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1.
Environ Sci Pollut Res Int ; 31(27): 39650-39662, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38829501

RESUMEN

In order to replace conventional diesel, biodiesel from various feedstocks is being researched for diesel engines. This study explores novel biodiesel blends produced from unconventional resources such as mentha piperita (peppermint), pontederia crassipes (water hyacinth), tamarindus indica (tamarind), and trichosanthes cucumerina (snake gourd) to assess the outcomes of a diesel engine. The fuel samples are designated as MP20, PC20, TC20, and TI20, which consist of 80% biodiesel and 20% diesel. The assessment is carried out on a four-stroke, one-cylinder diesel engine that is water-cooled and set to operate at 1500 rpm with a 17.5 compression ratio under various engine loading scenarios with quarter-incremental loading from one-fourth to full loading conditions. The fuel samples are injected with 220 bar injection pressure into the combustion chamber 23° before TDC. An extensive analysis of engine parameters is performed using engine configuration, fuel characteristics, and applied boundary conditions. This comprises brake-specific energy consumption (BSEC), fuel consumption (BSFC), thermal efficiency (BTE), cylinder pressure (CP), heat release rate (HRR), particulate matter (PM), nitrogen oxide (NOx), and carbon dioxide (CO2) emissions. At 100% load, the biodiesel blends show an increase in BSFC (2.8-12.6%) and BSEC (1.1-7.1%) but a minor decrease in CP (0.9-6.9%), HRR (0.8-16.2%), and BTE (1.2-2.9%). For biodiesel blends at full engine load, the emissions of PM (8.9-21.4%), NOx (1.4-16.2%) and CO2 (2.4-7.9%) are all significantly reduced. The results emphasize the distinct benefits of biodiesel blends, demonstrating enhanced engine performance and substantial decreases in emissions, which supports the aim of providing sustainable energy solutions.


Asunto(s)
Biocombustibles , Emisiones de Vehículos , Biocombustibles/análisis , Emisiones de Vehículos/análisis , Gasolina
2.
Heliyon ; 10(4): e26442, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38420411

RESUMEN

The reduction of carbon dioxide emissions is crucial to reduce the atmospheric greenhouse effect, fighting climate change and global warming. Electrochemical CO2 reduction is one of the most promising carbon capture and utilization technologies, that can be powered by solar energy and used to make added-value chemicals and green fuels, providing grid-stability, energy security, and environmental benefits. A two-dimensional finite-elements model for porous electrodes was developed and validated against experimental data, allowing the design and performance improvement of a porous zinc cathode morphology and its operational conditions for an electrolyzer producing syngas via the co-electrolysis of CO2 and water. Porosity, pore length, fiber geometric shape, inlet pressure, system temperature, and catholyte flow rate were explored, and these parameters were thoroughly tuned by using the smart-search Nelder-Mead's multi-parameter optimization algorithm to achieve pronouncedly higher, industrial-relevant current density values than those previously reported, up to 263.6 mA/cm2 at an applied potential of -1.1 V vs. RHE.

3.
Chemphyschem ; 25(4): e202300507, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38200663

RESUMEN

The nettle, sage, mint and lemon balm herbs were used for biochars preparation. The physicochemical parameters of obtained materials were related to the lignocellulose composition of the precursors. It has been proved that the content of mineral substance has a significant influence on development of surface area, whereas the amount of hemicellulose affects the content of surface functional groups. It has been also shown that the obtained biochars are characterized by great energy parameters. The higher heating values (HHV) of the carbonaceous materials are comparable to the typical energy sources. The greatest HHV value (20.36 MJ/kg) was characteristic for the biochar obtained by pyrolysis of the lemon balm. In addition, the biochars were used for ionic polymers adsorption from one- and two-components solutions. Despite the adsorbed amounts of macromolecules are not great is has been proved that polyethylenimine and polyacrylic acid have positive influence on their mutual adsorption.


