Biofuel Combustion Research Articles

Combustion, emission, and performance characteristics of hybrid biofuel at different compression ratios

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and smoke from diesel engines. The current study aimed to improve the performance and emission characteristics of a variable compression ratio (VCR) diesel engine operated with hybrid biodiesel. Experiments were done with the best hybrid biodiesel, which was made by mixing 20% rubber seed oil (RSO) with 80% waste plastic oil (WPO). The tests were done at four compression ratios (CRs): 16:1, 17:1, 18:1, and 20:1. Under a CR of 20:1 and at full load, the engine?s brake thermal efficiency went up by 30.5%, its brake-specific fuel consumption went down by 0.347 kg/kWh, and notably diminished emissions of carbon monoxide (0.43% volume), hydrocarbons (79 ppm), and smoke (22%). However, with increasing CRs, NOx emissions rose unfavourably (1092 ppm) compared to diesel (820 ppm). Also, diesel and clean (WPO) were compared to see how the CR values affected combustion, performance, and emissions. Compared to diesel, under maximum load and the CR of 20:1, hybrid biodiesel demonstrated approximately 3.7% higher brake thermal efficiency. The findings suggest potential applications for this hybrid biodiesel in the automobile sector, the power generation industry, and marine applications.

Analyzing the interconnected dynamics of domestic biofuel burning in India: unravelling VOC emissions, surface-ozone formation, diagnostic ratios, and source identification

The impacts of burning biomass fuels for cooking and heating in indian homes on public health and communities.

Critical review on the formations and exposure of polycyclic aromatic hydrocarbons (PAHs) in the conventional hydrocarbon-based fuels: Prevention and control strategies

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the atmosphere and primarily originate from the incomplete burning of fossil fuels and biofuels. Exposure to PAHs leads to harmful effects on human health and the environment. Diesel engines are a major source of PAH production in the transportation sector. Various approaches have been employed to reduce PAH emissions from diesel engines, including the use of biodiesel, green gaseous fuels, exhaust gas recirculation, exhaust after-treatment, and genetically modifying biodiesel with nanoparticles. This review focuses on PAH emissions from different generations of fuels and examines the remedial control actions taken to mitigate PAH formation. The study underscores the necessity for effective regulation of emissions from diesel engines, especially in developing countries where the reliance on fossil fuels is significant. Biodiesel has shown promise in reducing PAHs and carcinogenic pollutants, with higher biodiesel concentrations resulting in lower PAH formation. Replacing diesel with biodiesel and optimizing engine operating conditions are feasible methods to reduce PAH levels in the atmosphere. The use of nanoparticles in fuel blends and higher oxygen content in combustion chambers are also considered potential strategies for pollutant reduction. Additionally, the utilization of hydrogen and ammonia as secondary fuels has been explored as promising alternatives to fossil fuels. The study highlights the importance of further research on the presence of residual PAHs in the atmosphere and the implementation of strategies to curtail vehicular emissions.

Environmental, combustion, and performance investigation of low viscous biofuel in port fuel injection spark-ignition engine

Environmental, combustion, and performance investigation of low viscous biofuel in port fuel injection spark-ignition engine

Automatic mechanism generation for the combustion of advanced biofuels: A case study for diethyl ether

AbstractAdvanced biofuels have the potential to supplant significant fractions of conventional liquid fossil fuels. However, the range of potential compounds could be wide depending on selected feedstocks and production processes. Not enough is known about the engine relevant behavior of many of these fuels, particularly when used within complex blends. Simulation tools may help to explore the combustion behavior of such blends but rely on robust chemical mechanisms providing accurate predictions of performance targets over large regions of thermochemical space. Tools such as automatic mechanism generation (AMG) may facilitate the generation of suitable mechanisms. Such tools have been commonly applied for the generation of mechanisms describing the oxidation of non‐oxygenated, non‐aromatic hydrocarbons, but the emergence of biofuels adds new challenges due to the presence of functional groups containing oxygen. This study investigates the capabilities of the AMG tool Reaction Mechanism Generator for such a task, using diethyl ether (DEE) as a case study. A methodology for the generation of advanced biofuel mechanisms is proposed and the resultant mechanism is evaluated against literature sourced experimental measurements for ignition delay times, jet‐stirred reactor species concentrations, and flame speeds, over conditions covering φ = 0.5–2.0, P = 1–100 bar, and T = 298–1850 K. The results suggest that AMG tools are capable of rapidly producing accurate models for advanced biofuel components, although considerable upfront input was required. High‐quality fuel specific reaction rates and thermochemistry for oxygenated species were required, as well as a seed mechanism, a thermochemistry library, and an expansion of the reaction family database to include training data for oxygenated compounds. The final DEE mechanism contains 146 species and 4392 reactions and in general, provides more accurate or comparable predictions when compared to literature sourced mechanisms across the investigated target data. The generation of combustion mechanisms for other potential advanced biofuel components could easily capitalize on these database updates reducing the need for future user interventions.

