Fuel Communications最新文献

Fusel alcohol mixtures containing ethanol, isobutanol, isopentanol, and 2-phenylethanol have been shown to be a promising means to maximize renewable fuel yield from various biomass feedstocks and waste streams. We hypothesized that use of these fusel alcohol mixtures as a blending agent with gasoline can significantly lower the greenhouse gas emissions from the light-duty fleet. Since the composition of fusel alcohol mixtures derived from fermentation is dependent on a variety of factors such as biocatalyst selection and feedstock composition, multi-objective optimization was performed to identify optimal fusel alcohol blends in gasoline that simultaneously maximize thermodynamic efficiency gain and energy density. Pareto front analysis combined with fuel property predictions and a Merit Score-based metric led to prediction of optimal fusel alcohol-gasoline blends over a range of blending volumes. The optimal fusel blends were analyzed based on a Net Fuel Economy Improvement Potential metric for volumetric blending in a gasoline base fuel. The results demonstrate that various fusel alcohol blends provide the ability to maximize efficiency improvement while minimizing increases to blending vapor pressure and decreases to energy density compared to an ethanol-only bioblendstock. Fusel blends exhibit predicted Net Fuel Economy Improvement Potential comparable to neat ethanol when blended with gasoline in all scenarios, with increased improvement over ethanol at moderate to high bio-blendstock blending levels. The optimal fusel blend that was identified was a mixture of 90% v/v isobutanol and 10% v/v 2-phenylethanol, blended at 45% v/v with gasoline, yielding a predicted 4.67% increase in Net Fuel Economy Improvement Potential. These findings suggest that incorporation of fusel alcohols as a gasoline bioblendstock can improve both fuel performance and the net fuel yield of the bioethanol industry.

This article presents the actual AFR of the vehicular emission from the tailpipe data of motorcycles with petrol engine in Southwest Nigeria. It also presents the ratio between the actual air-fuel ratio (AFR_actual) and the ideal/stoichiometric air-fuel ratio (AFR_ideal) known as the equivalence air-fuel ratio or lambda (λ). This was compared with the expected value for lambda by the catalytic technology for exhaust gases emission, which is 1 (± 5%). In this study, over 95% of the sampled motorcycles have higher lambda values than expected, thereby emitting very high concentrations of carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO₂). The Portable, Hand-Held, battery-operated Kane automotive 4-gas analyser with detector tube (Model Auto 4-1) was used to measure the automobile emissions. The air-fuel ratio is a significant indicator and very important measure for gasoline engine performance controlling and tuning, and anti vehicles exhaust emissions pollution reasons [1]. Internal combustion (IC) gasoline fuelled engines exhaust gases emission depend heavily and mainly on the air-fuel ratio. For a gasoline fuelled engine, carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) exhaust gases emission are significantly influenced by air-fuel ratio. CO and HC are majorly generated or produced with rich air–fuel mixture, while NOx with lean air-fuel mixtures which mean that there is no fixed air-fuel mixture for which it can obtain the minimum for all exhaust gases emission [2]. This study can help in reducing fuel consumption, improving the quality of fuel combustion and reducing vehicle exhaust emissions in Nigeria.

The efficiency of R600a an eco-friendly refrigerant with graphene nanolubricant was investigated and compared in a domestic refrigerator with R134a refrigerant a zero Ozone Depleting Potential (ODP) but higher Global Warming Potential (GWP) refrigerant. Type K thermocouples were attached to the refrigerator components to track the temperature of the system. Two pressure gauges were also attached to the compressor to determine the pressure at suction and discharge of the domestic refrigerator. A digital wattmeter was used to measure the refrigerator's compressor power consumption. The results showed the evaporator air temperature and pull-down time of R600a with graphene nanolubricant were lower compared to R134a. A higher COP was achieved with R600a in graphene nanaolubricant with an increase in cooling capacity within the range of 5.2% to 14.2% and the power consumption reduced within the range of 8.8% to 26.4%. Hence, R600a/graphene nano lubricant can successfully replace R134a/POE oil in a domestic refrigerator system.

In this work, the tolerance window defined as the variations of gains and penalty associated with the earliness component of the Linear Composite Objective Function (LCOF) of Earliness–Tardiness (E/T) scheduling problems were explored to establish three different classes of the problem. Two variants of E/T problems has been established in the literature; the problems with unknown due-date with the objective of optimizing jobs due-date and the problems with a known due-date for optimizing the E/T cost function. The latter variant considered in this work applies the concept of Just-In-Time (JIT) as the basis for optimizing the E/T cost function. However, while the ideal JIT schedule which tends towards zero LCOF is notional, the deviation is a function of the tolerance window. To the best of the researchers’ knowledge, there is a gap between the measures of the deviation called the delivery reliability or penalty cost function and the tolerance window. This work closes the gap. A numerical example was solved to demonstrate the three problem classes’ utility using the Early Due Date (EDD) algorithm as the hypothetical solution.

