Fuel Processing Technology最新文献

The difference between vitrinite and inertinite in coal has been regarded as the starting point, and the vitrinite and inertinite stripped from a coal sample were conducted by high-temperature (600 °C and 900 °C) and high-pressure (1.0, 1.5, and 2.0 GPa) experiments. The samples' molecular structure was examined with element analysis, Fourier-transform infrared spectroscopy, and X-ray diffraction. The results reveal that pressure has an inhibitory effect on the evolution of molecular structure at 600 °C, and the vitrinite shows a lower molecular structure evolution degree than inertinite. For the two macerals at 900 °C, with increasing pressure, the molecular structure parameters exhibit opposite regularities to those at 600 °C, and the vitrinite shows a higher molecular structure evolution degree than inertinite. The evolution rate of molecular structures caused by pressure in vitrinite remains consistent under different temperature conditions, whereas that in inertinite exhibits jumping changes. There must be a transition interval between 600 °C and 900 °C that can change the pressure from inhibiting coalification to promoting coalification. When the temperature exceeds the transition interval, pressure can accelerate the molecular structure evolution in vitrinite, causing it to catch up with and surpass the evolution degree of inertinite's molecular structure.

Furfural is one of the most prospective platform chemicals derived from biomass. This review summarises the principal factors governing the yield/selectivity of furfural by solvolysis technique, with a particular attention to the conversion of C6 cellulose feedstock. So far, most studies focused on the C5 sugar-rich feedstock, which requires solely dehydration to convert into furfural. In contrast, the conversion of C6 sugars to furfural is more challenging, requiring dehydration and CC bond breakage. Depending on the type of biomass and catalyst, the reaction temperature and residence time have an optimum value of ∼160–180 °C and ∼ 30–120 min respectively in traditional heating mode. The low optimum temperature (∼140 °C) for the microwave-assisted technique and that C5 polymers do not necessarily require longer reaction time than their monomers indicate that microwave irradiation is more efficient in depolymerisation reaction of polymers. Additionally, the organic solvent systems containing <10 wt% water were the most promising. For catalysts, sulphates/sulphonated catalysts showed the highest potential for furfural production, and Zn²⁺, Cu²⁺ and Fe³⁺ are the most promising cationic candidates. Finally, the future perspectives were proposed, including development of novel heterogeneous catalysts and microwave-assisted technique, kinetic study and mechanistic study for the conversion of C6 sugars.

Benzene, mostly produced from fossil fuel sources, is an essential chemical to many modern industries. Alternatively to non-renewable methods currently used, the present work explores using fast pyrolysis biomass-derived bio-oils to furnish this valuable platform molecule. Notably, we report for the first time the impact of different operational parameters on the highly selective continuous catalytic hydrodeoxygenation of guaiacol, a bio-oil model compound, into benzene using a Mo₂C/CNF-based catalyst. The parametric study includes a first evaluation of the effect of the hydrogen pressure (25, 50 and 75 bar), temperature (300, 325 and 350 °C) and weight hourly space velocity (4 and 10 g_org g_cat⁻¹ h⁻¹) on the guaiacol conversion and product distribution, and a subsequent long-term evaluation (30 h on stream) of the catalyst under appropriate processing conditions The experimental results revelated that our Mo₂C/CNF was able to achieve a conversion of 90–98% with a relative amount of benzene in the liquid product up to 81% for at least 30 h without any sign of deactivation at 75 bar of H₂ and 350 °C, which is a landmark achievement in the conversion of bio-oil derived molecules into platform chemicals.

Identification of the underlying cause of carbon loss in fatty acid hydrodeoxygenation (HDO) on the acidic catalyst is very important to understand the reaction mechanism and design high efficiency catalyst for biomass conversion. Herein, HDO reactions of palmitic acid catalyzed by Ni supported on mesoporous Beta (HBeta-M) zeolites with different acidities were investigated. It was found that a significant carbon loss (47.5%) occurred during the entire reaction process on Ni/HBeta-M catalyst with high acid density. This is because the hexadecyl ether intermediate was formed and trapped in the porous structure of the catalyst and interacted with strong acidic sites. On the Ni/HBeta-M-0.5 catalyst with medium acid density, carbon loss occurred in the initial reaction stage because hexadecanol was trapped in the porous catalyst. Investigations further demonstrated that the hexadecyl ether intermediate can also be converted to hexadecanol and hexadecane via hydrogenolysis on Brønsted acid and Ni sites.

Drop-in biofuels can play an important role in the transition from fossil-based fuels to carbon-neutral energy carriers. This work focuses on performance and emission of hydrotreated pyrolysis oil (HPO) for heavy-duty (HD) engines application. The HPO is blended with marine gas oil (MGO) in various mass ratios and tested both in combustion research unit (CRU) and engine facilities. Typical cruise speeds and multiple loads are selected in the heavy-duty engine tests. Both inlet temperature and EGR rate are varied to investigate the effects of control parameters on HPO. The results reveal that HPO present lower reactivity than MGO and diesel under CRU condition. It can function as a drop-in fuel without any modification to the engine and no recalibration was required. Specifically, key combustion phases are noticed to be identical. The engine can run smoothly and safely at 50% blend ratio with 1% reduction on net indicated efficiency (NIE) and 0.002 g/kWh particulate matter emissions (PM). At low load, the NOx emissions decrease to 1 g/kWh at 40% EGR, yet 1% decrease of NIE is shown. While all fuels yield more NOx but less PM emissions as the increase of inlet temperature. Inlet heating does decrease the NIE by 1%.

The co‑carbonization of refined coal tar pitch (RCTP) and brominated industrial methyl naphthalene (BIMNP) employing benzoyl chloride (BC) as a catalyst has been explored to create an isotropic spinnable pitch for carbon fibers with notable tensile strength. BIMNP is derived from industrial methyl naphthalene (IMNP) via photo-bromination assisted by visible light using N-bromosuccinimide (NBS) as a brominating agent. This research investigates the impact of the mass ratio of RCTP and BIMNP on the composition, molecular structure, and thermophysical characteristics of the co‑carbonized pitch. A tentative elucidation of the co‑carbonization mechanism involving RCTP, BIMNP, and BC is presented. Adjusting the NBS-to-IMNP mass ratio leads to the complete conversion of 1-methylnaphthalene (1-MNP) and 2-methylnaphthalene (2-MNP) in IMNP into 1-bromomethylnaphthalene (1-BMNP) and 2-bromomethylnaphthalene (2-BMNP), respectively. The co‑carbonized pitch exhibits enhanced pitch production, increased thermal stability, and improved spinnability compared to pitch synthesized via thermal polycondensation. The resulting carbon fibers experience a rise in tensile strength by 947 MPa and an increase in Young's modulus by 41.3 GPa as BIMNP content varies from 10% to 30%. Using BIMNP as a co‑carbonization agent offers a promising avenue for producing pitch-based carbon fibers meeting automotive industry requirements.

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.