Asunto(s)
Carbón Orgánico , Pirólisis , Adsorción , Carbón Orgánico/química , Iones
4.
Heliyon ; 9(11): e22271, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38045221

RESUMEN

The Climate Change Act recently enacted in Germany highlights the urgency of understanding the future demand for renewable fuels. In this study, we combine technological progress and socio-economic pathways in an energy system analysis to assess future renewable fuel demands in Germany. We apply the whole-system optimisation model, TIMES, to investigate transition pathways with varying electrification levels and socio-economic developments. The results show that renewable fuels demand varies between 388 PJ and 1310 PJ depending on the electrification rates. Furthermore, our findings demonstrate that considering socio-economic aspects and behavioural change, as represented by different Shared-Socio-economic Pathways, can significantly alter the demand for renewable fuels within a narrower yet still noteworthy range compared to the electrification scenarios. This provides country-level evidence highlighting the often-overlooked influence of social developments on demand projections. Consequently, it becomes crucial to prioritize the consideration of the climate mitigation potential arising from socioeconomic-induced changes in demand patterns within the broader framework of energy efficiency measures.

5.
Biotechnol Biofuels Bioprod ; 16(1): 190, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38057826

RESUMEN

BACKGROUND: Significant genetic diversity exists across Saccharomyces strains. Natural isolates and domesticated brewery and industrial strains are typically more robust than laboratory strains when challenged with inhibitory lignocellulosic hydrolysates. These strains also contain genes that are not present in lab strains and likely contribute to their superior inhibitor tolerance. However, many of these strains have poor sporulation efficiencies and low spore viability making subsequent gene analysis, further metabolic engineering, and genomic analyses of the strains challenging. This work aimed to develop an inhibitor tolerant haploid with stable mating type from S. cerevisiae YB-2625, which was originally isolated from bagasse. RESULTS: Haploid spores isolated from four tetrads from strain YB-2625 were tested for tolerance to furfural and HMF. Due to natural mutations present in the HO-endonuclease, all haploid strains maintained a stable mating type. One of the haploids, YRH1946, did not flocculate and showed enhanced tolerance to furfural and HMF. The tolerant haploid strain was further engineered for xylose fermentation by integration of the genes for xylose metabolism at two separate genomic locations (ho∆ and pho13∆). In fermentations supplemented with inhibitors from acid hydrolyzed corn stover, the engineered haploid strain derived from YB-2625 was able to ferment all of the glucose and 19% of the xylose, whereas the engineered lab strains performed poorly in fermentations. CONCLUSIONS: Understanding the molecular mechanisms of inhibitor tolerance will aid in developing strains with improved growth and fermentation performance using biomass-derived sugars. The inhibitor tolerant, xylose fermenting, haploid strain described in this work has potential to serve as a platform strain for identifying pathways required for inhibitor tolerance, and for metabolic engineering to produce fuels and chemicals from undiluted lignocellulosic hydrolysates.

6.
Materials (Basel) ; 16(24)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38138711

RESUMEN

As a push towards alternative and renewable resources for heat and power generation, biomass and thermally treated fuels from biomass may be viable options in the upcoming economic reality. This study the verified mass and energy balance of spruce woody biomass after low temperature pyrolysis between 250 and 550 °C. The results showed that low-temperature pyrolysis can yield high-grade biochar suitable for substitution of fossil fuels. Crucially, the net calorific value of biochar processed at 350 °C substantially exceeded that of brown coal. An economic analysis was carried out on the assumption of the current economic reality in the Czech Republic. It was shown that even if the price of the biochar slightly increased, it would still be beneficial to invest in torrefaction technology over paying carbon credits.

