This study investigates the thermochemical energy recovery during butanol exhaust-gas-assisted fuel reforming in gasoline direct injection (GDI) engines. The production of hydrogen (H2) through catalytic reforming was studied in a full-scale reactor loaded with rhodium (Rh)-platinum (Pt) catalysts and integrated within the engine exhaust. Thermodynamic equilibrium analyses are conducted via ANSYS-CHEMKIN based on Gibbs energy minimisation. Both experimental and numerical studies revealed that butanol (in this case, blended in gasoline- B33%) promotes endothermic reactions in the reforming reactor, yielding higher H2 production with improved heat recovery by up to 11% compared to gasoline. Theoretical calculations of using the reformed gas in the engine for combustion as reformed exhaust gas recirculation (REGR) predicted fuel savings and a nearly 8% reduction in CO2. The work underlines the advantages of butanol reforming in enhancing fuel economy and reducing emissions in GDI engines and highlights the importance of the fuel properties in overall system efficiency.

The world has been facing a growing crisis in textile waste due to global population growth and improved living conditions, combined with a decrease in the life cycles of textile products. Textile recycling is one of the key aspects for reducing the massive waste problem generated by the fashion and textile industries. Despite the need to develop textile waste recycling industries, acceptable practical interim measures still need to be taken. Textile waste can affect people's lives economically and environmentally. Producing apparel from natural or synthetic origin can produce pollutants and waste at each stage. In this review article, the effects of the fashion and textile industry have been studied from economic and environmental perspectives. The available technologies and methods for waste recovery and recycling at each stage have been studied, and the uses of products after recycling have been systematically investigated. Despite all the progress made in the waste recycling processes of the fashion industry, many deficiencies and challenges still need to be addressed. Among the most critical challenges are the large scale of industries, the problems of collecting and classifying waste materials, and the presence of contaminants including blends and chemicals. There is also need for more awareness among consumers about the importance of fiber-to-fiber recycling processes, because to date the progress in this field is out of proportion to its necessity. Overall, this article is a valuable resource for anyone interested in understanding the current state of recycling and recovery in the textiles, garment, and fashion industries.

This experimental study investigates the palladium/ rhodium based three-way catalyst (TWC) in a hydrogen-gasoline dual-fuel spark ignition (SI) engine under stoichiometric and lean conditions. The work focused on lean-burn engine operating conditions with the aim of reducing nitrogen oxides (NOx) emissions during the combustion process, where the TWC is not effective, while improving the thermal efficiency of the engine. Under these lean- burn engine conditions, the combustion promoting properties of hydrogen allowed for maintained engine combustion stability as determined by the cycle-to-cycle variation (COVimep) imep ) values even up to ultra lean conditions (lambda= lambda= 2.0). It was found that by reducing the combustion temperature through the application of lean conditions, engine-out NOx emissions could be reduced or even eliminated, while under these conditions the TWC was effective in reducing engine-out carbon-based gaseous emissions.

This experimental work investigates oxygenated bio-fuel component blends of butanol, pentanol and cyclopentanone with diesel on the combustion characteristics, gaseous emissions and particulate matter (PM). Furthermore, PM characteristics, including size distributions, morphology and nanostructure are investigated. The oxygen content on the sustainable fuel blend components (bio-alcohols and bio-ketone) and the lower cetane number leading to a longer ignition delay, larger premixed combustion phase and high mean peak combustion temperature reduced the total number of particle concentration by up to 91%. Characterisation of particles demonstrated morphological and nanostructural alterations, such as the reduction in primary particle size that would lead to greater particle oxidation reactivity. Furthermore, the combustion of oxygenated blends showed a reduction in the total hydrocarbon emissions and an increase in NO2 concentration. This research provides new knowledge to understand the effects of fuel properties on gaseous and particle emissions formation and characteristics. Overall this work demonstrates bio-alcohols and bio-ketones as low carbon fuels in unveiling strategies for vehicular emissions abatement.

Hollow fibre (HF)-based technologies for emission control, as an alternative to the traditional monolithic technology, offers a promising route to the uptake of non-PGM catalytic systems. In this work, a series of Cu-doped LaCoO3 perovskites were investigated as potential non-PGM Diesel Oxidation Catalysts (DOC). Two HF-based modules, comprising single-channel (i.e., 1CM) and four-channel (i.e., 4CM) HFs respectively, were impregnated with the best catalyst candidate, and their performance was tested under real exhaust gas conditions, using a single-cylinder diesel engine. Compared to the 1CM, the 4CM demonstrated enhanced CO conversion, and reduced performance towards Total Hydrocarbon (THC) conversion. Overall, these findings reveal the influence of HF morphology on catalytic performance, and in turn, will contribute towards the refinement of HF-based technology for emission control, as well as enabling the transition towards non-PGM catalytic systems.

