Diesel Engine Exhaust Gas Research Articles

Desulfurization performance comparison of a 162‐kW marine diesel engine's exhaust gas based on two kinds of alkaline liquid scrubbing models

AbstractA cascade‐scrubbing technology was proposed to improve the current once‐through desulfurization solutions. Desulfurization experiments were performed for a 162‐kW marine diesel engine's exhaust gas so as to confirm the alkali‐lean/alkali‐rich lye cascade‐scrubbing advantages compared with the closed‐loop solution. In the closed‐loop scrubbing model, desulfurization efficiency presented multiple change patterns, such as initially decreasing but then increasing with the liquid–gas ratio, decreasing with SO2 concentration, and increasing with Na/S. At the high SO2 concentration of 2,860 mg/Nm3 and Na/S = 2, desulfurization complying with emission control area's (ECA's) requirements necessitated a liquid–gas ratio above 4.5 L/Nm3. Although raising Na/S could decrease the liquid–gas ratio requirement, the alkali‐utilization efficiency dropped. In the alkali‐lean/alkali‐rich lye cascade‐scrubbing model under the same SO2 and Na/S conditions, the auxiliary scrubbing section allowed a desulfurization capacity of 500–750 mg/Nm3 with an alkali‐rich liquid–gas ratio of 1–2 L/Nm3. With the alkali‐rich lye fed at liquid–gas ratios of 1, 1.5, and 2 L/Nm3, the main scrubbing section's alkali‐lean lye necessitated liquid–gas ratios of 2.8, 2.4, and 3.1 L/Nm3 to comply with ECA's requirements, respectively. Two setups approaching the former two liquid–gas ratio assembles (i.e., a total liquid–gas ratio of 4 L/Nm3 gaining a high alkali‐utilization efficiency above 98%) thus confirmed that this cascade‐scrubbing model was superior to the closed‐loop solution in cutting the liquid–gas ratio requirement and alkali consumption, because of the latter necessitating a liquid–gas ratio of 4.5 L/Nm3 at Na/S = 2 or 4 L/Nm3 at Na/S = 2.16 but with the alkali‐utilization efficiency dropping below 91%.

NO Removal from Simulated Diesel Engine Exhaust Gas by Cyclic Scrubbing Using NaClO2 Solution in a Rotating Packed Bed Reactor

Experiments were conducted to remove NO from simulated flue gas in a rotating packed bed (RPB) reactor with NaClO2 as wet scrubbing oxidant and diesel exhaust gas as carrier gas. The effects of various operating parameters (rotational speed, solution pH, NaClO2 concentration, liquid-gas ratio, and NO and SO2 concentrations) on NO removal performance were investigated preliminarily. The results showed that with the increase of rotational speed, oxidant concentration, and liquid-gas ratio, NO removal efficiency increased obviously. NO removal efficiency increased largely with the decrease of solution pH, and a complete removal of NO could be attained at pH 4. NO concentration imposed little effect on NO removal efficiency while coexisting SO2 in exhaust gas could enhance NOx removal greatly.

Reducing Exhaust Gas Emissions of Stationary Diesel Engines Using Water Bath

This work was conducted with the aim of reducing exhaust gas emissions of stationary diesel engines, particularly those used locally by the private sector for electric power generation. A specially designed water bath equipped with perforated tubes submerged in water and supplied with water circulation to maintain the cleanness of water was used for this purpose. The diesel engine exhaust gas was admitted to the water bath through the perforated tubes such that the exhaust gas is “cleaned up” thoroughly before being released to the atmosphere. An experimental work was conducted on a four-stroke, air-cooled, one-cylinder diesel engine to verify the feasibility of using this technique in reducing exhaust gas emissions before applying it to large size diesel engines. The experimental results indicated that the use of the proposed water bath led to enormous reductions in oxides of Nitrogen (NOx), unburnt Hydrocarbons (HC), Carbon Monoxide (CO), and exhaust gas temperatures. In addition to a relatively small reduction in exhaust noise. For the engine power range considered in this work (0.4-2 kW), NOx was reduced by 62-73%, unburned HC was reduced by 72-85%, CO was reduced by 41-68%, exhaust gas temperature was reduced by 89-91% and exhaust noise was reduced by 1-7%.

