Fuel Processing Technology最新文献

In the context of increasing global energy demand, there is an urgent need to find alternative sustainable and renewable resources to mitigate the impact of climate change and avoid an energy crisis. The annual regeneration rate of global biomass is approximately 100 billion tons, and currently, hydrogen energy is considered an ideal clean energy for achieving carbon neutrality goals. Therefore, by utilizing the abundant biomass waste and abundant solar energy produced globally, it is possible to develop a bioeconomic combination of hydrogen energy with high combustion value and no pollution, effectively alleviating the energy crisis and environmental pollution issues in the world today. This review describes the thermodynamic mechanism of hydrogen production by photocatalytic reforming of biomass and analyzes the current photocatalytic reforming of H₂ technology for different lignocellulosic biomass. Finally, the prospects and future challenges of photocatalytic biomass reforming for H₂ technology are discussed.

This study investigates the influence of EGR (exhaust gas recirculation) coupled with injection pressure on the combustion and emission characteristics of an engine fueled with methanol-gasoline blends. Increasing the methanol blending ratio can improve the knocking phenomenon, BTE (brake thermal efficiency) and regulated emissions. As the methanol blending ratio increases, the optimal fuel injection pressure for achieving the optimal combustion process, BTE and CO (carbon monoxide) emissions increases. The optimal EGR rate for achieving the highest BTE also increases. As the methanol blending ratio increases, the optimal injection pressure for achieving the lowest TPN (total particle number) and NPN (nucleation mode particle number) also increases. Increasing the fuel injection pressure leads to a decrease in APN (accumulation mode particle number). Increasing the methanol blending ratio and EGR rate can reduce TPN and NPN. With increasing methanol blending ratio, APN initially increases and then decreases. When using a lower methanol blending ratio, increasing the EGR rate leads to a higher proportion of APN to TPN. However, when using a higher methanol blending ratio, the opposite is true. The optimal engine performance can be achieved by using M100 fuel with a 35 MPa injection pressure and a 30% EGR rate.

The technology of electrocatalytic reduction of CO₂ to produce hydrocarbon fuels not only alleviates energy shortages but also suppresses the greenhouse effect, demonstrating enormous potential applications. In this context, we aim to explore new reliable materials for reducing CO₂ (CO₂RR) through electrocatalysis. Hence, we investigated the performance of Cu₃(C₁₂X)₂, where X signifies organic-ligands (N₁₂H₆, N₉H₃O₃, N₉H₃S₃, N₆O₆, N₆S₆) for the CO₂RR using density functional theory (DFT). The 2D Cu₃(C₁₂X)₂ monolayers show metallic characteristics because of the presence of adequate π electron conjugation network as-well-as a constructive interaction between the metal atom, organic-ligands, and benzene-rings, with the exception of Cu₃(C₁₂N₉H₃O₃)₂, which displayed semiconducting characteristic. The catalytic activity of Cu₃(C₁₂X)₂ can be tuned by adjusting the organic-ligands' ability to facilitate interaction between the CO₂RR intermediates and the metal complex (Cu-X₄). Among all MOFs, Cu₃(C₁₂N₆S₆)₂ have excellent CO₂RR activity towards CO and formic acid. All other Cu₃(C₁₂X)₂ monolayers demonstrated dynamic CO₂RR catalytic activity as well as superior selectivity over hydrogen evolution (HER) suggesting that these materials have the potential to be useful as CO₂RR electrocatalysts. This study introduces the concept of building MOFs with favorable features to meet the specific needs of a number of research domains including catalysis, energy conversion and storage.

