High Water Production Rate Research Articles

Assessing Geothermal Energy Production Potential of Cambrian Geothermal Complexes in Lithuania

Lithuania has a geothermal anomaly situated in the southwestern region of the country. This anomaly is comprised of two primary geothermal complexes located in western Lithuania. The first complex is characterized by the Pärnu–Kemeri Devonian sandstone aquifers, which exhibit exceptionally good flow properties. However, the reservoir temperatures in this complex only reach up to 45 °C. The second complex encompasses Cambrian sandstone reservoirs. Although these Cambrian sandstone reservoirs exhibit high temperatures, with the highest reservoir temperatures reaching up to 96 °C, these Cambrian sandstone reservoirs have less favorable petrophysical properties. This study focuses on the high temperature Cambrian Geothermal sandstone reservoirs. The study aims to conduct a geological screening of the existing and depleted hydrocarbon reservoirs with high water production rates. After initial data gathering, numerical modeling is employed with the help of mechanistic box models to evaluate the geothermal potential of the selected sites for commercial development. Ultimately, the study identifies the top five screened sites, which could be developed further for techno-economical modelling.

Micro–Nano Water Film Enabled High-Performance Interfacial Solar Evaporation

HighlightsMicro–nano water film enhanced interfacial solar evaporator enables a high evaporation rate of 2.18 kg m−2 h−1 under 1 sun.An outdoor device with an enhanced condensation design demonstrates a high water production rate of 15.9–19.4 kg kW−1 h−1 m−2.A multi-objective predictive model is established to assess outdoor water production performance.

Evaporation-Assisted Humidification–Dehumidification Cycles for Desalination Application in Tropical and Subtropical Regions

The present study aims to evaluate the performance of evaporation-assisted humidification–dehumidification (E-HDH) desalination, specifically direct evaporative (DE-HDH), indirect evaporative (IE-HDH), and Maisotsenko evaporative (ME-HDH) systems. To achieve this, a thermodynamic modeling approach is utilized, which incorporates the wet bulb effectiveness method, psychrometric relationships of humid air, and equations that govern heat and mass balance. The key performance indicators of the studied E-HDH desalination systems are estimated concerning operating parameters. The results show that the ME-HDH system is capable of producing a comparatively higher water production rate (WPR) ranging between 0.01 and 7.92 g/s as compared to the DE-HDH and IE-HDH systems. The sensible cooling flux was observed to be high at a dry-bulb temperature (Tdb) of 50 °C and relative humidity (RH) < 0.2, having a value of 5.26 kW for the DE-HDH system, followed by the ME-HDH system (3.23 kW) and the IE-HDH system (3.11 kW) due to relatively high mass flow rates. The latent heat flux was observed to be relatively high in the case of the ME-HDH system. Minimum specific energy consumption was observed from the ME-HDH system, and consequently, a maximum gain output ratio (3.32) was realized. In addition, the study realized that an increment in air velocity and wet bulb effectiveness significantly improves the WPR. In accordance with the climatic conditions of the studied Saudi Arabia cities, it has been realized that Al-Hofuf and Riyadh produce relatively high WPRs with minimum energy consumption. In the case of Al-Hofuf, the average WPR was recorded as 185.51 kg/day, followed by Riyadh (180.33 kg/day). The energy required was estimated to be 0.042 kWh/kg and 0.034 kWh/kg for both cities, accordingly.

Simultaneous removal of natural organic matters and copper (II) with ultrafiltration for drinking water treatment