Diesel Fuel Multiple Injection Effects on Emission Characteristics of Diesel Engine Mixed Ammonia Gas Into Intake Air

This study focuses NH3 as an alternative fuel for internal combustion engines, because NH3 is known as a H2 carrier and its combustion does not produce CO2 causing global warming. On the other hand, some reports show that unburned NH3 and N2O appear in exhaust gas, when NH3 is used as fuel for compression ignition or spark ignition engines. NH3 is toxic and N2O is one of the greenhouse gases. These emissions should not be emitted. These reports point out that exhaust gas after treatments and/or injection strategies can be effective to reduce these emissions. From our previous investigations, it was confirmed that NH3 and N2O were contained in the exhaust gas of a conventional diesel engine with NH3 gas mixed into the engine intake. In this study, NH3 combustion processes in the diesel engine were investigated from the experimental results. Based on the investigations, a pilot or postinjection was conducted to reduce emissions of NH3 and N2O. In this paper, first the experimental results of the combustion and exhaust emission characteristics on the conventional diesel engine with NH3 gas mixed into the engine intake are shown. NH3 and N2O emissions are then verified by analyzing the exhaust gas. Next, NH3 combustion processes in the diesel engine are considered from the experimental results to report on the effects of a pilot and postdiesel fuel injection on NH3 and N2O production processes. The experimental results suggest that the multiple diesel fuel injections would be one of the effective measures to reduce N2O and NH3 emissions on NH3 and diesel dual-fueled engine.

Analysis of the spray wall impingement of urea-water solution for automotive SCR De-NOx systems

Selective catalytic reduction (SCR) is the most popular automotive exhaust after-treatment solution for nitrogen oxides (NOx) emission reduction. The mitigation of solid deposit formation is a big challenge for SCR system operation. Urea-water spray impingement is an important parameter which effects on solid deposit formation, should be investigated duly. This study presents an experimental investigation of urea-water spray impingement on the heated wall of automotive SCR systems for diesel engine exhaust gases. The investigation focused on the impingement conditions and distribution of the spray droplets, which are important parameters for system performance. This work was conducted with a commercial pressure driven SCR injector into an optically accessible test chamber at different wall temperatures and injection height. The spray impingement phenomena captured by means of Z-type shadowgraph high-speed Imaging technique. The injection quantity of the injector was measured to determine the injection rate. The high-speed imaging reveals in detail spray distributions, liquid film formation and urea crystallization. Relevant dimensions of spray distribution after the impingement have been estimated with digital image processing. The investigation reveals that high wall temperature produces swirl and bouncing that entrain rebounded droplets of the impinging spray on the wall, which leads to improved mixing. High temperature also causes longer spray front projection length which is an important factor for the mitigation of urea deposits.

Deterioration effects on the performance of a steam plant for the waste heat recovery from a marine diesel engine

ABSTRACTThe study aims to investigate the effects of the steam plant components deterioration in a marine Waste Heat Recovery (WHR) system. WHR technology can significantly improve the energy efficiency of merchant ships, because it allows to recover thermal energy from the exhaust gas of the main diesel engines, in order to produce electric energy through a steam turbo-generator. On the other hand, the complexity of the power plant is obviously increased together with its maintenance procedures. For this reason, it is essential to monitor and foresee, as far as possible, the health status of the steam plant components. Then the overall performance of the WHR system is numerically evaluated in design and off-design conditions, taking into account the effects of the increased back-pressure (due to the steam plant components degradation) on the diesel power plant efficiency. The obtained results are presented in graphical form and suitably discussed.

New experimental results of NO removal from simulated marine engine exhaust gases by Na2S2O8/urea solutions

NO is the main precursor of photochemical smog. Since the SCR system of marine diesel engines has many disadvantages, this paper proposes an effective wet method to remove NO from the exhaust gases of marine diesel engines. Experiments were performed in a bubble column reactor to study the absorption of NO using sodium persulfate (Na2S2O8)/urea ((NH2)2CO) solutions from a simulated gas stream. The effects of various operating parameters on NO removal were investigated, including reaction temperature, urea concentration, Na2S2O8 concentration and the initial pH value of Na2S2O8/urea solutions. The experimental results showed that the NO removal efficiency increased with increasing reaction temperature (25–80 °C) and increasing Na2S2O8 concentration (0.01–0.2 mol/L). When the concentration of urea was higher than 0.5 mol/L at 60 °C, 1 mol/L at 70 °C or 2 mol/L at 80 °C, the NO removal efficiency increased with the increase of urea concentration (0.1–4 mol/L). The highest NO removal efficiency was 99.7%, occurring at 80 °C when the concentrations of Na2S2O8 and urea were 0.1 mol/L and 4 mol/L, respectively, and the concentration of nitrate was 14.93 mg/L. The optimal urea conditions were well below the legal limit of 60 mg/L. The NO removal efficiency increased with the increase of initial pH value within the herein investigated range of 7–9. All the experimental data showed that the novel system not only achieved effective NO removal efficiency, but also reduced the nitrate in wastewater, which could thus be applied to denitrification of marine engine exhaust gases.

