Steam Vapor Research Articles

Salt Mitigation Strategies of Solar‐Driven Interfacial Desalination

AbstractSolar‐driven interfacial desalination (SDID), which is based on localized heating and interfacial evaporation, provides an opportunity for developing environmentally friendly and cost‐effective seawater thermal desalination. However, localized heating and rapidly generated interfacial steam may cause salt to accumulate on the evaporator's surface and block the channel of steam evaporation. Salt accumulation inevitably reduces the light absorption and service period of the solar absorber, resulting in a significant decrease in evaporation efficiency over time. Salt accumulation makes it difficult to produce SDID devices with high energy efficiency and long‐term stability for large‐scale use in remote poverty‐stricken areas. Therefore, the exploration of novel and effective strategies for addressing salt accumulation through both material design and structural engineering has attracted more attention in recent years. This review presents an overview of the state‐of‐the‐art advancements in salt‐resistant photothermal evaporation and discusses the critical issues for achieving salt mitigation SDID, focusing on the classification of salt mitigation strategies based on photothermal evaporation configurations, the basic mechanism of salt mitigation, and the architectural design of photothermal materials. Finally, the important challenges and prospects of SDID are discussed to providing a meaningful roadmap to efficient salt mitigation SDID.

Highly Anisotropic Corncob as an Efficient Solar Steam-Generation Device with Heat Localization and Rapid Water Transportation.

Solar steam generation is receiving considerable interest because of its potential application in wastewater treatment and desalination. Many devices with various photothermal materials and structures have been demonstrated to be solar steam evaporators by improving their light absorption, heat loss, water transportation, and vapor escape. However, developing a biomass-based evaporator with heat localization and rapid water transportation is highly desired yet still challenging. Here, corncobs, a kind of agricultural waste with vascular bundle and "vesiculose" structures, are used to fabricate solar steam-generation devices. After high-temperature treatment, the carbonized corncobs maintain the highly anisotropic porous framework and favorable hydrophilicity and thereby have excellent thermal management and water transportation. With efficient solar absorption, heat localization, and rapid water transportation, the lightweight carbonized corncobs can float on water and generate water vapor with a high steam generation efficiency of 86.7% under 1 sun.

Exergoeconomic Assessment of a Compact Electricity-Cooling Cogeneration Unit

This study applies the SPecific Exergy COsting (SPECO) methodology for the exergoeconomic assessment of a compact electricity-cooling cogeneration system. The system utilizes the exhaust gases from a 126 hp Otto-cycle internal combustion engine (ICE) to drive a 5 RT ammonia–water absorption refrigeration unit. Exergy destruction is higher in the ICE (67.88%), followed by the steam generator (14.46%). Considering the cost of destroyed exergy plus total cost rate of equipment, the highest values are found in the ICE, followed by the steam generator. Analysis of relative cost differences and exergoeconomic factors indicate that improvements should focus on the steam generator, evaporator, and absorber. The cost rate of the fuel consumed by the combustion engine is 12.84 USD/h, at a specific exergy cost of 25.76 USD/GJ. The engine produces power at a cost rate of 10.52 USD/h and specific exergy cost of 64.14 USD/GJ. Cooling refers to the chilled water from the evaporator at a cost rate of 0.85 USD/h and specific exergy cost of 84.74 USD/GJ. This study expands the knowledge base regarding the exergoeconomic assessment of compact combined cooling and power systems.

Rolling membrane powered by low-temperature steam as a new approach to generate mechanical energy

How to convert heat energy into other forms of usable energy more efficiently is always crucial for our human society. In traditional heat engines, such as the steam engine and the internal combustion engine, high-grade heat energy can be easily converted into mechanical energy, while a large amount of low-grade heat energy is usually wasted owing to its disadvantage in the temperature level. In this work, for the first time, the generation of mechanical energy from both high- and low-temperature steam is implemented by a hydrophilic polymer membrane. When exposed to water vapor with a temperature ranging from 50 to 100 °C, the membrane repeats rolling from one side to another. In nature, this continuously rolling of membrane is powered by the steam, like a miniaturized “steam engine”. The differential concentration of water vapor (steam) on the two sides of the membrane generates the asymmetric swelling, the curve, and the rolling of the membrane. In particular, results suggest that this membrane based “steam engine” can be powered by the steam with a relatively very low temperature of 50 °C, which indicates a new approach to make use of both the high- and low-temperature heat energy.