Membrane technology plays important roles in drinking water treatment in last decades; ultrafiltration (UF) is typically used to separate natural organic matters (NOM) and nanofiltration (NF) is used primarily to reject divalent ions, due to the different pore sizes of the used membranes. However, high water production rate at low energy consumption will be achieved if NOM and heavy metals can be simultaneously removed via UF-based water treatment process, which is necessary nowadays due to the carbon neutrality target worldwide. Here, a polyethersulfone (PES)-based UF membrane, modified chemically by grafting and crosslinking polyethylenimine (PEI, 25,000 Da) in two steps, was used to simultaneously remove humic acid (HA) and copper (Cu) from water. The molecular weight cut-off of the PEI-modified membrane was ∼110 kDa, and results showed that the efficiencies of HA and Cu2+ removal substantially increased because of the smaller pore size and additional adsorption effects compared to pristine PES membrane. Although the flux of the PEI-modified membrane was reduced, the membrane fouling was significantly alleviated compared with the pristine UF membrane. In comparison with Fe-based coagulants, Al-based coagulants as pretreatment performed better on removing HA and Cu2+, and the membrane flux greatly improved compared to only UF. The higher the coagulant dosage, the better the membrane performance was, particularly the pollutants removal efficiency. In addition, the PEI-modified UF membranes presented excellent pollutants removal after 4 months of storage in water. Besides, the as-modified UF membrane has only limited influence on removing mineral substances (e.g., Ca2+, Mg2+), indicating a potential application in actual water treatment. Furthermore, the PEI-modified membrane can be easily chemically cleaned; the removal efficiencies for hybrid Al-coagulation and UF process were as high as 88.2% ± 0.8% (HA) and 82.8% ± 0.1% (Cu2+) even after 4 cycles of filtration and subsequent chemical cleaning.

Thermal Balance and Water Ice Sublimation on the Surface of Hyperactive Comet 103P/Hartley 2

AbstractHyperactive comets have attracted attention due to their high water production rate with an unclear mechanism, though some hypotheses have been proposed to explain it. Based on the thermal theories of the comet nuclei, this paper studied a comet surface thermal model considering the sublimation of H2O. In this paper, a method for solving the sublimation rate of water ice by infrared spectroscopy is proposed. The method adopts the assumption of subpixel temperature nonuniformity on the comet nucleus surface and uses the numerical solution of the Fredholm equation. We use the HRI‐IR spectrum (1.05–4.8 μm) data by EPOXI to analyze the pixel‐by‐pixel water sublimation rate of hyperactive comet 103P/Hartley 2. The results show that sublimation exists in most areas of the surface with or without surface roughness, and most of the water production rate (70%–90%) may come from the comet nucleus when Gauss random surface roughness is adopted. According to the sublimation law, it is estimated that the sublimation temperature of water ice on 103P is above 180 K. If the dust‐to‐ice volume ratio is 3:1, the sublimation temperature is about 200–210 K, which indicates that the water ice may sublimate underneath. This may explain why exposed water ice on the surface can hardly be observed while the active fraction of this comet is up to 100%.

Transforming Ti3C2Tx MXene's intrinsic hydrophilicity into superhydrophobicity for efficient photothermal membrane desalination.

Owing to its 100% theoretical salt rejection capability, membrane distillation (MD) has emerged as a promising seawater desalination approach to address freshwater scarcity. Ideal MD requires high vapor permeate flux established by cross-membrane temperature gradient (∆T) and excellent membrane durability. However, it’s difficult to maintain constant ∆T owing to inherent heat loss at feedwater side resulting from continuous water-to-vapor transition and prevent wetting transition-induced membrane fouling and scaling. Here, we develop a Ti3C2Tx MXene-engineered membrane that imparts efficient localized photothermal effect and strong water-repellency, achieving significant boost in freshwater production rate and stability. In addition to photothermal effect that circumvents heat loss, high electrically conductive Ti3C2Tx MXene also allows for self-assembly of uniform hierarchical polymeric nanospheres on its surface via electrostatic spraying, transforming intrinsic hydrophilicity into superhydrophobicity. This interfacial engineering renders energy-efficient and hypersaline-stable photothermal membrane distillation with a high water production rate under one sun irradiation.

Tailoring the Salt Transport Flux of Solar Evaporators for a Highly Effective Salt-Resistant Desalination with High Productivity.