Modeling of power and torque curves of a diesel at the design stage

An external speed characteristics outlines the upper limit of the field of possible operating conditions of the engine. With its help, therefore, it is possible to judge the extreme values of the indicators and parameters of the engine when it is running at a specific speed of the crankshaft. It is at theexternal speed characteristics of the engine parts are subjected to the greatest mechanical and thermalloads, the maximum is also the smoke of the exhaust gases of diesel engines. This indicates the particular importance of techniques that allow to determine the performance of the engine in the modes of external speed characteristics. Get external speed characteristics when testing the engine on the test bench. However, this possibility is not always available, especially it is not at the design stage. When calculating the cycle, the engine performance is obtained in two modes – rated power and maximum torque. Therefore, the external speed characteristics, built by calculation is important at the stage of justification of the main indicators and parameters of the designed engine.

Аналіз способів зменшення шкідливих викидів суднових двигунів рециркуляцією відпрацьованих газів

Розвиток судноплавства на водних шляхах призвів до будівництва нового, сучасного флоту з потужними енергетичними установками. Масова експлуатація такого флоту супроводжується інтенсивним зростанням його впливу на навколишнє середовище. Один з найважливіших компонентів суспільного і економічного розвитку, який поглинає значну кількість ресурсів і надає серйозний вплив на природне середовище, є морський транспорт. В роботі проаналізовано можливість зменшення кількості шкідливих викидів судновими ДВЗ за рахунок системи рециркуляції відпрацьованих газів.

Ammonium-Salt Formation and Catalyst Deactivation in the SCR System for a Marine Diesel Engine

Due to the low temperature and complex composition of the exhaust gas of the marine diesel engine, the working requirements of the selective catalytic reduction (SCR) catalyst cannot be met directly. Moreover, ammonium sulfate, ammonium nitrate, and other ammonium deposits are formed at low temperatures, which block the surface or the pore channels of the SCR catalyst, thereby resulting in its reduction or even its loss of activity. Considering the difficulty of the marine diesel engine bench test and the limitation of the catalyst sample test, a one-dimensional simulation model of the SCR system was built in this paper. In addition, the deactivation reaction process of the ammonium salt in the SCR system and its influencing factors were studied. Based on the gas phase and the surface reaction kinetics, the models of the urea decomposition, the surface denitrification, the nitrate deactivation, and the sulfate deactivation were both constructed and verified in terms of accuracy. Moreover, the formation/decomposition reaction pathway and the catalytic deactivation of ammonium nitrate and ammonium bisulfate, as well as the composition concentration and the exhaust gas temperature range were correspondingly clarified. The results showed that within a certain range, the increase of the NO2/NOx ratio was conducive to the fast SCR reaction and the NH4NO3 formation’s reaction. Increasing the exhaust gas temperature also raised the NO2/NOx ratio, which was beneficial to both the fast SCR reaction and the NH4NO3 decomposition reaction, respectively. Furthermore, the influence of the SO2 concentration on the denitrification efficiency decreased with the increase of the exhaust gas temperature because of increasing SCR reaction rate and reversibility of ammonia sulfate formation, and when the temperature of the exhaust gas was higher than 350 °C, the activity of the catalyst was almost unaffected by ammonia sulfate.

Reducing the emission of solid particles from the exhaust gases of the internal combustion engine by increasing the efficiency of the catalytic converter

