Sustainable Energy & Fuels最新文献

We studied the potential of producing biocrude with ultralow nitrogen content via hydrothermal coliquefaction (co-HTL) of sewage sludge digestate and various polyphenolic extracts from apple pomace, olive pomace, spent coffee grounds, and sweet orange peels. We investigated the combined effects of the polyphenol profile, reaction temperature (280–370 °C), and feedstock pH (3–11) on product formation and element migration and speciation including the responsible reaction mechanisms and their kinetics and thermodynamics. In general, high contents of epicatechin, quercetin, caffeic acid, ferulic acid, and gallic acid in the feedstock mixture caused a significant reduction in the N-content of biocrude by trapping cellulose-derived α-dicarbonyls/α-hydroxycarbonyls (i.e., key precursors for N-fixing reactions in biocrude) and converting them into solid and aqueous N-polyheterocycles and amidated O-polyheterocycles via several mechanisms, e.g., electrophilic aromatic substitution, nucleophilic addition, Paal–Knorr furan synthesis, and amination. Coupled with more acidic conditions and higher reaction temperatures, the rate of carbonyl trapping was improved as the activation energy decreased and the nitrogen distribution into hydrochar was enhanced via endothermic amidation of the –COOH group on hydrochar. This was followed by the promoted depolymerization of lignocellulose into more-stable biocrude constituents and the improved deoxygenation of biocrude via dehydration, minimizing carbon loss. Thus, co-HTL of acidic (pH 3) mixtures of digestate and polyphenolic extracts at 370 °C for 60 min produced biocrude with an acceptable mass yield of around 30% and desirable elemental content compatible with upgrading in oil refineries, i.e., C: 72.0–73.8%, H: 9.1–10.4%, N: 0.04–0.27%, S: 0.01–0.03%, and O: 16.3–18.3%.

Over the past few years, photovoltaic technology has become increasingly crucial for modernizing the energy industry. As the most promising device, perovskite solar cells have developed rapidly in a shocking way. We witnessed the power conversion efficiency (PCE) increase from 3.8% to 26.1%, which is very close to the boundary of the Shockley–Queisser theory. Due to their excellent photoelectric properties and solution processability, hybrid organic–inorganic materials show the potential to be next-generation solar cells. However, hybrid organic–inorganic perovskite materials are still subject to certain conditions, such as moisture in the surroundings, thermal conditions, toxicity of the organic components, etc. In consideration of modifying these defects, all-inorganic perovskite materials are designed to enhance the stability of devices and reduce pollution in the natural environment. Among all of these materials, CsPbX₃ has been considered as the most potential and workable material. In this review, we will introduce the development of CsPbX₃ and its latest research status, hoping that this perspective provides guidance and insight toward the improvement of material design and application in actual production as quickly as possible.

In this paper, the geometric structures and electronic and optical properties of h-BAs/MoXTe (X = S, Se) heterojunctions are systematically investigated based on first-principles calculations. It is demonstrated that the h-BAs/TeMoS, h-BAs/SMoTe, h-BAs/TeMoSe, and h-BAs/SeMoTe heterojunctions are highly stable at room temperature. The four heterojunctions have extremely high carrier mobility in the order of 10⁵ cm² V⁻¹ s⁻¹ and excellent visible light absorption. Among them, the h-BAs/TeMoS, h-BAs/SMoTe, and h-BAs/SeMoTe heterojunctions have type-II band alignment. Specifically, the h-BAs/TeMoS heterojunction has a solar-to-hydrogen (STH) efficiency of up to 33.7%. The h-BAs/SeMoTe heterojunction is expected to be a direct Z-scheme photocatalyst for overall water splitting. Moreover, we also find that the h-BAs/SMoTe heterojunction has both preeminent photocatalytic performance and a high photoelectric conversion efficiency (PCE) of 22.96%. Our study shows that the h-BAs/MoXTe (X = S, Se) van der Waals heterojunctions are promising candidate materials for applications in photocatalytic water splitting, optoelectronic devices, and photovoltaic cells.