This study focuses on developing a new class of high energy density (HED) bio-aviation fuel. Alkyl bicyclo[2.2.2]octanes (ABCOs) were designed as potential HED aviation fuel, and a C₁₂ ABCOs mixture was synthesized from renewable resources (α-phellandrene and maleic anhydride) using the Diels–Alder cycloaddition followed by hydrotreating. The synthesized ABCOs exhibited favorable fuel properties as HED fuel, including a gravimetric net heat of combustion comparable to Jet A-1 and higher density and volumetric net heat of combustion. ABCOs standalone showed poor low-temperature viscosities than Jet A-1 specifications but demonstrated no freezing behaviors even at extremely low temperatures. Fuel properties after blending ABCOs with Jet-A1 were also investigated, determining an upper limit of blending ratio of 44.1 vol%. These findings suggest that ABCOs can serve as a promising drop-in fuel for conventional jet fuel, while also potentially contributing to the formulation of bio-based and zero-aromatic high-performance jet fuels as a density-increasing component.

Soot has harmful effects on the environment and human health. The formation process of soot includes six steps: fuel pyrolysis, soot nucleation, coalescence, surface growth, aggregation, and soot oxidation. However, the formation of soot is very complex and is influenced by factors such as fuel type, combustion conditions, and environmental temperature. Oxygenated fuels additives have a positive effect on reducing soot emissions, but recent studies have shown that oxygenated fuels can lead to an increase in the number of small particles of soot. In this paper, the effect of oxygenated fuel additives such as alcohol, ether, and esters on soot emissions is discussed in terms of the mechanism of soot formation. Subsequently, the role of after-treatment systems in reducing soot emissions is summarized. This work can update our understanding of the impact of oxygenated fuels on soot emissions.

Catalytic transfer hydrodeoxygenation of lignin-derived guaiacol using formic acid (FA) as a hydrogen donor is a sustainable and secure way to obtain value-added phenol. In this work, we prepared N-doped carbon encapsulated CoNi and FeCoNi nanoparticles (CoNi@NC and FeCoNi@NC) for this reaction and found that NC shells rather than the alloy cores are the active sites. Ultraviolet photoelectron spectroscopy (UPS) results and Density Functional Theory (DFT) calculations suggested that Mott-Schottky heterostructures were constructed in CoNi@NC and FeCoNi@NC, leading to the spontaneous electron transfer from alloy cores with smaller work functions to NC shells. DFT calculations also confirm that the number of electrons transfer from alloy cores to NC shells with 1.46 a.u. and 1.59 a.u. for CoNi@NC and FeCoNi@NC, respectively. The increased electron density on NC shells improved the absorption strength of reactants and the intermediate, thereby reducing the energy barriers for the dehydrogenation of FA and hydrodeoxygenation of guaiacol. FeCoNi@NC, due to its higher surface electron density, exhibited better catalytic activity than that of CoNi@NC, 93.4% conversion of guaiacol and 87.3% selectivity to phenol can be achieved at 260 °C within 12 h, which is even better than commercially available Pd/C catalyst. The mechanistic studies revealed that guaiacol is first converted into catechol via the demethylation and hydrolysis, then to phenol via hydrogenolysis over FeCoNi@NC with the aid of FA. Moreover, the magnetically separatable FeCoNi@NC possessed high catalytic stability because NC shells protect alloy cores from the acidic solution.

Hydrogen energy, a promising clean source, holds potential to combat global warming. To achieve efficient and low-carbon H₂ production, we proposed an isothermal sorption-enhanced chemical looping reforming (SE-CLR) process to realize the high-purity hydrogen production and in-situ CO₂ capture at mild temperatures (550–650 °C). For practical application, the process is characterized to use Fe-Ni double metal oxide particles as steam methane reforming oxygen carriers, and K₂CO₃-promoted Li₄SiO₄ particles as CO₂ sorbent. The oxygen transfer capacity of metal oxide matintained high at 57.4%, and the K-Li₄SiO₄ absorbents remained at 22.5% CO₂ absorption capacity over 200 isothermal absorption-regeneration cycles. Conducting a synergistic conversion mechanism within double metal oxides and absorbents, and adjusting the absorbent-to-metal oxide mass ratio to 7:4, enhanced hydrogen purity to 92% and CO₂ uptake to 95%. Furthermore, in-situ CO₂ removal in CLR processes achieved methane conversion and H₂ production rates equivalent to conventional CLR processes under the same reaction conditions, but at temperatures ∼60 °C lower. The effects of the reaction temperature, pressure, steam-to-methane and methane-to-solid ratios on SE-CLR performance were studied systematically. Finally, stable hydrogen production with a purity of 91%–89% and CO₂ uptake of 94%–91% were obtained over 25 CLR cycles, with minimal changes in mechanical strength of particles.