Creating Sustainable Climate Change Havens for Migrating Populations in the United States and Other Global Sites

A model for constructing sustainable Climate Change Haven communities in appropriate areas of the United States and globally is presented. The model proposes the construction of walkable communities of 20,000 to 30,000 residents with electricity provided by hydropower generators and biofuel combustion. The remediation of surface-mined areas using switchgrass and flood control dams to redirect excess rainfall will be required in some areas. This model also addresses the multiple social and cultural considerations required to resettle groups of migrants in Climate Change Haven communities, together with the preparation and preservation of nearby farmland for feeding the community.

Effect of operation conditions on particulate matter removal by a packed-bed wet scrubber for a small-scale biofuel boiler

In 2013 the EU’s Clean Air Policy Package was established, aiming to reduce air pollution to half by 2030 compared to the level in 2005. Small-scale (<500 kW)biofuel boilers play a key role in particulate matter emission, and exposure to particulate matter even in the short term can cause different diseases. With the aim of reducing particulate matter emission in Europe, this study presents an approach to improve the removal of particulate matter emitted by small-scale boilers. A biofuel combustion boiler was equipped with a packed-bed wet scrubber, and the flue gas emitted through combustion was cleaned through the wet scrubber using a saltwater mixture. The performance of a packed-bed wet scrubber was investigated under different operating conditions. The effect of the salt concentration of the absorption solution, the temperature of the absorption solution fed to the absorber, and the height of the packed-bed material on the particle collection efficiency were measured. The operating conditions were selected based on the results obtained in a previous computational fluid dynamic simulation study. The results obtained in the present study show that an absorption solution temperature of 30 °C and an absorption solution concentration of 75 % with a full height of the packed-bed material lead to the best performance in the system. Totally keeping the absorption solution temperature as low as possible, increasing the absorption solution concentration, and raising the packed-bed material height could improve the particle collection efficiency by enhancing the effect of the diffusiophoresis and thermophoresis forces and the contact time between the flue gas and solution.

Statistical investigation of combustion and emission characteristics of biofuels according to their physical properties: A way to explore suitable alternative fuels

The Pollutant emissions and limited fossil fuel resources attracted researchers toward alternative fuels. Therefore, the combustion of liquid biofuels (as an alternative fuel) is gaining importance in research for the power generation sector for gas turbine engines and internal combustion engines. The physical properties of these fuels play an important role in the combustion characteristics (in terms of flame characteristics, emission characteristics, and flame temperature profile characteristics), and their experimental testing is costly. Considering the importance of research and cost in the experiment, the analysis is carried out to develop a new model for evaluating post-combustion emission characteristics based on the physical properties of liquid fuels. Raw data is extracted from experimental investigations to establish the present analysis models. Experimental studies have been carried out to evaluate the properties of different fuels and their composition-wise effects on flame, temperature, and emission characteristics. Thereby, reliable combustion performance and low emission profiles (in terms of physical fuel properties) can be ensured for potential alternative fuels. The results of the analysis show that specific properties such as high viscosity, high density, and high aromatic content of the fuel have the potential to generate high CO. In contrast, a decrease in these properties promotes high CO2 formation. In addition, low NOx emissions and low CO trends are unlikely to be achieved by simultaneously changing the value of fuel properties. The analysis shows that the low viscosity of the fuel induces low soot emission and flame length retardant.

