In this study, Sulphated/AlMCM-41 (S/AlMCM-41) catalysts were synthesized and used to produce biodiesel from CFMO. Different percentages of S/AlMCM-41 catalysts were prepared and characterized by X-ray diffraction, BET studies, TPD, and SEM-EDS analysis. Sulphur incorporation to the MCM framework though reduced the surface area, and pore volume of the catalyst, sufficient acidity were produced in the catalyst surface. The existence of functional groups and the composition of the biodiesel obtained was analysed by FTIR and GC-MS. S/AlMCM-41 (80%) catalyst presented a high catalytic activity with maximum biodiesel conversion % when compared to other variants. The bio-ester produced from CFMO with S/AlMCM-41 (80%) catalyst possessed the higher calorific value of 50 MJ/kg and flashpoint of 153 °C and other properties analogous to the standard biodiesel. The engine performance was examined for biodiesel blends with neat diesel, where biodiesel blends performed better than neat diesel. The exhaust gas emission studies also highlighted that the obtained biodiesel showed emission characteristics similar to the standard biodiesel, whereas marginally higher emission for CO and CO2 of about 2.2 and 7.9% was reported.
This comprehensive paper conducts an in-depth review of personal exposure and air pollutant levels within the microenvironments of Asian city transportation. Our methodology involved a systematic analysis of an extensive body of literature from diverse sources, encompassing a substantial quantity of studies conducted across multiple Asian cities. The investigation scrutinizes exposure to various pollutants, including particulate matters (PM10, PM2.5, and PM1), carbon dioxide (CO2), formaldehyde (CH2O), and total volatile organic compounds (TVOC), during transportation modes such as car travel, bus commuting, walking, and train rides. Notably, our review reveals a predominant focus on PM2.5, followed by PM10, PM1, CO2, and TVOC, with limited attention given to CH2O exposure. Across the spectrum of Asian cities and transportation modes, exposure concentrations exhibited considerable variability, a phenomenon attributed to a multitude of factors. Primary sources of exposure encompass motor vehicle emissions, traffic dynamics, road dust, and open bus doors. Furthermore, our findings illuminate the influence of external environments, particularly in proximity to train stations, on pollutant levels inside trains. Crucial factors affecting exposure encompass ventilation conditions, travel-specific variables, seat locations, vehicle types, and meteorological influences. The culmination of this rigorous review underscores the need for standardized measurements, enhanced ventilation systems, air filtration mechanisms, the adoption of clean energy sources, and comprehensive public education initiatives aimed at reducing pollutant exposure within city transportation microenvironments. Importantly, our study contributes to the growing body of knowledge surrounding this subject, offering valuable insights for policymakers and researchers dedicated to advancing air quality standards and safeguarding public health.
With the synchronous development of highway construction and the urban economy, automobiles have entered thousands of households as essential means of transportation. This paper reviews the latest research progress in using phytoremediation technology to remediate the environmental pollution caused by automobile exhaust in recent years, including the prospects for stereoscopic forestry. Currently, most automobiles on the global market are internal combustion vehicles using fossil energy sources as the primary fuel, such as gasoline, diesel, and liquid or compressed natural gas. The composition of vehicle exhaust is relatively complex. When it enters the atmosphere, it is prone to a series of chemical reactions to generate various secondary pollutants, which are very harmful to human beings, plants, animals, and the eco-environment. Despite improving the automobile fuel quality and installing exhaust gas purification devices, helping to reduce air pollution, the treatment costs of these approaches are expensive and cannot achieve zero emissions of automobile exhaust pollutants. The purification of vehicle exhaust by plants is a crucial way to remediate the environmental pollution caused by automobile exhaust and improve the environment along the highway by utilizing the ecosystem's self-regulating ability. Therefore, it has become a global trend to use phytoremediation technology to restore the automobile exhaust pollution. Now, there is no scientific report or systematic review about how plants absorb vehicle pollutants. The screening and configuration of suitable plant species is the most crucial aspect of successful phytoremediation. The mechanisms of plant adsorption, metabolism, and detoxification are reviewed in this paper to address the problem of automobile exhaust pollution.
