Demand For Fuels Research Articles

Opportunities and barriers for biofuel and bioenergy production from poplar

AbstractDue to the growing demand for transportation fuels and concerns about the greenhouse gas emissions derived from the use of fossil fuels, the development of alternative fuels from renewable resources, such as lignocellulosic biomass, is of paramount importance. This is compounded by the fact that there are increasing pressures and limitation on available arable land for renewable biomass production, and therefore, how to obtain more biomass resources and how to make full use of these biomass resources are key issues. Poplar (Populus spp.) is one of the fastest‐growing temperate trees in the world and is a very promising raw material for the production of biofuels and other bio‐based commodities. As the first tree species to have its genome sequenced, and significant continuing efforts towards resequencing of different species/varieties, poplar resources will undoubtedly pave the way for the targeted cultivation of new poplar varieties suitable for biofuel production. In this article, we summarized that the main problems faced by using poplar as a biomass resource for biofuel production are the inherent recalcitrance of lignocellulosic biomass, and highlighted the response status on improving the biomass yield and efforts towards developing efficient poplar varieties for biofuel production.

Close the carbon loophole

Close the carbon loophole

Transformation of lignocellulose from corn stove for bioethanol production

The use of fossil fuels, as well as the environmental issues associated with their burning, has pushed for the development of clean, renewable energy sources. Biofuels made from lignocellulosic biomass are considered a carbon-neutral and sustainable method. As the demand for non-petroleum fuels grows, more attention will be placed on developing a cost-competitive liquid transportation biofuel like ethanol. This study was conducted to produce bioethanol utilizing the SHF (separate hydrolysis and fermentation) technique from corn stove lignocellulose. Pretreatment with sodium hydroxide at various concentrations was also studied. The influence of enzymatic saccharification, fermentation time, and substrate concentration on sugar yield and, eventually, ethanol production was investigated. Fermentation was carried out by using the enzymatically saccharified hydrolysate and monoculture of Saccharomyces cerevisiae. The results reveal that pretreatment with 2% NaOH followed by 48 hours of hydrolysis produced the maximum bioethanol production (30.21 ±0.13 g/L). This study findings indicated that alkali-pretreated corn stove might be used as a feedstock for bioethanol production, reducing reliance on fossil fuels.

An attempt for improving the performance, combustion and exhaust emission attributes of an existing unmodified diesel engine powered with Palmyra biodiesel blends

The demand for petroleum fuels has been swiftly escalating due to the widespread use of automobiles and other agricultural engines which favour diesel as the most important fuel. The usage of diesel imposes negative impact on environment due to the inherent engine emissions. So there is a need for a suitable substitute for liquid fuels in the form of biodiesel which reduces the emissions. In search of potential feedstock, the extraction of palmyra oil from palmyra fruit and subsequent transesterification process for the preparation of palmyra oil methyl esters (POME10, POME20, POME30 and POME40) was carried out. The various physical-chemical properties of Palmyra biodiesel and its blends are determined as per the ASTM standards and are compared with diesel fuel. From the experimental tests, it is found the exhaust emissions like CO, HC and smoke emissions are reduced by 15.86%, 18.5% and 14.28% for the POME20 blend when compared to the diesel.

Experimental Investigation on Effect of LHR in Diesel Engine Fuelled with Waste Cooking Oil Biodiesel

Diesel-powered engines are best suitable for light and heavy-duty vehicles. Because of the high thermal efficiency, it is widely used in the transportation sector. The rapid increase in global fossil fuel demand has raised fuel prices and causes a huge demand for petroleum fuels. And the stringent Emission norms increased the need for a highly efficient engine. In this work, a low heat rejection diesel engine coated with thermal barrier coating is used to test the biodiesel obtained from waste cooking oil. The Thermal barrier coating is given for 30pm, 40 pm, and 60 pm with yttrium stabilized zirconia. It is observed that the thermal barrier coating with 30pm shows better results. The brake thermal efficiency of the engine with LHR and biodiesel observed an increase in its efficiency. And emission concentrations were increasing with respect to waste cooking oil biodiesel when compared with diesel. The experiment was performed in the laboratory with a single-cylinder water-cooled diesel engine. The emission concentrations are measured with a portable emission analyzer.