7.
Bioengineered ; 14(1): 2283264, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37986129

RESUMEN

The Colombian sugarcane industry yields significant residues, categorized as agricultural and industrial. While bagasse, a widely studied industrial residue, is employed for energy recovery through combustion, agricultural residues are often left in fields. This study assesses the combustion behavior of these residues in typical collection scenarios. Additionally, it encompasses the characterization of residues from genetically modified sugarcane varieties in Colombia, potentially exhibiting distinct properties not previously documented. Non-isothermal thermogravimetrical analysis was employed to study the thermal behavior of sugarcane industrial residues (bagasse and pith) alongside agricultural residues from two different sugarcane varieties. This facilitated the determination of combustion reactivity through characteristic combustion process temperatures and technical parameters like ignition and combustion indexes. Proximate, elemental, and biochemical analyses revealed slight compositional differences. Agricultural residues demonstrated higher ash content (up to 34%) due to foreign matter adhering during harvesting, as well as soil and mud attachment during collection. Lignin content also varied, being lower for bagasse and pith, attributed to the juice extraction and milling processes that remove soluble lignin. Thermogravimetric analysis unveiled a two-stage burning process in all samples: devolatilization and char formation (~170°C), followed by char combustion (~310°C). Characteristic temperatures displayed subtle differences, with agricultural residues exhibiting lower temperatures and decomposition rates, resulting in reduced ignition and combustion indexes. This indicates heightened combustion reactivity in industrial residues, attributed to their elevated oxygen percentage, leading to more reactive functional groups and greater combustion stability compared to agricultural residues. This information is pertinent for optimizing sugarcane residues utilization in energy applications.


Weather in collection time affects composition of sugarcane agricultural residues.Combustion of sugarcane residues occurs over similar temperature ranges.Industrial residues are more reactive to combustion than agricultural residues.Overall thermal behavior of sugarcane residues depends on their composition.


Asunto(s)
Lignina , Saccharum , Temperatura , Oxígeno , Biomasa
8.
ACS Appl Mater Interfaces ; 15(47): 54353-54372, 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-37963084

RESUMEN

Catalytic CO2 hydrogenation is an effective approach to producing clean fuels, but this process is expensive, in addition to the low efficiency of catalysts. Thus, photothermal CO2 hydrogenation can effectively utilize solar energy for CH4 production. Metal-organic framework (MOF) derived materials with a controlled structure and morphology are promising to give a high number of active sites and photostability in thermal catalytic reactions. For the first time, a novel heterostructure catalyst was synthesized using a facile approach to in situ grow MOF-derived 0D Co3O4 over 1D TiO2 nanowires (NWs). The original 3D dodecahedral structure of the MOF is engineered into novel 0D Co3O4 nanospheres, which were uniformly embedded over Ni-dispersed 1D TiO2 NWs. In situ prepared 10Ni-7Co3O4@TiO2 NWs-I achieved an excellent photothermal CH4 evolution rate of 8.28 mmol/h at 250 °C under low-intensity visible light, whereas UV light treatment further increased activity by 1.2-fold. UV irradiations promoted high CH4 production while improving the susceptibility of the catalyst to visible light irradiation. The photothermal effect is prominent at lower temperatures, due to the harmonization of both solar and thermal energy. By paralleling with mechanically assembled 10Ni-7Co3O4/TiO2 NWs-M, the catalytic performance of the in situ approach is far superior, attributing to the morphological transformation of 0D Co3O4, which induced intimate interfacial interactions, formation of oxygen vacancies and boosted photo-to-thermal effects. The co-existence of metallic/metal oxide Ni-Co provided beneficial synergies, enhanced photo-to-thermal effects, and improved charge transfer kinetics of the composite. This work uncovers a facile approach to engineering the morphology of MOF derivatives for efficient photothermal CO2 methanation.

