Biofuel Blends Research Articles

Late post-injection of biofuel blends in an optical diesel engine: Experimental and theoretical discussion on the inevitable wall-wetting effects on oil dilution

In a diesel engine, diesel particulate filter is used to reduce particle matter emissions. Diesel particulate filter requires periodic regenerations under high-temperature conditions in the exhaust pipe in order to oxidize the accumulated soot. A common strategy to produce high exhaust gas temperature is to inject late post-injections after the main injection. However, this practice may dilute the engine oil, causing engine wear. Biofuel addition to petroleum diesel may increase oil dilution even more. This is related to the fuel spray characteristics, the post-injection control and the vaporization process of fuel in engine oil. In this study, spray properties of late post-injection were studied with petroleum diesel and two types of transport biofuel blends containing 30% either fatty acid methyl ester or hydro-treated vegetable oil. Three different late post-injection timings were investigated. Image sequences of the main spray flame as well as the non-combusting late post-injection spray were extracted. In order to verify oil dilution during regeneration cycle and late post-injection, oil samples from six-cylinder test engine were analyzed. According to the present experiments, differences in the spray characteristics are not significant with the tested fuels. However, higher oil dilution rates were observed with fuel blend composed of 30% fatty acid methyl ester. All the studied late post-injection timings were noted to lead to the unwanted cylinder spray/wall interaction and wall-wetting consequently diluting the engine oil. The spray/wall interaction is thoroughly explained by introducing a theoretical/computational framework which characterizes any spray/wall interaction in terms of a phase diagram for any considered operation conditions. The novelty of this study arises from (1) first comparison of fatty acid methyl ester and hydro-treated vegetable oil blends in an optical engine, (2) strong evidence on the phenomena related to post-injection phase in six-cylinder and single-cylinder optical engine configurations and (3) the development of a single-droplet model showing inevitable wall-wetting.

Combustion Instability during Starting of Turbocharged Diesel Engine Including Biofuel Effects

AbstractA series of starting tests was conducted on a turbocharged diesel engine to investigate combustion instability for various coolant temperatures, ranging from 20 to 80°C, and fuel blends (neat diesel, blend of diesel with 30% biodiesel, and blend of diesel with 25% n-butanol). A statistical analysis was performed in order to quantify the effects of the coolant temperature and fuel properties on the extent of the instability phenomena. As expected, the engine thermal status was found to play an influencing role, with cold starting leading to combustion instability; a difference up to 38 bar between successive cycles was documented. The biodiesel blend exhibited higher instability and the n-butanol one showed higher absolute pressures but somewhat more stable operation. Both biofuel blends led to higher in-cylinder pressure irregularities compared to the neat diesel operation. For all examined blends, instability phenomena were still apparent even after several seconds from the engine start-up.

Effect of additives on particulate matter formation of solid biofuel blends from wood and straw

The combustion of solid biofuels is characterized by the formation of particulate matter emissions harmful to humans and the environment. Inorganic elements which are volatile under high temperatures (∼600–1200 °C) are emitted as vapor, then cooling down in the flue gas, and are re-sublimated and emitted as solid particulate matter emissions (fly ash). Thus, the objective of this paper is it to summarize the current knowledge of the forming mechanism of these particulate matter emissions taking place during the combustion of wood and straw, and bring the elements in particulate matter with the help of additive in a stable solid phase, so they stay in the bottom ash and are not emitted. Here, two different additives are tested, based on Al, Mg and Ca. Important in this respect is the knowledge of the chemical formations during the combustion process of the different ash-forming elements contained within solid biofuels. Therefore, the chemical binding forms of the ash-forming elements (Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S, and Cl) within the solid biofuel are presented. Based on this, possible conversion products are discussed including theoretical calculated intermediates; this includes the chemical conversion pathway. On this basis, additives are identified based on the difference of the elemental composition of wood/straw blends to wood and the results of the formation of particulate matter during combustion are assessed in lab scale. The additives are composed of Al2O3, CaHPO4, and CaCO3 or Al2O3, MgHPO4, and MgCO3. The results from the characterization techniques TGA, AAS, IC, and XRD show that the formation of particulate matter during a complete thermo-chemical conversion can be suppressed to certain extend.

