long as the fuel can be heated to the point of ignition. In particular, HCCI engines can run on “wet ethanol:” ethanol-in-water mixtures with high concentration of water. Considering that much of the energy required for processing fermented ethanol is spent in distillation and dehydration, direct use of wet ethanol in HCCI engines considerably shifts the energy balance in favor of ethanol. The results of the paper show that a HCCI engine with efficient heat recovery can operate on a mixture of 35% ethanol and 65% water by volume while achieving a high brake thermal efficiency (38.7%) and very low NOx (1.6ppm, clean enough to meet any existing or oncoming emissions standards). Direct utilization of ethanol at a 35% volume fraction reduces water separation cost to only 3% of the energy of ethanol and coproducts (versus 37% for producing pure ethanol) and improves the net energy gain from 21% to 55% of the energy of ethanol and coproducts. Wet ethanol utilization is a promising concept that merits more detailed analysis and experimental evaluation.