Search Results (3)

This study investigates the impact of different biofuels, such as pure hydrogenated vegetable oil, hydrogenated vegetable oil, and biobutanol, as well as their blends, on the non-energetic operational characteristics of a compression ignition internal combustion engine. The research investigations were conducted using a turbocharged direct injection compression ignition engine that was put within a Skoda Octavia 1.9 TDI automobile. Throughout the investigation, the primary emphasis was placed on analyzing energy characteristics such as power, brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), and other related factors. The analysis involved the utilization of multiple combinations of bio-based fuels, namely four mixes of HVO with biobutanol (HVO100, HVOB5, HVOB10, and HVOB20), which were subsequently compared to fossil diesel (D100). The findings of the study indicate that the utilization of HVO100 fuel results in notable reductions in power output and mass fraction when compared to D100 gasoline. HVO100 fuel demonstrates superior performance to D100 gasoline, exhibiting a range of 1.7% to 28% improvement in brake-specific fuel consumption. Additionally, at an engine speed of 4500 rpm, the use of HVO100 fuel leads to a decrease in brake thermal efficiency of 4.4%. Full article

The article analyses energy and environmental operating parameters of a compression ignition internal combustion engine running on HVO-biobutanol and castor oil fuel blends, also comparing them with parameters of an engine running on convection diesel. Since biobutanol is known for poor lubrication characteristics, it was mixed with 5% of castor oil. The obtained blend of biobutanol and castor oil was mixed with HVO at 2/95, 10/90, and 20/80 v/v and fed to the compression ignition internal combustion engine. The presented physicochemical indicators justified the use of the said fuel blends. Constant engine crankshaft speed of 2000 rpm and a variable load expressed as BMEP of 0.1–0.9 MPa was selected in the research. When using the biobutanol–castor oil additive (hereafter simply biobutanol additive) in HVO, an increase in the rate of heat release (ROHR) and the convergence of its value to that of to conventional diesel fuel was observed. A decrease in BTE values was also observed with increasing biobutanol concentration in the blend. Increasing concentration of biobutanol in blends led to an increase in BSFC both in terms of volume and mass; HC and NO_x emissions grew as well, but smoke emissions declined, and no material changes in CO and CO₂ emissions were observed. Full article

Current policies focus on encouraging the use of renewable energy sources in transport to reduce the contribution of this sector to global warming and air pollution. In the short-term, attention is focused on developing renewable fuels. Among them, the so-called advanced biofuels, including non-crop and waste-based biofuels, possess important benefits such as higher greenhouse gas (GHG) emission savings and the capacity not to compete with food markets. Recently, European institutions have agreed on specific targets for the new Renewable Energy Directive (2018/2001), including 14% of renewable energy in rail and road transport by 2030. To achieve this, advanced biofuels will be double-counted, and their contribution must be at least 3.5% in 2030 (with a phase-in calendar from 2020). In this work, the fuel properties of blends of regular diesel fuel with four advanced biofuels derived from different sources and production processes are examined. These biofuels are (1) biobutanol produced by microbial ABE fermentation from renewable material, (2) HVO (hydrotreated vegetable oil) derived from hydrogenation of non-edible oils, (3) biodiesel from waste free fatty acids originated in the oil refining industry, and (4) a novel biofuel that combines fatty acid methyl esters (FAME) and glycerol formal esters (FAGE), which contributes to a decrease in the excess of glycerol from current biodiesel plants. Blending ratios include 5, 10, 15, and 20% (% vol.) of biofuel, covering the range expected for biofuels in future years. Pure fuels and some higher ratios are considered as well to complete and discuss the tendencies. In the case of biodiesel and FAME/FAGE blends in diesel, ratios up to 20% meet all requirements set in current fuel quality standards. Larger blending ratios are possible for HVO blends if HVO is additivated to lubricity improvers. For biobutanol blends, the recommended blending ratio is limited to 10% or lower to avoid high water content and low cetane number. Full article