Effect of straight vegetable oil blends and biodiesel blends on wear of mechanical fuel injection equipment of a constant speed diesel engine

Vegetable oils and biodiesel have emerged as strong alternative fuels worldwide. However use of new fuels in existing engines leads to issues such as wear of vital moving components, and fuel injection equipment (FIE). It is important to ensure that new alternative fuel does not affect the FIE adversely. In this experimental study, a non-firing engine FIE simulator test rig prototype was developed and 250 h endurance test of FIE was performed with an objective to ensure the long-term compatibility and durability of biofuel blends. The components of FIE such as plunger, nozzle needle, valve, and valve holder were investigated for wear. Test fuels used in this study were Karanja blends (K20, K5), Jatropha blends (J20, J5), Biodiesel blends (B20, B5) and baseline mineral diesel in a non-firing engine FIE simulator. The compatibility of FIE with test fuels in terms of dimensional loss, weight loss and surface texture variations using optical microscopy before and after the endurance test was compared. Biodiesel blends showed relatively lower wear compared to mineral diesel however SVO blends showed no definite trend of the wear results compared to baseline mineral diesel.

The influence of the biofuel blends on the energetic and ecological performances of the Diesel engine

This study presents the influence of the diesel fuel blended with biodiesel fuel obtained from sunflower oil, corn oil and peanut oil on the energetic performances, combustion process and pollutant emissions. This research was done virtually and experimentally. In this study pure diesel fuel and two concentrations (6% and 10%) of blends with biofuels were used for experimentally tests on a Renault K9K diesel engine. Five parameters were observed during experimental tests: engine power, fuel consumption, cylinder pressure, and the amount of CO and NOx emissions. The same five parameters were simulated using AVL Boost program. The variations of effective power and maximal cylinder pressure are caused due to the lower calorific value of the tested fuels. Better oxidation of the biofuels induces a better combustion in cylinder and less CO and NOx emissions. The CO emissions are either influence by the lower carbon content of biofuels. The results of this study sustain that using 6% and 10% of blended biofuels with diesel fuel decrease the pollutant emissions of the diesel engine. Deviations between experimental and the simulation results confirm the validity of the mathematical model adopted for the simulation.

A cleaner and greener fuel: Biofuel blend formulation and emission assessment

Biofuel is an attractive vehicular fuel option for the transportation sector. Diverse biofuel blends can be produced from biomass. Complexity arises when optimum biofuel blends need to be designed to comply with fuel regulation standards as well as generate less emission. This paper discusses an integrated computational and experimental technique to design economically viable and environmentally friendly tailor-made biofuel blends from palm biomass that is abundant in Malaysia. An experimental based trial-and-error method is time consuming and uses up resources. Computational approaches adopt a systematic blend formulation methodology that assists focused experimental work. The biofuel design problem has been formulated as a Non-Linear Program to satisfy specified target properties such as density, kinematic viscosity, cetane number, gross calorific value, distillation temperature, and sulphur content. Target properties predicted through mixture property models were experimentally validated according to ASTM standard test methods. Five optimum tailor-made biofuel blend formulations were generated based on cost, gross calorific value and emission limitations. The result indicates that biofuel blends with butyl levulinate could increase the price of biofuel up to 80% from the retail price of B5 diesel. However, cleaner biofuel with less cost and highest calorific value can be achieved for biofuel blends that contain B5 diesel, butanol and ethanol. The application of this model yields about 26% CO2 emission reduction and about 22% less sulphur content as well as comply with the EN590 fuel regulation standard.