To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO2) emission by up to 90% and the total annual production cost by nearly RM 450 million. Therefore, SPO-HVO production is a potential and alternative process to produce biobased diesel fuels with waste oil.
Road transport contributes over 70% of air pollution in urban areas and is the second largest contributor to the total carbon dioxide emissions in Malaysia at 21% in 2016. Transport-related air pollutants (TRAPs) such as NOx, SO2, CO and particulate matter (PM) pose significant threats to the urban population's health. Malaysia has targeted to deploy 885,000 EV cars on the road by 2030 in the Low Carbon Mobility Blueprint (LCMB). This study aims to quantify the health co-benefits of electric vehicle adoption from their impacts on air quality in Malaysia. Two EV uptake projections, i.e. LCMB and Revised EV Adoption (REVA) projections, and five electricity generation mix scenarios were modelled up to 2040. We used comparative health risk assessment to estimate the potential changes in mortality and burden of diseases (BoD) from the emissions in each scenario. Intake fractions and exposure-risk functions were used to calculate the burden from respiratory diseases (PM2.5, NOx, SO2, CO), cardiovascular diseases and lung cancer (PM2.5). Results showed that along with a net reduction of carbon emissions across all scenarios, there could be reduced respiratory mortality from NOx by 10,200 mortality (176,200 DALYs) and SO2 by 2600 mortality (45,400 DALYs) per year in 2040. However, there could also be additional 719 mortality (9900 DALYs) per year from PM2.5 and 329 mortality (5600 DALYs) from CO per year. The scale of reduction in mortality and BoD from NOx and SO2 are significantly larger than the scale of increase from PM2.5 and CO, indicating potential net positive health impacts from the EV adoption in the scenarios. The health cost savings from the reduced BoD of respiratory mortality could reach up to RM 7.5 billion per year in 2040. In conclusion, EV is a way forward in promoting a healthy and sustainable future transport in Malaysia.
Increasing the range of vehicles on traffic roads in the urban area has led to traffic-related air pollution (TRAP) and is currently becoming the main concern for health, especially among children. The study aimed to determine associations between TRAP and respiratory health, also to identify the main factors that influenced them. A cross-sectional comparative study was carried out among children in high and low traffic areas. Air quality monitoring was conducted in six primary schools. A set of standardized questionnaires was distributed to obtain respondents' exposure history and respiratory health symptoms, while spirometry test was carried out to determine the lung function status. There were associations between TRAP and abnormality of FEV1% among children. NO2 was the main predictor that influenced both chest tightness and abnormality of FEV1%. Children exposed to a high level of traffic-related air pollution have an increased risk of respiratory symptoms and abnormality of lung function.
This study aims to determine the inorganic and carbonaceous components depending on the seasonal variation and size distribution of urban air particles in Kuala Lumpur. Different fractions of particulate matter (PM) were measured using a Nanosampler from 17 February 2017 until 27 November 2017. The water-soluble inorganic ions (WSIIs) and carbonaceous components in all samples were analysed using ion chromatography and carbon analyser thermal/optical reflectance, respectively. Total PM concentration reached its peak during the southwest (SW) season (70.99 ± 6.04 μg/m3), and the greatest accumulation were observed at PM0.5-1.0 (22%-30%, 9.55 ± 1.03 μg/m3) and PM2.5-10 (22%-25%, 10.34 ± 0.81 μg/m3). SO42-, NO3- and NH4+ were major contributors of WSIIs, and their formation was favoured mainly during SW season (80.5% of total ions). PM0.5-1.0 and PM2.5-10 exhibited the highest percentage of WSII size distribution, accounted for 28.4% and 13.5% of the total mass, respectively. The average contribution of carbonaceous species (OC + EC) to total carbonaceous concentrations were higher in PM0.5-1.0 (35.2%) and PM2.5-10 (26.6%). Ultrafine particles (PM<0.1) consistently indicated that the sources were from vehicle emission while the SW season was constantly dominated by biomass burning sources. Using the positive matrix factorization (PMF) model, secondary inorganic aerosol and biomass burning (30.3%) was known as a significant source of overall PM. As a conclusion, ratio and source apportionment indicate the mixture of biomass burning, secondary inorganic aerosols and motor vehicle contributed to the size-segregated PM and seasonal variation of inorganic and carbonaceous components of urban air particles.