The use of alternative fuels, such as bio-alcohols, in advanced propulsion systems could a feasible strategy to address several of the current issues associated to the use of internal combustion engines fuelled by carbonaceous fossil fuels. Particularly, soot particles, are one of the key pollutants emitted from compression ignition engines. Therefore, the development of soot formation prediction models providing new understanding on the impact of alternative fuels combustion in compression ignition engines become essential for soot mitigation purposes.This study proposes a new semi-empirical model that predicts in-cylinder soot primary particle growth from an engine fuelled with alcohol-diesel fuel blends. The model uses macroscopic experimental measurements of engine parameters such as instantaneous in-cylinder pressure. Furthermore, an empirical correlation is presented predicting the mean soot primary particle size as a function of alcohol-diesel fuel blend properties and fuel/air ratio. The experimental measurement of primary soot particle mean size are obtained from High Resolution Transmission Electron Microscope (HT-TEM) micrographs obtained from soot particles collected via thermophoresis. Overall, the research findings presented in this work contributes to propose environmentally friendly fuel candidates for transportation.

Reduction of CO2 emissions is a prevalent subject in the transportation sector. Cylinder deactivation (CDA) provides a method to reduce CO2 emissions at part load. However, there is little consideration of how these strategies affect catalyst performance. Effects of two CDA strategies on catalyst performance were studied. The first strategy of open-loop lambda control CDA improved catalyst CO conversion to 100 % and prevented NH3 formation over the catalyst. There was a NOX penalty if the duration exceeded 5 seconds. The closed-loop CDA strategy increased catalyst temperature by 300 degrees C for durations of 60 seconds.Open-loop CDA can prevent NH3 formation and improve CO conversion. Closed-loop CDA strategy has potential to increase catalyst temperature and be effective at reducing light-off during cold starts without additional hardware. This gives the strategy an advantage over more complex heating options. Both strategies provide opportunities to help meet current and future emission regulations.

In recent decades, many kinds of research have been conducted on alternative fuels for compression ignition (CI) engines. Low/zero-carbon fuels, such as bioalcohols and hydrogen, are the most promising alternative fuels and are extensively studied because of their availability, ease of manufacturing, and environmental benefits. Using these promising fuels in CI engines is environmentally and economically beneficial. The most common alcohols are methanol, ethanol, isopropanol, propanol, butanol, n-butanol, tert-butanol, iso-butanol, and pentanol. The primary objective of this review paper is to examine the impact of bioalcohols and their blends with conventional diesel fuel in CI engines since these fuels possess characteristic properties that impact overall engine performance and exhaust emissions. This research also indicated that alcohols and blended fuels could be used as fuels in compression ignition engines. Chemical and physical properties of alcohols were examined, such as lubricity, viscosity, calorific value, and cetane number, and their combustion characteristics in compression ignition engines provide a comprehensive review of their potential biofuels as alternative fuels.

This study proposes 3D-printed diamond-based lattice substrates as catalytic converters in the automotive aftertreatment system to improve vehicle cold-start emissions. The study aimed to compare the influence of 3D-printed diamond-based catalyst structures on the light-off behaviour compared to the conventional 400 Cell Per Square Inch (CPSI) honeycomb catalyst design in a real exhaust gas environment. Moreover, the benefits of H-2 addition on the performance of advanced lattice structures are examined for the first time to further increase the low-temperature catalytic efficiency. Digital Light Processing (DLP) technology was effectively utilised to manufacture lattice structures with high cell density to allow a comparison between conventional and advanced geometry designs. Further, the 3D-printed substrates were catalyst coated, and their light-off behaviour was studied in a diesel exhaust environment. The results of the light-off showed a significant improvement in the light-off temperatures for CO, THC and NO in the 3D-printed lattice structures. Furthermore, H-2 presence additionally enhanced the low-temperature activity of the AM lattice structures. (c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Transport sector decarbonisation is leading to increased demand for electrified powertrains including hybrid vehicles. The presence of an internal combustion engine and electric motor offer multiple performance and efficiency advantages. However, changes in the conditions that catalytic aftertreatment systems are subjected to can present challenges in meeting forthcoming emissions standards. This work investigated the three-way catalyst performance to abate regulated and unregulated emissions from a gasoline direct injection engine working under conditions related to hybrid vehicle operation. The focus on unregulated emissions of NH 3 and N 2 O is of interest due to limited literature on their formation in conventional, and particularly hybrid, vehicle aftertreatment systems. Furthermore, the likelihood of their regulation when the EURO 7 emissions standards are introduced increases the pertinence of this work. For this particular engine and aftertreatment setup, it was found that starting the engine whilst the three-way catalyst temperature was below 150 ℃ led to an increase in tailpipe regulated emissions and N 2 O. Whilst, starting the engine when three-way catalyst temperatures were above 350 ℃ lead to tailpipe NH 3 emissions. This was due to the selectivity of NO to form N 2 O at lower temperatures and NH 3 at higher temperatures. For the case of the studied catalyst, a vehicle energy management strategy opting to start the engine with the three-way catalyst within a targeted temperature range allowed for a trade-off between regulated emissions, N 2 O and NH 3 . These findings are significant since it can be used to optimise hybrid vehicle control strategies minimising both regulated and unregulated emissions.

