Higher Nitrogen Oxides Research Articles

WITHDRAWN: An empirical research on the investigation of DI diesel engine fuelled by ethanol

Abstract In Upcoming Generations of automotive industries and in the increasing in the demand for fossil fuel, renewable energy resources in easier form of extraction and utilization have been a finding of industries and consumers. Owing to that major causes of unburnt ignitions, engine performance, combustion laggings, injection timings and other factors an experimental investigation on a high ethanol DI diesel engine in a constant speed of an engine at different fuel ignition pressures has been observed. From this research the cylinder peak pressure attained at full load is 62.1 bar for standard injection timing and 64.4 bar for advanced injection timing. At this advanced pressure the efficiency of engine by means of Co, Unburned HC gases and smoke emissions with higher oxides of nitrogen was observed compared to diesel. The analysis draws the outcomes of ignition delay is minimised at higher injection of pressure and peak pressure also increasing at full load. Thus, the combustion of duration is similar in all variance in pressure. This research paved a way to bio-diesel in ethanol mixture and draws best outcome in emission less and to maintain eco-friendly environment.

Study of Annona squamosa as alternative green power fuel in diesel engine

In this study, the nano biochar derived from sugarcane was added with custard seed biodiesel (CBD) at different concentrations of 25 and 50 ppm to assist the emission and performance pattern of a compression ignition engine. The study monitored harmful gases, namely, hydrocarbon (HC), carbon monoxide (CO), nitrogen oxide (NO), and smoke as emission parameters and investigated brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) as performance parameters are analyzed at diverse loads by altering the concentration the biochar with CBD and compared with diesel. Experimental results revealed that the biochar addition at 50 ppm to CBD reduced smoke emission by 1.9%, CO by 0.005%, and HC by 6 ppm at all top load conditions with 71 ppm higher NO. Further, biochar addition at 50 ppm to CBD enhances the brake thermal efficiency by 0.7% and lower brake specific fuel consumption by 0.4 kg/kWh.

Rapid production of highly oxidized molecules in isoprene aerosol via peroxy and alkoxy radical isomerization pathways in low and high NOx environments: Combined laboratory, computational and field studies

Recently, we identified seven novel hydroxy-carboxylic acids resulting from gas-phase reactions of isoprene in the presence of nitrogen oxides (NOx), ozone (O3), and/or hydroxyl radicals (OH). In the present study, we provide evidence that hydroxy-carboxylic acids, namely methyltartaric acids (MTA) are: (1) reliable isoprene tracers, (2) likely produced via rapid peroxy radical hydrogen atom (H) shift reactions (autoxidation mechanism) and analogous alkoxy radical H shifts in low and high NOx environments respectively and (3) representative of aged ambient aerosol in the low NOx regime. Firstly, MTA are reliable tracers of isoprene aerosol because they have been identified in numerous chamber experiments involving isoprene conducted under a wide range of conditions and are absent in the oxidation of mono- and sesquiterpenes. They are also present in numerous samples of ambient aerosol collected during the past 20 years at several locations in the U.S. and Europe. Furthermore, MTA concentrations measured during a year-long field study in Research Triangle Park (RTP), NC in 2003 show a seasonal trend consistent with isoprene emissions and photochemical activity. Secondly, an analysis of chemical ionization mass spectrometer (CIMS) data of several chamber experiments in low and high NOx environments show that highly oxidized molecules (HOMs) derived from isoprene that lead to MTAs may be produced rapidly and considered as early generation isoprene oxidation products in the gas phase. Density functional theory calculations show that rapid intramolecular H shifts involving peroxy and alkoxy radicals possess low barriers for methyl-hydroxy-butenals (MHBs) that may represent precursors for MTA. From these results, a viable rapid H shift mechanism is proposed to occur that produces isoprene derived HOMs like MTA. Finally, an analysis of the mechanism shows that autoxidation-like pathways in low and high NOx may produce HOMs in a few OH oxidation steps like commonly detected methyl tetrol (MT) isoprene tracers. The ratio of MTA/MT in isoprene aerosol is also shown to be significantly greater in field versus chamber samples indicating the importance of such pathways in the atmosphere even for smaller hydrocarbons like isoprene.