Studies on utilization of different preheated straight vegetables oil in a CI engine

Renewable energy befits as an attractive and sustainable solution to compensate for the imbalance in the supply and demand of fossil fuels. Continuous depletion of fossil fuels, price variations and detrimental effect of greenhouse gas emissions are the burning issues in the current scenario. Non-edible vegetable oil can be considered as a comparable alternative to replace conventional diesel fuel. There are some operational issues with straight vegetable oils (SVOs) such as their less calorific value, higher density and higher viscosity etc. which may be dealt with by adopting an appropriate treatment before combustion. Present study has been undertaken on the use of non-edible oils available in the vicinity of the Institute Research Lab. Oils derived from the seeds of Jatropha and Mahua have been preheated to reduce their high viscosity, surface tension and density for meeting the fuel requirements and to use on engines. Experimental and comparative study about the emission and performance parameters has been carried out on a 3.5 KW diesel engine fuelled with preheated straight vegetable oils and diesel fuel. It has been found that at full load the brake thermal efficiency (BTE) of preheated straight vegetable oil is lower by about 8–10% as compared to diesel. Brake specific fuel consumption (BSFC) has been found comparable to diesel with a variation of approximately 2-5%. Emission components hydrocarbon and carbon mono oxide have been found to be reduced significantly in case of preheated oils. The results support the use of non-edible straight vegetable oils directly on the engine in preheated form without converting them into biodiesel by transesterification process. This research motivates the rural areas of developing countries to become self-reliant in energy production as most of these areas are enriched with huge amount of vegetation which can be used to produce edible and non-edible vegetable oil.

Syngas fermentation for production of ethanol

The global demand for fossil fuels has increased sharply in the past 50 years. Plant biomass is one of the fourth largest non-fossil renewable energy sources after geothermal, solar, and wind energy. Biomass can be first converted into another energy form, such as ethanol, to provide a more efficient energy source. Syngas fermentation enables converting all biomass components, including lignin, into ethanol, thereby increasing the biomass quantity. The development of the syngas fermentation process will be reviewed in this article, which focuses on the types of microorganisms used, the effect of syngas composition, and the gas-liquid mass transfer to be used as a reference for optimizing the syngas fermentation process.

Bibliometric Studies on Emissions from Diesel Engines Running on Alcohol/Diesel Fuel Blends. A Case Study about Noise Emissions

The growing demand for fossil fuels, the rise in their price and many environmental concerns strengthen the incessant search for fuel alternatives. Recently, traffic noise has been described as a threat to human health and the environment, being responsible for premature deaths. In this context, the usage of alcohol/diesel fuel blends in diesel engines has gained increasing impact as a substitute fuel for use in internal combustion engines. Moreover, alcohol can be derived from environmentally friendly processes, i.e., fermentation. Furthermore, alcohols can enhance combustion characteristics due to a rise of the oxygen concentration, thus decreasing major emissions such as soot and reducing knock. The commonly used alcohols blended with diesel fuel are methanol and ethanol, recently followed by butanol. In contrast, there are very few studies about propanol blends; however, emissions reduction (including noise) could be remarkable. In the present work, an analytical literature review about noise and exhaust emissions from alcohol/diesel fuel blends was performed. The literature review analysis revealed a continuous increase in the number of publications about alcohol/diesel fuel blend exhaust emissions since 2000, confirming the growing interest in this field. However, only few publications about noise emission were found. Then, an experimental case study of noise emitted by an engine running on different alcohol (ethanol, butanol and propanol)/diesel fuel blends was presented. Experimental results showed that although diesel fuel provided the best results regarding noise emissions, butanol displayed the least deviation from that of diesel fuel among all tested alcohol blends. It may be concluded that tested alcohol/diesel fuel blends in general, and butanol blends in particular, could be a promising alternative to diesel fuel, considering noise behavior.

Effect of EGR on a diesel engine fueled with waste plastic oil blend

With the increasing global demand for fuels, there is a need to reduce vehicular emissions which are one of the major causes of air pollution around the globe. NOx emissions leads to health issues, acid rain, global warming, etc. Diesel engines are the major sources for NOx emissions. Hence there is a need to reduce the emissions from the engines by means of alternate fuels and emission control technologies. This investigation deals with the effect of exhaust gas recirculation (EGR) on single cylinder, direct injection diesel engine using plastic oil and diesel blend (10% plastic oil + 90% diesel) at EGR rates of 5%, 10% and 15%. Plastic oil blends were able to operate in diesel engines without any modifications and based on the results, EGR decreases the NOx emissions with a minimum increase in specific fuel consumption. The engine with the EGR rate of 15% and at the full load condition, the emission level of NOx has been decreased from 1327 to 661 ppm. Hence it was concluded that the low emission level of NOx can be obtained using EGR for the plastic oil blend. The results showed that DPB+EGR15 blend had the least NOx emission.