Ionic Liquid and Biofuel Blend: A Low–cost and High Performance Hypergolic Fuel for Propulsion Application

AbstractHypergolic fuel has unique importance in missiles and satellite launch vehicles. Hydrazine and its derivatives (Monomethyl hydrazine, MMH and Unsymmetrical Dimethyl Hydrazine, UDMH) are the continuous choices of fuel in bipropellant though it is carcinogenic and toxic. Development of new, green and cost‐effective fuel blends based on trust‐worthy, ionic liquid and biofuel in different volume proportion have been reported. The blends exhibit reasonably good stability (chemical and thermal), low viscosity (η < 15 mPa⋅s), high density (ρ > 1 g/cm3), low ignition delay and high performance in comparison with UDMH ‐ a proven liquid fuel presently being used as promising fuels for liquid rocket application. The reported blends appear to be a technologically promising, eco‐friendly and affordable fuel blend to replace currently used liquid toxic fuels.

Analysis of Performance and Emission Parameters on Diesel Engine Using Various Blended Bio-Fuels

Analysis of Performance and Emission Parameters on Diesel Engine Using Various Blended Bio-Fuels

Influence of CME-Diesel Blends on the Performance of a Light Duty Common Rail Direct Inject Engine

Coconut Methyl Ester (CME) is the main feedstock used for biodiesel in the Philippines, As of this year only 2% of CME is mandated to be blended in locally distributed fuel, but by 2016 the target is to increase the mandated biofuel blend to 5%. Given the mixed results about the effect of biofuels blends in engine perfomance by various studies it is imperative to further assess the impact of the target biodiesel blends. The effect CME Biodiesel blends in the performance of a light duty automotive common rail direct injection engine is determined in this study. Total of six fuel blends – B0 (Neat Diesel), B2 (2%CME, 98%B0), B5 (5% CME, 95%B0), B10 (10%CME, 90%B0), B15 (15%CME, 85%B0) and B20 (20%CME, 80% B0) were tested for performance at 100% load with varying speeds from 800 RPM to 2400 RPM at an interval of 400 RPM. At this typical engine speed range, no significant differences for biodiesel blends versus neat diesel were observed for torque.

An experimental analysis on the influence of fuel borne additives on the single cylinder diesel engine powered by Cymbopogon flexuosus biofuel

Researchers all around the world are making strenuous efforts to find alternative fuel to ameliorate the problem of depletion of fossil fuel. we have identified a novel plant based biofuel, namely Cymbopogon flexuous biofuel. It has excellent fuel properties and is widely available in India and it seems to have the potential to make India self-sufficient in energy production. Cerium oxide nanoparticles were synthesized using sol–gel combustion methods. Their structural, morphological and elemental properties were studied with the help of XRD, SEM, TEM and EDS respectively. On volume basis, 20% raw Cymbopogon flexuous biofuel was blended with diesel fuel, and various proportions of Cerium oxide nanoparticles, namely C20-D80 + 10 ppm, C20-D80 + 20 ppm andC20-D80 + 30 ppm were prepared. The properties like density, kinematic viscosity, calorific value of the test fuel were measured as per ASTM standards and compared with those of diesel fuel. An experimental study of its performance, emission, and combustion behavior was conducted at varied load conditions at a constant speed of 1500 rpm. NOx and smoke emission was simultaneously reduced by 3% and 6.6% respectively as compared with biofuel blend. Due to higher thermal stability and oxygen buffer of Cerium oxide nanoparticle the brake thermal efficiency was higher by 4.76% and cylinder pressure and heat release rate was also higher.

Exploring the Relationship Between Octane Sensitivity and Heat-of-Vaporization

The latent heat-of-vaporization (HoV) of blends of biofuel and hydrocarbon components into gasolines has recently experienced expanded interest because of the potential for increased HoV to increase fuel knock resistance in direct-injection (DI) engines. Several studies have been conducted, with some studies identifying an additional anti-knock benefit from HoV and others failing to arrive at the same conclusion. Consideration of these studies holistically shows that they can be grouped according to the level of fuel octane sensitivity variation within their fuel matrices. When comparing fuels of different octane sensitivity significant additional anti-knock benefits associated with HoV are sometimes observed. Studies that fix the octane sensitivity find that HoV does not produce additional anti-knock benefit. New studies were performed at ORNL and NREL to further investigate the relationship between HoV and octane sensitivity. Three fuels were formulated for the ORNL study with matched RON and octane sensitivity, but with differing HoV. Experiments with these fuels in a 1.6-liter GTDI engine showed that the fuels exhibited very similar combustion phasing under knock-limited spark advance (KLSA) conditions. Fuels having a range of RON, octane sensitivity, and HoV were tested at NREL in a single-cylinder GDI engine under conditions where octane sensitivity has littlemore » effect on knock resistance. KLSA was found to be well correlated with RON. These results reinforce the concept that HoV anti-knock effects can be viewed as a contributor to octane sensitivity. From this viewpoint, HoV effects manifest themselves as increases in octane sensitivity.« less