Ammonia Combustion Catalysts

Abstract Recent developments for ammonia (NH3) combustion catalysts are covered in this highlight review. NH3 has been proposed as a renewable and carbon-free energy source. However, use of NH3 fuel poses the problems of high ignition temperature and nitrogen oxide (N2O/NOx) production. In order to overcome these issues, a novel catalytic combustion system was probed, and high performance catalysts were developed. This review introduces their research with including related studies.

Air Pollution Is Associated with Poor Cognitive Function in Taiwanese Adults.

The issue of air pollution is gaining increasing attention worldwide, and mounting evidence has shown an association between air pollution and cognitive decline. The aim of this study was to investigate the relationships between air pollutants and cognitive impairment using the Mini-Mental State Exam (MMSE) and its sub-domains. In this study, we used data from the Taiwan Biobank combined with detailed daily data on air pollution. Cognitive function was assessed using the MMSE and its five subgroups of cognitive functioning. After multivariable linear regression analysis, a high level of particulate matter with an aerodynamic diameter of ≤2.5 μm (PM2.5), low ozone (O3), high carbon monoxide (CO), high sulfur dioxide (SO2), high nitric oxide (NO), high nitrogen dioxide (NO2), and high nitrogen oxide (NOx) were significantly associated with low total MMSE scores. Further, high SO2 and low O3 were significantly associated with low MMSE G1 scores. Low O3, high CO, high SO2, high NO2, and high NOx were significantly associated with low MMSE G4 scores, and high PM2.5, high particulate matter with an aerodynamic diameter of ≤10 μm (PM10), high SO2, high NO2, and high NOx were significantly associated with low MMSE G5 scores. Our results showed that exposure to different air pollutants may lead to general cognitive decline and impairment of specific domains of cognitive functioning, and O3 may be a protective factor. These findings may be helpful in the development of policies regarding the regulation of air pollution.

Study of performance parameters and emissions of four stroke CI engine using solketal-biodiesel blends

Evaluation of performance parameters, emission and brake specific fuel consumption (BSFC) were made for different blends of solketal in soybean biodiesel with 9%, 10%, 12%, 15% of solketal (volume to volume). These experiments were performed on a single-cylinder water-cooled diesel engine at different speeds and 50% load conditions. In comparison to pure diesel, it was observed that soybean biodiesel and its blends with solketal were higher BSFC. On the addition of solketal to biodiesel higher oxides of nitrogen (NOx) and carbon dioxide (CO2) emissions were reported for all the blends. total hydro carbon (THC) and carbon mono-oxide (CO) emissions were found lower for soybean biodiesel and it’s all four blends as compared to pure diesel and further decreases with the increase in solketal percentage in a blend. A decrease in CO and THC emissions were also observed with the increase in percentage of Solketal fuels. Solketel was found suitable and as an effective additive for biodiesel blends.

Mineral-derived catalysts optimized for selective catalytic reduction of NOx with NH3

A type of novel mineral-derived catalyst (MDC) composed of vanadium–titanium magnetite and sintering ore was prepared via calcination or acid modification for selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3) to reduce the production cost and simplify the preparation process. Characterizations by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction of hydrogen (H2–TPR) characterizations were performed to observe the evolution of the physicochemical properties of the mineral catalyst during modification, which were corelated to their catalytic activity. The in-situ DRIFTS was also investigated to discuss the reaction mechanism for different catalysts. The results show that the mineral catalysts with sulfuric acid modification exhibit high NOx conversion (above 90% at 350 °C) and sulfur resistance due to the formation of ferric sulfate species and the presence of Fe3+/Fe2+ and V5+/V4+ couples in the catalysts that results in abundant Brønsted acid sites and promotes the redox properties of catalysts. The in-situ DRIFTS results indicate that the catalysts modified by calcination-pretreatment primarily follow the Langmuir-Hinshelwood (L–H) mechanism where gaseous NO is more easily adsorbed on α-Fe2O3 to form stable nitrates and react with a small number of NH3 species adsorbed on α-Fe2O3, leading to decreased activity. On the other hand, the catalysts modified with acid mainly follow the Eley-Rideal (E–R) mechanism in which adsorbed nitrogen species show less thermal stability and a large amount of adsorbed NH3 on the ferric sulfate species directly react with gaseous NO, resulting in the higher activity.