Ethanol Fuel Demand Forecasting in Brazil Using a LSTM Recurrent Neural Network Approach

Ethanol is a biofuel widely consumed in Brazil, which functions as a substitute for gasoline since the late 1970s. Due to several fluctuations in the characteristics of the Brazilian vehicle fleet and the political-economic conditions of the country, forecasting ethanol consumption has become a difficult task to perform. Under this scenario, the aim of this paper was to forecast ethanol consumption in Brazil using an approach of Long-Short Term Memory (LSTM) Recurrent Neural Networks (RNN) and Autoregressive Integrated Moving Average (ARIMA) models. The above, taking into consideration univariate and multivariate models for each case. Likewise, single-layer and multi-layer topologies of LSTM RNN were explored in this study. The results show that LSTM models overperformed ARIMA models even working with a relatively small training dataset of just 180 instances. This, for both univariate and multivariate models. A novel approach for searching suitable LSTM Neural Network topologies is proposed in this paper.

Heterogeneous Catalysis of Second Generation Oil for Biodiesel Production: A Review

AbstractThe demand for cleaner fuels has been on the rise lately, prompting researchers to explore alternative cleaner technologies to meet the growing demand. This has led to the introduction of renewable fuels such as bioethanol and biodiesel. Depending on the feedstock employed for production, renewable fuels can be divided into first, second, and third generation. Reliance on first generation biofuel feedstocks has led to inherent competition between foods versus fuels in the society in the last decade. Further technological prospects in research and development have provided insight into the use of second generation biofuel feed‐stocks from non‐edible agricultural waste products, energy crops, and crop residues. Zeolites and modified zeolites as heterogeneous catalysts have been highly prospective for the transesterification process of these oils. Modified zeolite can act as a bi‐functional catalyst because of its acidic and basic sites. Here, a review of transesterification reaction technology, zeolite and modified zeolite as a heterogeneous catalyst to generate biodiesel was discussed. Current status, challenges and future prospects are also discussed.

Smoke Gets in Your Eyes: Misleading Fossil Fuel Advertisement in the Climate Crisis

To meet the goal set by the Paris Agreement, greenhouse gas emissions must be reduced by as much as 45% by 2030. Fossil industry advertising subverts this objective: It stimulates continued demand for fossil fuels, and creates doubts about their enormously harmful effects. Misleading advertising is prohibited under the Unfair Commercial Practices Directive, as well as other regulatory instruments. This article explores under which circumstances fossil fuel advertising must be regarded as misleading, and thus prohibited. Drawing from the example of tobacco regulation it will be argued that advertising is misleading if it normalizes a harmful commodity, i.e., if it portrays its production and use as acceptable and normal. It will then be shown that fossil industry advertising systematically normalizes fossil fuel products in such a manner, and must therefore typically be understood as misleading.

Toward net-zero sustainable aviation fuel with wet waste–derived volatile fatty acids

With the increasing demand for net-zero sustainable aviation fuels (SAF), new conversion technologies are needed to process waste feedstocks and meet carbon reduction and cost targets. Wet waste is a low-cost, prevalent feedstock with the energy potential to displace over 20% of US jet fuel consumption; however, its complexity and high moisture typically relegates its use to methane production from anaerobic digestion. To overcome this, methanogenesis can be arrested during fermentation to instead produce C2 to C8 volatile fatty acids (VFA) for catalytic upgrading to SAF. Here, we evaluate the catalytic conversion of food waste-derived VFAs to produce n-paraffin SAF for near-term use as a 10 vol% blend for ASTM "Fast Track" qualification and produce a highly branched, isoparaffin VFA-SAF to increase the renewable blend limit. VFA ketonization models assessed the carbon chain length distributions suitable for each VFA-SAF conversion pathway, and food waste-derived VFA ketonization was demonstrated for >100 h of time on stream at approximately theoretical yield. Fuel property blending models and experimental testing determined normal paraffin VFA-SAF meets 10 vol% fuel specifications for "Fast Track." Synergistic blending with isoparaffin VFA-SAF increased the blend limit to 70 vol% by addressing flashpoint and viscosity constraints, with sooting 34% lower than fossil jet. Techno-economic analysis evaluated the major catalytic process cost-drivers, determining the minimum fuel selling price as a function of VFA production costs. Life cycle analysis determined that if food waste is diverted from landfills to avoid methane emissions, VFA-SAF could enable up to 165% reduction in greenhouse gas emissions relative to fossil jet.

