• Energy Research

This research compares the air pollution (CO, CO2, HC, NOx, smoke), energy (brake-specific fuel consumption, thermal efficiency) and noise indicators of a compression ignition engine fueled by first-generation biodiesel (rapeseed methyl ester (RME)) and second-generation biodiesel (hydrogenated vegetable oils (HVO)), or conventional (fossil) diesel fuel blends. The concentration of first- and second-generation biodiesel in two-component blends with diesel fuel was up to 15% and 30% (RME15, RME30, HVO15, and HVO30); for comparison, the three-component blend of diesel fuel, HVO and RME (RME15–HVO15) was considered. The fuels’ physical and chemical properties were tested in a specialized laboratory, and the engine load conditions were ensured by the engine brake stand. Referring to ship power plants with constant-speed engines, detailed research was carried out in one speed mode (n = 2000 rpm). Studies have shown that two-component fuel blends with HVO are superior to conventional diesel fuel and two-component blends with RME in almost all cases. The HVO in fuel blends reduced fuel consumption up to 1.8%, while the thermal efficiency was close to that of fossil diesel fuel. In addition, a reduction in pollutants was observed: CO by ~12.5–25.0%; HC by ~5.0–12.0%; NOx by ~6.5%; smokiness by ~11–18% (two-component blend) and up to ~29% (three-component blend). The CO2 and noise characteristics were close to those of fossil diesel fuel; however, the trend of reduced smoke emission was clearly seen. A fundamental obstacle to the wide use of HVO can be seen, however, which is the price, which is 25–90% (depending on the EU country) higher than the price of conventional (fossil) diesel fuel.

Increasing the use of renewable energy sources is essential to reduce the use of fossil fuels in internal combustion engines and to reduce greenhouse gas emissions. An experimental and numerical simulation study of the combustion process of a compression ignition engine was carried out by replacing fossil diesel with a dual fuel produced from renewable energy sources. In conventional dual-fuel applications, fossil diesel is used to initiate the combustion of natural gas or petroleum gas. In the present study, fossil diesel was replaced with advanced biodiesel – hydrotreated vegetable oil, and natural gas was replaced with biogas. In the experimental study, a gas mixture of 60% natural gas (by volume) and 40% carbon dioxide (by volume) was used to replicate the biogas while maintaining a 40%, 60%, and 80% gas energy share in the fuel. It was observed that using fossil diesel and biogas in the dual-fuel engine significantly slowed down the combustion process, which normally resulted in poorer energy performance. One way to compensate for the lack of energy (due to the presence of carbon dioxide) in the cylinder is to use a gas such as hydrogen, which has a high energy content. To analyze the effect of hydrogen on the dual-fuel combustion process, hydrogen gas was added to the replicated biogas at 10%, 20%, and 30% of the natural gas volume, maintaining the biogas at a (natural gas + hydrogen)-to-carbon dioxide volume ratio of 60%/40% and the expected gas energy share. The combustion process analysis, which was conducted using the AVL BOOST software (Austria), determined the heat release rate, temperature, and cylinder pressure rise in the dual-fuel operation with different renewable fuels and compared the results with those of fossil diesel. It was found that when the engine was operated at medium load and with the flammability of the biogas approaching the limit, the addition of hydrogen significantly improved the combustion characteristics of the dual-fuel engine.

This article presents our research results on the physical-chemical and direct injection diesel engine performance parameters when fueled by pure diesel fuel and retail hydrotreated vegetable oil (HVO). This fuel is called NexBTL by NESTE, and this renewable fuel blends with a diesel fuel known as Pro Diesel. A wide range of pure diesel fuel and NexBTL100 blends have been tested and analyzed: pure diesel fuel, pure NexBTL, NexBTL10, NexBTL20, NexBTL30, NexBTL40, NexBTL50, NexBTL70 and NexBTL85. The energy, pollution and in-cylinder parameters were analyzed under medium engine speed (n = 2000 and n = 2500 rpm) and brake torque load regimes (30–120 Nm). AVL BOOST software was used to analyze the heat release characteristics. The analysis of brake specific fuel consumption showed controversial results due to the lower density of NexBTL. The mass fuel consumption decreased by up to 4%, and the volumetric consumption increased by up to approximately 6%. At the same time, the brake thermal efficiency mainly increased by approximately 0.5–1.4%. CO, CO2, NOx, HC and SM were analyzed, and the change in CO was negligible when increasing NexBTL in the fuel blend. Higher SM reduction was achieved while increasing the percentage of NexBTL in the blends.