Assessment of wood chip combustion and emission behavior of different agricultural biomasses

The increased interest in using farm-grown biomass for energy production makes it necessary to expand and deepen knowledge on combustion of agricultural residues. The lack of data and studies on solid fuel quality, and combustion related emissions, represents an obstacle to the sustainable development of agricultural biomass industry. In the Mediterranean basin, large quantities of lignocellulosic biomass are obtained yearly from pruning operations carried out largely widespread in fruit plantations such as citrus, grapevine and olive orchards. The most common practice to eliminate this type of residue is the open burning, carried out directly on the field by farmers, without any emissions control or energy recovery. The aim of this study was to obtain a clear description of three different wood biomasses and their behavior during combustion. The physicochemical properties were studied to determine their influence on combustion emissions. Measurements were conducted in laboratory and subsequently carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), nitrogen oxides (NOx), sulfur dioxide (SO2), Total Organic Compounds (TOC), and particulate matter (PM) emissions were evaluated during combustion in a 30 kW boiler equipped with a multicyclone filter bags for emission abatement. Principal Component Analysis (PCA) was applied to the data of biomass properties and emissions parameters in order to elucidate which feedstock features had a more determinant influence on the combustion process. Grapevine and citrus showed high N content and consequent high NOx production. Olive highlighted the best characteristics, high energetic potential and low emissions under regulation limits; in addition, olive pruning residues is the most available woodfuel in the Mediterranean area of Europe, confirming its great potential on agricultural biomass industry sustainable development.

Effects of ethane addition on diesel-methane dual-fuel combustion in a heavy-duty engine

The present study is a continuation of the previous work by Ahmad et al. (2020), in which ethane (C2H6) enriched diesel-methane (CH4) dual-fuel (DF) combustion was experimentally investigated in a single-cylinder heavy-duty engine. Here, the experiments of ethane enriched DF combustion are carried out with new details together with supporting zero-dimensional (0D) and one-dimensional (1D) chemical kinetics simulations. Three port-fuel injected (PFI) gaseous blends of pure methane with varying ethane concentrations of 0%, 10%, and 20% are used as the main fuels. The PFI gaseous blend provides 97% of the total-fuel energy (TFE), which is ignited by a small 3% (TFE based) pilot diesel. Experiments are performed under lean condition (∅gas = 0.52) for two engine speeds while keeping the TFE and other operating conditions constant. Calculated results from 0D and 1D simulations under engine relevant conditions including theoretical combustion mode analysis (β-curve) are used to deepen the phenomenological understanding of the experimental results. The results reveal that adding ethane into pure methane has minor effects on the pilot-diesel ignition timing. However, ethane addition greatly enhances the ignitability of methane after the start of combustion. Ethane enriched gaseous blends yield higher thermal efficiency and reduce combustion duration compared to pure methane. According to combustion mode analysis, ethane tendency to promote spontaneous autoignition may be one of the reasons for improving overall combustion performance. It is observed that ethane enriched gaseous blends produce lower unburned methane (UB-CH4) and unburned hydrocarbons (THC) accompanied with higher nitrogen oxides (NOx) because of the higher combustion efficiency. Furthermore, ethane addition considerably helps to reduce cycle-to-cycle variations under lean conditions compared to pure methane.

Incorporating upstream emissions into electric sector nitrogen oxide reduction targets

Electricity production is a major source of air pollutants in the U.S. Policies to reduce these emissions typically result in the power industry choosing to apply controls or switch to fuels with lower combustion emissions. However, the life-cycle emissions associated with various fuels can differ considerably, potentially impacting the effectiveness of fuel switching. Life-cycle emissions include emissions from extracting, processing, transporting, and distributing fuels, as well as manufacturing and constructing new generating capacity. The field of life-cycle analysis allows quantification of these emissions. While life-cycle emissions are often considered in greenhouse gas mitigation targets, they generally have not been included in air quality policymaking. We demonstrate such an approach, examining a hypothetical electric sector emission reduction target for nitrogen oxides (NOx) using the Global Change Assessment Model with U.S. state-level resolution. When only power plant emissions are considered in setting a NOx emission reduction target, fuel switching leads to an increase in upstream emissions that offsets 5% of the targeted reductions in 2050. When fuel extraction, processing, and transport emissions are included under the reduction target, accounting for 20% of overall NOx reduction goal, the resulting control strategy meets the required reductions and does so at 35% lower cost by 2050. However, manufacturing and construction emissions increase and offset up to 7% of NOx reductions in electric sector, indicating that it may be beneficial to consider these sources as well. Assuming no legal obstacles exist, life-cycle-based approaches could be implemented by allowing industry to earn reduction credits for reducing upstream emissions. We discuss some of the limitations of such an approach, including the difficulty in identifying the location of upstream emissions, which may occur across regulatory authorities or even outside of the U.S.