A diesel engine running on diesel/biodiesel mixtures containing ethylene glycol diacetate (EGDA) was investigated from the exergoeconomic and exergoenvironmental viewpoints. Biodiesel was mixed with petrodiesel at 5% and 20% volume ratios, and the resultant mixtures were then doped with EGDA at 1-3% volume ratios. The exergetic sustainability indicators of the engine operating on the prepared fuel formulations were determined at varying engine loads. The indicators were selected to support decision-making on fuel composition and engine load following thermodynamic, economic, and environmental considerations. The engine load markedly affected all the studied exergetic parameters. The highest engine exergetic efficiency (39.5%) was obtained for petrodiesel doped with 1 v/v% EGDA at the engine load of 50%. The minimum value of the unit cost of brake power exergy (49.6 US$/GJ) was found for straight petrodiesel at full-load conditions, while the minimum value of the unit environmental impact of brake power exergy (29.9 mPts/GJ) was observed for petrodiesel mixed with 5 v/v% biodiesel at the engine load of 75%. Overall, adding EGDA to fuel mixtures did not favorably influence the outcomes of both exergetic methods due to its energy-intensive and cost-prohibitive production process. In conclusion, although petrodiesel fuel improvers such EGDA used in the present study could properly mitigate pollutant emissions, the adverse effects of such additives on thermodynamic parameters of diesel engines, particularly on exergoeconomic and exergoenvironmental indices, need to be taken into account, and necessary optimizations should be made before their real-world application.
This paper provides a specific deliberation on occupational hazards confronted daily by Malaysian Traffic Police. Traffic police is a high-risk occupation that involves a wide range of tasks and, indirectly, faced with an equally wide variety of hazards at work namely, physical, biological, psychosocial, chemical, and ergonomic hazards. Thereupon, occupational injuries, diseases, and even death are common in the field. The objective of this paper is to collate and explain the major hazards of working as Malaysian traffic police especially in Point Duty Unit, their health effects, and control measures. There are many ways in which these hazards can be minimised by ensuring that sufficient safety measures are taken such as a wireless outdoor individual exposure indicator system for the traffic police. By having this system, air monitoring among traffic police may potentially be easier and accurate. Other methods of mitigating these unfortunate events are incorporated and addressed in this paper according to the duty and needs of traffic police.
Present data article based on the investigation which enumerates the influence of CNG (compressed natural gas) and HCNG (hydrogen enriched compressed natural gas) on performance and emission parameters of direct injection diesel engine at 200, 220, and 240 bar injection pressures. The CNG and HCNG gaseous alternative fuels were injected in amount (by mass) of 10%, 20% and 30% as secondary fuels to enrich the pilot fuel (pure diesel) during the operation. The performance and emission data of dual fuel (CNG + pure diesel, HCNG + pure diesel) operation was analysed to compare with the pure diesel data. The data for present investigational work were assessed at 25%, 50%, 75% and 100% diverse engine loads for all trials under diverse injection pressures. Eddy current dynamometer was employed to raise the engine load from quartile to maximum. AVL DiGAS 444 N multi gas analyser was used to measure the values of carbon monoxide (CO), unburned hydrocarbon (UHC), and oxides of nitrogen (NOx) detrimental emissions in engine exhaust.
