Water-in-diesel (W/D) emulsion is a promising alternative fuel candidate, as it can simultaneously reduce nitrogen oxides (NOx) and particulate matter (PM) while improving engine performance. Wide scale adoption of this fuel is difficult due to high production and storage costs. Hence, Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES) is a proposed technology to solve these issues by mixing diesel and water in-line directly to the engine. This study presents an updated RTES prototype which incorporated a modular design, with a feedback system to control water injection rate. In this paper, RTES was installed to a common rail injection diesel-powered vehicle and the biodiesel-diesel W/D produced by RTES was analyzed to determine the effect of common rail pressure toward water droplet size and distribution. The vehicle was then tested under the New European Driving Cycle (NEDC) to evaluate vehicle emissions, which will serve as the basis for evaluating the emissions profile of W/D produced by RTES under urban and extra-urban driving conditions. It was found that when subjected to high common rail pressures, W/D droplets produced by RTES reduced by 21.1

In road transport, varying fuel flow rates make it hard to maintain a consistent water ratio in non-surfactant emulsion fuels using the Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES). Thus, it becomes more reasonable to establish an appropriate range of water content tailored to a road condition. Therefore, this study aims to evaluate fuel consumption and exhaust emissions of non-surfactant emulsion fuel in light-duty trucks equipped with RTES, focusing specifically on urban conditions. On-road testing and 300-s idling tests were used as the urban conditions to compare diesel with non-surfactant Water-in-Diesel Emulsion (WiDE) fuel with water percentages from low to high concentrations of water, namely WiDE low%, WiDE med%, and WiDE high%. During idling tests, all emulsion variants reduce fuel consumption. WiDE high% exhibits the most substantial NOx reduction of 9.2%. On-road testing reveals comparable WiDE and diesel fuel consumption, despite the RTES increased electrical load. WiDE high% shows an increment for NOx and CO emissions by 11.71% and 202.19%. In conclusion, a 7.4% to 21.1% water content range was suggested for non-surfactant emulsion fuel in urban road conditions.

Malaysia is one of the top exporters of palm oil, and although currently facing fierce resistance towards palm oil imports in some parts of the globe, one of the ways to utilize this commodity is by increasing palm biodiesel content in local commercial diesel. However, due to the oxygen-rich nature of biodiesel, its utilization suffers from increased nitrogen oxides (NOx) emission compared to conventional diesel. To mitigate this issue and improve diesel engine performance and emissions using biodiesel-diesel blends, this study attempted to investigate implementation of a real-time non-surfactant emulsion fuel supply system (RTES) which produces water-in-diesel emulsion as fuel without surfactants. NOx reducing capability of water-in-diesel produced by RTES has been well documented. Therefore, in this study, 30% biodiesel-diesel (B30) was used as the base fuel while B30-derived emulsions consisting of 10 wt%, 15 wt% and 20 wt% water content were supplied into a 100 kVA, 5.9-L common rail turbocharged diesel engine electric generator. Fuel consumption and exhaust emissions were measured and compared with commercially available Malaysian low grade diesel fuel (D2M). Evidence suggested that emulsified B30 biodiesel-diesel produced by RTES was able to increase brake thermal efficiency (BTE) up to a maximum of 36% and reduce brake specific fuel consumption (BSFC) up to 8.70%. Furthermore, B30 biodiesel-diesel emulsions produced significantly less NOx, carbon monoxide and smoke at high engine load. In conclusion, B30 biodiesel-diesel emulsions can be readily utilized in current diesel engines without compromising on performance and emissions.

The energy crisis that the world facing right now causes researchers all over the world to opt for alternative fuels. Alternative fuels such as water in diesel emulsion gained attention in various studies due to their performance and capability in reducing harmful emissions such as NOx and PM. A new concept was introduced to make water in diesel emulsion without using a surfactant through a device called Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES) and directly supply the fuel to the engine. This real-time emulsification concept requires a strong mixer, however, it consumes high energy. Thus, this study focused on the effect of different in-line mixers producing emulsifier-free bio-diesel emulsions on stability, diesel engine combustion, performance, and exhaust emission. The original RTES consists of a high shear mixer and ultrasonic mixer, while a new parameter for RTES (RTES-SM) is the high shear mixer and static mixer. The effect of the different inline mixers of RTES and RTESSM was tested on the stability testing, engine dynamometer under various loading of 2 kW, 4 kW, and 6 kW, and real vehicle testing. The water percentage was set in the range of 7-10 %. Overall, the RTES showed better results on stability and engine dynamometer, but on real vehicle testing, the result is comparable to RTES-SM. Thus, this new concept of an inline mixing system of non-surfactant biodiesel emulsion (RTES-SM) showed better energy efficiency, promising results in real vehicle testing, and potential options in emulsion mixing technologies.