Developing highly effective salt-resistant solar evaporators for a long-term desalination with a high evaporation rate and water production rate remains a great challenge. Herein, we fabricated a three-dimensional printed hierarchical porous reduced graphene oxide/carbon black (3DP-HP rGO/CB) solar evaporator constructed with a thin layer of porous photothermal interface and a grid of hierarchical porous transport channel possessing a large-sized porous microstructure. The 3DP-HP rGO/CB solar evaporator demonstrates a tailored high-salt transport flux of up to 4.3 kg·m-2·h-1, which displays a highly effective salt-resistant performance at a high evaporation rate of 10.5 kg·m-2·h-1 during a desalination of 10 wt % NaCl brine under 8 kW·m-2 illumination. Experiments and theoretical calculations prove that the large porous microstructure with abundant and low-resistance salt ion channels endows solar evaporators with a high salt transport flux, therefore boosting salt resistance compared to traditional solar evaporators. A 10 d desalination experiment shows the long-term salt resistance of a 3DP-HP rGO/CB solar evaporator for a high-rate and stable evaporation and water production. Furthermore, the 3DP-HP rGO/CB evaporator can purify 10 wt % NaCl brine at an ultrafast water production rate of up to 5.6 L·m-2·h-1 under natural sunlight. This work demonstrates great potential for the practical implementation of solar desalination with high productivity.

Nondetection of Water-ice Grains in the Coma of Comet 46P/Wirtanen and Implications for Hyperactivity

Abstract Hyperactive comets have high water production rates, with inferred sublimation areas of order the surface area of the nucleus. Comets 46P/Wirtanen and 103P/Hartley 2 are two examples of this cometary class. Based on observations of comet Hartley 2 by the Deep Impact spacecraft, hyperactivity appears to be caused by the ejection of water-ice grains and/or water-ice-rich chunks of nucleus into the coma. These materials increase the sublimating surface area and yield high water production rates. The historic close approach of comet Wirtanen to Earth in 2018 afforded an opportunity to test Hartley 2–style hyperactivity in a second Jupiter-family comet. We present high spatial resolution, near-infrared spectroscopy of the inner coma of Wirtanen. No evidence for the 1.5 or 2.0 μm water-ice absorption bands is found in six 0.8–2.5 μm spectra taken around perihelion and closest approach to Earth. In addition, the strong 3.0 μm water-ice absorption band is absent in a 2.0–5.3 μm spectrum taken near perihelion. Using spectroscopic and sublimation lifetime models, we set constraints on the physical properties of the ice grains in the coma, assuming they are responsible for the comet’s hyperactivity. We rule out pure water-ice grains of any size, given their long lifetime. Instead, the hyperactivity of the nucleus and lack of water-ice absorption features in our spectra can be explained either by icy grains on the order of 1 μm in size with a small amount of low-albedo dust (greater than 0.5% by volume) or by large chunks containing significant amounts of water ice.

Modification in energy and productivity of high-temperature variable pressure humidification–compression

Abstract One of the important approaches in thermal desalination processes is consumed energy reduction. To achieve this aim, three arrangements of humidification–compression (HC) processes are designed. Two single-stage processes and one double-stage HC process are designed and their performances are compared based on desalinated water production, gained output ratio (GOR) and power consumption. An attempt is made to reduce the power consumption and improve the system performance. All three processes are simulated to examine the effect of operation parameters on HC performance. To validate these simulations, the theoretical results are compared with an experimental rig with a humidifier column of 1.5 m height. The results indicate that the simulation values conform to the experimental data. The effect of minimum approach temperature (ΔTmin) on system performance is investigated for three processes subject to constant operating conditions (feed temperature, water mass flow, air mass flow, and pressure ratio). For this purpose, four values of ΔTmin are considered (7.5, 10, 12.5 and 15 °C) for heat exchanger operations. The results indicate that an increase in ΔTmin in all three cases increases desalinated water volume and GOR. Also, the double-stage HC system has higher water production rate (66.08 kg/h) and higher GOR (17.19) compared with its counterparts.