This review is dedicated to the removal of heteroatoms from plastic pyrolysis liquid products for use in the petrochemical industry. The chapters are devoted to removing individual groups of heteroatoms and summarizing the current scientific knowledge on the subject. Attention is given to the possibilities of heteroatom removal at all stages of the recycling process except sorting. Most of the findings in this area relates to the halogen removal, where high efficiencies can be achieved already in the pyrolysis process. In contrast, the removal of other heteroatoms has mainly been studied in the liquid product, usually in a hydrogen atmosphere and in the presence of a catalyst. It seems economically feasible to remove the heteroatoms as early as possible in the recycling process. This can be achieved in part by washing the waste plastic in water, which can remove a large proportion of the heteroatoms present as impurities. The work highlights the need for comprehensive mapping of heteroatoms in products and, in many cases, the need for more data regarding their removal. Finally, conclusions are drawn for further research in this area.

An efficient and sustainable catalyst is urgently needed for the actual oil refining process. Different amounts of peroxophosphotungstate (PW₄) were successfully encapsulated into the pore of ZIF-8 framework material to obtain composites (x%-PW₄@ZIF-8, x = 10.7, 14.6, 27.5 and 34.8) through a stirring process at room temperature for desulfurization of model diesel. The successful encapsulation of the active component PW₄ in the pore was verified by a variety of characterization methods, and there is weak force between the PW₄ and the ZIF-8. The composite 27.5%-PW₄@ZIF-8 showed good catalytic activity for various sulfides under moderate conditions. In addition, DBT removal rate catalyzed by 27.5%-PW₄@ZIF-8 could still reach levels of 95.1% after 10 cycles. The high efficiency of activity and excellent reusability are attributed to the high matching of host and guest sizes. This work provides new inspiration for designing and preparing catalysts with high activity and excellent reusability by a simple and environmentally friendly method.

To develop a structure-tailoring catalyst for catalytic conversion of lignin for value-added chemicals, a series of novel Fe-Ce-Al metal oxide catalysts was synthesized via different methods to tailor activity and structure for catalytic pyrolysis of lignin to enhance hydrocarbon-rich bio-oil. The results revealed that FeCeAl-CO catalysts derived from coprecipitation method with smaller particle sizes exhibited excellent catalytic deoxygenation activity due to higher Lewis/Brønsted acid, reversible Ce³⁺/Ce⁴⁺ redox pairs, tailorable oxygen vacancies and promoted β-O-4, aromatic-OCH₃ and side-chain cleavage. Additionally, coprecipitation method was facilitated to enhance hydrogen transfer, side-chain cleavage and aromatization reactions, while wet impregnation was beneficial to enhance demethoxylation and H-abstraction activity. During catalytic pyrolysis process, over 57.91% of hydrocarbon, including 20.21% and 25.71% for aromatics and olefins were achieved over FeCeAl-CO catalyst. Over 60.74% phenols and 52.48% alkylphenols were obtained over Fe-Ce/Al₂O₃-IM catalyst due to synergistic effect of FeOx and CeOx species. Fe-Ce-Al catalyst exhibited great activity and stability after fourth run, greater Brønsted acid-favored lignin cleavage and coke deposition, and metal active species leaching, oxidation and pore blockage were the key reasons for deactivation. Therefore, these findings could provide a cost-effective method for designing structure-tailoring catalysts for direct catalytic deoxygenation of lignin to generate hydrocarbon-rich upgrading bio-oil.