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The utilization of hydrogen as a gaseous fuel in CI engines in dual fuel mode, has gained significant interest due to its clean-burning nature, high energy share, and higher availability in nature. In this experimental study, hydrogen was used as a secondary fuel along with tri-ethylene glycol mono methyl ether (TGME) as a fuel additive in diesel to investigate the effects on the engine performances and emissions using a modified duel fuel diesel engine (power of 3.5 kW at 1500 rpm). It revealed that addition of hydrogen (30–35%) enhanced the brake thermal efficiency of the engine at each load conditions, but in accordance it also reduces with the lower hydrogen (15–25%). Reduction in oxides of nitrogen was observed with the hydrogen insertion up to 50% load while carbon mono oxide, carbon dioxide and un-burnt hydrocarbon were significantly reduced at entire load conditions. Further, the addition of fuel additive (TGME) enhanced the brake thermal efficiency at each loads. A reduced ignition delay was also observed by the inclusion of TGME and hydrogen due to pre-ignition of the fresh charge. Moreover, this study concluded that addition of 1% fuel additive in diesel with 25% of hydrogen at 30% load, performance and emissions were optimum. • Addition of TGME with higher H 2 enhanced the BTE at entire loads. • NO x reduced up to 50% loads with TGME, increased at highest load. • CO and HC emission at all loads reduced with 5% TGME and 35% H 2. • Use of 1% TGME with 25% H 2 at all loads, BTE and emissions were optimum. [ABSTRACT FROM AUTHOR]

Today, the world faces a number of challenges on global level. The optimum replacement for fossil fuels is one of these challenges. Hydrogen in the past has been and continues to be used by numerous researchers in diesel engines. However, high NO x emissions and low replacement of hydrogen fuel are the concern with many researchers. In the present study, di-tert butyl peroxide (DTBP) has been used as an additive in diesel fuel, to investigate the performance and exhaust emissions of the diesel engine working on dual fuel mode by using hydrogen as secondary fuel. At low, medium and high load conditions, the maximum increase in brake thermal efficiency was observed to be 87.50%, 14.68% and 5.89% respectively for 1%, 3% and 5% of additive (DTBP) by 40% of hydrogen fuel substitution, as compared to diesel fuel operation. Moreover, by addition of 4% di-tert butyl peroxide (DTBP) in diesel engine working on dual fuel mode showed 33.82%, 10.27% and 29.27% reduction in NO x emission at low, medium and high load conditions respectively at 40% hydrogen substitution, as compared to dual fuel operation using hydrogen as secondary fuel without additives. By addition of 5% additive (DTBP) at 69% load condition and 40% hydrogen substitution, reduces CO emissions by 38.66% as compared to dual fuel operation, using hydrogen as secondary fuel. • BTE increased by 13% use of 5% DTBP at 69% load as compared to diesel fuel. • BTE increased by 6% with 3% DTBP at 40% use of H 2 as compared to diesel fuel. • NO x reduced by 27% with 1% DTBP and 40% H 2 at 69% load as compared with DFD mode. • DTBP reduces NO x as well as the CO, HC and smoke opacity of the DFD engine. [ABSTRACT FROM AUTHOR]

Recently, the great challenges in the use of compression ignition (CI) engines are to reduce the reliance on conventional petroleum fuels and exhaust emissions. While the current available technologies for reducing engine emissions are nearly close to the limits of statute and those limits are expected to be, more stringent in the near future. Although hydrogen-diesel operation can provide significant benefits in thermal efficiency and harmful emissions, the combination of the two fuels, often leads to increased NO x emissions. To reduce the NO x emissions the addition of additive Di-tert butyl peroxide (DTBP) has a very good potential. The formation of NO x is depending upon reaction of atmospheric oxygen and nitrogen at elevated temperatures. Therefore, it is essential to study the effect of DTBP on net heat release rate and mean in-cylinder temperature which affects the formation of NO x. This paper presents the results of H 2 -diesel co-combustion in the diesel engine, working on dual fuel mode, with and without blending of additive (di tert butyl peroxide) in the diesel fuel. The net heat release (NHR) and in cylinder mean temperature have been analysed experimentally on the single cylinder power 3.5 KW @ 1500 rpm, four strokes, compression ignition, model Kirloskar TV1 diesel engine. It was observed that by 14% substitution of hydrogen and 1% of additive, net heat release and temperature decreased by 2 and 10% respectively, while, NO x get increased by 60% at high load condition as compared to diesel operation. In last, it is concluded that NO x formation is minimum by addition of 1% of DTBP with 14% of hydrogen in dual fuel diesel engine. [ABSTRACT FROM AUTHOR]