9.
Sci Total Environ ; 901: 166005, 2023 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-37541501

RESUMEN

This study analyzes the technical performance, costs and life-cycle greenhouse gas (GHG) emissions of the production of various fuels using air-captured water and CO2, and concentrated solar energy as the source of high-temperature process heat. The solar thermochemical fuel production pathway utilizes a ceria-based redox cycle for splitting water and CO2 to syngas - a tailored mixture of H2 and CO - which in turn is further converted to liquid hydrocarbon fuels. The cycle is driven by concentrated solar heat and supplemented by a high-temperature thermal energy storage for round-the-clock continuous operation. The study examines three locations with high direct normal irradiation using a baseline heliostat field reflective area of 1 km2 for the production of six fuels, i.e. jet fuel and diesel via Fischer-Tropsch, methanol, gasoline via methanol, dimethyl ether, and hydrogen. Two scenarios are considered: near-term future by the year 2030 and long-term future beyond 2030. In the near-term future in Sierra Gorda (Chile), the minimum fuel selling price is estimated at around 76 €/GJ (2.5 €/L) for jet fuel and diesel, 65 €/GJ for methanol, gasoline (via methanol) and dimethyl ether (DME), and 42 €/GJ for hydrogen (excluding liquefaction). In the long-term future, with advancements in solar receiver, redox reactor, high-temperature heat recovery and direct air capture technologies, the industrial-scale plant could achieve a solar-to-fuel efficiency up to 13-19 %, depending on the target fuel, resulting in a minimum fuel selling price of 16-38 €/GJ (0.6-1.3 €/L) for jet fuel and diesel, and 14-32 €/GJ for methanol, gasoline, and DME, making these fuels synthesized from sunlight and air cost-competitive vis-à-vis e-fuels. To produce the same fuels in Tabernas (Spain) and Ouarzazate (Morocco) as in Sierra Gorda, the production cost would increase by 22-33 %. Greenhouse gas savings can be over 80 % already in the near-term future.

10.
Sci Prog ; 106(1): 368504221148342, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36617880

RESUMEN

For evaluating the significance of renewable alternative fuels for optimized engine performance and lower emissions, methanol has been extensively utilized as a blend with gasoline in spark-ignition engines. However, rare attempts have been rendered to examine the consequence of methanol-gasoline fuel blends (M6, M12, and M18) on lubricant oil operating for a longer period in engines. The highest and least decrease of 9.62% and 6.68% in kinematic viscosity (KV) was observed for M0 and M18, respectively. However, the flash point (FP) of degraded lubricant oil for M6, M12, and M18 was 3%, 5%, and 7% higher than that of M0, respectively. Total acid number (TAN) and ash content of degraded lubricant oil for M18 were the highest among M0, M6, and M12. An inclusive optimization of engine performance, emissions, and lubricant oil properties has been made for various methanol-gasoline fuel blends at distinct operating conditions by employing the response surface methodology (RSM) technique. RSM-based optimization portrayed the composite desirability value of 0.73 for 2137.13 watt brake power (BP), 6.08 N-m torque, 0.37 kg/kwh brake-specific fuel consumption, 22.10% brake thermal efficiency, 4.02% carbon monoxide emission, 7.15% carbon dioxide emission, 134.12 ppm hydrocarbon emission, 517.02 ppm nitrogen oxides emission, 12.44 cst KV, 203.77°C FP, 2.23 mg/g KOH TAN, and 2.65%wt ash content as responses for fuel blend M8 at 3400 rpm and higher loading condition. RSM predicted results demonstrated significant compliance with empirical findings, with absolute percentage error (APE) below 5% for each response. However, the highest APE of 4.68% was obtained for FP owing to inefficient desirability as a consequence of manual testing. The least APE of 1.57% was obtained for torque because of the highest desirability. Overall, the RSM predicted results of the designed models are effective and viable. RSM technique was found to be effective for the optimization of the broader engine characteristics spectrum.

11.
Sci Bull (Beijing) ; 67(20): 2124-2138, 2022 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-36546112

RESUMEN

Ammonia, primarily made with Haber-Bosch process developed in 1909 and winning two Nobel prizes, is a promising noncarbon fuel for preventing global warming of 1.5 °C above pre-industrial levels. However, the undesired characteristics of the process, including high carbon footprint, necessitate alternative ammonia synthesis methods, and among them is chemical looping ammonia production (CLAP) that uses nitrogen carrier materials and operates at atmospheric pressure with high product selectivity and energy efficiency. To date, neither a systematic review nor a perspective in nitrogen carriers and CLAP has been reported in the critical area. Thus, this work not only assesses the previous results of CLAP but also provides perspectives towards the future of CLAP. It classifies, characterizes, and holistically analyzes the fundamentally different CLAP pathways and discusses the ways of further improving the CLAP performance with the assistance of plasma technology and artificial intelligence (AI).