The subject of consideration in the article was the assessment of the possibility of reducing the emission of solid particles from the exhaust gases of reciprocating internal combustion engines, which is needed to intensify the activities to reduce their harmful effects on the environment and on the human body. The aim of the work was to assess the possibility of increasing the efficiency of reducing emissions of solid particles with diesel exhaust gases due to the possible stabilization of the temperature of their exhaust gases in front of the catalytic converter. The object of the study was the emissions of solid particles with exhaust gases of diesel engine 4ChN13/15. The experiments were carried out with a KND-Rila type catalytic converter. To reduce the temperature fluctuations of the exhaust gases entering it when the diesel engine is operating in various modes, the authors have created a shell-and-tube type heat exchanger with a heat storage substance - lithium hydroxide. A gravimetric method was used to determine the solids content. The test complex included the MT-120 dilution tunnel developed by the TUV-UVMV institute (Czech Republic), the sampling system on a loading test bench, the Mettler Toledo AX26DR weigher for filter weighing (in a climate chamber on a vibration-insulating foundation, with an accuracy of 2 μg) and filters - “Pall Flex”. The study was conducted when the diesel engine operates on test cycles for variable speed engines according to UNECE Regulation No. 96-02. The method of assessing the effect of stabilization of the exhaust gas temperature on the efficiency of the catalytic converter with respect to the emission of solid particles was to determine the average degree of conversion of solid particles in the neutralizer during the test cycle. The test results showed that the stabilization of the temperature of the exhaust gases in front of the catalytic converter provided a relative improvement in the degree of conversion of solid particles by 56.7%.

Heat Recovery Systems for Agricultural Vehicles: Utilization Ways and Their Efficiency

The focus of today’s agriculture is to reduce fuel consumption and pollutant emission. More than 50% of the fuel energy is lost with the exhaust gas and coolant of diesel engines. Therefore, waste heat recovery systems are a promising concept to meet economical and ecological requirements. Agricultural vehicles have an operating cycle that is quite different from on-road trucks (higher engine load factor and less annual utilization). This has influence on the efficiency of waste heat recovery. The purpose of this paper was to analyze different waste heat recovery technologies to be used in agricultural applications. In the study, technical and economic indicators have been used. According to suggested classification, four pathways for utilization were studied. Turbocompounding, electric turbocompounding, and heating of transmission oil for hydraulic clutch gearboxes have proved to be effective for agricultural vehicles. For the economical conditions of the European Union (EU), a turbocompounding diesel engine is acceptable if agricultural tractor rated power is more than 275 kW, and combine harvester rated power is more than 310 kW. In cold climates, heat recovery transmission warm-up may be recommended. Waste heat absorption refrigerators have proven to be a viable technology for air conditioning and intake air cooling systems.

Method and Device for Reducing the Toxicity of Diesel Engine Exhaust Gases

The aim of the article is to develop a method and a device for reducing the toxicity of exhaust gases of diesel engines and reducing noise taking into account the current mode of operation of the engine. This is done with the help of installing a liquid catalyst (LC) into the exhaust system, ensuring the processes of trapping, chemical bonding and neutralization of toxic components and soot particles in the aerosol chamber while the vortex flow is being processed by a neutralizing solution supplied under pressure. Then the flow is divided into phases and toxic components and soot are separated in the centrifugal swirl drop separator (SDS).The developed and tested design of an exhaust gas cleaning device installed instead of the standard D-120 engine exhaust system and an automated cleaning process control system make it possible to reduce the toxicity of exhaust gases (EG): nitrogen oxides by 40 %, hydrocarbons by 43 % and soot by 70 %. The noise level of its work in enclosed spaces was reduced by 16–22 %. The device also had low gas-dynamic resistance.The investigation methodology is based on the use of modern methods and measuring devices. Exhaust gas tester META “Autotest CO – CH – CO2 – O2 – λ – NOx” was used to measure the toxicity of exhaust gases. To measure smoking at the exhaust of the diesel engine, the opacity meter META-01MP was used. The gas flow velocity was measured with ATT-1004 thermo-anemometer, the noise level of the tractor was recorded with noise and vibration meter VSHV–003–M2, and the fuel consumption with SIRT-1 meter.Theoretical studies were carried out on the basis of the laws of gas dynamics, the modern theory of statistical analysis, and experiment planning techniques. When developing an experimental LC model, dependencies were obtained, which allow to achieve the optimal design and technological parameters of the wet cleaning system for diesel exhaust gases.The optimization of the design parameters and the processing of experimental data were carried out with the help of modern software using the methods of mathematical statistics using computers.The current methods of reducing the toxicity of engines consist primarily in improving the design of engines, in order to influence the nature of the working process, the use of alternative fuels and additives, exhaust gas recirculation, as well as installing various types of exhaust gas catalytic systems. Measures related to the introduction of constructive changes in engines require some major restructuring of the industry, which is difficult to achieve in modern conditions. Alternative fuels have not yet been widely used in agriculture. Therefore, today the most effective and acceptable means of achieving environmental standards is the installation of various mobile catalysts in the exhaust system, as well as devices for trapping soot particles. The use of this exhaust gas cleaning system for diesel engines functioning in enclosed spaces can significantly improve the working conditions of the personnel and have a slight effect on the power and fuel-economic performance of the power unit, reducing the power of the D-120 engine of the T-30 tractor equipped with an upgraded exhaust system when taking external speed characteristics averaged 1.6 %, the torque was 1.5 % and the increase in specific fuel consumption was 1.8 %.In this paper we used materials from scientific publications indexed by bibliographic abstract databases of Scopus and Web of Science.