Biomimetic Antigravity Water Transport and Remote Harvesting Powered by Sunlight.

Antigravity water transport plays important roles in various applications ranging from agriculture, industry, and environmental engineering. In natural trees, ubiquitous water‐flow over 100 m high from roots through the hierarchical xylem to leaves is driven by sunlight‐powered continuous evaporation and the negative pressure. Inspired by natural trees, herein an artificial trunk‐leaf system is built up to structurally mimic natural trees for a continuous antigravity water delivery. The artificial tree consists of directional microchannels for antigravity water transport, and a top leaf‐like hybrid hydrogel that are acts as continuous solar steam evaporator, plus a purposely engineered steam collector. It is found that continuous uniform microchannels of acetylated chitin optimize and enhance capillary rise (≈37 cm at 300 min) and reduce vertical water transport resistance. A remote water harvesting, and purification is performed with a high rate of 1.6 kg m−2 h−1 and 184 cm in height under 1 sun irradiation and the collection efficiency up to 100% by evaporative cooling technique. It is envisioned that the basic design principles underlying the artificial tree can be used to transform solar energy into potential energy.

Decontamination and reuse of surgical masks and N95 filtering facepiece respirators during the COVID-19 pandemic: A systematic review.

Surgical masks and N95 filtering facepiece respirators (FFRs) prevent the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and protect medical personnel. Increased demands for surgical masks and N95 FFRs during the coronavirus disease 2019 (COVID-19) pandemic has resulted in the shortage crisis. However, there is no standard protocol for safe reuse of the N95 FFRs. In this systematic review, we aimed to evaluate the effectiveness of existing decontamination methods of surgical masks and N95 FFRs and provide evidence-based recommendations for selecting an appropriate decontamination method. We performed systematic searches of Ovid MEDLINE and Ovid EMBASE electronic databases. The last search was performed April 11, 2020. Any trials studying surgical masks and/or N95 FFRs decontamination were included. Outcomes were disinfections of virus and bacteria, restoration of the filtration efficiency, and maintenance of the physical structure of the mask. Overall, 15 studies and 14 decontamination methods were identified. A low level of evidence supported 4 decontamination methods: ultraviolet (UV) germicidal irradiation (9 studies), moist heat (5 studies), microwave-generated steam (4 studies), and hydrogen peroxide vapor (4 studies). Therefore, we recommended these 4 methods, and we recommended against use were given for the other 10 methods. A low level of evidence supported the use of UV germicidal irradiation, moist heat, microwave-generated steam, and hydrogen peroxide vapor for decontamination and reuse of N95 FFRs. These decontamination methods were effective for viral and bacterial disinfection as well as restoration of the filtration efficiency, and the physical structure of the FFRs.

Conventional and Advanced Exergy-Based Analysis of Hybrid Geothermal–Solar Power Plant Based on ORC Cycle

Today, as fossil fuels are depleted, renewable energy must be used to meet the needs of human beings. One of the renewable energy sources is undoubtedly the solar–geothermal power plant. In this paper, the conventional and advanced, exergo-environmental and exergo-economic analysis of a geothermal–solar hybrid power plant (SGHPP) based on an organic Rankin cycle (ORC) cycle is investigated. In this regard, at first, a conventional analysis was conducted on a standalone geothermal cycle (first mode), as well as a hybrid solar–geothermal cycle (second mode). The results of exergy destruction for simulating the standalone geothermal cycle showed that the ORC turbine with 1050 kW had the highest exergy destruction that was 38% of the total share of destruction. Then, the ORC condenser with 26% of the total share of exergy destruction was in second place. In the hybrid geothermal–solar cycle, the solar panel had the highest environmental impact and about 56% of the total share of exergy destruction. The ORC turbine had about 9% of all exergy destruction. The results of the advanced analysis of exergy in the standalone geothermal cycle showed that the avoidable exergy destruction of the condenser was the highest. In the hybrid geothermal–solar cycle, the solar panel, steam economizer and steam evaporator were ranked first to third from an avoidable exergy destruction perspective. The avoidable exergo-economic destruction of the evaporator and pump were higher than the other components. The hybrid geothermal–solar cycle, steam economizer, solar pane and steam evaporator were ranked first to third, respectively, and they could be modified. The avoidable exergo-environmental destruction of the ORC turbine and the ORC pump were the highest, respectively. In the hybrid geothermal–solar cycle, steam economizers, solar panel and steam evaporators had the highest avoidable exergy destruction, respectively. For the standalone geothermal cycle, the total endogenous exergy destruction and exogenous exergy destruction was 83.61% and 16.39%. Moreover, from an exergo-economic perspective, 89% of the total destruction rate was endogenous and 11% was exogenous. From an exergo-environmental perspective, 88.73% of the destruction rate was endogenous and 11.27% was exogenous. For the hybrid geothermal–solar cycle, the total endogenous and exogenous exergy destruction was 75.08% and 24.92%, respectively. Moreover, 81.82% of the exergo-economic destruction rate was endogenous and 18.82% was exogenous. From an exergo-environmental perspective, 81.19% of the exergy destruction was endogenous and 18.81% was exogenous.