Water-in-diesel emulsion fuel has become a popular alternative fuel for diesel engines. The main limitation is related to its stability, whereby it relies heavily on surfactants to remain homogeneous, therefore causing production costs to rise. This paper highlights the application of real-time non-surfactant emulsion fuel supply system (RTES), a water/diesel emulsifying device without surfactants, to produce water-in-diesel emulsion fuel in a common rail direct injection diesel engine powered vehicle. In this study, RTES was installed near to the diesel fuel pump to ensure water-in-diesel emulsions were continuously fed to the engine. The test vehicle was set up on a roller dynamometer and operated following a modified West Virginia University (WVU) 5-Peak cycle. Fuel consumption and exhaust emissions were measured to determine the optimum water percentage of emulsion fuel and suitable timing for emulsion fuel to be introduced into the fuelling system based on the vehicle speed. The results revealed that the optimum water percentage of the emulsion fuel for the test vehicle is 10 wt%, as it was capable to reduce fuel consumption as well as nitrogen oxides and smoke emissions of a common rail direct injection diesel engine powered vehicle.

Palm oil mill secondary effluent (POMSE) is a byproduct of the biological treatment of palm oil mill effluent. This research aims to investigate the mechanism of membrane fouling in the treatment of POMSE using a hybrid membrane photocatalytic reactor (MPR). The effectiveness of MPR in POMSE treatment is currently limited due to membrane fouling on the membrane surface. This study focuses on understanding the various mechanisms of membrane fouling, including complete blocking, intermediate blocking, standard blocking, and cake filtration. The determination of each fouling mechanism is achieved through an analysis of normalized flux data employing the Wiesner and Aptel equation. The results demonstrate a high degree of model fitness (R2 = 0.9576) for MPR Run 3, confirming its effectiveness. Based on the (R2) values and the fitted parameter (Ks^(-1)), it is evident that, under varying pH levels, catalyst types, catalyst loading, and initial POMSE concentrations, the cake formation fouling mechanism prevails in MPR Run. In conclusion, this research holds promising potential for implementation in the wastewater treatment industry while ensuring compliance with environmental regulations.

Palm oil mill effluent (POME) is an ideal option as feedstock for biogas production by anaerobic digestion since it is abundant and problematic for the environment. This work tried to observe the anaerobic digestion of POME with empty oil-palm fruit bunch (EFB) as co-substrate. An inoculum containing POME-diluted cow manure was prepared. The EFB samples were pre-treated with a thermal process in an autoclave at 120, 150 and 200°C. The biogas production of the samples was measured for 31 days and compared to each other. The sample with the 200°C treatment process was observed to produce 139% more gas than the baseline. However, at 150°C, the pre-treatment yielded gas with the highest methane content of 40%. It can be concluded that the thermal pre-treatment process on EFB co-substrate has a beneficial impact on POME biogas production and quality.

The depletion of petroleum diesel has prompted the use of biofuels and other alternative sources of energy. The direct use of neat crude palm oil (CPO) has mostly resulted in the increase of oxides of nitrogen (NOx). Emulsification has demonstrated the capability of reducing NOx emissions. An experiment is conducted to investigate the effect of increasing water content in CPO. Water-in-CPO emulsions with varying water contents by volume (5%, 10%, and 15%) with 1% SPAN 80 surfactant are labeled as W5CPO, W10CPO, and W15CPO. The fuels were tested on a single-cylinder diesel generator at 2900 and 3200 rpm with varying electrical load. For all load conditions at 3200 rpm, the smoke opacimeter reading is highest at 35% with W15CPO and the lowest smoke reading is 15% with W5CPO as fuel. The NOx of CPO was higher than ordinary diesel up to 29% at lower load. The NOx emissions of the CPO was reduced when the amount of water was increased. The maximum reduction in NOx of W15CPO was 66% whereas the minimum NOx reduction was 31%. At 3200 rpm and 4 kW, the CO emission of W5CPO was 21% lower in relation to CPO. The W5CPO showed a different trend in the exhaust emissions compared to Water-in-CPO emulsions with higher water content. Overall, emulsification has the potential to reduce NOx emissions in relation to neat CPO.