Asunto(s)
Amoníaco , Inteligencia Artificial , Nitrógeno/química
12.
Materials (Basel) ; 15(19)2022 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-36234094

RESUMEN

A facile and versatile process to produce lithium metasilicate (Li2SiO3) from non-conventional silicon sources (two different sand sources from the central area of México) was developed. The synthesis protocol based on a solid-state reaction followed by a hydrothermal treatment resulted in highly pure lithium metasilicate, as corroborated by XRD, SEM-EDS, and XPS analysis. Furthermore, lithium metasilicate was used as a heterogeneous catalyst for biodiesel production from soybean oil, where conversion yields were compared according to the silicon source used (based on chemical purity, stability, and yield efficiency). The best performing metasilicate material displayed a maximum of 95.5% of biodiesel conversion under the following conditions: 180 min, 60 °C, 5% catalyst (wt./wt., catalyst-to-oil), and 18:1 (methanol:oil). This contribution opens up alternatives for the production of lithium metasilicate using non-conventional precursors and its use as an alternative catalyst in biodiesel production, displaying better chemical stability against humidity than conventional heterogeneous catalysts.

13.
Front Chem ; 10: 979353, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36072701

RESUMEN

Efficient conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to renewable fuels such as 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF) is of significance for sustainable energy supply. For efficient catalyst design, it is important to understand the catalytic behavior and clarify the influence of physico-chemical properties of catalyst on reaction performance. Herein, to study the structure-activity relationships of monometallic Cu catalysts for HMF hydrogenolysis, a series of Cu/SiO2 catalysts with different physico-chemical properties were prepared and compared for their catalytic performance in HMF hydrogenolysis. It was found that Cu/SiO2-HT-8.5 catalyst prepared by hydrothermal method showed excellent activity in HMF hydrohydrolysis reaction. Under the optimal reaction condition, the total yield of liquid fuels reaches 91.6% with 57.1% yield of DMF and 34.5% yield of DMTHF in THF solvent. Characterizations such as XRD, H2-TPR, N2-adsorption/desorption, TEM and XPS revealed that the Cu particles in the Cu/SiO2-HT-8.5 catalyst have uniform size and high dispersion. The Cu species and the SiO2 support have relatively weak interaction and are easy to be reduced to Cu0, which makes it show excellent activity in the hydrogenolysis of HMF.

14.
Sci Total Environ ; 845: 157206, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35810906

RESUMEN

In efforts to achieve a sustainable development goal, the utilization of CO2 to generate renewable fuels is promising, as it is a sustainable technology that provides affordable and clean energy. To realize the production of renewable green fuels, a proficient and low-cost technology is required. Using photo/thermal catalytic process, the goal of sustainable CO2 hydrogenation can be achieved. There have been several types of catalysts under exploration, however, they are expensive with limited availability. In the current development, green materials such as mineral clays are emerging as cocatalyst/supports for CO2 hydrogenation. Clays are bestowed with various beneficial properties such as a large surface area, high porosity, abundant basic sites, excellent thermal stability and chemical corrosion resistance. Clays are promising materials that can drastically reduce the cost in catalyst preparation, partially fulfil the energy demand and reduce greenhouse gas emission. This review aims to focus on the various types of clays and their applications in the field of photo/thermal CO2 hydrogenation to renewable fuels. Firstly, the classifications of clays are provided, whereby they can be differentiated based on their silicate layers, namely 1:1 and 2:1 type clay and their properties are thoroughly discussed to provide advantages and applications. The applications of various clays such as kaolinite, halloysite, montmorillonite, attapulgite, saponite and volkonskoite for CO2 hydrogenation reactions are systematically discoursed. In addition, various approaches to improve the capability of raw clays as catalyst support are critically discussed, which include thermal treatment, exfoliation, acid-leaching and pillaring approaches. A critical discussion regarding the engineering aspects to further enhance clay-based catalyst for CO2 hydrogenation are further disclosed. In short, clays are freely available materials that can be found in abundance. However, there are many more different types of natural green clays that have not been studied and explored in various energy applications.