Size-segregated airborne fine (PM2.1) and coarse (PM>2.1) particulates were measured in an urban environment over central Indo-Gangetic plain in between 2015 and 2018 to get insights into its nature, chemistry and sources. Mean (±1σ) concentration of PM2.1 was 98 (±76) μgm-3 with a seasonal high during winter (DJF, 162 ± 71 μgm-3) compared to pre-monsoon specific high in PM>2.1 (MAMJ, 177 ± 84 μgm-3) with an annual mean of 170 (±69) μgm-3. PM2.1 was secondary in nature with abundant secondary inorganic aerosols (20% of particulate mass) and water-soluble organic carbon (19%) against metal enriched (25%) PM>2.1, having robust signature of resuspensions from Earth's crust and road dust. Ammonium-based neutralization of particulate acidity was essentially in PM2.1 with an indication of predominant H2SO4 neutralization in bisulfate form compared to Ca2+ and Mg2+-based neutralization in PM>2.1. Molecular distribution of n-alkanes homologues (C17-C35) showed Cmax at C23 (PM2.1) and C18 (PM>2.1) with weak dominance of odd-numbered n-alkanes. Carbon preference index of n-alkanes was close to unity (PM2.1: 1.4 ± 0.3; PM>2.1: 1.3 ± 0.4). Fatty acids (C12-C26) were characterized with predominance of even carbon with Cmax at n-hexadecanoic acid (C16:0). Low to high molecular weight fatty acid ratio ranged from 2.0 (PM>2.1) to 5.6 (PM2.1) with vital signature of anthropogenic emissions. Levoglucosan was abundant in PM2.1 (758 ± 481 ngm-3) with a high ratio (11.6) against galactosan, emphasizing robust contribution from burning of hardwood and agricultural residues. Receptor model resolves secondary aerosols and biomass burning emissions (45%) as the most influential sources of PM2.1 whereas, crustal (29%) and secondary aerosols (29%) were found responsible for PM>2.1; with significant variations among the seasons.
The aim of the present study was to investigate the potential sources of heavy metals in fine air particles (PM2.5) and benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) in gas phase indoor air. PM2.5 samples were collected using a low volume sampler. BTEX samples were collected using passive sampling onto sorbent tubes and analyzed using gas chromatography-mass spectrometry (GC-MS). For the lower and upper floors of the evaluated building, the concentrations of PM2.5 were 96.4 ± 2.70 μg/m3 and 80.2 ± 3.11 μg/m3, respectively. The compositions of heavy metals in PM2.5 were predominated by iron (Fe), zinc (Zn), and aluminum (Al) with concentration of 500 ± 50.07 ng/m3, 466 ± 77.38 ng/m3, and 422 ± 147.38 ng/m3. A principal component analysis (PCA) showed that the main sources of BTEX were originated from vehicle emissions and exacerbate because of temperature variations. Hazard quotient results for BTEX showed that the compounds were below acceptable limits and thus did not possess potential carcinogenic risks. However, a measured output of lifetime cancer probability revealed that benzene and ethylbenzene posed definite carcinogenic risks. Pollutants that originated from heavy traffic next to the sampling site contributed to the indoor pollution.
To identify seasonal fluxes and sources of dissolved inorganic nitrogen (DIN) wet deposition, concentrations and δ15N signatures of nitrate (NO3-) and ammonium (NH4+) in wet precipitation were measured at four typical land-use types in the Three Gorges reservoir (TGR) area of southwest China for a one-year period. Higher DIN fluxes were recorded in spring and summer and their total fluxes (averaged 7.58 kg N ha-1) were similar to the critical loads in aquatic ecosystems. Significant differences of precipitation δ15N were observed for NH4+-N between town and wetland sites in spring and between urban and rural sites in summer. For NO3--N, significant differences of precipitation δ15N were observed between town and rural sites in spring and between urban and town sites in autumn, respectively. Quantitative results of NO3--N sources showed that both biomass burning and coal combustion had higher fluxes at the urban site especially in winter (0.18 ± 0.09 and 0.19 ± 0.08 kg N ha-1), which were about three times higher than those at the town site. A similar finding was observed for soil emission and vehicle exhausts in winter. On the whole, DIN wet deposition averaged at 12.13 kg N ha-1 yr-1 with the urban site as the hotspot (17.50 kg N ha-1 yr-1) and regional NO3--N fluxes had a seasonal pattern with minimum values in winter. The contribution to NO3--N wet deposition from biomass burning was 26.1 ± 14.1%, which is the second dominant factor lower than coal combustion (26.5 ± 12.6%) in the TGR area during spring and summer. Hence N emission reduction from biomass burning, coal combustion and vehicle exhausts should be strengthened especially in spring and summer to effectively manage DIN pollution for the sustainable development in TGR area.