The global focus in emulsion fuels is due to the advantages over conventional diesel fuels. It has the capabilities to simultaneously reduce the emissions of NOx and smoke. It also said to reduce the fuel consumption of diesel engine by significant percentages. However, due to the interdependency on surfactant, emulsion fuel does not seem to be possible as alternative fuel in an economic perspective. This is because of the high market price of the commercial surfactant. Therefore, this research focused on non-surfactant W/D that produced by a system known as Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES). RTES has been applied with the goal of investigating the impact on exhaust emissions and fuel consumption of a mechanical pump fuel injection system diesel vehicle (MP) and a common rail fuel injection system diesel vehicle (CR). A one-ton truck represents as MP (Mechanical Pump) and an SUV represent as CR (Common rail) are the test vehicles for the said research. The non-surfactant W/D with 6.5 wt.% of water produced by the RTES used as the test fuel and named as E6.5. It has been emulsified in the RTES right before being injected into the diesel vehicles. The testing was performed on a chassis dynamometer following the West Virginia University 5-peak cycles. The findings show that the utilization of non-surfactant W/D has increased the fuel consumption by 7.39% for MP and 3.2% for CR respectively as compared with base diesel fuel. NOx, smoke emissions and exhaust temperature have significantly reduced by the MP relative to CR vehicles. Overall, the concept of non-surfactant W/D seems to have implementation potential for reducing harmful emissions from both diesel-powered vehicles.

In a previous study, a device that combined two existing mixing methods to produce water-in-diesel emulsion fuel (W/D) without surfactant had been developed and tested on a small-scale engine by Ithnin et al. However, it is inapplicable for industrial burners with high fuel flow rate. Therefore, a device with a similar concept was developed in this study. W/D has been proven to improve combustion, but it was unknown if non-surfactant W/D made by the device can improve burner performance and exhaust emissions. The aim of this study is to analyse the fuel consumption, flame temperature and emissions of the industrial burner utilising Malaysian Diesel grade 2 (D2M) labelled as D2, surfactant-added W/D and non-surfactant W/D produced by the device. Both emulsion fuels tested contained 5%, 10% and 15% water by volume. Based on the comparative evaluation, the performance of non-surfactant W/D was comparable to surfactant-added W/D. Compared to D2, non-surfactant W/D reduced fuel consumption, nitrogen oxides, particulate matter, carbon monoxides and hydrocarbons emissions by up to 17%, 53%, 34%, 24% and 44%, respectively. Although the increase in water content decreased the flame temperature, W/D with 5% water had higher flame temperature and had better fuel consumption than D2.

Non-surfactant Water-in-Diesel emulsion fuel (NWD) has short stability period and tend to separate immediately into water and diesel. NWD needs to be supplied into the diesel engine or combustor as soon as it was formed. Since the combustion and emission performance are closely related to the water content of an emulsion fuel, the immediate water content of NWD needs to be more closely inspected. The ASTM D95 standard provides a method to determine the water content of an NWD, but this method takes a long time to perform (up to 2 hours) and arduous. This paper describes the estimation of water content in a non-surfactant emulsion fuel by bomb-calorimetry, which can deliver quicker results than ASTM distillation. Experiments were performed with samples of emulsion fuel using and void of surfactant. The samples were first homogenized using an ultrasonic bath before they were sent to a bomb-calorimeter. The higher heating value of the emulsion was estimated using the weighted average since the components were deemed to be non-reactive. The bomb-calorimetric results of the non-surfactant emulsion fuel showed a close proximation, while the emulsion fuel with surfactant delivered less conclusive results. It was concluded from this study that an estimation of water content in NWD could be performed using bomb-calorimetry eight times faster than using the ASTM D95 standard with a deviation of maximum 3%.

Diesel engine is known for its durable operation and capability of utilizing various type of fuels, however, dangerous exhaust emissions are emitted from diesel engines. Non-surfactant emulsion fuel is a potential fuel for diesel engine to reduce for Nitrogen oxides (NOx) and Particulate matter (PM) emission compare to conventional diesel fuel in a diesel engine. In this study, emulsion fuel was prepared using a mixer known as Circulation Non-Surfactant Emulsion Fuel System. The study carried out with different water percentages in the emulsion fuel given as follows: 3%, 6%, and 9% and at a different engine load condition from 1-4 kW with a constant speed of 3200 rpm. Results show that, 6% emulsion fuel shows average 4.38% reduction in NOx emission and 1.10% reduction in fuel consumption. 9% emulsion fuel show higher amount of CO emission compare to Diesel while it reduces CO2 emission. Overall, 6% when prepared are recommended for the formation of non-surfactant emulsion fuel.

