Performance and Environmental Impact Assessment of Diesel Engine Operating on High Viscous Punnai Oil - Diesel Blends

The increasing demand for energy consumption because of the growing population and environmental concerns has motivated the researchers to ponder about alternative fuel that could replace diesel fuel. A new fuel should be cheaply available, clean, efficient, and environmentally friendly. In this paper, the engine operated with neat punnai oil blends with diesel were investigated at various engine load conditions, keeping neat punnai oil and diesel as base fuels. The performance indicators such as Brake Specific Energy consumption (BSEC), Brake thermal efficiency (BTE) and Exhaust gas temperature (EGT); emission indicators such as Carbon monoxide (CO), Oxides of Nitrogen (NOx), smoke opacity; and combustion parameters like cylinder pressure and heat release rate were examined. The Brake thermal efficiency of diesel is 29.2% whereas, it was lower for neat punnai oil and its blends at peak load conditions. Concerning the environmental aspect, Oxides of Nitrogen emission showed a decreasing trend with higher smoke emissions for Punnai oil blends. Detailed combustion analysis showed that on smaller concentrations of punnai oil in the fuel blend, the duration of combustion has improved significantly. However, for efficiency and emissions, the P20 (20% Punnai oil and 80% Diesel) blend performs similar to that of diesel compared to all other blending combinations. When compared with diesel, the P20 blend shows an improvement in BSEC by 26.37%. It also performs closer in HC emission, a marginal increase in smoke opacity of 4% with reduced NOx and CO2 emission of 7.9% and 4.65% respectively. Power loss was noticed when neat punnai oil and higher blends were used due to the high density and low calorific value of punnai oil blends which leads to injecting more fuel for the same pump stroke.

Possibilities of Ammonia as Both Fuel and NOx Reductant in Marine Engines: A Numerical Study

Nowadays, the environmental impact of shipping constitutes an important challenge. In order to achieve climate neutrality as soon as possible, an important priority consists of progressing on the decarbonization of marine fuels. Free-carbon fuels, used as single fuel or in a dual-fuel mode, are gaining special interest for marine engines. A dual fuel ammonia-diesel operation is proposed in which ammonia is introduced with the intake air. According to this, the present work analyzes the possibilities of ammonia in marine diesel engines. Several ammonia-diesel proportions were analyzed, and it was found that when the proportion of ammonia is increased, important reductions of carbon dioxide, carbon monoxide, and unburnt hydrocarbons are obtained, but at the expense of increments of oxides of nitrogen (NOx), which are only low when too small or too large proportions of ammonia are employed. In order to reduce NOx too, a second ammonia injection along the expansion stroke is proposed. This measure leads to important NOx reductions.

A modelling assessment of hydrocarbons (HC) and oxides of nitrogen (NOx) from transport sectors over Delhi

Two models IT Line Source Model (IITLS) and H1WAY-2 model have been used to estimate the concentrations of the hydrocarbons (HC) and oxides of nitrogen (NOx) due to transportation sector. An elaborate source inventory for the extrapolation of the HC and NO. emissions by vehicular transport has been developed in IITLS model. The model's predicted concentrations have been compared with the observed values at three receptors namely, Mool Chand, Ashram and AIIMS in Delhi. A statistical error analysis of the model's results and observed values has been made for evaluating the model 's performance. In the present study, it has been observed that IITLS model performs better than HIWAY-2 model.

NUMERICAL STUDY ON NOX EMISSION REDUCTION MECHANISM OF HCCI MARINE DIESEL ENGINE FOR IMO TIER III EMISSION LIMITS

With the advantages of ultra-low emissions of oxides of nitrogen (NOX) and high thermal efficiency, the homogeneous charge compression ignition (HCCI) mode applied to marine diesel engine is expected to be one of the technical solutions to meet the International Maritime Organization (IMO) MARPOL73/78 Convention-Annex VI Amendment Tier III requirement. According to the NOX chemical reaction mechanism, taking a marine diesel engine as the application object, the numerical study on the NOX formation characteristics of n-heptane for HCCI combustion process is performed. The results indicate that NO is usually the main component in the generation and emissions of NOX with the n-heptane HCCI mode. The combustor temperature plays more important role in the proportion of NO generation and emission. Compared with the experimental data of conventional marine diesel engine, the emission reduction rate of NOX can achieve an average of more than 95% in using HCCI technology.

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF NOx AND OTHER POLLUTANTS IN THE MAN B&W 7S50MC MARINE ENGINE AND EFFECT OF EGR AND WATER ADDITION

Marine engines represent a significant contribution to global emissions. In order to overcome this problem, a great attention was given to reduce their exhaust emissions in the last years, and marine engines have to adapt to regional, national and international restrictions. In this regard, the purpose of this paper is to develop a numerical model to study NOx (oxides of nitrogen) and other pollutants in engines. EGR and water addition were studied too as measures to reduce NOx. The main advantage of this study is that it provides a cheap and fast method to analyze emissions, contrary to experimental setups which are too expensive and laborious. Particularly, a commercial marine engine was analyzed and validated with experimental data. Results showed that increasing EGR and water addition leads to reduce NOx, but increase carbon monoxide and unburnt hydrocarbons due to an incomplete combustion.