Asunto(s)
Dióxido de Carbono , Nanoestructuras , Dióxido de Carbono/química , Arcilla , Hidrogenación , Minerales
15.
Environ Pollut ; 308: 119677, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35753542

RESUMEN

We investigated the biological response of soluble organic fraction (SOF) and water-soluble fraction (WSF) extracted from particulate matter (PM) emitted by an automotive diesel engine operating in a representative urban driving condition. The engine was fueled with ultra-low sulfur diesel (ULSD), and its binary blends by volume with 13% of butanol (Bu13), and with hydrotreated vegetable oil (HVO) at 13% (HVO13) and 20% (HVO20). Cytotoxicity, genotoxicity, oxidative DNA damage and ecotoxicity tests were carried out, and 16 polycyclic aromatic hydrocarbons (PAH) expressed as tbenzo(a)pyrene total toxicity equivalent (BaP-TEQ) were also analyzed. The Hepatocarcinoma epithelial cell line (HepG2) was exposed to SOF for 24 h and analyzed using comet assay, with the inclusion of formamidopyrimidine DNA glycosylase (FPG) and endonuclease III (Endo III) to recognize oxidized DNA bases. The WSF was evaluated through acute ecotoxicity tests with the aquatic microcrustacean Daphnia pulex (D. Pulex). Results showed that there was no cytotoxic activity for all tested SOF concentrations. Genotoxic responses by all the SOF samples were at same level, except for the HVO13 which was weaker in the absence of the enzymes. The addition of the FPG and Endo III enzymes resulted in a significant increase in the comet tail, indicating that the DNA damage from SOF for all tested fuel blends involves oxidative damage including a higher level of oxidized purines for ULSD and Bu13 in comparison with HVO blends, but the oxidized pyrimidines for HVO blends were slightly higher compared to Bu13. The WSF did not show acute ecotoxicity for any of the fuels. Unlike other samples, Bu13-derived particles significantly increase the BaP-TEQ. The contribution to the genotoxic activity and oxidative DNA from SOF was not correlated to BaP-TEQ, which means that the biological activity of PM might be affected also by other toxic compounds present in particulate phase.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Biocombustibles/análisis , Carbono , ADN/metabolismo , Gasolina/análisis , Gasolina/toxicidad , Material Particulado/análisis , Material Particulado/toxicidad , Aceites de Plantas , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Medición de Riesgo , Emisiones de Vehículos/análisis , Emisiones de Vehículos/toxicidad
16.
Molecules ; 27(7)2022 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-35408622

RESUMEN

This paper discusses the epochal change in the reputation of carbon dioxide, which is now considered as a raw material alternative to fossil C for the synthesis of chemicals, materials and fuels, as opposed to a waste material that must be confined underground. In particular, its use as renewable C is compared to biomass. In this paper, a specific point is discussed: is ethanol (or any fuel) produced via the catalytic conversion of atmospheric CO2 different from the relevant biomass-sourced product(s)? The answer to this question is very important because it ultimately determines whether or not fuels derived from atmospheric CO2 (either e-fuels or solar fuels) have the right to be subsidized in the same way that biofuels are. Conclusions are drawn demonstrating that ethanol derived from atmospheric CO2 deserves the same benefits as bio-ethanol, with the additional advantage that its synthesis can be less pollutant than its production via the fermentation of sugars. The same concept can be applied to any fuel derived from atmospheric CO2.


Asunto(s)
Dióxido de Carbono , Etanol , Biocombustibles , Biomasa , Fósiles
17.
Bioresour Technol ; 351: 127020, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35307524

RESUMEN

The expanding use of fossil fuels has caused concern in terms of both energy security and environmental issues. Therefore, attempts have been made worldwide to promote the development of renewable energy sources, among which biofuel is especially attractive. Compared to other biofuels, lipid-derived biofuels have a higher energy density and better compatibility with existing infrastructure, and their performance can be readily improved by adjusting the chemical composition of lipid feedstocks. This review thus addresses the intrinsic interactions between lipid feedstocks and lipid-based biofuels, including biodiesel, and renewable equivalents to conventional gasoline, diesel, and jet fuel. Advancements in lipid-associated biofuel technology, as well as the properties and applicability of various lipid sources in terms of biofuel production, are also discussed. Furthermore, current progress in lipid production and profile optimization in the context of plant lipids, microbial lipids, and animal fats are presented to provide a wider context of lipid-based biofuel technology.