A new straight-line reserve evaluation method for water bearing gas reservoirs with high water production rate

A material balance equation (MBE) is usually used to estimate hydrocarbon reserves, to judge driving mechanism, and to predict the dynamic performance of oil and gas reservoirs. Few straight-line methods have been proposed for estimating original gas in place (OGIP) of water bearing gas reservoirs with high water production until now. For this type of gas reservoir, gas and mobile water mostly coexist in the same formation because of low permeability. Lots of water is produced even though there is no bottom or edge aquifer. Thus, the effect of water production on average pressure should not be ignored.In this work, an MBE for water bearing gas reservoirs considering the effects of water compressibility, pore compressibility, and water production, is derived step by step from the basic material balance principle, and the corresponding straight-line reserve evaluation method is developed. Then the proposed reserve evaluation method is validated against a computer modelling group (CMG) simulation case and two field cases using pressure transient analysis (PTA) method in the dynamic data analysis software KAPPA Ecrin. Finally, the necessity and importance of the proposed reserve evaluation method in water bearing gas reservoirs are discussed.Validation cases prove that the proposed straight-line reserve evaluation method for water bearing reservoirs is reliable and rational. The OGIP of water bearing reservoirs can be evaluated directly using the y-intercept divided by the minus slope of the straight line. If ignoring the effect of water production, the OGIP of water bearing gas reservoirs will be underestimated, especially for gas wells with high water production rate and short producing time.

Investigation of Performance of Solar Powered Water Generator

The objective of this study is to investigate and analyze the performance of solar water generator that produces potable clean water after a dehumidification process. The numerical model presented in this study was established after the conservation of mass and energy equations of the different subsystems of the solar powered water generator. The model was numerically solved under different conditions such as solar radiation, air humidity, air temperature and different air stream flows. the ratings of the dehumidifier are higher of at higher water production rate at lower solar radiation. the results showed that the lower the humidity ratio the higher the evaporator thermal capacity and that the higher the rate of water production the higher the evaporator thermal capacity as well as higher water production was associated with higher air flow and compressor power consumption. In addition, it was concluded that the lower the ambient temperature the higher the hybrid system efficiency and also the hybrid system efficiency increased at lower ambient temperature and higher water production rate. Finally, the predicted results were in fair agreement with experimental data published in the literature.

Improved Desalination Pipeline System Utilizing the Temperature Difference under Sub-Atmospheric Pressure

Based on the principles of mass conservation, momentum, and energy, an improved version of the Desalination pipeline called Improved Desalination Pipeline System (IDPS) has been studied in the present paper. The main features of IDPS are the high transfer rate and the high raw water production rate. IDPS works with the help of thermal gradient generated due to the temperature difference between the seaside/destination. Heat injection has also been used to increase the efficiency of IDPS. In the condensation part, the heat pipe concept is adopted to facilitate the vapor-liquid process. The main portion of heat injected to the IDPS is recovered by generating electrical power using water flow due to available water head. To show the efficiency of IDPS, a case study is performed from Bandar Abbas (seaside) to Mount GNU (the destination) located30 km away with 2347 m height. The results show that IDPS does not necessarily require large diameter pipes for greater efficiencies. The energy consumption for distillation and transferring1 m3 of water is about 6.6 Kwh. In addition to the distilled transferred water, a significant amount of water is distilled on the site, which is about 25% of the transferred water.

Metal-organic framework materials for adsorption heat pumps

Adsorption technology offers a potential in vital applications like energy storage, cooling and heating, and water desalination which can be driven by low-grade or renewable heat sources leading to significant reduction in CO2 emissions. The adsorbent material is a key element in adsorption heat pump systems determining the performance, size and cost of such technology. Metal-organic frameworks (MOFs) are class of adsorbents with superior water uptake, high pore volume and surface area. This study describes the experimental testing of adsorption heat pumps using aluminium fumarate, CPO-27(Ni) and MIL-100(Fe) for various adsorption applications. Results showed that energy storage density of 1200 W h kg−1 was achieved using MIL-100(Fe) regenerated at 95°C, and cycle time of 90 min. For cooling applications, MIL-100(Fe) showed high specific cooling power of 226 W kg−1 at 95°C while aluminium fumarate produced 136 W kg−1 specific cooling power (SCP) at 90°C. Regarding water desalination, MIL-100(Fe) showed high water production rate specific daily water production (SDWP) of 19 m3 ton−1 day−1. For power generation, including a turbine in the adsorption system can increase the effective coefficient of performance (COP) of the adsorption cooling system by 22%. Integrating the adsorption cooling system with Organic Rankine Cycle (ORC) can produce an effective COP of 0.8.

