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The direct CO2 Fischer–Tropsch synthesis (CO2-FTS) process has been proven as one of the indispensable and effective routes in CO2 utilization and transformation. Herein, we present a core-shell structured Na/Fe@Co bimetallic catalyst to boost CO2 conversion and light hydrocarbon (C2 to C4) selectivity, as well as inhibit the selectivity of CO. Compared to the Na/Fe catalyst, our Na/Fe@CoCo-3 catalyst enabled 50.3% CO2 conversion, 40.1% selectivity of light hydrocarbons (C2-C4) in all hydrocarbon products and a high olefin-to-paraffin ratio (O/P) of 7.5 at 330 °C and 3.0 MPa. Through the characterization analyses, the introduction of CoCo Prussian Blue Analog (CoCo PBA) not only increased the reducibility of iron oxide (Fe2O3 to Fe3O4), accelerated the formation of iron carbide (FexCy), but also adjusted the surface basic properties of catalysts. Moreover, the trace Co atoms acted as a second active center in the CO2-FTS process for heightening light hydrocarbon synthesis from CO hydrogenation. This work provides a novel core-shell structured bimetallistic catalyst system for light hydrocarbons, especially light olefin production from CO2 hydrogenation.

The separation of light hydrocarbon compounds is an important process in the chemical industry. Currently, its separation methods mainly include distillation, membrane separation, and physical adsorption. However, these traditional methods or materials have some drawbacks and disadvantages, such as expensive equipment costs and high energy consumption, poor selectivity, low separation ratios, and separation efficiencies. Therefore, it is important to develop novel separation materials for light hydrocarbon separation. As a new type of organic–inorganic hybrid crystalline material, metal–organic frameworks (MOFs) are promising materials for light hydrocarbon separation due to their designability of structure and easy modulation of function. This review provides an overview of recent advances in the design, synthesis, and application of MOFs for light hydrocarbon separation in recent years, with a focus on the separation of alkane, alkene, and alkyne. We discuss strategies for improving the adsorption selectivity and capacity of MOFs, including pore size limitation, physical adsorption, and chemisorption. In addition, we discuss the advantages/disadvantages, challenges, and prospects of MOFs in the separation of light hydrocarbon.

Light olefins are important raw materials in the petrochemical industry for the production of many chemical products. In the past few years, remarkable progress has been made in the synthesis of light olefins (C2–C4) from methanol or syngas. The separation of light olefins by porous materials is, therefore, an intriguing research topic. In this work, single-component ethylene (C2H4) and propylene (C3H6) gas adsorption and binary C3H6/C2H4 (1:9) gas breakthrough experiments have been performed for three highly porous isostructural metal–organic frameworks (MOFs) denoted as Fe2M-L (M = Mn2+, Co2+, or Ni2+), three representative MOFs, namely ZIF-8 (also known as MAF-4), MIL-101(Cr), and HKUST-1, as well as an activated carbon (activated coconut charcoal, SUPELCO©). Single-component gas adsorption studies reveal that Fe2M-L, HKUST-1, and activated carbon show much higher C3H6 adsorption capacities than MIL-101(Cr) and ZIF-8, HKUST-1 and activated carbon have relatively high C3H6/C2H4 adsorption selectivity, and the C2H4 and C3H6 adsorption heats of Fe2Mn-L, MIL-101(Cr), and ZIF-8 are relatively low. Binary gas breakthrough experiments indicate all the adsorbents selectively adsorb C3H6 from C3H6/C2H4 mixture to produce purified C2H4, and 842, 515, 504, 271, and 181 cm3 g−1 C2H4 could be obtained for each breakthrough tests for HKUST-1, activated carbon, Fe2Mn-L, MIL-101(Cr), and ZIF-8, respectively. It is worth noting that C3H6 and C2H4 desorption dynamics of Fe2Mn-L are clearly faster than that of HKUST-1 or activated carbon, suggesting that Fe2M-L are promising adsorbents for C3H6/C2H4 separation with low energy penalty in regeneration.