The one-step oxidative esterification of ethylene glycol (EG) is an effective and promising route for methyl glycolate (MG) synthesis, during which the development of efficient catalysts is critically crucial. Herein, Au/ZnO catalysts were prepared using impregnation (IM), colloidal-deposition (CD), deposition–precipitation (DP) and co-precipitation (CP) methods. The results of catalytic activity revealed that the Au/ZnO-DP catalyst was far superior to the other three catalysts, achieving an EG conversion rate of 90.4% and a selectivity towards MG of 93.8%. The catalysts were systematically characterized by N₂ adsorption–desorption, XRD, TEM, XPS, H₂-TPR, EPR, O₂-TPD and CO₂-TPD. The results showed that a large number of Au–ZnO interfaces facilitated the adsorption and activation of O₂. Moreover, it was found that the basic sites promoted the cleavage of O–H bonds in the EG molecules, and the acidic sites were responsible for the selectivity of MG. This work offers a simple strategy for the design of gold catalysts in EG oxidative esterification.

The solar dish Stirling power generation system has become a potential technical solution in the field of renewable energy because it combines efficient light concentration and thermal cycle technology and shows excellent solar energy conversion efficiency. Compared with other solar power generation technologies, the peak efficiency of the solar disc Stirling power generation system is as high as 30%, and the average power generation efficiency is between 15% and 27%. This paper studies the system deeply, and discusses its commercial progress, technical and economic problems, challenges and future development direction. In order to further popularize this technology, it is necessary to improve system efficiency, reduce costs, improve maintenance and extend service life.

Utilization of wet waste to produce renewable fuels, including aviation fuel, is key to a sustainable energy portfolio. Currently, hydrothermal liquefaction (HTL) and subsequent hydrotreating steps can successfully produce drop-in fuels which meet standards for gasoline and diesel. A remaining obstacle for development of sustainable aviation fuels (SAF) is the presence of nitrogen containing compounds (NCCs). Aviation fuels have more stringent regulations on permissible concentrations of NCCs, which have been associated with fuel instability for use in jet engines and the emission of harmful pollutants into the environment. Currently, NCCs are removed through the hydrodenitrogenation (HDN) process, which requires severe operating conditions along with significant H₂ and energy consumption, resulting in yield lost due to cracking. Alternatively, adsorptive denitrogenation (ADN) is being investigated as a more energy efficient process. This work achieved over 99% nitrogen removal, supported by computational work showing nitrogen adsorption correlates with surface acidity. Among the adsorbents screened, silica gel exhibited high adsorption capacity of 150 mg g⁻¹ for pyridine and 80 mg g⁻¹ for indole, coupled with impressive regeneration performance through thermal treatment. The recyclability of the silica gel showed good adsorption efficiency of NCCs for up to five cycles. This research demonstrates mechanism of nitrogen removal using adsorption technologies for future waste-derived aviation fuel.

The aviation sector contributes approximately 2.5% to global GHG emissions, driving a growing interest in mitigating its environmental impacts through use of sustainable aviation fuel (SAF). A critical component in SAF development lies in securing sustainable feedstock supplies to ensure competitive pricing and minimal environmental impact. This novel study compares the techno-economic and life-cycle environmental impacts from cradle-to-gate of SAF production from forest residues as a lignocellulosic biomass feedstock. The fuel production pathway considered in this study includes conversion of lignocellulosic biomass (forest residues) to renewable jet fuel through gasification, producing synthesis gas and subsequently SAF (FT-SPK-SAF) through Fischer–Tropsch synthesis in the presence of a catalyst. Techno-economic models of feedstock (forest residues) supply, pretreatment, and conversion processes for SAF production at 90 Mg per day capacity were developed and evaluated. Considering the value of co-products, the minimum selling price (MSP) of FT-SPK-SAF was $1.87 per kg or $1.44 L ($5.45 per gallon). The global warming impact of forest residue-based SAF was estimated to be 24.6 g_{CO2 eq.} per MJ of SAF, which was lower than that of SAF from other lignocellulosic feedstock types. Additionally, this study evaluated the changes in carbon removal efficiency of SAF when accounting for soil carbon change. The outcomes of this study are useful for developing strategies to achieve economic feasibility and greenhouse gas reduction goals of SAF production from biobased sources, while also outlining performance targets for enhancing its environmental sustainability at a commercial scale.