One of the most effective passive techniques for heat transfer enhancement in heat exchanger devices is the surface roughness flow augmentation model. In this study, the surface pressure and heat transfer are measured using experimental and computational methods in a rectangular channel. Three aspect ratios, AR, 0.05, 0.035, and 0.025, dimple channel with pitch to depth ratios, P/δ = 6 are tested in this study. The angled dimple surface comprises of two cases; case 1 0 °Circular - 45°Oval dimple (0 °C – 45°O) and Case2 45° Oval - 0° Circular dimple (45° O – 0 °C). The computational study is conducted for Reynolds number, Re 600–11000. The data from the compound-dimple channel is normalized with the smooth channel data of heat transfer and friction factor parameters. It is revealed that friction factors, f, friction factors ratio, f/f_o, average Nusselt number, Nu_avg, Nusselt number ratios, Nu/Nuo, are dependent on Re. The performance index on the compound dimple surface using the ratio of Nusselt numbers, Nu/Nu_o, to friction factors, f/f_o. The arrangement and location of the dimple have momentous consequences for the pressure drop parameters f and f/f_o. The surface pressure and temperature show that the flow is uniformly distributed in the channel. The performance index improves and Re has strong influence on it. The compound dimple geometry does indicate a strong model for application in heat exchanger devices. Optimum performance of 49% for case 1 and 23% for case 2 are observed.

Ammonia pyrolysis reactions have implications for its ignition and oxidation in engines and gas turbines. In the present work, the chemistry of ammonia pyrolysis is investigated by kinetic modeling and theory. Rate constants for key reactions are carefully evaluated based on available experimental and theoretical results. The high pressure limit k${}_{1,\infty }$ for NH${}_2$ + H (+M) $\rightleftarrows$ NH${}_3$ (+M) (R1) is calculated to be essentially the collision frequency, indicating that dissociation of ammonia in combustion processes will be at or close to the low pressure limit even at engine and gas turbine conditions. The chemical kinetic model is validated against reported shock tube measurements of NH${}_3$, NH${}_2$, and NH in ammonia pyrolysis. Predictions are in good agreement with observations for dilute conditions ($\le$ 0.5% NH${}_3$), but the model appears to underpredict the NH${}_3$ consumption rate at longer times in less dilute mixtures. At short reaction times, thermal dissociation of NH${}_3$, together with the NH${}_3$ + H reaction, controls conversion. At longer times, secondary reactions involving NH${}_2$ and NH become important due to their impact on the radical pool. Predictions become sensitive to formation and consumption of diazene (tHNNH and cHNNH). Several of the key steps in the ammonia pyrolysis mechanism are radical-radical reactions that are difficult to measure accurately and challenging to calculate theoretically, and a more comprehensive experimental characterization is desirable to support further model development.

Harmful substance tends to come into water bodies through geodesic and human-induced sources, therefore persistent drinking water monitoring schemes are crucial. The goal of this paper was to estimate the human health threat posed through high sodium and iron accumulation in borehole water used for both consumption and domestic activities. As this will help in the prevention of water-related sicknesses and maintenance of good health for human being that rely on water to survive. Specially, rural region need to be enlightened about biochemistry of the mineral elements ingested, since excessive intake of some minerals can upset homeostatic balance and cause toxic side effects. For instance, excess sodium ingestion ensuing from daily intake of saline origins is associated with high blood pressure, while excess iron intake can stimulate liver impairment or brain damage which connected to aging and protein-misfolding neurodegenerative ailments. More importantly, when an individual suffering from a chronic sickness take prescriptions with water of unknown quality as human being believes that groundwater possess safe water quality, the health situation becomes worst. In this paper, iron accumulation in borehole water varied at distinct sites, span between 0.01 mg/L and 2.95 mg/L with a mean value of 1.02 mg/L whereas that of sodium range from 55.98 mg/L to 515.45 mg/L with mean value of 260.19 mg/L. The Hierarchical cluster scrutiny revealed three common clusters wherein the samplings could be grouped. The non-carcinogenic threat was calculated and the Total Threat Index above 1.0 for sodium ingestion in the scrutinized sites was gotten from all locations.

This research investigates the use of biogas to run a spark ignition petrol engine and test for the engine performance. Conventional spark ignition petrol engine was modified into a dual fuel engine by changing the engine single fuel carburettor to dual fuel carburettor. The air orifice was closed by 50% to enable cooled start with natural biogas as the low calorific value won't facilitate combustion. The speed, torque, and other engine parameters where measured using a TD200 small engine test set (hydraulic brake dynamometer) interface and emissions of SO₂, CO were measured using an emissions analyser. The torque, brake power was higher for petrol by 39% than the biogas due to the lower calorific value of biogas. The exhaust temperature, SO₂ and CO was 49% lower for the biogas than the petrol. The comparative analysis of the modified engine showed that petrol can be substituted partly with biogas and the engine used for varying applications because it offers window escape on the hydrocarbon reservoir depletion, green gasses emission from the use of these petrol and landfill emission as well.

This paper looks into the issues around renewable energy with a view to identify the opportunities for Nigeria and critically review the nation's renewable energy policy vis-à-vis the efforts and achievement of governments and indigenous practitioners. It identified the inherent opportunities of renewable energy resources at ameliorating the incidents of climate change and global warming and also surveyed international statistics on the relationships between energy and renewable energy adoption, national development, population explosion, job creation and rural-urban integration. It found out that for Nigeria to sustain economic growth especially as it relates to agriculture and food security, renewable energy for power generation must be included in the nation's rural development plan. It also demonstrated that renewable energy poses an opportunity for mitigating the nation's contributions to anthropogenic climate change.