Reduced Graphene Oxide/Carbon Fiber Composite Membrane for Self-floating Solar-thermal Steam Production

Solar-thermal water evaporation has attracted increasing attention owing to the promising potential to solve the global clean water and energy crisis. But, the development of this strategy is limited by the lack of materials with high solar-thermal conversion efficiency, local heating of superficial water, easy preparation and low cost. Herein, we proposed a facile strategy to prepare a reduced graphene oxide/carbon fiber composite membrane, denoted as RGO/CF membrane. The surface of the RGO/CF membrane was highly hydrophobic, endowing the composite membrane with the self-floating ability on the water without any assistance. The light absorbance ability achieved as high as ca. 98% in the wavelength range of 300–1200 nm. The steam evaporation efficiency under the illumination of 3-sun was 97%, generating water steam at a rate of 4.54 kg·m−2·h−1. Moreover, the solar-thermal steam production rate showed high stability during successive 30 cycle tests.

Double-layer cellulose hydrogel solar steam generation for high-efficiency desalination

Solar steam generation is one of the most promising technologies for desalination. In order to further promote the development of solar steam generation, a double-layer cellulose hydrogel (DCH) was designed and used as solar steam generation for seawater desalination. Under one sun illumination intensity (1 kW·m−2), the average evaporation rate and the steam evaporation efficiency reaches 1.582 kg·m−2 h-1 and 91.4 %, respectively. The durability test was performed to verify the long-time durability and antifouling property. Outdoor experiment was carried out to prove the high steam evaporation efficiency and desalination performance of DCH. This paves a way for the cellulose-based hydrogel as a biodegradable, low-cost and promising solar steam generation.

Sewage sludge pyrolysis coupled with self-supplied steam reforming for high quality syngas production and the influence of initial moisture content

A technology of sewage sludge (SS) pyrolysis coupled with self-supplied steam reforming of the volatile is developed to utilize the latent heat of the steam vapor released in the SS drying & pyrolysis process. An integrated reactor consisting of a vertical free-falling pyrolysis section and a horizontal screw-moved reforming section is designed for this purpose. The performance of the reactor shows that by changing the moving speed of the char in the reforming section, high quality syngas with an H2/CO ratio of 4.37 and a percentage of H2 + CO up to 66.58 vol% can be obtained at approximately 570–600 °C for the dry SS. There is an optimum moving speed of the screw for producing the highest volume of the syngas. A higher moving speed of the screw also results in a higher concentration of the aromatic compounds in the final pyrolysis oil. When the initial moisture content of SS increases from 0 to 65.50%, the H2/CO ratio and H2/CO2 ratio in the syngas increase from 4.37 to 30.87 and from 2.1 to 2.6 correspondingly, and the final oil yield decreases from 24.03 wt% to 14.16 wt%. Moreover, the total energy recovery efficiency decreases from 88.85% to 61.92%, while the energy portion of syngas shows a peak of 44.18% of the total energy input when the initial moisture content is 41.26%. The integrated reactor also provides a good opportunity for adding a catalyst such as dolomite to make the process more effective. The technology developed in this paper provides an approach to deal with SS with a relatively high moisture content.