Regulated, Unregulated, and Particulate Emissions From Biodiesel Blend Fueled Transportation Engine

Abstract Engine experiments were performed for measurement of regulated, unregulated, and particulate emissions using a 2.2 L transportation compression ignition engine fueled with blends of diesel and biodiesels derived from Jatropha and waste cooking oils. JB20 (20% v/v Jatropha biodiesel blended with 80% v/v diesel), WCOB20 (20% v/v waste cooking oil biodiesel blended with 80% v/v diesel), and baseline mineral diesel were used as test fuels in this study. Experiments were performed at an engine speed of 2000 rpm at five engine loads (0%, 25%, 50%, 75%, and 100% rated load). Regulated emission results exhibited that JB20 and WCOB20 emitted higher hydrocarbons and carbon monoxide (CO) at low engine loads compared to baseline diesel, whereas WCOB20 exhibited relatively higher oxides of nitrogen (NOx) emissions compared to baseline diesel. Unregulated emissions were higher at low engine loads and decreased with increasing engine load. Biodiesel blends showed relatively higher methane and ethylene trace emissions compared to baseline diesel, whereas WCOB20 showed higher formaldehyde, formic acid, iso-pentane, sulfur dioxide, and n-octane emissions compared to diesel at no load. Particulate number concentrations were relatively higher from biodiesel blends compared to baseline diesel at most engine operating conditions.

Study of Performance, Emissions, and Combustion of a Common-Rail Injection Engine Fuelled with Blends of Cocos nucifera Biodiesel with Diesel Oil

Renewable alternatives to fossil fuels, such as biodiesel, are necessary to lessen emission of greenhouse gases that are causing climate change. Using a high-pressure, medium-duty, common-rail, turbocharged four-cylinder diesel engine, this work studies the effect of adding Cocos nucifera biodiesel to conventional diesel on exhaust emissions, engine performance, and combustion characteristics. An analysis and characterization of the key physicochemical properties of diesel, biodiesel, and biodiesel–diesel blends were carried out. The engine was fuelled with pure petroleum diesel and blended diesel containing a 10%, 20%, 30%, and 50% volume of coconut oil at full throttle and six different speed settings, respectively. The results showed relatively close physicochemical properties between the biodiesel blend and conventional petroleum fuel. Observations made over the entire speed range indicated that a higher coconut oil biodiesel (COB) content lowers the torque and brake power compared to diesel. In the case of engine exhaust gas, a reduction in carbon monoxide (CO) and smoke emissions were observed. Notably, COB50 gives out the highest nitrogen oxides (NOx) but it is raised even for other blends. The experimental results also demonstrated that a higher COB content achieves a lower peak pressure while the peak heat release rate (PHRR) was lower than that of conventional diesel as the speed of the engine increases.

A comparative study of performance and emission characteristics of neat biodiesel operated diesel engine: a review

Environmental concern and fossil fuel depletion, researchers are forced to find alternate fuel lead to the internal combustion (IC) engines. One of the best options is biodiesel and substitute wholly or partially in the diesel engine for diesel fuel. It is obvious that the use of biodiesel in diesel engine reduced emissions such as Carbon monoxide (CO), hydrocarbon (HC), and smoke because of its higher oxygen content. The drawback of neat biodiesel-operated diesel engine is higher oxides of nitrogen (NOx) and lower performance. In order to improve the brake thermal efficiency and to reduce the emissions of diesel engine using neat biodiesel, a detailed review has been carried out in the present study. The in-cylinder treatment method is the most suitable because the efficiency and emission can be modified in the combustion chamber itself which will make it a viable solution for diesel engines. Neat nerium biodiesel with ZrO2-coated piston and l-ascorbic acid of are combined together and experiments are conducted. From the investigation, it has been found that ZrO2-coated piston and nerium biodiesel with l-ascorbic acid showed better results, which is very closer to diesel when compared in all aspects. From the investigation, it has been found that catalyst-coated piston with biodiesel along with antioxidant additive showed better results, which is very closer to diesel when compared in all aspects.