What happens to biomass burning-emitted particles in the ocean? A laboratory experimental approach based on their tracers

Wildfires, controlled burns, and biofuel combustion (biomass burning or BB) are major contributors to particulate matter in the atmosphere and thus have an impact on climate, human health, and ecosystems. Once emitted, the particulate matter derived from BB can be taken up by the oceans. However, the fate and impact of BB in the marine biological carbon pump, and carbon cycle are largely unknown. This work presents the first attempt to investigate the bioavailability of two BB tracers, levoglucosan and galactosan, in seawater inoculated with marine prokaryotes. Levoglucosan and galactosan were incubated with a marine bacterial inoculum and monitored for six weeks under controlled laboratory conditions. Along with the anhydrosugar concentrations, multiple chemical and biological parameters were monitored over time. The results indicate that levoglucosan and galactosan can be assimilated by marine prokaryotes as their concentrations decreased by 97 ± 4 % and 36 ± 21 % (n = 3) of their initial values. However, this decrease occurred only after a 9 and 15 days from the beginning of the experiment, respectively. The decrease in the levoglucosan and galactosan concentrations was accompanied by an increase in both heterotrophic prokaryotic production, and abundance. These results demonstrate that these anhydrosugars have the potential to be assimilated by heterotrophic prokaryotes and thus contribute to the microbial food web functioning. Under our experimental conditions, levoglucosan exhibited a bacterial growth efficiency of 17 ± 5 % (n = 3), suggesting that most of the levoglucosan is mineralized into CO2. Prokaryotic diversity analyses revealed the predominance of a few bacterial genera from the Roseobacter clade that were selected after the addition of the anhydrosugars. The presence of this widespread marine bacterial clade reflects its ability to process semilabile compounds (here levoglucosan and galactosan) originating from BB and contribute to the dissolved organic matter pool in surface seawaters.

A thermokinetic characterization study on combustion of solid biofuels from Aloe vera residue

A thermokinetic characterization study on combustion of solid biofuels from Aloe vera residue

New insight into dissociation of molecular oxygen at temperatures below 5000 K

The data available in the literature on measurements of the rate coefficient of molecular oxygen dissociation were considered and structured. Modern models of hydrocarbons combustion were analyzed considering values of the O2 dissociation rate constant. Precision measurements of the rate of O2 dissociation behind shock waves at temperatures of 2500–5000 ± 50 K and pressures of 1.2–2.5 bar were carried out using atomic resonance absorption spectrometry on O atom (O-ARAS). The ARAS measurements of the absolute concentration of oxygen atoms were calibrated in the conditions of complete dissociation of N2O and O2, considering the temperature splitting of the calibration curves. Using kinetic modeling, a detailed analysis of experimental uncertainties was carried out with an assessment of the influence of impurities of various origin at the dissociation of O2. An updated expression for the rate constant of the reaction O2 + Ar = 2O + Ar was obtained in the form kdiss(±15%)=1.30·1014·exp(−108.95[kcalmol]/RT) cm3 mol−1 s−1. A significant influence of the O2 dissociation rate constant on the predictive ability of modern models of hydrocarbons (on the example of biofuels) combustion at high temperatures was shown. Recommendations were formulated on the use of the corresponding oxygen dissociation rate constant in the development and/or refinement of combustion kinetic models.

Physical Mechanisms of Vibrating Combustion of Solid Biofuel

Physical Mechanisms of Vibrating Combustion of Solid Biofuel

Chemically distinct particle-phase emissions from highly controlled pyrolysis of three wood types