Hydro‐upgrading of light cycle oil‐synthesis of NiMo/SiO2-Al2O3-TiO2 porous catalyst

The demand for transportation diesel fuels has been increasing in most countries for the last decade. As is one of the primary sources for diesel distillates, light cycle oil (LCO), having the advantages of inheriting similar density and boiling point range to diesel fuels, but high contents of aromatics, sulfur, and nitrogen, needs to be upgraded before being utilized. This work reports a trinary porous SiO2–Al2O3–TiO2 (SAT) synthesized by sol–gel method and used as the NiMo catalyst support for the LCO hydro-upgrading. NiMo/Al2O3-zeolite (AZ) was used as a reference to evaluate the performances of the NiMo/SAT. The catalysts were characterized by XRD, BET, Pyridine-FTIR, and TEM; and evaluated in a 20-mL fixed-bed microreactor using a Fluid Catalytic Cracking LCO as feedstock. It was found that the SAT support possessed a high surface area, high pore volume, and good acid properties. The NiMo/SAT catalyst exhibited even better hydrodesulfurization, hydrodenitrogenation, and hydrodearomatization performances than NiMo/AZ when the reaction was performed at 375 °C and 1100 psi. Compared with the zeolite addition catalyst, the SAT catalyst has the advantages of simple synthesis procedures and low input cost.

Firewood in the forest: Social practices, culture, and energy transitions in a remote village of the Brazilian Amazon

The substitution of firewood for cooking energy is one of the pillars of sustainable energy transition. Despite efforts in promoting the diffusion of less pollutant and modern technologies, such as improved cookstoves, Liquefied Petroleum Gas (LPG) and electric cookers, there is a persistent demand for traditional fuels, particularly in rural areas of the world. But what drives the persistency of firewood use for cooking? While previous attempts to understand the persistent uses of firewood in rural and peri-urban areas largely focused on access and affordability, few studies assess the dietary and sociocultural aspects of firewood. Methodologically, this paper uses the case study of a remote village of the Brazilian Amazon as approach, to help identify the sociocultural drivers behind the use of firewood and adoption of cleaner cookstoves. Findings suggest that the persistency of firewood consumption for cooking is strongly related to cultural indicators, such as food preferences, cooking habits, rituals, house materials and ethnobotanical knowledge.

Why can't we just burn hydrogen? Challenges when changing fuels in an existing infrastructure

The current global consumption of natural gas as a fuel is roughly 4 trillion cubic meters per year. In terms of energy, the demand for natural gas exceeds the global demand for fossil fuels for transportation. Despite this observation, the challenges to natural gas end use that arise when changing the composition of the fuel are largely absent from public, policy, and research agendas, whereas for transportation fuels the issues are more appreciated. Natural gas is delivered via complex networks of interconnected pipelines to end users for direct and indirect heating in household and industrial sectors, and for power generation. This interconnectedness is a crucial aspect of the challenge for introducing new fuels.In this paper we discuss the issues that arise from changing fuel properties for an existing population of end-use equipment. To illustrate the issues, we will consider the changes in (combustion) performance of domestic combustion equipment and gas engines for power generation in response to substituting natural gas by hydrogen or hydrogen/natural gas blends. During the discussion, we shall also indicate methods for characterizing the properties of the fuel and identify the combustion challenges that must be addressed for a successful transition from the current fuel mix to whatever the future mix may be.

Energetic valorisation of agricultural residues by solvent-based liquefaction

The energy demand worldwide is ever-increasing with a growth of 2.3% registered in 2018. This means that there has also been an increasing demand for fuels. Biomass is an interesting alternative to fossil fuels as it contributes to a decrease of their adverse environmental effects. Nonetheless, biomass combustion may present several problems related to, for example, the initial moisture content and the increase of the emission of fine particles. This work describes the study undertaken regarding acid-catalysed liquefaction of different lignocellulosic biomasses as an alternative to process biomasses with high moisture contents and to decrease the emission of fine particles through the partial removal of the mineral matter of biomass. This process allows the production of a liquid biofuel which is more easily burned than the original biomass; moreover, it is also expected to reduce fly-ash forming species. Thus, olive stone/pits, olive bagasse, grape seeds and rice husk liquefaction was carried out at 160 °C using 2-Ethylhexanol as the solvent and a high biomass to solvent ratio of 1:1. In these conditions, a maximum conversion of 55% of the biomass into bio-oil was obtained for olive stone. On the other hand, 60–70% of the inorganic content of the biomasses was removed in the liquefaction stage. This result is an indication that, together with the production of a liquid biofuel, liquefaction can also be used as a pre-treatment to decrease the emission of fine particles associated to biomass combustion.