The main challenges of compressed natural gas (CNG) engine fuelling in terms of methane abatement in the aftertreatment system are addressed in this study using differently loaded platinum group metal (pgm) catalysts. A dualfuel injection strategy of methane-gasoline was implemented where methane gas was port-injected into the intake in stoichiometric conditions at levels corresponding to 20% and 40% energy density replacement of gasoline fuel. High, medium and low loaded palladium-rhodium catalysts were used and compared to study the effect of pgm loading on the catalyst light-off activity for methane. Results indicate that increasing the palladium loading led to significantly earlier light-off temperatures achieved at relatively lower temperatures of 340 degrees C, 350 degrees C and 395 degrees C respectively. However, the benefit diminishes above palladium loading >142.5 g ft(-3). The study has also demonstrated that ammonia is formed over the CNG catalyst due to steamreforming reactions from the increased levels of methane in the exhaust with dual-fuelling. Hence aftertreatment technologies such as selective catalytic reduction (SCR) should be adopted to remove them. This further highlights the need to regulate the harmful ammonia emissions from future passenger cars fuelled with CNG. In addition, the benefits of the dual-fuel system in terms of lower engine output carbon dioxide, non-methane hydrocarbon (NMHC) and particulate matter (PM) emissions compared to the gasoline direct injection (GDI) mode alone are presented.

Electrically heated catalyst (EHC) is integrated with the exhaust aftertreatment system to reduce cold start emissions. Implementation of this proposed emission control technology will also provide addition CO2 and fuel consumption benefits. Developing an energy-efficient heating strategy has shown a significant reduction in the time required for the catalysts to light-off from the cold-start. In this study, it was found for the first time that the novel pulsating heating strategy with the pulse width of 30 s compared with typical heating strategy improved the CO and THC emissions conversion efficiency up to 34% and 31%, respectively. In contrast, a further increase in the heating pulse leads to lower emissions' conversion performance due to extending heating off period and consequently leading to the catalyst's light-out. Furthermore, combined electrical and fuel post-injection catalyst heating can benefit from the EHC's quick catalyst light-off and higher heating efficiency of the fuel post-injection, which showed a significant improvement in the DOC's emissions conversion performance. This approach can result in higher catalyst heating efficiencies and lower THC emissions which can be critical to meet the emissions legislations. An increase in the DOC's outlet temperature can be also beneficial for downstream after treatment component heating, e.g. DPF regeneration. (C) 2021 Elsevier Ltd. All rights reserved.

This research investigates the effects of a synthetic diesel-like fuel (Fischer-Tropsch diesel) and biofuels (ethanol and biodiesel) fuel blends on the energy-exergy efficiencies and gaseous exhaust emissions characteristics of a compression ignition engine. Two blends of alternative fuels denoted as E15B35FTD50 (15% ethanol, 35% biodiesel, and 50% Fischer-Tropsch diesel) and E15B35D50 (15% ethanol, 35% biodiesel, and 50% diesel) were experimentally studied on a single-cylinder diesel engine and compared to diesel fuel. The results show that the energetic and the exergetic efficiencies of the alternative fuels are comparable to those of the engine fueled with diesel fuel. The unburnt HC, NO, N2O, and NH3 emissions were reduced for the two alternative fuel blends compared to diesel, while CO emissions increased. The light HC species were found to slightly increase for the alternative fuel blends in comparison with diesel fuel. However, the total HC was considerably reduced by the combustion of E15B35FTD50 not only when compared to the diesel fuel combustion, but also when compared to E15B35D50. Overall, these results may contribute to identifying advantages and limitations in terms of energetic-exergetic analysis and emissions for the new generation of conventional diesel and hybrid electric vehicles that aim to achieve future emissions regulations.