Ignition delay (ID) is one of the important parameters that make influenced on the combustion process inside the cylinder. This ignition delay affects not only the performances but also the noise and emissions of the engine. In this regards the experiments were conducted on single cylinder 4–stroke compression ignition research diesel engine, power 3.50 kW at constant speed 1500 rpm Kirloskar model TV1 with base fuel as diesel and hydrogen as secondary fuel with and without Di-tertiary-butyl-peroxide (DTBP). Experiments were conducted to measure the ignition delay of the dual fuel diesel (DFD) engine at different load conditions and substitution of diesel by hydrogen with or without DTBP and then it was compared with predicted ID given by Hardenberg-Hase equation and modified Hardenberg-Hase equation. The experimental values of ignition delay were compared with theoretical ignition delay which was predicted on the basis of Hardenberg-Hase equation by considering mean cylinder temperature, pressure, activation energy and cetane number and variations are found in between 6.60% and 21.22%. While, the Hardenberg-Hase equation was modified (by considering variation in activation energy) for DFD engine working on diesel as primary fuel and hydrogen as secondary fuel shows variations 1.20%–11.96%. Furthermore, with DTBP it gives variation up to 18.01%. It was found that ID decreases with increase in percentage of DTBP and hydrogen in air-fuel mixture. This might be due to the cetane improver nature of DTBP, pre-ignition reaction rate and energy release rate of hydrogen fuel. The polytropic index get increased by addition of (Di-tert butyl peroxide) DTBP. Similarly, 5% Di tertiary butyl peroxide reduces Ignition delay. • The polytropic index get increased by addition of (Di-tert butyl peroxide) DTBP. • 5% Di tertiary butyl peroxide reduces Ignition delay. • Hydrogen based Modified Heisenberg-Hase equation shows variation up to 11.96%. • Ignition delay based on DTBP by modified Heisenberg-Hase equation shows variation up to 18.01%. [ABSTRACT FROM AUTHOR]

The diesel engine process including fuel injection, fuel spray, air and fuel mixing, ignition and combustion which influences its performance and emission characteristics. The fuel injection and fuel spray are important process as they are directly related to the quality of fuel which results into fluctuating the ignition and combustion characteristics. Ignition in a diesel engine occurs at the edge of the spray depending on the in-cylinder pressure and temperature. Experiments were conducted on a modified dual-fuel diesel engine (3.5 kW power) with fuel additives, diesel and hydrogen (gaseous fuel) at a stable speed of 1500 rpm. Spray behavior and ignition delay were analyzed to determine the impact of fuel additives in neat diesel combined with hydrogen. Additionally, for dual-fuel Cases, the ignition delay correlations provided for diesel engines have been modified as per the experimental results. The injection velocity was maximized with a 15–25% hydrogen substitution range because the fuel density was reduced to a minimum, but it was decreased with the addition of fuel additives. The SMD for hydrogen with neat diesel and diesel with fuel additives both increased up to 20% hydrogen substitution, whereas for higher hydrogen substitution, the Sauter mean diameter decreased. It was found that the addition of fuel additives in diesel resulted into an increased fuel injection velocity (3.3%) with reduced sauter mean diameter of 3.4% while with the lower substitution of H 2 (15%), a maximum increment of 32% in the injection velocity was seen as compared with neat diesel operation. With 15% hydrogen substitution, the change in pressure and density of diesel along with fuel additives accommodated the optimum spray penetration equivalent to neat diesel. In all Cases of hydrogen substitution, the experimental and theoretical values obtained for the chemical ignition delay were found to be consistent with one another except for 35% H 2 showing a maximum deviation of 0.2%. • Addition of fuel additives with higher hydrogen reduced the chemical delay. • TID reduced up to 25% hydrogen, increased with higher hydrogen substitution. • Injection velocity was found optimum in the range of 15–25% hydrogen substitution. • Spray penetration and sauter diameter increased up to 20% hydrogen substitution. [ABSTRACT FROM AUTHOR]

The urge for cleaner and greener sources of energy is rising day by day. Developed countries are already in process of shifting their energy needs from conventional sources to non-conventional/renewable/green sources of energy. These developed countries are also trying to incorporate developing countries to join the battle against global warming and pollution. Examples, of some non-conventional sources of energy are nuclear energy, wind energy etc. One of such cleaner energy source is hydrogen. The high calorific value, availability in abundance and cleaner nature of hydrogen makes it an appropriate substitute for conventional source of energy. An engine using gaseous hydrogen is in the process of being developed. This may revolutionize the battle against pollution and global warming. Use of hydrogen in a diesel engine working on dual-fuel mode has been the interest of many researchers. However utilization of hydrogen fuel changes the ignition delay, combustion duration, peak mean temperature, peak pressure and other combustion parameters change. In the present work, such research works are examined and analyzed in detail. It is also shown, amount of inducted hydrogen dictates many engine parameters such as engine power, torque etc. a separate section is dedicated to study different emissions from the improvised engine. Lastly, it will be clear from the discussion that introduction of gaseous hydrogen to a diesel engine working on dual fuel mode will have optimistic effect on environment. [Display omitted] • The high calorific value, availability in abundance and cleaner nature of H 2. • An engine using gaseous hydrogen is in the process of being developed. • Use of gaseous H 2 to a diesel engine will have optimistic effect on environment. • Combustion parameters like ID, CD and mean temperature of gas increases. • NOx increases with substitution of hydrogen fuel. [ABSTRACT FROM AUTHOR]