Engineering Co/MnO heterointerface inside porous graphitic carbon for boosting the low-temperature CO2methanation

Direct conversion of CO2 into CH4 provides an eco-friendly way of mitigating CO2 emissions and reducing the demand for fossil fuels, but this process was kinetically hindered under low temperature because of the high stability of CO2 molecule. The search for efficient low-cost catalysts capable of converting CO2 into CH4 with a high space-time yield (STYCH4) at low temperature is becoming more desirable. Here we report a highly efficient, stable and core-shell catalyst with abundant Co/MnO heterointerface inside porous graphitic carbon (Co/MnO@PGC), which can be easily obtained by one-step calcination of a bimetal-organic framework (CoMn-MOF-74). The combination of various the nanoscale characterizations and theoretical modeling ascertain that the in situ generated Co/MnO heterostructured nanoparticles (NPs) not only create many metal defects and oxygen vacancies, but also enhance the Co-MnO interaction at Co/MnO heterointerface, which promote CO2 adsorption and facilitate CO2 activation. The resulting Co/MnO@PGC is able to convert CO2 to CH4 at temperature even as low as 160 °C with >99% selectivity and exceptional high STYCH4 of 0.14 μmolCH4·s−1·gcat.−1, surpassing by far the most active Co catalysts reported up to now under the identical condition. Most astonishingly, at a higher pressure (30 bar), the STYCH4 can reach up to 5.60 μmolCH4·s−1·gcat.−1 at 160 °C, which is comparable to the optimal level of Ru-based catalyst, and simultaneously sets a new benchmark for the Co-based methanation catalyst. On the basis of catalytic studies and in situ FTIR spectroscopy of CO2 methanation experiments, the active sites responsible for this superior performance for Co/MnO@PGC can be associated with a synergy between Co° and MnO at the Co/MnO heterointerface, where H2 is efficiently dissociated on the Co° and the strong adsorption and activation of CO2 taking place on the adjacent MnO. This work provides a promising way for the design of advanced CO2 methanation catalysts.

Optimal techno-economic sizing of a solar-biomass-battery hybrid system for off-setting dependency on diesel generators for microgrid facilities

Increase in energy demand and scarcity of fossil fuels have increased concerns over rudimentary energy security. The adverse impact on the environment by fossil fuel based power generation has supervened the focus on renewable energy. To ascertain the reliability of power, diesel generator (DG-set) based backup system is predominant. DG-set based power generation has become very costly and has an adverse impact on the environment. Renewable energy (RE) based power generation (solar/wind) proves to be an effective alternative but is intermittent and variable in nature. One of the key solutions is by providing energy storage in multi-generation systems (MGS). Energy storage plays a vital role in MGS by smoothening the variations in the intermittent generation and arresting the net load variations. However, an approach for obtaining optimal asset configuration of MGS for mitigating DG-set along with operating strategy for a battery energy storage system (BESS) is the real challenge. A generic adaptable model for techno-economic optimization has been developed and presented. This paper attempts to find the optimal sizes for a battery bank with solar PV system for eliminating DG-set for microgrids. The problem has been solved using mixed integer linear programming (MILP) based optimization. The economic viability along with carbon mitigation for different microgrids have been presented. The evaluation of the optimization model is carried out with six different real case studies (Educational, micro industrial, residential, medical institutions) of India. The techno-economic analysis has been presented for different scenarios of each case study and compared with the existing solution.

INTRODUCTION OF BIOFUELS AS A WAY OF SOLVING ECOLOGICAL PROBLEMS

Since environmental issues have become a priority for everyone on the planet, and the fact that growing demand for fossil fuels will soon lead to a reduction in world reserves, except for climate change due to their use and greenhouse gas emissions. The aim of this work was to assess the potential for the introduction of biofuels and find the optimal conditions for the enzymatic hydrolysis of Japonica Rice husk. In addition, evaluate the positive and negative consequences because of the use and implementation of this technology. The methodology used variables: substrate FPU, pH, time, temperature and concentration surfactants using the screening construct obtained statistically, all variables are significant. Then an optimization plan was applied for the variables: pH, FPU and time, dropping those with a lower level of significance. Finally, the best conditions found in previous projects were (pH 5.0, 13 h, and 30 FPU / g of substrate); later, these conditions were applied in experiments to assess the effect of an increase in hydrolyzed cellulose. They use 6%; 8% and 10% of pulp is available with a recycling yield of 74%, 42% and 16%. The community has its own interests in the use of biofuels; therefore, this study provides an opportunity for biofuel producers to reduce environmental, economic, and social costs.Keywords: biofuel; environment; alternative energy; bioethanol. JEL Classifications: C30, D12, Q41, Q48DOI: https://doi.org/10.32479/ijeep.10686