This study relates to developing future alternative fuels and focuses on the effects of a fuel’s molecular structure on its properties and performance in advanced propulsion systems. The tribological performance of various biomass-derived oxygenated alternative fuels, including butanol, pentanol, cyclopentanol, cyclopentanone, and gasoline and their blends with diesel, was investigated. Lubricity tests were conducted using a high-frequency reciprocating rig (HFRR). Cyclopentanone-diesel and cyclopentanol-diesel blends result in smaller wear scar sizes compared to using their neat forms. A lower steel disc contaminated with the alternative fuels during the HFRR tests resulted in worn surface roughness values lower than those of the neat diesel by up to 20%. It is believed that these reductions are mainly due to the presence of the hydroxyl group and the carbonyl group in alcohols and ketones, respectively, which make them more polar and consequently helps the formation of the protective lubrication film on the worn moving surfaces during the sliding process. Overall, the results from this study indicate that environmentally friendly cyclopentanol and cyclopentanone are practical and efficient fuel candidates for future advanced propulsion systems.

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.

The optimization of cobalt oxide (Co3O4) loading on silica for the low-temperature Fischer-Tropsch (LTFT) synthesis process employing simulated nitrogen-rich syngas (50 vol%) to produce highly paraffinic biodiesel is studied. Four different amounts of Co3O4 varying from 15 to 36 wt% were loaded on silica in order to examine the catalytic performance of Co/SiO2 catalysts. The supported catalysts were characterized using XRF, nitrogen physisorption, XRD, TPR, DRIFT and SEM fixed with EDS analysis. The performances of the catalysts were examined in a single channel fixed bed reactor employing simulated nitrogen-rich syngas (CO:H-2:N-2 = 17:33:50 vol%). The reactor was operated at P = 20 bar, T = 237 degrees C and WHSV = 3.0 Nl/h.g(cat). The active site concentration was maximized by (i) utilizing all the available surface area of the sphere's porous support, (ii) using ethanolic impregnation solution to hinder sintering of Co3O4 phases due to presence of ethoxyl groups, and (iii) connecting oxide crystallites to the neighbouring pores by increasing the active metal content. As a result, the production of heavy hydrocarbons per unit of time was maximized with 36 wt% cobalt loading on silica (CO conversion and C5+ selectivity were 87.65 and 81.78 mol%, respectively, and also paraffin: olefin ratio was 98:2).

This research provides an understanding of the synergies between the combustion of bio-oxygenated fuels and thermal management of the aftertreatment systems for the control of diesel gaseous and particulate matter emissions. Blends of diesel with bio-alcohols and a bio-ketone with different molecular structure including butanol, pentanol, cyclopentanol and cyclopentanone proved to be promising alternative fuels in terms of energy density, viscosity, lubricity, tribological mechanisms, combustion behaviour and emissions reduction. Using bio-oxygenated fuels with a higher polarity (mainly cyclic compounds) resulted in lower wear scar size by up to 38%, compared to the diesel baseline, during the lubricity test. Engine-out hydrocarbons and particulate matter emissions were lower by up to 37% and 91%, respectively. The modified exhaust gas composition from the combustion of the aforementioned oxygenated fuel blends, improved the catalyst oxidation reactions, and light-off was achieved at lower exhaust gas temperatures. Furthermore, an active control strategy of heating the aftertreatment system was studied. Due to reduced catalyst light-off temperature when using the alternative fuels for combustion, e.g. by up to 26 °C for CO, a lower heater energy input was required for the catalytic light-off when compared to diesel combustion only. Importantly, modifying the exhaust gas composition of the diesel baseline by adding 500 ppm of H2 gas upstream of the catalyst decreased the CO light-off temperature by approximately 50 °C.

To reduce cold-start emissions, a thermal energy storage (TES) system can be used in conjunction with the exhaust aftertreatment system. Phase change materials (PCM) can be used in the TES system to absorb the exhaust gas thermal energy, thus liquefying and storing it as latent heat. This allows storage of the exhaust gas thermal energy during the engine’s high-load conditions and gradually releases the thermal energy back to the catalyst substrate during the engine-off period. Based on the results, implementing a TES system into the diesel aftertreatment system has shown great potential in reducing a vehicle’s emissions, particularly for hybrid vehicles. This approach can assist the catalyst to activate the emissions’ conversion reactions straight after the cold-start. However, its effectiveness largely depends on the duration of the engine-off periods between the driving cycles. In this study, it was found that facilitating the heat transfer between the PCM and the catalyst can significantly improve the emissions’ reduction performance by avoiding the catalyst to light-out after the cold-start. A substantial improvement in the system’s thermal behaviour was observed by using PCM additives and metallic catalyst substrates to increase the system’s thermal conductivity. Although a TES system increases the aftertreatment cost and complexity, it can result in substantial emissions’ reduction over the vehicle’s operating life. This can also translate into reduced vehicle fuel consumption and CO2 emissions, as the emissionsrelated fuel penalty will be minimized.