Anionic surfactants are one of the pollutants derived from particulate matter (PM) and adversely affect the health of living organisms. In this study, the compositions of surfactants extracted from PM and vehicle soot collected in an urban area were investigated. A high-volume air sampler was used to collect PM sample at urban area based on coarse (> 1.5 µm) and fine (
In an attempt to mitigate the effects of extreme natural events caused by greenhouse gases (GHGs), a significant number of researchers and environmentalists have repeatedly stressed the importance of implementing protective measures, including the promotion of green consumption. This study examined the elements that motivated the willingness and the practice of green behavior (GB) among low-income households in coastal Peninsular Malaysia. To meet the research objectives, this study adopted the survey questionnaire method to collect data from 380 low-income households. The findings revealed that self-efficacy (SE) and environmental concerns (EC) have statistically significant effects on the attitude toward green products (ATT), while subjective norms (SN) and perceived behavioral control (PBC) have influence on the intention of green vehicles. Eventually, the study discovered the effects of the intention to adopt green vehicle on green vehicle adoption behavior. Hence, the findings of this study provide new insights for policymakers in Malaysia to place more emphasis on improving consumer attitudes, social standards, and PBC, which will ultimately contribute to the adoption of environment-friendly vehicles. In addition, car manufacturers should support this program by designing products and options that would encourage those in the low-income group to replace their conventional vehicles with green alternatives in Malaysia.
The availability of natural energy resources and the environmental issues are the most significant issues that are often highlighted by the world communities. With regard to these problems, isobutanol is a higher chain alcohol with four carbons which can be derived from biomass resources and it is potential to become an alternative fuel source besides the biodiesel for a diesel engine. The aim of this study is to evaluate the effect of isobutanol with Calophyllum inophyllum methyl ester and diesel as the ternary blend on physicochemical properties, engine performance, and emission characteristics. Five different fuel blends containing Calophyllum inophyllum biodiesel and isobutanol were tested on a single-cylinder direct injection diesel engine at different engine load of brake mean effective pressure. The physicochemical properties of the fuel blends were measured and then compared with neat diesel. The results indicate that the blend containing isobutanol and CIME gives a slight increase in BSEC and EGT and a minimal drop in BTE as compared to that of neat diesel. Besides that, the tested blends show a reduction of carbon monoxide and unburned hydrocarbon emissions. Meanwhile, all the fuel blends show a minimal increase in carbon dioxide and nitrogen oxides emissions, compared to that of neat diesel. Isobutanol can be proved as a preferred substitute for biodiesel and diesel fuels to achieve desired engine performance and emissions level.
Plant (vegetable) oil has been evaluated as a substitute for mineral oil-based lubricants because of its natural and environmentally friendly characteristics. Availability of vegetable oil makes it a renewable source of bio-oils. Additionally, vegetable oil-based lubricants have shown potential for reducing hydrocarbon and carbon dioxide (CO2) emissions when utilized in internal combustion (IC) engines and industrial operations. In this study, sunflower oil was investigated to study its lubricant characteristics under different loads using the four-ball tribometer and the exhaust emissions were tested using a four-stroke, single-cylinder diesel engine. All experimental works conformed to American Society for Testing and Materials standard (ASTM D4172-B). Under low loads, sunflower oil showed adequate tribological characteristics (antifriction and antiwear) compared with petroleum oil samples. The results also demonstrated that the sunflower oil-based lubricant was more effective in reducing the emission levels of carbon monoxide (CO), CO2, and hydrocarbons under different test conditions. Therefore, sunflower oil has the potential to be used as lubricant of mating components.Implications: An experimental investigation of the characteristics of nonedible sunflower oil tribological behaviors and potential as a renewable source for biofluids alternative to the petroleum oils was carried out. The level of emissions of a four-stroke, single-cylinder diesel engine using sunflower oil as a biolubricant was evaluated.