The article consists of analysis of existing and planned air pollution from ships control and prevention tools such Marpol 73/78 Annex VI, Energy Efficiency Design Index, Energy efficiency operational indicator, Ship energy efficiency management plan, Regulation on the Monitoring Reporting and Verification of shipping emissions, Carbon tax, Maritime emission trading scheme. Norms of these control and prevention tools are difficult to ensue using traditional marine fuels. Pollution rates getting tighter and alternatives have to be used, and some of them have long been known and are not widely used due to objective reasons. Such alternative is natural gas, and its use in ship power plants could reduce concentrations of nitrogen, sulphur, carbon compounds and other pollutants in engine exhaust gas up to acceptable level. The part of maritime sector choosing gas or dual-fuel engines due to tighter pollution rates, and the supply of these engines analyzed in last part of article.

Abstract This article shows the research results and the analysis of the engine properties of diesel fuel, rape seed methyl ester and methanol (M). In the test two blends, 30 V/V% biodiesel (FAME, B30) and 30 V/V% FAME with 10 V/V% methanol (M, B30 + M10) were investigated compared to the reference diesel fuel (D). These properties were researched using an Audi 1.9 TDI 1Z compression ignition (diesel) engine loaded in wide range BMEP = 0.236–1.203 MPa ( M B = 36–179 N m) and 4 speed regimes in range n = 2000–3500 min −1 . The change of energy and ecology properties during engine work on different fuels was analysed as well dQ / dφ max and dp / dφ max for the assessment of thermal and mechanical load of engine parts. While BSCF increased up to 3.5% for B30 and varied in range of 2–13% for B30 + 10M the BTE increased 1–2% and 2–2.5% respectively. The part of ecology indicators improved by adding M to B30: high engine loads characterized by 2–13% reduced CO and whole engine load range – 13–45% reduced concentration of soot. However emission rates of NO X , HC and CO 2 were close to or higher than reference diesel fuel (D). Research of thermal and mechanical load criteria (values of dQ / dφ max and dp / dφ max ) showed that the additive of M to B30 blend has no such a strong effect as expected.

Abstract This paper presents the comparable research results of the physical–chemical and direct injection (DI) diesel engine properties of diesel fuel and BTL (biomass-to-liquid) blend (85/15 V/V). The energy, ecological and in-cylinder parameters were analysed under medium engine speed and brake torque load regimes; the start of fuel injection was also adjusted. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that the BTL additive shortened the fuel ignition delay phase, reduced the heat release in the pre-mixed intensive combustion phase, reduced the nitrogen oxide (NOx) concentration in the engine exhaust gases and reduced the thermal and mechanical load of the crankshaft mechanism. BTL additive reduced the rates of carbon dioxide (CO2), incompletely burned hydrocarbons (HC) emission and smokiness due to its chemical composition and combustion features. BTL also reduced Brake Specific Fuel Consumption (BSFC, g/kW h) and improved engine efficiency (ηe); however, the volumetric fuel consumption changed due to the lower density of BTL. The start of fuel injection was adjusted for maximum engine efficiency; concomitantly, reductions in the CO2 concentration, HC concentration and smokiness were achieved. However, the NOx and thermo-mechanical engine load increased.

Paper provides the summarized results of high-speed and direct-injection compression ignition engines (further diesel engines) VALMET 320 DMG (ship gen-set) and Audi 1Z (passenger vehicle) performance research, which was carried out using different kinds and types of biofuel. Main attention focused on energy and environmental characteristics of diesel engine performance using 1st, 2nd and 3rd generation alcohol, fatty acid methyl and butyl esters blends with conventional diesel fuel (EN 590). Results of biofuel blends use instead diesel fuel showed that the efficiency of energy use increases 1–4%; at practically unchanged NOX concentration unburned product (CO, CH) concentration decreases up to 20% and exhaust gas smokiness – 55–85%.