Waterflooding Process in an Irregularly Shaped Oil Reservoir: A Finite-Volume Approach

Oil reservoirs are porous and permeable rocks that allow the hydrocarbon accumulation. Reservoir simulations are necessary to obtain the best fluid flow conditions in the porous medium and increase oil recovery capacity. The aim of this paper was to study the influence of the absolute rock permeability on the oil recovery of a complex geometry oil reservoir, using water injection with the black oil model. Numerical simulations in boundary-fitted coordinates were performed in a two-dimensional and irregularly shaped reservoir. Finite volume method was used to solve the governing equations and two inverted five-spot meshes were set in parallel for a total injection time of 30 years. Results of injected porous volume per recovered oil volume, the water cut charts and the water saturations maps showed that the lower porous medium permeability increased the oil recovery, once the permeability intensified fingers and early breakthrough, which leads to high water production rates and consequent reduction of the waterflooding efficiency.

Simultaneous production of fresh water and electricity via multistage solar photovoltaic membrane distillation

The energy shortage and clean water scarcity are two key challenges for global sustainable development. Near half of the total global water withdrawals is consumed by power generation plants while water desalination consumes lots of electricity. Here, we demonstrate a photovoltaics-membrane distillation (PV-MD) device that can stably produce clean water (>1.64 kg·m−2·h−1) from seawater while simultaneously having uncompromised electricity generation performance (>11%) under one Sun irradiation. Its high clean water production rate is realized by constructing multi stage membrane distillation (MSMD) device at the backside of the solar cell to recycle the latent heat of water vapor condensation in each distillation stage. This composite device can significantly reduce capital investment costs by sharing the same land and the same mounting system and thus represents a potential possibility to transform an electricity power plant from otherwise a water consumer to a fresh water producer.

Estimation of Utsira CO2 Storage Capacity Based on Water Producing Modelling and Identification of Proper Water Producer Architecture

Utsira aquifer is well known from the CCS community as Sleipner gas project is storing CO2 in that aquifer since 1996. More than 17 million tons of CO2 have been injected to date. According to previous studies, CO2 storage capacity of the Utsira varies between 0.3 and 50.4 Gt. In this study, assuming specific parameters, the storage capacity is estimated about 1.7 Gt using analytical method. A full scale flow model of the aquifer has been used to model CO2 storage, considering CO2 migration and pressure raise to estimate the CO2 storage capacity, with or without water production. Water-CO2 relative permeabilities are selected based on a vertical equilibrium approach and validated when CO2 migration is compared to high resolution grid refinement around the injector areas. Optimizing injector well locations lead to an estimation of CO2 storage capacity of about 1.6 Gt without water production. This capacity can be increased to 3 Gt with about 1 Gt of formation water being produced during injection. The location and architecture of the water production wells were optimized: the wells should be subsea and should be operated with minimal requirement. Two production methods were compared: eruptive wells, producing water based on the formation overpressure induced by the CO2 storage; and activated wells using electrical submersible pumps (ESP). For each scenario, an optimization is proposed in terms of well count, well locations and well architecture designs. For the reservoir depth ranging between 500–1200 m below sea level and for such a high water production rate, the electrical submersible pumps (ESP) technology is a suitable application.

Confined Redox Reactions of Iodide in Carbon Nanopores for Fast and Energy-Efficient Desalination of Brackish Water and Seawater.

Faradaic deionization is a promising new seawater desalination technology with low energy consumption. One drawback is the low water production rate as a result of the limited kinetics of the ion intercalation and insertion processes. We introduce the redox activities of iodide confined in carbon nanopores for electrochemical desalination. A fast desalination process was enabled by diffusionless redox kinetics governed by thin-layer electrochemistry. A cell was designed with an activated carbon cloth electrode in NaI aqueous solution, which was separated from the feedwater channel by a cation-exchange membrane. Coupled with an activated carbon counter electrode and an anion-exchange membrane, the half-cell in NaI with a cation-exchange membrane maintained performance even at a high current of 2.5 A g-1 (21 mA cm-2 ). The redox activities of iodide allowed a high desalination capacity of 69 mg g-1 (normalized by the mass of the working electrode) with stable performance over 120 cycles. Additionally, we provide a new analytical method for unique performance evaluation under single-pass flow conditions regarding the water production rate and energy consumption. Our cell concept provides flexible performance for low and high salinity and, thus, enables the desalination of brackish water or seawater. Particularly, we found a low energy consumption (1.63 Wh L-1 ) for seawater desalination and a high water production rate (25 L m-2 h-1 ) for brackish water.