Why is the Indo-Gangetic Plain the region with the largest NH<sub>3</sub> column in the globe during pre-monsoon and monsoon seasons?

Abstract. Satellite observations show a global maximum in ammonia (NH3) over the Indo-Gangetic Plain (IGP), with a peak from June to August. However, it has never been explained explicitly. In this study, we investigated the causes of high NH3 loading over the IGP during the pre-monsoon and monsoon seasons using WRF-Chem (Weather Research and Forecasting model coupled to chemistry). The IGP has relatively high NH3 emission fluxes (0.4 t km−2 month−1) due to intensive agricultural activities and high air temperature from June to August. Additionally, low sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions and high air temperature limit the gas-to-particle conversion of NH3, particularly for ammonium nitrate formation. Moreover, the barrier effects of the Himalayas in combination with the surface convergence weaken the horizontal diffusion of NH3. The high NH3 loading over the IGP mainly results from the low gas-to-particle partitioning of NH3 caused by low SO2 and NOx emissions. It contrasts to those in the North China Plain, where high SO2 and NOx emissions promote the conversion of gaseous NH3 into particulate ammonium.

CFD Simulation and a Pragmatic Analysis of Performance and Emissions of Tomato Seed Biodiesel Blends in a 4-Cylinder Diesel Engine

Rising global concerns about global warming caused by pollution from excessive fossil fuels consumption, along with the high price of them in diesel engines, are the important reasons to search for fuels which is readily available and do not have destructive effects on the environment. Biodiesel is arguably the most appropriate and sustainable alternative to diesel fuel. Tomato seeds are one of the potential sources of biodiesel. They make up about 72% by weight of tomato waste, which contains an average of 24% oil. Tomato seed oil (TSO) can be used as a cheap and non-edible source of biodiesel. This paper investigated, both experimentally and numerically, the effects of different diesel–TSOB (tomato seed oil biodiesel) blends on the performance and emissions parameters of a four-cylinder, four-stroke, indirect injection diesel engine. The main goal of the paper was the simulation of the formation process of the emissions in the combustion chamber. The experimentally measured parameters such as torque, brake specific fuel consumption, exhaust gas temperature, nitrogen oxides, carbon monoxide, carbon dioxide, particulate matter, peak in-cylinder pressure, in-cylinder temperature and Reaction_Progress_Variable at different engine loads and speeds from 1200 to 2400 rpm at increments of 200 rpm are analyzed through ANOVA. The highest brake specific fuel consumption (BSFC) was observed for pure diesel and the lowest for the fuel blend with 10% biodiesel. The fuel blend with 20% biodiesel produced the highest torque. The engine was modeled using the AVL FIRE software. The model simulation results revealed that the highest nitrogen oxide (NOx) is produced in the throat of the combustion chamber to the top of the piston, the place of carbon dioxides (CO2) formation is near the combustion chamber boundaries and the location of carbon monoxides (CO) formation is near the combustion chamber boundaries and at the center area of the top of the piston. These results also show that the particulate matter (PM) emissions are formed where the fuel is injected into the combustion chamber.

Evaluation of Low-Temperature NOx Removal Over Ag/ZSM5 and Cu/ZSM5 Catalysts Coupled With Plasma

A high nitrogen oxides (NOx) removal rate under fluctuating temperature condition still remains a challenge to be solved. The plasma can be a potential solution to overcome this problem. This article reported catalytic NOx removal coupled with plasma in a wide temperature range below 350 °C. Silver (Ag) and copper (Cu) supported on ZSM5 zeolite were used as the catalysts to remove NOx. The results showed that the NOx removal rate over Ag/ZSM5 was higher than that over Cu/ZSM5. The NOx removal efficiency based on Ag/ZSM5 catalyst coupled with plasma exceeded 80% at low operating temperatures. The oxidation of NO to NO2 was approximately 100% at temperatures of 200–300 °C. Plasma-catalytic NOx removal mechanisms at low temperatures were discussed. This article demonstrated that the plasma-coupled Ag/ZSM5 catalyst can be an efficient solution for low-temperature NOx removal.