Asunto(s)
Biocombustibles , Gasolina , Combustibles Fósiles , Lípidos , Tecnología
18.
Waste Manag ; 137: 81-88, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34749180

RESUMEN

In this work, the use of biomethane produced from local biogas plants is proposed as renewable fuel for light marine transport. A profitability analysis is performed for three real biogas production plants located in Cornwall (United Kingdom), considering a total of 66 different scenarios where critical parameters such as distance from production point to gas grid, subsidies, etcetera, were evaluated. Even though the idea is promising to decarbonize the marine transport sector, under the current conditions, the approach is not profitable. The results show that profitability depends on the size of the biogas plant. The largest biogas plant studied can be profitable if feed-in tariffs subsidies between 36.6 and 45.7 €/MWh are reached, while for the smallest plant, subsidies should range between 65 and 82.7 €/MWh. The tax to be paid per ton of CO2 emitted by the shipping owner, was also examined given its impact in this green route profitability. Values seven times greater than current taxes are needed to reach profitability, revealing the lack of competitiveness of renewable fuels vs traditional fuels in this application. Subsidies to make up a percentage of the investment are also proposed, revealing that even at 100% of investment subsidized, this green approach is still not profitable. The results highlight the need for further ambitious political actions in the pursuit of sustainable societies.


Asunto(s)
Biocombustibles , Metano , Reino Unido
19.
Environ Sci Pollut Res Int ; 29(13): 19054-19071, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34709545

RESUMEN

A compact sedan vehicle powered by a 1.4 dm3 spark ignition engine fueled with compressed natural gas (CNG), Brazilian gasoline, hydrous ethanol 95% v/v and wet ethanol 88% v/v was evaluated throughout the Worldwide harmonized Light vehicles Test Cycle (WLTC) key points. The vehicle operating points with longest residence time on the WLTC were selected to fuel consumption and emissions evaluation at steady state conditions. The top five key operating points reported in this work accounted for 22% of the total time spent in the entire cycle. The results indicated a significant reduction on greenhouse gases (GHG) emissions and energy demand for operation with CNG. The ethanol-water blends provided reduced emissions of nitrogen oxides (NOx), but increased specific fuel consumption, carbon monoxide (CO) and GHG emissions in comparison to CNG and gasoline. The operation with gasoline resulted in the minimum CO emissions for all fuels tested, as well as the best fuel consumption between liquid fuels, despite the highest values of carbon dioxide (CO2), and increased NOx. Even though ethanol produced little total unburned hydrocarbons (THC), the emissions of alcohols and aldehydes raised an alert for this renewable fuel, whereas CNG emitted the least amount of such pollutants.


Asunto(s)
Contaminantes Atmosféricos , Gas Natural , Contaminantes Atmosféricos/análisis , Etanol/análisis , Gasolina/análisis , Emisiones de Vehículos/análisis
20.
ChemSusChem ; 14(23): 5254-5264, 2021 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-34623036

RESUMEN

Model-based fuel design can tailor fuels to advanced engine concepts while minimizing environmental impact and production costs. A rationally designed ketone-ester-alcohol-alkane (KEAA) blend for high efficiency spark-ignition engines was assessed in a multi-disciplinary manner, from production cost to ignition characteristics, engine performance, ecotoxicity, microbial storage stability, and carbon footprint. The comparison included RON 95 E10, ethanol, and two previously designed fuels. KEAA showed high indicated efficiencies in a single-cylinder research engine. Ignition delay time measurements confirmed KEAA's high auto-ignition resistance. KEAA exhibits a moderate toxicity and is not prone to microbial infestation. A well-to-wheel analysis showed the potential to lower the carbon footprint by 95 percent compared to RON 95 E10. The findings motivate further investigations on KEAA and demonstrate advancements in model-based fuel design.

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