Abstract Low-carbon fertilizer production requires redesigning conventional urea manufacturing unde210 Col:2438r electrified, renewable-based schemes. This study evaluates a fully electrified green urea pathway integrating water electrolysis, cryogenic air separation, ammonia synthesis, carbon capture, and urea synthesis under hybrid renewable electricity supply. The validated process produces 42.57 t/h of urea (approximately 373 kt/yr) with a fully electrified demand of 3,168,588 MW h/yr, corresponding to 8.50 MW h/t urea. Fourteen scenarios combining solar photovoltaic, onshore wind, 0/170/340 MW h storage, and grid electricity were retained. A location-neutral 8,760 h energy-material integration layer was coupled to the steady-state process model to evaluate renewable intermittency, storage states, and hydrogen buffering without altering scenario definitions. Eleven scenarios were operationally feasible after renewable adequacy corrections of 0.3–9.0%, whereas Cases 1, 10, and 12 were infeasible under their original storage and backup architecture. Annual environmental screening alone proved insufficient to establish continuous operability, and Case 11 emerged as a balanced high-renewable configuration.
Abstract The photo-oxidative degradation of the epoxy matrix is a factor limiting the long-term environmental stability of carbon fiber reinforced polymer (CFRP) composites. This study investigates the physicochemical and thermal degradation mechanisms of DGEBA-based CFRP laminates exposed to prolonged (1000 h) ultraviolet radiation. To evaluate the synergistic effects of environmental factors, standard photoaging (PN-EN ISO 4892-2) was compared with a novel in-house method utilizing narrow-band UV radiation (UVA, UVB, UVC) in both dry and continuous underwater immersion conditions. ATR-FTIR and Raman spectroscopy revealed extensive photo-oxidation of the epoxy matrix, evidenced by the formation of carbonyl-containing moieties (ketones and carboxylic acids) and the deterioration of the aromatic skeleton. While the flexural and tensile strengths remained largely unaffected due to the shielding effect of the carbon fibers, the chemical degradation of the matrix led to severe surface damage, resin microcracking, and subsequent fiber exposure. Crucially, dynamic mechanical analysis (DMA) demonstrated a significant decrease in the glass transition temperature (Tg), from approximately 98 to 92 °C (a 6% drop) after 1000 h of exposure, indicating a reduction in the polymer network’s cross-linking density and thermal stability. Under the coupled action of UV radiation and water immersion, a specific evolution mechanism of material property degradation was identified: UV-induced chain scission caused severe surface microcracking, which compromised the matrix barrier and facilitated deeper moisture penetration into the composite. This synergistic effect deteriorated the fiber-matrix interface, leading to a noticeable reduction in interlaminar shear strength (ILSS). While the macroscopic flexural and tensile strengths remained largely unaffected due to the shielding effect of the carbon fibers, the chemical degradation of the matrix led to severe surface damage and fiber exposure. These findings highlight that UV exposure fundamentally limits the high-temperature operational range of CFRPs, proving that Tg and interfacial properties are significantly more sensitive and reliable indicators of early-stage photodegradation than conventional static mechanical testing.
Abstract Building materials that integrate thermal insulation, fire safety, structural durability, and passive cooling are highly desirable for reducing building energy consumption. Achieving this combination in sustainable biomass-derived materials remains challenging. Here, a multifunctional sodium alginate-based aerogel (SPCA) was fabricated via directional freezing and reinforced by a dual-cross-linked framework formed through PA-mediated hydrogen bonding and Ca2+ coordination. The resulting network produced a denser, more uniform honeycomb-like porous structure, thereby strengthening the aerogel skeleton. SPCA achieved a compressive strength of 4.57 MPa and a compressive modulus of 37.97 MPa, along with improved water stability. Despite moderate structural densification, SPCA retained a low thermal conductivity of 0.044 W m–1 K–1 and outperformed several commercial insulation materials under both hot and cold conditions. The aerogel also exhibited rapid self-extinguishing behavior and enhanced char formation. Furthermore, the combined effects of thermal insulation and radiative cooling enabled effective daytime cooling, resulting in a temperature reduction of 4.2 °C under simulated solar irradiation and a maximum temperature drop of 7.2 °C under outdoor conditions. Model-house experiments demonstrated reductions in roof and indoor temperatures, while EnergyPlus simulations predicted annual cooling-energy savings across different climate regions. The work provides a promising strategy for developing structurally durable, fire-safe, and thermally functional biomass aerogels for energy-efficient buildings, with great potential for practical applications in thermal management.
Replacing liquid electrolytes with solid ones is regarded as an essential strategy to mitigate safety concerns in lithium-ion batteries. However, the lower ionic conductivity of solid polymer electrolytes (SPEs) compared to conventional liquid electrolytes still hinders their practical application. In this work, we propose a composite polymer electrolyte (CPE) by incorporating a poly(ethylene oxide) (PEO) matrix with high-content lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) into an electrospun polyacrylonitrile (PAN)-based three-dimensional nanofiber framework. Active fillers of LLZTO nanoparticles and LiClO4 were further introduced into the PAN skeleton to construct additional ion-conducting pathways (designated as PLLP). This design of coembedding dual active fillers inside the electrospun nanofibers, rather than simply dispersing them in the PEO matrix, is distinct from conventional CPEs and provides continuous and fast-ion channels. The morphology and diameter distribution of electrospun fibers were optimized by varying PAN concentration. Consequently, the optimized PLLP composite electrolyte achieves a superior ionic conductivity of 1.12 & times; 10-4 S cm-1 at 30 degrees C, an electrochemical stability window up to 4.75 V, and a lithium-ion transference number of 0.53, which is substantially higher than those of conventional PEO-based electrolytes. Moreover, the LiFePO4/PLLP/Li solid-state battery delivers a high specific discharge capacity of 161 mAh g-1 at 60 degrees C at 0.5C after 95 cycles with a capacity retention of 96%, as well as excellent rate capability. These results demonstrate that the synergistic coupling of active fillers and a 3D electrospun framework provides an effective strategy for simultaneously enhancing ionic conductivity, electrochemical stability, and cycling performance in all-solid-state lithium batteries.