Biochemical production of bioenergy from agricultural crops and residue in Iran

The present study assessed the potential for biochemical conversion of energy stored in agricultural waste and residue in Iran. The current status of agricultural residue as a source of bioenergy globally and in Iran was investigated. The total number of publications in this field from 2000 to 2014 was about 4294. Iran ranked 21st with approximately 54 published studies. A total of 87 projects have been devised globally to produce second-generation biofuel through biochemical pathways. There are currently no second-generation biorefineries in Iran and agricultural residue has no significant application. The present study determined the amount and types of sustainable agricultural residue and oil-rich crops and their provincial distribution. Wheat, barley, rice, corn, potatoes, alfalfa, sugarcane, sugar beets, apples, grapes, dates, cotton, soybeans, rapeseed, sesame seeds, olives, sunflowers, safflowers, almonds, walnuts and hazelnuts have the greatest potential as agronomic and horticultural crops to produce bioenergy in Iran. A total of 11.33million tonnes (Mt) of agricultural biomass could be collected for production of bioethanol (3.84gigaliters (Gl)), biobutanol (1.07Gl), biogas (3.15billion cubic meters (BCM)), and biohydrogen (0.90BCM). Additionally, about 0.35Gl of biodiesel could be obtained using only 35% of total Iranian oilseed. The potential production capacity of conventional biofuel blends in Iran, environmental and socio-economic impacts including well-to-wheel greenhouse gas (GHG) emissions, and the social cost of carbon dioxide reduction are discussed. The cost of emissions could decrease up to 55.83% by utilizing E85 instead of gasoline. The possible application of gaseous biofuel in Iran to produce valuable chemicals and provide required energy for crop cultivation is also studied. The energy recovered from biogas produced by wheat residue could provide energy input for 115.62 and 393.12 thousand hectares of irrigated and rain-fed wheat cultivation in Iran, respectively. The nitrogen requirement for 33.6% of the total wheat cultivation area could be supplied by the ammonia acquired from biohydrogen. A discussion of the logistics of collection and transportation of the biomass and sensitivity analysis are carried out to evaluate the effect of field cover factor, crop yield, and well-to-wheel GHG emission on collectable residue, biofuel production, and GHG emissions.

Effects of Fuel Aging on the Combustion Performance and Emissions of a Pyrolysis Liquid Biofuel and Ethanol Blend in a Swirl Burner

Pyrolysis liquid biofuel (also called bio-oil or pyrolysis oil) is a promising renewable fuel for stationary heat and power generation; however, the fuel properties, combustion performance, and combustion emissions degrade with fuel aging. The aging effects of softwood bark pyrolysis liquid biofuel on fuel properties and combustion performance are studied. To investigate the aging effects on fuel properties, the solid content, viscosity, estimated Sauter mean diameter (SMD), and thermogravimetric analysis (TGA) residue of pure pyrolysis liquid are considered. Furthermore, the CO emission, unburned hydrocarbon (UHC), and organic fraction of particulate matter (PM) emissions [also called carbonaceous residue (CR)] from combustion of the aged pyrolysis liquid biofuel/ethanol blend are measured to investigate the effect of aging on the combustion performance in a swirl spray burner. All measurements are employed for two batches of pyrolysis liquid biofuel with two levels of solid content. Results show that fu...