Analysis of the Pre-Injection System of a Marine Diesel Engine Through Multiple-Criteria Decision-Making and Artificial Neural Networks

The present work proposes several pre-injection patterns to reduce nitrogen oxides in the Wärtsilä 6L 46 marine engine. A numerical model was carried out to characterise the emissions and consumption of the engine. Several pre-injection quantities, durations, and starting instants were analysed. It was found that oxides of nitrogen can be noticeably reduced but at the expense of increasing consumption as well as other emissions such as carbon monoxide and hydrocarbons. According to this, a multiple-criteria decision-making (MCDM) model was established to select the most appropriate parameters. Besides, an artificial neural network (ANN) was developed to complement the results and analyse a huge quantity of alternatives. This hybrid MCDM-ANN methodology proposed in the present work constitutes a useful tool to design new marine engines.

Spatio-temporal variations of lower tropospheric pollutants and their relation with meteorological factors in Karachi, Pakistan

Despite being one of the most populated cities globally, the air quality of Karachi is hardly ever comprehended. The present paper investigates the outdoor concentrations of 10 air pollutants, viz. NO, NO2, NOx, SO2, CO, O3, CH4, methane carbon, non-methane hydrocarbons, and total hydrocarbons at three different city sites, viz., Sohrab Goth, Defense Housing Authority, and North Nazimabad. The results demonstrate that these pollutants severely affected the city's air quality. The annual mean concentrations of both NO2 and SO2 exceeded the WHO guidelines at some study sites. The city experiences varied concentrations of major air pollutants because three types of fuel, viz. diesel, gasoline, and compressed natural gas, operate the motor vehicles in this conurbation. The study also correlates the various air pollutants with each other and with various meteorological factors. All the three oxides of nitrogen are statistically associated at all three sites with one another, with SO2 at Defense Housing Authority, with CO at North Nazimabad, and with meteorological factors at Sohrab Goth and Defense Housing Authority. Carbon monoxide is statistically associated with the meteorological factors only at North Nazimabad. The study suggests that higher air pollution in the city is due to the adoption of lenient vehicular emission standards because stringent emission standards cannot be adopted due to the non-availability of low or zero sulfur fuel. Moreover, ineffective regulation of exiting standards also contributes to higher vehicular emissions in the city.

Impact of Diwali firework emissions on air quality of New Delhi, India during 2013-2015

Diwali is one of the major and most important festivals celebrated all over India which falls in the period late October to early November every year. It is associated with burning of firecrackers especially during the night of Diwali day that leads to degradation of air quality that lasts for a longer duration of time. Firecrackers on burning releases huge amount of trace gases such as NOx, CO, SO2 and O3 and huge amount of aerosols and particulate matter. The present study focuses on the influence of firecrackers emissions on surface ozone(O3) ,oxides of nitrogen (NOx) and particulate matter (PM10 and PM2.5)concentration over the capital urban metropolis of India, New Delhi during Diwali festivity period from 2013-2015. A sharp increase is observed in surface ozone, NOx and particulate matter concentration during the Diwali day as compared to control day for 2013 to 2015 which is mainly attributed to burning of firecrackers. However the average concentration levels of the gaseous pollutants and particulate matter (PM10 and PM2.5) on Diwali day exhibited a decline in 2015 and 2014 as compared to 2013 due to increase in awareness campaigns among public and increased cost of firecrackers.

Deferoxamine Treatment Improves Antioxidant Cosmeceutical Formulation Protection against Cutaneous Diesel Engine Exhaust Exposure

Skin is one of the main targets of the outdoor stressors. Considering that pollution levels are rising progressively, it is not surprising that several cutaneous conditions have been associated with its exposure. Among the pollutants, diesel engine exhaust (DEE) represents one of the most toxic, as it is composed of a mixture of many different noxious chemicals generated during the compression cycle, for ignition rather than an electrical spark as in gasoline engines. The toxic chemicals of most concern in DEE, besides the oxides of nitrogen, sulfur dioxide and various hydrocarbons, are metals that can induce oxidative stress and inflammation. The present study aimed to evaluate the effects of topical application, singularly or in combination, of the iron-chelator deferoxamine and a commercially available formulation, CE Ferulic, in up to 4-day DEE-exposed skin. DEE induced a significant increase in the oxidative marker 4-hydroxy-nonenal (4HNE) and matrix-metallopeptidase-9 (MMP-9), the loss of cutaneous-barrier-associated proteins (filaggrin and involucrin) and a decrease in collagen-1, while the formulations prevented the cutaneous damage in an additive manner. In conclusion, this study suggests that iron plays a key role in DEE-induced skin damage and its chelation could be an adjuvant strategy to reinforce antioxidant topical formulations.