Abstract Bagasse sugarcane (BSC) has low fibre strength due to low cellulose content. Hence, by adding a strong secondary fibre that is high in cellulose such as pineapple leaf fibre (PALF), the fibre strength of the system can be improved. High portion of PALF decreased the composite paper performance because the high composition of PALF tends to produce flocs and agglomerates fibres. The arrangement of the fibres in composite paper should be improved so that this agglomerate’s effect could be overcome. A novel multilayer hybrid fibre composite was used. BSC/PALF with several hybrid ratios was studied in terms of the mechanical and moisture properties of the produced paper sheet and the results showed that multilayer hybrid composite paper produced higher in hybrid composite paper’s properties compared with random hybrid composite paper. The colour of multilayer hybrid fibre composite paper resembled the natural bright colour of BSC and the multilayer hybrid fibre composite paper also shown a slightly low weight loss percentage compared with the random hybrid fibre composite paper after 60 days of soil burial test. As a conclusion, multilayer hybrid fibre composite produced the stronger interfibre bonding and overcome the agglomerate’s effect between BSC/PALF compared with random hybrid fibre composite.

Water-in-diesel (W/D) emulsion is one of the promising alternative fuel that improves the combustion efficiency of a diesel engine and simultaneously reduces harmful exhaust emissions. To ensure a stable emulsion, surfactant is used during the formation of W/D emulsion which causes additional costs for this alternative fuel. A device called as Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES) was invented to eliminates the use of surfactant and rapidly supply the W/D emulsion to the engine. The efficiency of 1-ton light-duty diesel truck fueled with W/D emulsion fuel produced by RTES was tested. Two types of the experimental method were used which chassis dynamometer testing and on-road are testing. The optimum water percentage and vehicle speed were evaluated from the result of exhaust emissions and fuel consumption measurement. Chassis dynamometer testing showed that the optimum water percentage for DE2 were 6.5% and vehicle speed aimed at 52 km/h was selected as the optimum vehicle speed. In on-road testing, the urban route gave the deficient results for both exhaust emissions and fuel consumption which agree with chassis dynamometer testing result where emulsion fuel is not suitable to be used at low speed vehicle operation.

A device known as Real-Time Non-Surfactant Emulsion Fuel Supply System (RTES) was developed to eliminate the dependency of surfactant by rapidly supply the water in diesel (W/D) emulsion into the engine. The objective of this research is to run RTES under long term of operation. A new RTES was fabricated using ultrasonic transducer frequency is 50 kHz and speed of rotor is 1400 rpm. The amount of water injected into the system was constantly at 6.5 vol%. At the end of the test, temperature measurement and observation of RTES component were recorded and droplet size before and during the durability test was measured. It can be concluded that RTES can only withstand the long-term operation for total 26 hours. On the droplet size measurement, initial droplet size is 1.441 mu m, as the temperature of ultrasonic transducer increase, the droplet size also increases.

The focus of this work is to investigate the effect of emulsifier-free emulsion fuel via steam emulsification (SD) to the diesel engine through physical properties, combustion performance, and exhaust analysis, and compare with conventional emulsion fuel with water percentages of 5% and 10% (E5 and E10) and biodiesel blend (B5). The SD was prepared using a custom 200 mL glass mixing column. The B5 fuel quantitatively was filled in the column, and then the steam was injected from the bottom of the mixing column through the porous frit glass with the pores ranging from 40 to 100 µm. The average water droplet size of SD is 0.375 µm with the average water percentage of 6.18%. The brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) of SD improved 4.19% and 3.92%, respectively, as compared to B5. The in-cylinder pressure (ICP) was lower than B5, however, yielding close to the B5 at 4 kW engine load. As for the exhaust emission test, NOx and PM for SD were reduced significantly with a percentage reduction of 25.22% and 10.68%, respectively, as compared to neat B5. The steam emulsification method offers a huge potential to be explored further as the concept offers the alternative method of making emulsion fuel without the use of conventional mechanical mixers.

y measuring the smoke opacity, which is known to be proportional with PM. The smoke/PM measurements were mostly of the particulate trap type, which is lengthy, arduous and only offers cumulative results. In this study, the smoke opacity was measured in real-time by using a smoke opacimeter to obtain faster, simpler and continuous results. The results were compared to the results of Legal Particulate Sampling (LPS). The types of fuel used in this study were an emulsion fuel denoted as E10 and Malaysian EURO2 diesel (D2M). Even though the PM emission of E10 was 20% lower than D2M, the smoke opacity of E10 was 200% higher. It was concluded that the opacimeter could not be used to predict the PM reduction in emulsified D2M.