Air quality and thermal comfort analysis of kitchen environment with CFD simulation and experimental calibration

During cooking fume particulate and high temperature are unavoidable in indoor environment and could pose serious threat to human health. This paper presents the theoretical formulas with experimental calibration and establishes an improved computational fluid dynamics (CFD) model based on Fluent V19.04. The present CFD model can accurately reflect the variation of fume concentration and assess air pollution in kitchen so as to improve thermal environment. In the present model, a hybrid grid by combing structured and unstructured grids is used to discretize the computational domain. The standard k-e turbulence model combined with a wall function is utilized to analyze the violent turbulent movement of particulate matter. The model is calibrated by the test data obtained from fume concentration experiments during cooking in kitchen. A relationship between the measured cooking fume concentration and the simulated steam vapor concentration is established approximately. Based on the improved CFD model, the movement of particulate matter under the effect of range hood with air curtain is simulated. The effects of exhaust volume on the particulate matter movement, air age, PMV and PPD indices are also investigated. The present CFD model provides a practical tool to evaluate the air quality and thermal comfort of the kitchen environment.

Modeling the Conformance Improvement Using Flow Control Devices in Infill Wells Adjacent to SAGD Well Pairs: No Flashing

Summary Late in the life of the steam-assisted gravity drainage (SAGD) process, drilling a single, horizontal infill well (called a wedge well by some) has become a common practice in the oil bank located between two mature SAGD well pairs to produce bitumen that has been heated and mobilized but could not be effectively drained by gravity because of the large lateral location relative to that of the SAGD producers. Because this oil bank is surrounded by a large, depleted steam chamber created by the existing well pairs, little heat is required to mobilize bitumen. Consequently, the incremental steam/oil ratio (SOR) to produce this bitumen can be reduced using these infill wells. One of the challenges, however, in producing such wells is that nonuniform drainage and local hot spots can be readily created in the first year of their operation that in many cases require steam stimulations and completion retrofits, such as with flow control devices (FCDs), to improve the drainage profile. This work is a continuation of three previous parts (presented in Irani 2018, 2019, and Irani and Gates 2018) on SAGD near-wellbore drainage behavior, control, and some of the modeling challenges. In previous parts, productivity index (PI) models were formulated specifically for an SAGD well producing emulsion from the liquid pool under changing operational subcool conditions. Given the conformance challenges, many infill wells have greater risk of developing hot spots than SAGD producers, suggesting that the wellbore modeling, which includes the response of the FCDs, should be coupled with a PI model appropriately for such wells. Currently, there is no suitable PI model to predict drainage rates in these SAGD infill wells. The production rate in these wells is highly pressure driven in contrast to the SAGD reservoir drainage process that is dominantly gravity driven. In this study, a time variable PI model is analytically developed for infill wells considering a developed pressure-driven formulation. The model accurately shows fluctuations in the production rate because of flowing bottomhole pressure (FBHP) variations and can be used for both oil rate prediction and forecasting and wellbore hydraulic design for infill wells. This novel approach is the first of its kind to incorporate temperature variation, pressure dependency, and steam interface velocity within a PI model for infill wells. To achieve higher efficiencies, the location and characteristics of the FCDs along the infill wells should be optimized. In this study, the mathematical PI model of infill wells is coupled with an FCD model, and the analysis of different configurations of FCDs is evaluated. The results of this work show an uplift in a well completed with liner-deployed FCDs, but because flashing is not incorporated in the PI model, the pressure drop predicted within these FCDs for produced fluids with free steam vapor is found to be less than reality. Ignoring flashing through the FCD provides higher density of the fluid passing through the venturi. Therefore, the FCD creates less choking with reduced conformance control than would be expected if flashing was considered.

The Origins of the High Performance of Pd Catalysts Supported on Carbon Black-Embedded Carbon Nanofiber for Formic Acid Oxidation

In this study, we developed a carbon black (CB)-embedded carbon nanofiber (CNF) as a Pd support, which showed a high level of formic acid oxidation reaction (FAOR) activity. For the support preparation, heat treatment involving calcination at 1000 °C in a nitrogen atmosphere (carbonization) followed by calcination at 850 °C in water vapor (steam activation) was conducted to form a CB, which contained carbon nanofibers made from a polyacrolynitrile (PAN) fiber prepared by electrospinning. This catalyst showed a high level of FAOR activity. In this situation, the CB was also heat-treated, therefore, it was unclear whether the origin of the high FAOR activity of the CB-embedded CNF was caused by the CNF itself or the heat treatment of the CB. In order to establish the cause of the high FAOR activity of the CB-embedded CNF, the CBs underwent several heat treatments; i.e., stabilization, carbonization, and steam activation. Two types of carbon black with different pore structures, i.e., Ketjen black and Vulcan XC-72, were used to investigate the FAOR activity. The appropriate heat treatment of the CB promotes the improved FAOR activity; however, excessive heat treatment caused a deterioration in the FAOR activity, especially for Ketjen due to the presence of numerous micropores. However, by embedding the CB into the CNF, the FAOR activity improved, especially in the case of Ketjen, even though the embedded CB underwent several heat treatments. The optimum ratio of CB/PAN in the CB-embedded CNF was also investigated. The highest FAOR activity was observed at 0.25 CB/PAN for both the Vulcan and Ketjen. The electronic state of Pd3d in which the binding energy of the metallic Pd shifted to a lower binding energy suggested that the metal–support interaction is strong at the CB/PAN ratio of 0.25. On the basis of these results, it was found that heat treatment of the CB by embedding it in the CNF is a promising way to achieve a metal–support interaction without destroying its structure.