Stakeholders' perceptions on challenges and opportunities for biodiesel and bioethanol policy development in Thailand

Thailand is Southeast Asia's largest promoter of biofuels. Although, Thailand promotes the use of biofuels, it has yet to achieve its policy targets. This paper focuses on the first generation biofuel development in Thailand and examines the perceptions of seven stakeholder groups to guide further policy development. These stakeholders were feedstock producers, biofuel producers, government agencies, car manufacturers, oil companies, non-profit organizations and end users. It combines a Strengths, Weakness, Opportunities and Threats (SWOT) framework with an Analytical Hierarchy Process (AHP) framework and a TOWS Matrix for analysis of stakeholder's perceptions to propose priorities for policy development. Five policies were of high priority for development of biofuel. These are: (1) promoting biofuel production and use in long term through government policies, (2) revising government regulations to allow sale of biofuel products to other domestic industries while keeping retail prices of blended biofuels below those of regular ethanol and biodiesel, (3) improving farm management and promoting contract farming, (4) expanding cultivation area and yield without affecting food production and environmental sustainability, and (5) balancing biofuel feedstock use between the food and energy industries.

An Economic Analysis of Biofuel Production and Food Security in India

Biofuels provide around 2% of total transport fuel today, by 2050, it is projected that 27% of the transport fuel will be shared by the biofuels globally. Some biofuels already perform well in economic terms, particularly sugarcane ethanol and other low cost agricultural biofuels. The biofuel program in India at niche stage though the policy has been framed out in 2003-04 to implement the biofuel blending program in India. India has carefully designed the biofuel policy and blending ratio to reduce CO2 emissions and import of the crude oil. In this study, the biofuel policy, biofuel production, biofuels requirement for blending, future biofuel production was estimated. The linear demand function was used to estimate the bioethanol and biodiesel demand. The possible ways to meet out the biofuels demand were explained. Proper policy making and domestic production support measures for sustainable biofuel production and infrastructure for anhydrous ethanol storage are the guidepost for the successful implementation of the biofuel program in India.

Performance and Emission Characteristics of a Direct Injection Diesel Engine fuelled with Jatropha and Rubber Seed Oil Blends with Pure Diesel Fuel

A dual bio-fuel (Jatropha oil and Rubber Seed oil) blend mixed with the pure diesel has been charged in to a single cylinder Direct Injection (DI) constant speed diesel engine to analyse the performance and emission characteristics. While conducting the experiment, the engine was running at 1500 rpm and the fuel injection pressure of 240 bar was maintained instead of the designed pressure of 220 bar. Biodiesel blends at different propositions were prepared by volume basis such as B20, B40, B60, B80 and B100. The test engine had been running at different load conditions of 0%, 25%, 50%, 75% and 100% at the engine rated power of 4.4 kW. From the experimental result, it was observed that the specific fuel consumption was lowered and the brake thermal efficiency increased for B20 blend at all load conditions. After the emission analysis, the parameters such as Carbon Monoxide (CO), Hydro Carbons (HC) and Nitric Oxide (NOx) were decreased for the blend B20, and the Carbon Dioxide (CO2) emission was increased. While using B100 at full load condition, the emission was increased considerably. Finally, for the increased injection pressure of 240 bar, the B20 blend shows the acceptable result compared to other biodiesel proportions at all engine loads.

Influence of Fuel Injection Pressure on Combustion and Gas Emissions in a TBC Diesel Engine Fuelled with Pongamia Bio-Fuel Blends for Sustainable Environment