Light hydrocarbon fuels are widely utilized in industrial production and transportation due to their high calorific value and clean combustion characteristics. Compared to traditional oil tanker transportation, pipelines not only reduce transportation costs but also minimize environmental impact. To understand the leakage and diffusion law of light hydrocarbon pipelines, this paper takes light hydrocarbon pipelines as the research object, establishes the conceptual model of the process of light hydrocarbon leakage and diffusion, divides the four major processes of leakage and diffusion, analyzes the relevant theory, and deduces a formula. The numerical model of pipeline–air–soil leakage and diffusion was established to analyze the whole process of light hydrocarbon leakage and diffusion. The diffusion behavior of individual hydrocarbon components is examined, along with a comparative analysis between multi-component and single-component leakage scenarios. Simulation results reveal that the leakage process comprises three stages: an initial rapid diffusion phase, a transitional phase where a stable region begins to form, and a final stage where the diffusion pattern stabilizes around 800 s. C3 and C5 exhibit the largest diffusion ranges among gaseous and liquid hydrocarbons, respectively. In multi-component systems, the vaporization sequence suppresses the overall diffusion range compared to single-component cases, though gas-phase hydrocarbons tend to accumulate near the leakage source. Understanding the leakage and diffusion behavior of light hydrocarbon pipelines is crucial for energy security. By accurately modeling these processes, we can determine the impact zones of potential pipeline failures and establish appropriate safety buffers. This proactive approach not only safeguards human life and the environment but also ensures the reliable and uninterrupted delivery of energy resources. Consequently, such research is instrumental in fortifying the resilience and dependability of energy infrastructure.

Observations of the Jovian upper atmosphere at high latitudes in the UV, IR and mm/sub-mm all indicate that the chemical distributions and thermal structure are broadly influenced by auroral particle precipitations. Mid-IR and UV observations have shown that several light hydrocarbons (up to 6 carbon atoms) have altered abundances near Jupiter’s main auroral ovals. Ion-neutral reactions influence the hydrocarbon chemistry, with light hydrocarbons produced in the upper stratosphere, and heavier hydrocarbons as well as aerosols produced in the lower stratosphere. One consequence of the magnetosphere-ionosphere coupling is the existence of ionospheric jets that propagate into the neutral middle stratosphere, likely acting as a dynamical barrier to the aurora-produced species. As the ionospheric jets and the background atmosphere do not co-rotate at the same rate, this creates a complex system where chemistry and dynamics are intertwined. The ion-neutral reactions produce species with a spatial distribution following the SIII longitude system in the upper stratosphere. As these species sediment down to the lower stratosphere, and because of the progressive dynamical decoupling between the ionospheric flows and the background atmosphere, the spatial distribution of the auroral-related species progressively follows a zonal distribution with increasing pressures that ultimately produces a system of polar and subpolar hazes that extends down to the bottom of the stratosphere. This paper reviews the most recent work addressing different aspects of this environment.

In this work, we studied the role of zinc in the composition of supported iron-containing catalysts for the hydrogenation of CO2. Various variants of incipient wetness impregnation of the support were tested to obtain catalyst samples. The best results are shown for samples synthesized by co-impregnation of the support with a common solution of iron and zinc precursors at the same molar ratio of iron and zinc. Catalyst samples were analyzed by various methods: Raman, DRIFT-CO, TPR-H2, XPS, and UV/Vis. The introduction of zinc leads to the formation of a mixed ZnFe2O4 phase. In this case, the activation of the catalyst proceeds through the stage of formation of the metastable wustite phase FeO. The formation of this wustite phase promotes the formation of metallic iron in the composition of the catalyst under the reaction conditions. It is believed that the presence of metallic iron is a necessary step in the formation of iron carbides—that is, active centers for the formation and growth of chain in the hydrocarbons. This leads to an increase in the activity and selectivity of the formation of hydrocarbons in the process of CO2 hydrogenation.

C5–C7 light hydrocarbons are important components in petroleum and are extensively employed as an auxiliary approach in petroleum research. Consensus on the mechanism of light hydrocarbon generation has not yet been achieved. In this study, 20 gas samples were collected from the western part and northern margin of the Qaidam Basin. The molecular and carbon isotopic compositions of C1–C3 gaseous hydrocarbons and C5–C7 light hydrocarbons, as well as the carbon isotopes of oils were analyzed. Based on the relationships between carbon isotopes (13C) of individual light hydrocarbons and calculated vitrinite reflectance, it suggests that organic matters play a fundamental role in the carbon isotopes of light hydrocarbons, and maturity mainly affects the carbon isotopes of n-alkanes in light hydrocarbons. In addition, carbon isotopic differences between n-, iso- and cyclo-alkanes indicate that light hydrocarbons with different structures are produced from various biological precursors. Besides, carbon isotopes of individual light hydrocarbons can be used to estimate the δ13Ckerogen and distinguish cracked gas. On the one hand, small isotope fractionation between iso-alkanes and kerogen is observed. Average carbon isotopic compositions of iso-pentane (i-C5), 2-methylpentane (2-MC5) and 3-methylpentane (3-MC5) can provide a similar δ13Ckerogen with actual values. On the other hand, the carbon isotopic difference between 2-MC5 and n-C6 generally decreases with increasing maturity. Combined with the parameter (2-MC6 + 3-MC6)/n-C6, kerogen-cracked gases are characterized by high δ13C2MC5–δ13CnC6 and low (2-MC6 + 3-MC6)/n-C6 values, whereas oil-cracked gases exhibit the opposite features.