Contrasting fragmentation and transportation dynamics during the emplacement of Dikkartın rhyodacitic dome; Erciyes stratovolcano, central Turkey

Dikkartin is a monogenetic lava dome emplaced on the southern flank of Erciyes stratovolcano (3917 m) in central Anatolia, Turkey. Stratigraphic, granulometric, morphometric and textural variations are presented to obtain quantitative physical volcanological insight and to interpret eruption and emplacement mechanisms in Dikkartin eruptive sequence. Contrasting fragmentation and transportation dynamics in the stratigraphic sequence of the Dikkartin eruption is related to the ratio of magma and external water during each phases of the activity. We suggest four eruptive phases. The eruption begins with a dry, purely magmatic Plinian eruption with a column height of 20 km. According to the isopleth and isopach maps, the plume stretched in a NNE-SSW direction. The amount of water interacting with magma modified the course of the Dikkartin eruption. During a phase dominated by phreatomagmatism, an explosion crater and a tuff ring were formed. Exhaustion of the water in the environment and depletion of initial magmatic volatiles in the course of time resulted in extrusion of a lava dome. Sequential Fragmentation/Transport (SFT) theory has been applied on tephra samples to comment on fragmentation and transportation dynamics using grain size data. The magmatic and phreatomagmatic characters contained in each explosion sequence were numerically demonstrated. The relationship between the porosity time and the magma-water interaction time was investigated by detailed SEM analysis and roughness values calculated on volcanic ash. Surface analysis on volcanic ash suggested that most of the phreatomagmatic eruptions producing the tuff ring were dry with superheated steam but little vapour condensation occurred allowing adhesion of fine material on surfaces. Considering the c. 20 km plume height calculated for the climactic eruption column (Phase 1), the prevailing winds directed the cloud to the south, but due to the decrease in the plume height (Phase 2), the cloud was later directed to the northeast. According to the direction of seasonal winds, it is suggested that Dikkartin erupted during winter.

Action of Water Vapor in the High-Temperature Hydrogenation of a Mixture of Coke-Plant Benzene and the Naphthalene Fraction of Coal Tar

Abstract—In the catalytic high-temperature hydrogenation (hydrodealkylation) of a mixture of raw coke-plant benzene and the 180–230°C naphthalene fraction of coal tar, water vapor (steam) acts in two ways: it blocks the smallest pores in the catalyst, from which the removal of products is difficult; and it facilitates their desorption from the large pores, thereby decreasing the likelihood of polymerization of the reactive products of intermediate hydrocracking and dealkylation. Steam is found to play a positive role in slowing the formation of high-molecular compounds, which are sources of coke deposits on the catalyst.

A facile and low-cost method to improve the efficiency of solar steam evaporation

The use of graphene and carbon nanotubes in solar steam evaporation systems not only increases the preparation costs, but also complicates the process of fabrication. In this study, a black fabric was designed and woven in order to improve the solar steam evaporation efficiency, and the water interface structure was optimized at low cost. The evaporation rate reached 0.57 kg/(m2·h), a value which is almost 3.2 times larger than that of pure water; meanwhile, the photothermal conversion efficiency reached 48.3%. This study provides some theoretical bases for the enhancement of water evaporation using porous media, promotes the low-cost application of water evaporation, and provides an effective solution to the problem of global water shortage.