The objective of this research work was to investigate the environmental aspects of Pongamia bio-fuel blends and diesel in a Thermal Barrier Coated (TBC) diesel engine with the influence of fuel injection pressure. The combustion chamber components including inlet and exhaust valves, cylinder head and piston crown were coated with yttria stabilized zirconia ceramic material over nickel aluminium alloy bond coat for 300 μm thickness. Biodiesel obtained by Transesterification process from non-edible Pongamia pinnata oil was blended with diesel in various proportions from 0–30% in steps of 5% by volume. Injection pressure was varied from 210 bar to 240 bar in steps of 10 bar by means of adjusting the injector spring tension. The effect of fuel injection pressure for specified biodiesel blends and diesel at full load are studied. Experimental results confirmed that in coated engine biodiesel blend 15% by volume (B15) with diesel showed significant reduction in emissions carbon monoxide (CO) of about 50%, unburnt hydrocarbon (UHC) of 26.5%, smoke of 20% with slightly higher values of 2.37% oxides of nitrogen (NOx) and 5.17% of carbon di oxide (CO2) at 230 bar injection pressure in full load condition compared with uncoated engine. Increase of injection pressure improved heat release rate of about 5.21%, 4.65% for diesel and blend B15 in coated engine and the occurrence of peak heat release rate is earlier around 2°CA before diesel fuel in coated engine at 230 bar pressure for blend B15. From the test results, it was found that blend B15 causes better atomization with improved emission characteristics at 230 bar injection pressure.

Performances and Emissions of a 2-Stroke Diesel Engine Fueled with Biofuel Blends

Diesel engines are worldwide used as a primary power source not only in motor vehicles, but also in off-road engine applications. Two-stroke Diesel engine is most commonly seen in applications demanding a large power output, such as ships and electric generation plants. The use of biofuels has increased during the last years in response to concerns about climate change and to increase security of supply.In this paper some results obtained with a 2-Stroke 6V53 Detroit Diesel (5.22L displacement, 150 kW at 2800 rpm) fueled with a commercial diesel fuel and biodiesel (100%RME) are discussed.CO, NO/NOx, CO2 and particulate matter (PM) have been sampled at 1 Hz in different load conditions and fuel consumption has been measured.A catalyzed Diesel particulate filter (DPF) has been also installed at the exhaust to reduce PM emissions and the influence of fuel quality on emissions and fuel consumption was analyzed.The installation of DPF has involved an average of less than 10% fuel economy penalty for both tested fuels.A passive DPF system can be easily installed at the exhaust of in-use engine and it permits to reduce more than 90% PM emissions.

Optimization of Biofuel Blends and Compression Ratio of a Diesel Engine Fueled with Calophyllum inophyllum Oil Methyl Ester

The twin crises in depletion of fossil fuels and environmental degradation have motivated researches to consolidate the use of biofuels for internal combustion engine applications. In the present study, the performance and emission characteristic of Calophyllum inophyllum oil-based methyl ester and its diesel blends are analyzed at various compression ratios. Comprehensive optimization by considering the performance parameter along with emission characteristic is rather involved and is done carefully with designed set of experiments and analyzed statistically using design expert software. Higher compression ratio (CR) induces high cylinder temperature which enhances vaporization and thereby better performance only to a certain extent, that is, up to a CR of 19. However, due to high operating temperature, the oxides of nitrogen emission increase with CR and also for high biofuel blends, but better combustion phenomenon at these conditions reduces the emissions of carbon monoxide and unburned hydrocarbon. The designed empirical statistical model for optimum performance with lower emission is found to be B30 (30 % biofuel) at a CR of 19, which is then tested and validated.

Scenario Based Assessment of CO2 Mitigation Pathways: A Case Study in Thai Transport Sector

“When to implement actions” and “how much to abate emissions” are two major concerns of policy makers when it comes to policy formulation and planning for CO2 mitigation. This study investigates CO2 mitigation potential in the Thailand transport sector under four possible mitigation pathways. Those pathways comprise four mitigation actions and three different time frames as implementation periods (2015, 2025 and 2035 as commencement years). To represent that, along with business as usual (BAU) case (as reference), four countermeasure scenarios were modeled namely L2035, L2025, L2015 and fuel switching (FS). Results show that the L2015 scenario can achieve the highest CO2 mitigation with 23% cumulative reduction against the BAU from 2010-2050. However, due to countermeasure implementation delays (by 10 years in L2025 and by 20 years in L2035), the mitigation potentials have dropped significantly. In addition, early in implementations of actions have resulted considerable reduction in energy consumption and it has allowed more penetrations of bio-fuel blends and electricity as replacements to fossil oils. Moreover, in terms of abatement costs, technologies such as efficient vehicles and modal shifts provide cost savings along with high mitigation potentials.