Study on Optimization Simulation of Scr Denitration System for Marine Diesel Engine

Abstract With the rapid development of shipbuilding industry exhaust world is also very harmful one kind of environmental issues, and the ship marine diesel engine exhaust gas is mainly produced, so in recent years it has developed a diesel engine SCR system. SCR system can control emissions of nitrogen oxides in the exhaust of vessel, furthermore air pollution can be reduced. The main goal of article was using fluent software to correct SCR system selection and flue gas flow under different size best deflector arrangement is simulated. Next goal is further optimize the structure of the SCR system.

ПОВЫШЕНИЕ ЭФФЕКТИВНОСТИ СУДОВЫХ ЭНЕРГЕТИЧЕСКИХ УСТАНОВОК

The foreground task of the development of inland water transport in the Russian Federation is increasing security, environmental protection and power efficiency of shipping operations. The article provides an overview of methods to improve the efficiency of marine power plants. The sources of secondary heat are considered and it is found that the most promising heat recovery sources for river vessels are the exhaust gases of diesel engines and cooling water of the main engines and diesel generators. The analysis shows that the secondary energy resources on ships, including modern ones, are practically not used or are used insufficiently and, in addition, the environment is being damaged. The reasons for the insufficient use of secondary energy resources on ships have been found, among them the lack of automated control systems for integrated heat recovery systems, which leads to a decrease of its economic efficiency. The integrated heat recovery systems are regarded by the operatives with distrust due to the increasing number of the repaired systems and bad quality of tap water. Deep heat recovery systems are good for sea-going ships, but are of little use in the river transport because of weaker secondary heat flows and poor fuel saving at the relatively high fuel cost. Today the important problem is to develop principles and algorithms of functioning of automated system of control over integrated heat recovery systems.

Differentiation between O2 and NO2 impact on PtOx formation in a diesel oxidation catalyst

NO oxidation activity of platinum-based catalysts undergoes reversible changes during operation in oxidative atmosphere typical for Diesel engine exhaust gas due to platinum oxides (PtOx) formation and reduction. In recent years, these changes were studied mostly with the mixtures containing both O2 and NO2 so that it was difficult to quantify individual impacts of the oxidants on PtOx formation. In this paper, Pt/Al2O3 catalyst deactivation and PtOx formation with O2 and NO2 was examined separately by the means of transient isothermal experiments at 150, 175 and 200 °C with alternating deactivation and probe periods. The largest extent of deactivation was detected at 175 °C where the NO conversion in the isothermal experiment dropped from 85% (reduced catalyst) down to 10% (steady-state PtOx level) over 4 h. The experimental data were then utilized for parameter evaluation in global kinetic model of NO oxidation on a diesel oxidation catalyst extended by the reactions describing PtOx formation and reduction. Though the rate coefficient for PtOx formation with NO2 is higher than with O2, the overall PtOx formation rate and the steady-state PtOx level are higher with O2 at typical component concentrations (8% O2 or 250 ppm NO2). Similar activation energies were observed for both PtOx formation reactions. Validity of the model was verified also at lower O2 and NO2 concentrations (4% O2 or 125 ppm NO2). The developed model is thus capable of sufficiently precise prediction of catalyst deactivation at various O2 and NO2 concentrations relevant to diesel exhaust gas.

Optimization and application of Stirling engine for waste heat recovery from a heavy-duty truck engine

The requirements for cleaner engines and less fuel consumption force vehicle manufacturers to investigate new technologies on recovering from losses. As the main contributor to losses is the waste heat, studies are carried out to convert the waste heat to mechanical work. In this paper, an evaluation of Stirling engines is presented for waste heat recovery (WHR) from exhaust gases of a heavy-duty truck diesel engine. Maximum theoretical dimensionless shaft work for three types of Stirling engines are calculated and compared by optimizing selected parameters with a new dimensionless method. Results are used to size a WHR system that utilizes the thermal power of a commercial truck exhaust gas. Calculations done with exhaust gas temperatures measured during road tests show that, the WHR system with Beta-type Stirling engine is more effective than Alpha and Gamma types due to its higher power density. The WHR system presented provides more than 1.3% of ICE power output and about 1% reduction in fuel consumption, which offers Stirling engine as a reasonable option for WHR on heavy-duty truck engine.