The synthesis of high-quality fuels from biomass-derived platform chemicals is challenging. Herein, Ru/WO₃–ZrO₂ (Ru/xWZ, where x is the wt% of WO₃) catalysts with varying WO₃ loadings were synthesized and explored for the hydrodeoxygenation (HDO) of biomass-derived furfural-acetone aldol adducts (FAc) to alkanes. Notably, WO₃ loadings had a marked effect on the catalytic HDO of FAc to alkanes. Complete FAc conversion with a 95% yield of alkanes (octane : heptane – 82 : 18) was achieved over the Ru/5WZ catalyst under optimized reaction conditions (150 °C, 2 MPa H₂, and 3 h). Control experiments and NH₃-TPD and HR-TEM results inferred that the optimum loading of WO₃ is crucial for tuning the acidic sites and the exposure of the Ru surface sites in the Ru/xWZ catalysts to achieve high catalytic activity for the HDO of FAc to alkanes.

The sluggish transfer of photogenerated charges is an intrinsic problem in the photoelectrochemical (PEC) conversion of solar energy into chemical energy. Constructing nanostructured heterostructure photoelectrodes is one of the most effective strategies for achieving energetic charge transfer kinetics. Herein, we fabricate a type II heterostructure film of BiVO₄/Bi₂Mo₂O₉ for PEC water splitting using the successive ionic layer adsorption and reaction (SILAR) method. Owing to the work function difference of ∼230 mV between the two semiconductors, free electrons will flow from Bi₂Mo₂O₉ to BiVO₄, causing positive charges to accumulate on the Bi₂Mo₂O₉ side and negative charges on the BiVO₄ side. This charge redistribution induces a built-in electric field pointing from Bi₂Mo₂O₉ to BiVO₄, facilitating the separation of photogenerated electrons and holes. Consequently, the corresponding photocurrent density in the BiVO₄/Bi₂Mo₂O₉ photoanode reaches 0.61 mA cm⁻², which is 3.4 times that of bare Bi₂Mo₂O₉ (0.18 mA cm⁻²) at 1.23 V vs. the Reversible Hydrogen Electrode (RHE). The interface charge interaction results in upward and downward band bending toward the interface for Bi₂Mo₂O₉ and BiVO₄ and also leads to enhanced oxidation kinetics (70.1%) and high photovoltage (340 mV).

Rechargeable iron-ion batteries (RIIBs) are considered one of the alternatives to lithium-ion batteries (LIBs) owing to their high volumetric energy density and low-cost fabrication under ambient conditions. A crucial aspect of RIIBs lies in developing high-performance cathode materials with high cycling stability and fast charge–discharge characteristics. We developed highly stable iron oxide microspheres (Fe₃O₄-MS) via solvothermal synthesis. Various electrochemical measurements were performed, including cyclic voltammetry (CV) to understand the redox mechanism and diffusion characteristics of iron-ions, galvanostatic charging discharging (GCD) for cycling stability analysis, and electrochemical impedance spectroscopy (EIS) for different electrode resistance analyses. RIIBs exhibit a high specific capacity of 155 mA h g⁻¹ at 25 mA g⁻¹ and 60 mA h g⁻¹ at a higher current density of 500 mA g⁻¹ (∼8C), with 92% retention capacity and fast charge–discharge characteristics. Electronically powered gadgets were used to demonstrate the practical utility of RIIBs. The remarkable electrochemical performance observed due to highly stable Fe₃O₄-MS is confirmed by ex situ characterization after the complete cycling of the cell compared to pristine electrodes, and these results strongly correlated with impedance analysis. Thus, the present work facilitates the development of an efficient cathode material for RIIBs.