Light hydrocarbons in shale oil readily volatilize during conventional coring, surface handling, storage, and laboratory preparation. The resulting evaporative loss causes systematic underestimation of Rock-Eval S1 peak (free hydrocarbons measured by programmed pyrolysis), which can bias oil-bearing evaluation, sweet-spot delineation, and resource assessment. Here we investigate Chang 73 lacustrine shale oil in the Ordos Basin (China) using frozen cores recovered by pressure-retained coring from four wells. Time-series Rock-Eval pyrolysis and thermal desorption–gas chromatography (TD–GC) were used to quantify the magnitude, temporal evolution, and practical equilibrium time of light-hydrocarbon loss and to establish a practical restoration model. S1 decreases with storage time and exhibits a clear two-stage behavior. Shale shows a rapid-loss stage during 0–90 days, followed by a practical equilibrium stage after 90 days (S1 change less than 5%). Sandstone interbeds lose light hydrocarbons faster and more completely, reaching practical equilibrium after 60 days. TD–GC indicates that the lost fraction is dominated by n-alkane components lighter than C13, with gaseous hydrocarbons showing the greatest depletion; medium and heavy fractions decrease modestly. Loss is coupled with progressive desorption from kerogen and clays, leading to enrichment of heavier components in the residual free hydrocarbons and a shift of the modal carbon number toward higher values. At the shale equilibrium time, total organic carbon (TOC) and vitrinite reflectance (Ro) jointly control the restoration factor K. We propose a two-parameter restoration model: K = (0.4024·ln (TOC) + 0.821)·(0.652·Ro + 0.4292). Applying the model to more than 50 conventionally cored wells reveals that the Qingyang–Zhengning area in the southwestern basin is the principal enrichment zone of original free hydrocarbons, followed by the Jiyuan area in the north and the Huachi area in the central basin, whereas the eastern basin is relatively depleted. The workflow provides a robust and transferable approach for correcting S1 and improving shale-oil evaluation in lacustrine systems.

Within the Tabei Uplift of the Tarim Basin, Ordovician reservoirs in both the northern Halahatang (N-Halahatang) and western Lunnan (W-Lunnan) areas experienced extensive biodegradation during the Late Hercynian (Permian). Subsequent Himalayan (Neogene–Quaternary) tectonism induced divergent burial-thermal histories: the N-Halahatang reservoirs underwent intensive maturation (> 6,500 m depth; 1.02–1.22% R o ), while the W-Lunnan reservoirs experienced milder maturation (< 5,800 m depth; 0.70–0.85% R o ). Despite similar δ 13 C oil values indicating genetic affinity, the relatively deeply buried biodegraded oils from the N-Halahatang area contain abundant C 6 –C 8 light hydrocarbons (LHs), while the biodegraded oils from the W-Lunnan area exhibit only trace amounts of C 6 –C 8 LHs. To elucidate the evolution of LHs compositions and fingerprints in biodegraded oils under thermal maturation, and to determine whether the more enriched C 6 –C 8 LHs in the N-Halahatang oils can be attributed to enhanced burial-thermal maturation, two relatively shallower-burial biodegraded oils (Well LG40: slight to moderate biodegradation‌; Well LG7: heavy to severe biodegradation) from the W-Lunnan area were artificially pyrolyzed to various maturities. Subsequently, LH parameters of the pyrolyzed oils were compared with those of the naturally matured, deeply buried oils (heavy to severe biodegradation) from the N-Halahatang area. The results indicated that both biodegraded oils generated C 6 –C 8 LHs through thermal cracking, and the more severely biodegraded oil (Well LG7) exhibited a lower LH maximum yield than that from Well LG40. Certain parameters for organic matter type classification ( n -C 7 –DMCP–MCH and 3RP–5RP–6RP diagrams) generally remained applicable during thermal maturation, whereas most parameters for secondary alteration identification and maturity assessment were significantly compromised. Additionally, LH parameters of the N-Halahatang oils (1.02–1.22% R o ) matched those of the LG7 pyrolyzed oils at Easy R o = 1.00–1.20%, confirming that the enriched C 6 –C 8 LHs in the N-Halahatang oils can be attributed to cracking of biodegraded oils (with ‌biodegradation levels equivalent to Well LG7‌) under intense burial-thermal maturation. Furthermore, the potential C 6 –C 13 LHs derived from biodegraded oil cracking constitute 11–16 wt% of N-Halahatang’s liquid hydrocarbon resources.