Fine particulate matter (aerodynamic diameter ≤2.5 μm) (PM2.5) has become a major concern because it can adsorb chemicals e.g. polycyclic aromatic hydrocarbons (PAHs) onto its surface. Although PAHs are priority pollutants that can cause adverse health effect, there is still limited information concerning indoor exposures to PAHs in Malaysia. This study aimed to characterise the distribution of PAHs bounded to PM2.5in primary school environments. Indoor and outdoor PM2.5 were collected between May and July 2017 using low volume samplers (LVS) at three public primary schools in the Federal Territory of Kuala Lumpur. PAHs were extracted by ultrasonic extraction with Dichloromethane: n-Hexane (1:1, v/v) as the extraction solvent and analysed using gas chromatography coupled with mass spectrometer (GC-MS). Based on the results, the average total concentration of PAHs (∑PAHs) ranged from 3.8 to 10.1 ng m-3and 1.6 to 8.0 ng m-3for outdoors and indoors, respectively. PAHs in PM2.5samples indicated the potential contribution of combustion at high temperature and indoor sources and the infiltration of outdoor PAHs were the important sources for outdoor and indoor, respectively. In addition, the diagnostic ratio analysis showed that vehicular emissions were the most predominant sources of PAHs in school environments.
Six different approaches are applied in the present study to apportion the sources of precipitation nitrogen making use of precipitation data of dissolved inorganic nitrogen (DIN, including NO3- and NH4+), dissolved organic nitrogen (DON) and δ15N signatures of DIN collected at six sampling sites in the mountain region of Southwest China. These approaches include one quantitative approach running a Bayesian isotope mixing model (SIAR model) and five qualitative approaches based on in-situ survey (ISS), ratio of NH4+/NO3- (RN), principal component analysis (PCA), canonical-correlation analysis (CCA) and stable isotope approach (SIA). Biomass burning, coal combustion and mobile exhausts in the mountain region are identified as major sources for precipitation DIN while biomass burning and volatilization sources such as animal husbandries are major ones for DON. SIAR model results suggest that mobile exhausts, biomass burning and coal combustion contributed 25.1 ± 14.0%, 26.0 ± 14.1% and 27.0 ± 12.6%, respectively, to NO3- on the regional scale. Higher contributions of both biomass burning and coal combustion appeared at rural and urban sites with a significant difference between Houba (rural) and the wetland site (p
The present work analyzes the effect of antioxidants on engine combustion performance of a multi-cylinder diesel engine fueled with PB30 and PB50 (30 and 50 vol.% palm biodiesel (PB)). Four antioxidants namely N,N'-diphenyl-1,4-phenylenediamine (DPPD), N-phenyl-1,4-phenylenediamine (NPPD), 2(3)-tert-Butyl-4-methoxyphenol (BHA), and 2-tert-butylbenzene-1,4-diol (TBHQ) were added at concentrations of 1000 and 2000 ppm to PB30 and PB50. TBHQ showed the highest activity in increasing oxidation stability in both PB30 and PB50 followed by BHA, DPPD, and NPPD respectively, without any negative effect on physical properties. Compared to diesel fuel, PB blends showed 4.61-6.45% lower brake power (BP), 5.90-8.69% higher brake specific fuel consumption (BSFC), 9.64-11.43% higher maximum in cylinder pressure, and 7.76-12.51% higher NO emissions. Carbon monoxide (CO), hydrocarbon (HC), and smoke opacity were reduced by 36.78-43.56%, 44.12-58.21%, and 42.59-63.94%, respectively, than diesel fuel. The start of combustion angles (SOC) of PB blends was - 13.2 to - 15.6 °CA BTDC, but the combustion delays were 5.4-7.8 °CA short compared to diesel fuel which were - 10 °CA BTDC and 11°CA respectively. Antioxidant fuels of PB showed higher BP (1.81-5.32%), CO (8.41-24.60%), and HC (13.51-37.35%) with lower BSFC (1.67-7.68%), NO (4.32-11.53%), maximum in cylinder pressure (2.33-4.91%) and peak heat release rates (HRR) (3.25-11.41%) than baseline fuel of PB. Similar SOC of - 13 to - 14 °CA BTDC was observed for PB blended fuels and antioxidants. It can be concluded that antioxidants' addition is effective in increasing the oxidation stability and in controlling the NOx emissions of palm biodiesel fuelled diesel engine.