High Rate Production of Clean Water Based on the Combined Photo-Electro-Thermal Effect of Graphene Architecture.

The use of abundant solar energy for regeneration and desalination of water is a promising strategy to address the challenge of a global shortage of clean water. Progress has been made to develop photothermal materials to improve the solar steam generation performance. However, the mass production rate of water is still low. Herein, by a rational combination of photo-electro-thermal effect on an all-graphene hybrid architecture, solar energy can not only be absorbed fully and transferred into heat, but also converted into electric power to further heat up the graphene skeleton frame for a much enhanced generation of water vapor. As a result, the unique graphene evaporator reaches a record high water production rate of 2.01-2.61 kg m-2 h-1 under solar illumination of 1 kW m-2 even without system optimization. Several square meters of the graphene evaporators will provide a daily water supply that is enough for tens of people. The combination of photo-electro-thermal effect on graphene materials offers a new strategy to build a fast and scalable solar steam generation system, which makes an important step towards a solution for the scarcity of clean water.

Hyperactivity and Dust Composition of Comet 103P/Hartley 2 During the EPOXI Encounter

Abstract Short-period comet 103P/Hartley 2 (103P) was the flyby target of the Deep Impact eXtended Investigation on 2010 November 4 UT. This comet has a small hyperactive nucleus, i.e., it has a high water production rate for its surface area. The underlying cause of the hyperactivity is unknown; the relative abundances of volatiles in the coma of 103P are not unusual. However, the dust properties of this comet have not been fully explored. We present four epochs of mid-infrared spectra and images of comet 103P observed from Gemini-South +T-ReCS on 2010 November 5, 7, 21 and December 13 UT, near and after the spacecraft encounter. Comet 103P exhibited a weak 10 μm emission feature ≃1.14 ± 0.01 above the underlying local 10 μm continuum. Thermal dust grain modeling of the spectra shows the grain composition (mineralogy) was dominated by amorphous carbon and amorphous pyroxene with evidence for Mg-rich crystalline olivine. The grain size has a peak grain radius range of a peak ∼ 0.5–0.9 μm. On average, the crystalline silicate mass fraction is ≃0.24, fairly typical of other short-period comets. In contrast, the silicate-to-carbon ratio of ≃0.48–0.64 is lower compared to other short-period comets, which indicates that the flux measured in the 10 μm region of 103P was dominated by amorphous carbon grains. We conclude that the hyperactivity in comet 103P is not revealing dust properties similar to the small grains seen with the Deep Impact experiment on comet 9P/Tempel 1 or from comet C/1995 O1 (Hale–Bopp).

Flexible and Salt Resistant Janus Absorbers by Electrospinning for Stable and Efficient Solar Desalination

AbstractWith recent progress in interfacial solar steam generation, direct solar desalination is considered a promising technology for providing a clean water solution through a cost effective and environmental‐friendly pathway. As a high and stable water production rate is the key to enable widespread applications, salt deposition becomes a critical issue that needs to be addressed. Herein, the authors demonstrate that a flexible Janus absorber fabricated by sequential electrospinning can enable stable and efficient solar desalination. Taking advantage of the unique structure of Janus, two functions of steam generation, solar absorption and water pumping, are decoupled into different layers, with an upper hydrophobic carbon black nanoparticles (CB) coating polymethylmethacrylate (PMMA) layer for light absorption, and a lower hydrophilic polyacrylonitrile (PAN) layer for pumping water. Therefore, salt can only be deposited in the hydrophilic PAN layer and quickly be dissolved because of continuous water pumping. Janus absorber demonstrates high efficiency (72%) and stable water output (1.3 kg m–2 h–1, over 16 days) under 1‐sun, not achieved in most previous absorbers. With a unique structure design achieved by scalable process, this flexible Janus absorber provides an efficient, stable and portable solar steam generator for direct solar desalination.