Abstract. Wood pyrolysis is a distinct process that precedes combustion and contributes to biomass and biofuel burning gas-phase and particle-phase emissions. Pyrolysis is defined as the thermochemical degradation of wood, the products of which can be released directly or undergo further reaction during gas-phase combustion. To isolate and study the processes and emissions of pyrolysis, a custom-made reactor was used to uniformly heat small blocks of wood in a nitrogen atmosphere. Pieces of maple, Douglas fir, and oak wood (maximum of 155 cm3) were pyrolyzed in a temperature-controlled chamber set to 400, 500, or 600 ∘C. Real-time particle-phase emissions were measured with a soot particle aerosol mass spectrometer (SP-AMS) and correlated with simultaneous gas-phase emission measurements of CO. Particle and gas emissions increased rapidly after inserting a wood sample, remained high for tens of minutes, and then dropped rapidly leaving behind char. The particulate mass-loading profiles varied with elapsed experiment time, wood type and size, and pyrolysis chamber temperature. The chemical composition of the emitted particles was organic (C, H, O), with negligible black carbon or nitrogen. The emitted particles displayed chemical signatures unique to pyrolysis and were notably different from flaming or smoldering wood combustion. The most abundant fragment ions in the mass spectrum were CO+ and CHO+, which together made up 23 % of the total aerosol mass on average, whereas CO2+ accounted for less than 4 %, in sharp contrast with ambient aerosol where CO2+ is often a dominant contributor. The mass spectra also showed signatures of levoglucosan and other anhydrous sugars. The fractional contribution of m/z 60, traditionally a tracer for anhydrous sugars including levoglucosan, to total loading (f60) was observed to be between 0.002 and 0.039, similar to previous observations from wildfires and controlled wood fires. Atomic ratios of oxygen and hydrogen to carbon, O:C and H:C as calculated from AMS mass spectra, varied between 0.41–0.81 and 1.06–1.57, respectively, with individual conditions lying within a continuum of O:C and H:C for wood's primary constituents: cellulose, hemicellulose, and lignin. This work identifies the mass spectral signatures of particle emissions directly from pyrolysis, including f60 and the CO+/CO2+ ratio, through controlled laboratory experiments in order to help in understanding the importance of pyrolysis emissions in the broader context of wildfires and controlled wood fires.

ПІЛЬГОВЕ ОПОДАТКУВАННЯ ВИКИДІВ ДВООКИСУ ВУГЛЕЦЮ ВІД СПАЛЮВАННЯ БІОПАЛИВА У КОНТЕКСТІ ПЕРЕОЦІНКИ ВПЛИВУ БІОЕНЕРГЕТИКИ НА КЛІМАТ

The present paper examines the problems and prospects of preferential taxation of carbon dioxide emissions from biofuel combustion in the context of reassessing climate impacts of bioenergy. Special attention is given to the analysis of the draft Law of Ukraine “On amendments to the Tax Code of Ukraine regarding the establishment of a zero-tax rate for carbon dioxide emissions from installations that produce such emissions as a result of biofuel combustion”, the latest version of which was published by the Ministry of Energy of Ukraine in August 2022. Scientific approaches that express a critical view of the carbon neutrality of bioenergy and indicate the possibility of its adverse climate impacts are generalized. Potentially conflict zones where bioenergy capacity growth may conflict with climate policy are discussed. It is demonstrated that recent changes in European Union legislation are designed to ensure that zero-emission biomass shall fulfil the sustainability and the greenhouse gas emissions saving criteria. The extension of these criteria to relations in the field of emissions trading indicates significant progress in ensuring the objectivity of assessing the climate potential of bioenergy. Joining such progressive changes is complicated in Ukraine by the lack of the criteria at the level of national legislation, the energy crisis, the reduction of sustainable biomass due to hostilities and other factors. In this regard, the paper provides suggestions to establish a zero-tax rate for carbon dioxide emissions from installations that use biofuel as the only type of fuel, without reference to the sustainability and the greenhouse gas emissions saving criteria, at least in the short term to stimulate investment processes in the field of renewable energy.

Improved biomass burning pollution in Beijing from 2011 to 2018

The prohibition of open straw burning and clean energy transitions, implemented in the last 10 years, resulted in remarkable reductions in ambient biomass burning pollution in Beijing. Here, we present the reduction of biomass burning molecular tracer (i.e., levoglucosan) concentrations using year-long filter sample results collected in Beijing respectively during 2010–2011 and 2017–2018. The annual mean concentrations (95% CI) of levoglucosan during 2010–2011 and 2017–2018 were 0.34 (0.29–0.38) μg m−3 and 0.11 (0.09–0.13) μg m−3, respectively, with a 67% decrease. Compared to 2011, the two traditional open biomass burning episodes in early summer and during the fall post-harvest season disappeared in 2018. Meanwhile, the intensity and duration of biomass burning episodes during the heating season in 2017–2018 was much weaker and shorter than that in 2010–2011. Our results indicate that the implemented clean air action plans were effective in reducing open biomass burning, but the control of biofuel combustion activities during the heating season remains a major challenge in China.