Numerical simulation on optimization of structure and operating parameters of a novel lean coal decoupling burner

Abstract Due to its low volatile characteristics of lean coal, it is difficult to catch fire and burn out. Therefore, high temperature is needed to maintain combustion efficiency, while, this leads to high nitrogen oxide emission. For power plant boilers burning lean coal, stable combustion with lower nitrogen oxide emission is a challenging task. This study applied the 3D numerical simulation on the analysis of a novel de-coupling burner for low-volatile coal and its structure and operation parameters optimization. Results indicate that although it was more difficult for lean coal decoupling burner to ignite lean coal than high volatile coal, the burner formed a stepwise ignition trend, which promoted the rapid ignition of lean coal. Comparison of three central partition plate structure shows that in terms of characteristics of the flow field distribution, rich and lean separation and combustion, the structure with an inclination of 0 ° showed good performance, with its rich-lean air ratio being 0.85 and concentration ratio being 22.94, and there was an apparent decoupling combustion characteristic. Finally, the structure of the selected burner was optimized for its operational conditions. The optimal operating parameters was determined as the primary air velocity of 24.9 m/s and the mass flow rate of pulverized coal of 2.5 kg/s, in which the pyrolysis products were utilized as reductive agent more fully. Eventually, the nitrogen oxide was efficiently reduced to nitrogen, which emission concentration was 61.88% lower than that in the design condition.

Passive Nitrogen Oxides Removal from a Diesel-engine Exhaust Gas using a Biomass-Carbon Catalyst

Nitrogen oxides (NOx) removal from a diesel-engine exhaust gas is limited to the utilization of ammonia/urea as a reducing agent (SCR) which arose environmental concerns over the use of this chemical. Therefore, this study explored the potential of a sustainable NOx removal system by replacing ammonia with intrinsic reductants present in the exhaust gas such as hydrocarbons and carbon monoxide, and by application of cost-effective carbon-supported transitional metals catalyst. Copper-cerium catalyst supported over palm kernel shell activated carbon (Cu-Ce/PKS) was synthesized via deposition-precipitation method. The characterization shows that the catalyst has a considerably high surface area (though lower than the support). The high NOx removal by Cu-Ce/PKS in a passive catalytic reaction is attributed to the surface area provided by the carbon support, the low copper reducibility giving the low optimum operating temperature, and the synergistic effect between Cu and Ce resulting in the wide temperature window at low-temperature range. It is concluded that Cu-Ce supported over palm kernel shell activated carbon can be further developed to reduce NOx in a passive catalytic removal for a sustainable and cost-effective SCR system.

Propagation and emissions of premixed methane-ammonia/air flames

In order to investigate the possible use of methane (CH4)-ammonia (NH3) blends as a low carbon fuel, the combustion characteristics of expanding spherical premixed CH4-NH3/air flames are studied, measuring and predicting their laminar burning velocities (SL∞), Markstein numbers (Ma) and structure. Results show that the premixed CH4-NH3/air flames are thicker and propagate slower than the pure CH4/air flames, with reduced carbon dioxide (CO2) emissions. Meanwhile, both flames are cellularly stable for the present various test conditions, showing 0.3 < Ma < 2.1, and this observation is weakly affected by the concentration of NH3 in the fuel blend. Moderate reduction in SL∞, i.e., reasonable burning intensity for practical applications, of the CH4-NH3/air flames even with reduced CO2 emissions supports the possible use of CH4-NH3 blends as a low carbon fuel. However, the problem of high local nitrogen oxides (NOx) emissions in the present flame configuration should be resolved for their practical application. The quantitative discrepancies between the measurements and predictions for a few conditions despite their generally and qualitatively good agreement indicate that a new mechanism optimized for the oxidation of CH4-NH3 blends at atmospheric condition is needed since no reaction mechanism for it is currently available.

A review on cold flow properties of biodiesel and their improvement

The depletion of petroleum derivatives and expanded contamination caused by the consuming of fossil fuel is a driving component to consider the renewable source. Biodiesel is considered as most promising fuel to use in diesel engines. Biodiesel obtains from animal fats, Straight vegetable oils and waste by transesterification and esterification process. The properties of biodiesel oil meet the requirement of fuels and it can build a huge positive impact on pollution and make the fuel eco-friendly. Biodiesel with its points of interest undergoes a notable downside in the low-temperature properties. Due to inferior low-temperature properties of biodiesel, fuel crystallization and gum formation occur at low-temperature which leads to stopping of channels and tubes. It indicated higher pour point and cloud point, higher nitrogen oxide (NOx) which cuts down engine speed and power, injector coking. The present study review is done on low-temperature properties and Impact of different actions taken to improve these properties.