Investigation of the speed regime of tractor diesel engine running on natural gas with recirculation

The work is devoted to the use of compressed natural gas as an alternative motor fuel to reduce the toxicity of exhaust gases of tractor diesel engines. At the same time, the urgency of using natural gas in combination with exhaust gas recirculation (EGR) (EGR was used to reliably reduce nitrogen oxides increased as a result of the use of natural gas) in diesel was substantiated. The paper presents the results of experimental studies on the effect of natural gas and EGR on the effective characteristics, combustion process indicators, the toxicity and smokiness of exhaust gases depending on the change in the speed of the crankshaft of the tractor diesel. On the basis of the results of the study, it is proposed to maintain the following ratio: natural gas – 80%, the fuse portion of diesel fuel – 20%. When working on natural gas with EGR, the regularity of supply of recirculated gases from 20 to 40% depending on the mode of operation of the tractor diesel is established. The paper defines and presents the optimal values of the effective parameters, characteristics of the combustion process, toxicity and smoke exhaust gases when working tractor diesel 4F 11.0/12.5 on natural gas with EGR. The translation of the specified diesel fuel oil to natural gas helped to reduce the contents in the exhaust gases when working with EGR 20% of the exhaust gas of nitrogen oxides by 43.2%, of carbon black in a 5.6 times that of carbon dioxide 33.3%, carbon monoxide by 10.0%.

Effect of biodiesel fuel from soybean oil on exhaust gas and combustion chamber temperature of diesel engine

Several researchers have researched combustion engines, especially those that use biodiesel fuel. However, most of the biodiesel raw materials used are derived from crude palm oil, castor seeds, used cooking oil, and palm oil mill effluent. This research uses biodiesel fuel with raw material from soybean oil and still very rarely done. Experimental results show that specific fuel consumption increases along with the increase in the biodiesel composition of soybean oil in the fuel mixture. The amount of CO and HC exhaust emissions decreased when using fuel B10, B20 and B30. Experimental data show that maximum power is 1.26 kW, specific fuel consumption is 373.15 g/kWh and maximum thermal efficiency is 23.04% when using diesel fuel. The maximum temperature of the diesel engine combustion chamber is obtained at 507.86°C when using diesel fuel. Minimum combustion temperature is obtained when the diesel engine uses B30 of 388.49°C, and this condition is strongly influenced by calorific value of the fuel.

Experimental study of the autoignition properties of n-butanol–diesel fuel blends at various ambient gas temperatures

One of the methods of reducing the nitrogen oxides and smoke emissions from the exhaust gas of diesel engines is to use fuels containing an increased fraction of oxygen compounds. This can be achieved by adding oxygen compounds, in the form of alcohols, to a standard diesel fuel including, for example, ethanol, methanol and n-butanol. Due to a number of advantages over ethanol and methanol, n-butanol is of particular interest. Particularly important, in regard to the functioning of the diesel engine, is to determine, among others things, the autoignition properties of diesel fuel to which such alcohol has been added. In this study, the autoignition properties of blends of standard diesel fuel and n-butanol were tested, with n-butanol volume fractions of up to 25%. The tests were carried out in a constant volume combustion chamber, which allowed for the determination of the effect of the ambient gas temperature (in the range 550 °C–650 °C) on the ignition and combustion delay periods of the tested fuels. The average and maximum pressure rise rates, as well as the maximum pressure rise values in the combustion chamber, were also analysed. Investigations of the autoignition properties were supplemented with the derived cetane number and the Lower and Higher Heating Values of the tested blends. This study has demonstrated a number of properties relating to such mixtures, including that with an increase in the n-butanol volume fraction in the n-butanol–diesel fuel blend, the periods of ignition and combustion delay increase, and that an increase in the ambient gas temperature into which the fuel is injected shortens these periods to a varying extent. It has also been shown that in the range of 5%–25% n-butanol volume fraction, for each increase in n-butanol fraction of 5%, the derived cetane number of the n-butanol–diesel fuel blend reduces by, on average, 2.9 units.