Clean Energy as an Alternative: Identification of Factors Determining the Willingness of Slum Dwellers

Increasing trends towards globalization and modern lifestyle are going to deplete, energy resources rapidly. Increasing trends towards energy use directly harness the environment and ecosystem of the earth, depicting that energy will be one of the most important future problems of the world. Clean and sustainable energy alternatives are required to meet this demand in order to combat the antagonistic environmental problems. Renewable energy sources have the potential to fulfill the energy gaps without affecting the ecosystem and the greenhouse gases emittance. The transformation of people causes the generation and creation of slum areas in the cities due to ever-increasing urbanization. Presently around one billion people are residing in slum areas. Most slum dwellers are found in less economically developed countries, which makes it 30% of the total population. The inhabitants of slum dwellers are more likely to be increased by two billion by 2030 and to three billion by 2050. Pakistan is facing a severe energy deficiency. The energy gap between energy supply and demand is widening with time. Limited fossil fuel resources allow the country to import nonrenewable energy resources to fill this gap. Gas connection problems and energy shortfalls compel urban households to use nonrenewable energy resources. The need of the hour is to diversify the energy resources like biogas, hydropower, solar, and wind to overcome the energy shortfall in the country. Fossil fuel usage for an energy source in households is the major cause of environmental degradation in urban households. Owed to bad smoke and insufficient ventilation, health-related problems like respiratory issues, stomach problems, and other contagious diseases are associated. The smoke that is caused by the combustion of biofuels impacts residents health badly, especially respiratory problems. The primitive aim of this research is an assessment of energy sources being used and to dig out reasons for their impacts on the health conditions of residents of slum dwellers in Pakistan stratified random sampling is used for data collection and correlation analysis was performed to find out the result.

 MODELLING AND SIMULATION OF THE COMBUSTION OF BIODERIVED FUELS IN A PT6A-27 TURBOPROP ENGINE

The motivation for venturing in alternative jet fuels has partly been due to the elevated level and volatility of the price of Jet A and environmental impacts on global climate change and air quality. The model of the annular combustor for the PT6A-27 engine was created using SOLIDWORKS and exported to ANSYS DESIGN MODELER. Creation of the computational mesh for the geometry using ANSYS MESHING was done in preparation for the setting up of the CFD simulation in ANSYS FLUENT. The simulation included, setting material properties and boundary conditions for a non-premixed combustion problem. Initiating the calculation with residual plotting, calculating the solution using the pressure-based solver and visually examining the flow and temperature fields using the post-processing in ANSYS FLUENT with the Standard k-ε 2 equation turbulence model used. The fuel blend from the range of 30% bioethanol and 70% biodiesel (BE30-BD70) to 70% bioethanol and 30% biodiesel (BE70-BD30) indicated a combustion characteristic consistency with that obtained from the combustion of Jet-A1. Further, from the comparisons of the blends in terms of performance and single biofuel combustion simulation the best blend combination was 40% bioethanol with 60% biodiesel (BE40-BD60) whose adiabatic flame temperature was about 2260 Kelvins. The blend of 40% bioethanol to 60% biodiesel was observed to have a reduced Fuel NOx footprint and the observed production rate values of Thermal NOx were a range of to Whereas a pure JetA-1 hydrocarbon fuel had a production rate of Thermal NOx ranging from to . This was indicative of a reduction in Thermal NOx when the two groups of fuels (Jet-A against 40BE &amp; 60BD blend) were compared. These results showed that reduction of NOx emissions is achievable for a blend of 40% bioethanol and 60% biodiesel in a combustion reaction as a substitute for the hydrocarbon JetA-1 in the PT6A-27 turboprop engine. KEY WORDS—PT6A-27, nonpremixed Combustion, NOx, Turbulence model

Smoke Formation during Combustion of Biofuel Blends in the Internal Combustion Compression Ignition Engine

The proposed changes to the legislation on diesel cars require intensification of work on the possibilities of reducing emissions of harmful substances into the atmosphere by these vehicles. The subject of experimental research included in the manuscript was the Skoda Octavia with a 1.9 TDI (turbocharged direct injection) compression ignition engine (type 1Z). Light absorption measurements of smokiness of the exhaust gases emitted after combustion of various biofuels (conventional diesel, pure hydrotreated vegetable oil, hydrotreated vegetable oil, biobutanol) and their blends with fossil diesel fuel were studied. The measured light absorption coefficient is the reciprocal of the thickness of the layer, after passing through which the light has a ten times lower intensity. Its unit is the reciprocal of the meter (1/m or m−1). The results obtained by means of a standard smokiness meter indicate that the use of biofuels or their blends, in general, reduces smoke formation.