Mesoporous cellulose/TiO2/SiO2/TiN-based nanocomposite hydrogels for efficient solar steam evaporation: low thermal conductivity and high light-heat conversion

Solar steam evaporation is regarded as a green and efficient method to achieve desalination and purification. However, the low-efficiency photothermal conversion of its evaporator is an obstacle to widespread application. Focusing on the interface evaporation method through photothermal conversion, the current bottleneck of the technology is that it is impossible to achieve in-depth interface control of the incident light path to obtain higher water evaporation efficiency. We propose a mesoporous cellulose-based hydrogel for the manufacture of a high-efficiency solar steam evaporator. This type of solar evaporator achieves an enhanced capillary force and optical path extension to increase the photothermal conversion efficiency and evaporation rate. These evaporation performance advantages can all be attributed to the dense mesoporous structure, low thermal conductivity, and high light absorption efficiency. The results showed that under a solar light intensity of 1.5 kW m−2, the mesoporous structure of the MCNT–TiO2–SiO2–TiN hydrogel-based evaporator has an excellent evaporation rate (1.853 kg m−2 h−1) and high solar energy conversion efficiency (77.39%) due to the low thermal conductivity (0.71997 W m−1 k−1), high light absorption efficiency (98.3%, wavelength 190–3000 nm) and good hydrophilic properties (XRD and FT-IR tests). Our results demonstrate a new full-hydrogel solar steam evaporation method by using a simple, easily obtained, reusable, and low-cost solar desalination and purification system based on evaporation can yield fresh water from seawater and sewage. The evaporation technique can be used to produce a simple, easily obtained, reusable, and low-cost solar desalination and purification system for pure freshwater resources from seawater and sewage.

Tuning the Closed Pore Structure of Hard Carbons with the Highest Na Storage Capacity

High-capacity anode materials are one of the bottlenecks to further improve the energy density of Na-ion batteries (NIBs). Except for introducing more defects to increase the sloping capacity, tuning the closed porous structure to boost the plateau capacity is another direction. Here by adopting phenol-formaldehyde resin (PF) as the carbon precursor and ethanol (EtOH) as the pore-forming agent, through precise chemical regulation of their relative content during a solvothermal process before further carbonization, carbon anodes with appropriate microstructure are achieved. It is found that the function of EtOH rests on generating steam vapor to create a pore cavity among cross-linked matrixes. The obtained optimal anodes exhibit a high Na storage capacity of ca. 410 mAh/g. When pairing with an O3-NaNi1/3Fe1/3Mn1/3O2 cathode, the full cell delivers a high initial Coulombic efficiency of 83% and energy density of ca. 300 Wh/kg. The proposed chemical regulation approach via a pore-forming strategy is simple and practical to enable high-energy-density NIBs.

Low-temperature formation and steam oxidation of β-FeAl coating on P92 steel

The poor steam oxidation resistance of P92 steel limits its long term application in 620 °C double reheat ultra-supercritical steam boilers. Aluminizing has been considered as one cost-effective solution to improve the oxidation resistance of substrate alloys without significantly worsening their mechanical performance. A modified aluminising was developed to form a thin β-FeAl layer on heat-resistant P92 steel under relatively lower temperatures. Oxidation behaviour of the layer and the P92 steel was probed in flowing pure steam vapour up to 500 h at 650 °C. An unstable Fe-rich oxide layer of over 100 μm in thickness grew on the steel, whereas only an extremely thin (<0.2 μm) and stable α-Al2O3 scale grew on the β-FeAl layer that ultimately evolved to FeCrAl solid solution phase during oxidation, implying great potentials of applying the β-FeAl coating for protecting practical boiler tubing systems against oxidation.

Flexible Anti-Biofouling MXene/Cellulose Fibrous Membrane for Sustainable Solar-Driven Water Purification

Solar-driven interfacial water evaporation is regarded as an effective, renewable, and environment-friendly technology for clean water production. However, biofouling caused by the nonspecific interaction between the steam generator and biofoulants generally hinders the efficient application of wastewater treatment. Herein, this work reports a facile strategy to fabricate flexible anti-biofouling fibrous photothermal membrane consisting of a MXene-coated cellulose membrane for highly efficient solar-driven water steam evaporation toward water purification applications. The as-prepared MXene/cellulose photothermal membrane exhibits light absorption efficiency as high as ∼94% in a wide solar spectrum range and a water evaporation rate up to 1.44 kg m-2 h-1 under one solar illumination. Also, the MXene/cellulose membrane shows very high antibacterial efficiency (above 99.9%) owing to the MXene coating as a highly effective bacteriostatic agent. Such a flexible, anti-biofouling, and high-efficiency photothermal membrane sheds light on practical applications in long-term wastewater treatments.