Identification of levoglucosan degradation pathways in bacteria and sequence similarity network analysis

Levoglucosan is produced in the pyrolysis of cellulose and starch, including from bushfires or the burning of biofuels, and is deposited from the atmosphere across the surface of the earth. We describe two levoglucosan degrading Paenarthrobacter spp. (Paenarthrobacter nitrojuajacolis LG01 and Paenarthrobacter histidinolovorans LG02) that were isolated from soil by metabolic enrichment using levoglucosan as the sole carbon source. Genome sequencing and proteomics analysis revealed the expression of a series of genes encoding known levoglucosan degrading enzymes, levoglucosan dehydrogenase (LGDH, LgdA), 3-keto-levoglucosan β -eliminase (LgdB1) and glucose 3-dehydrogenase (LgdC), along with an ABC transporter cassette and an associated solute binding protein. However, no homologues of 3-ketoglucose dehydratase (LgdB2) were evident, while the expressed genes contained a range of putative sugar phosphate isomerases/xylose isomerases with weak similarity to LgdB2. Sequence similarity network analysis of genome neighbours of LgdA revealed that homologues of LgdB1 and LgdC are generally conserved in a range of bacteria in the phyla Firmicutes, Actinobacteria and Proteobacteria. One group of sugar phosphate isomerase/xylose isomerase homologues (named LgdB3) was identified with limited distribution that is mutually exclusive with LgdB2, and we propose that they may fulfil a similar function. LgdB1, LgdB2 and LgdB3 adopt similar predicted 3D folds, suggesting overlapping function in processing intermediates in LG metabolism. Our findings highlight diversity within the LGDH pathway, through which bacteria utilize levoglucosan as a nutrient source.

IMPROVING THE PERFORMANCE OF BOILER PLANTS DUE TO THE USE OF DIRECT AND REVERSE RANKIN CYCLES

To generate electricity from biofuels at heat and power enterprises of Ukraine, the direct Rankine cycle is used, which ensures the efficiency of energy transformation within  = 0.25-0.55. To improve the efficiency of fuel energy, use in boiler plants, it is also proposed to implement a reverse Rankine cycle scheme. Such a proposal is good to use in enterprises where there is a need for drying biomaterials. Instead of a separate boiler for drying processes, it is proposed to use the energy of water condensation from flue gases. In this case, the cost of electricity for the operation of the compressor is significantly less than the amount of heat obtained by condensing water from flue gases. The efficiency coefficient or COP of the reverse Rankine cycle can have values greater than one  = COP  3. The combination of direct and reverse Rankine cycles in the technological scheme of the boiler plant increases the efficiency of using primary energy sources. The paper analyzes the representation of energy as a combination of two components: the potential P and the dynamics D. The Leibniz model, in which the power N is represented as the product of the potential P and the dynamics D with the unification of the unit of measure Watt, allows calculating the efficiency of transformation processes of different types of energy. To improve the energy performance of boiler plants, further development of the Newton model is proposed, which makes it possible to calculate the process dynamism indicator – . In Newton's model, within the framework of one type of energy, the dynamism indicator is calculated – as the ratio of dynamics to the initial potential  = D / P. Dynamism  can be calculated as the reciprocal of the resistance R, provided that the units of measurement of the energy components – potential and dynamics are unified. To increase the efficiency of biofuel combustion energy use, the idea of the reverse Rankine cycle has been implemented. The moisture condensation temperature of the flue gases increases due to an increase in the pressure of the medium. To do this, the smoke exhauster is moved from the discharge zone to the pressure zone. The additional energy from the flue gases of the boilers can be used to increase the efficiency of drying biomaterials. It is possible to refuse an additional boiler for drying materials, which significantly reduces fuel costs, and also improves the environmental performance of technological processes.