Hybrid seawater desalination-carbon capture using modified seawater battery system

Bae, Hyuntae,Park, Jeong-Sun,Senthilkumar, S.T.,Hwang, Soo Min,Kim, Youngsik Elsevier 2019 Journal of Power Sources Vol.410 No.-

<P><B>Abstract</B></P> <P>The water and carbon cycles are central to the Earth's ecosystem, enabling the sustainable development of human societies. To mitigate the global issues of water shortages and climate change, we report a new electrochemical system that fulfills two functions—seawater desalination and carbon dioxide air-capture—during the charge and discharge processes. The seawater desalination-carbon capture system utilizes a seawater battery platform, consisting of three major compartments (desalination, sodium-collection, and carbon-capture), which are separated by sodium superionic conducting ceramic membranes. It is found that the concentrations of sodium ions and chloride ions in fresh seawater (total dissolved solids ≈ 34,000 ppm) are significantly decreased by the charging of the seawater desalination-carbon capture system, resulting in brackish water (total dissolved solids ≈ 7000 ppm). The discharge process induces the air-capture of ambient carbon dioxide gases through carbonation reactions, which is demonstrated by the carbon dioxide gas removal in this compartment. The hybrid system suggests a new electrochemical approach for both desalination and carbon capture.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A Hybrid-type Seawater Desalination-Carbon Capture system is demonstrated. </LI> <LI> The hybrid system uses NASICON membranes to utilize Na<SUP>+</SUP> ions from seawater. </LI> <LI> Charging of the system can remove Na<SUP>+</SUP> and Cl<SUP>−</SUP> ions from seawater. </LI> <LI> Discharging of the system can capture CO<SUB>2</SUB> via formation of carbonate precipitates. </LI> </UL> </P>

해수담수화 농축수 처리를 위한 한국 해수 특성 및 결정화 연구

정상현,David von Eiff,변시영,이지은,Alicia Kyoungjin An 한국물환경학회 2021 한국물환경학회지 Vol.37 No.6

Seawater desalination is a technology through which salt and other constituents are removed from seawater to produce fresh water. While a significant amount of fresh water is produced, the desalination process is limited by the generation of concentrated brine with a higher salinity than seawater; this imposes environmental and economic problems. In this study, characteristics of seawater from three different locations in South Korea were analyzed to evaluate the feasibility of crystallization to seawater desalination. Organic and inorganic substances participating in crystal formation during concentration were identified. Then, prediction and economic feasibility analysis were conducted on the actual water flux and obtainable salt resources (i.e. Na2SO4) using membrane distillation and energy-saving crystallizer based on multi-stage flash (MSF-Cr). The seawater showed a rather low salinity (29.9~34.4 g/L) and different composition ratios depending on the location. At high concentrations, it was possible to observe the participation of dissolved organic matter and various ionic substances in crystalization. When crystallized, materials capable of forming various crystals are expected. However, it seems that different salt concentrations should be considered for each location. When the model developed using the Aspen Plus modular was applied in Korean seawater conditions, relatively high economic feasibility was confirmed in the MSF-Cr. The results of this study will help solve the environmental and economic problems of concentrated brine from seawater desalination.

해수담수화를 위한 나노버블 침투형 복합 하이드로싸이클론 전처리 기술개발

문상욱 ( Sang-uook Moon ),최호은 ( Ho-eun Choi ),최영익 ( Young-ik Choi ),성낙창 ( Nak-chang Sung ),정병길 ( Byung-gil Jung ) 한국환경기술학회 2020 한국환경기술학회지 Vol.21 No.6

The purpose of this research was to develop a nanobubble multihydrocyclone pretreatment technology that supplies SDI (Silt Density Index) of below 3 in order as alternative to, and etc. the existing coagulation filtration pretreatment process in seawater desalination. The used seawater in this research was sampled at a depth of 5 m in the sea located in B City. The average water quality of seawater was found to be turbidity of 1.28 NTU, TDS 29,800 mg/L, hardness 3,330 mg/L as CaCO₃, total colony counts 190 CFU/100 mL, total coliforms 1,400 CFU/100 mL, and SO₄ ^2- 1,890 mg/L. The nanobubble multi-hydrocyclone pretreatment process was consisted of a nanobubble generator, hydrocyclone, carbon filter, microfilter, RO pump, RO and UV systems. As a result of measuring (average of 5 times) the SDI of raw seawater, pretreated water, secondary treated water and final effluent were found to be 5.74, 3.42, 2.88 and 0.27, respectively. It was satisfied the SDI standard value of below 5 for seawater desalination pretreatment process. As a result of an economic evaluation for the coagulation sedimentation filtration process, the direct coagulation filtration process and the nanobubble multihydrocyclone process, which are the pretreatment processes for seawater desalination, the production cost per ton were 4,850 Won/m³, 4,528 Won/m³, and 3,821 Won/m³, respectively. Therefore, it was found that the nanobubble multi-hydrocyclone pretreatment process reduces operating costs by about 21 % compared to other pretreatment processes.

해수 히트펌프시스템을 이용한 냉동법 담수화시스템 성능해석

이호생(Ho-Saeng Lee),이승원(Seung-Won Lee),윤정인(Jung-In Yoon),김현주(Hyeon-Ju Kim) 한국마린엔지니어링학회 2010 한국마린엔지니어링학회 학술대회 논문집 Vol.2010 No.10

In this study, a freeze desalination cycle with seawater heat pump system is simulated and designed for the basic data for the design of freeze desalination system. The basic model of seawater heat pump system is refrigeration cycle and indirect freeze desalination method is used for seawater desalination. The cycle performance of seawater heat pump such as COP, compressor work, condensing capacity was analyzed and the desalination performance such as fresh water productivity and energy per unit fresh water productivity were compared with respect to the seawater temperature of condenser inlet and ice ratio in the evaporator. The compressor work and condensing capacity decreased with respect to the increase of seawater inlet temperature. The energy per unit fresh water productivity in case of 8℃ seawater inlet temperature showed 28.9% lower than that of 20℃.

Fabrication of core-shell particles for a fluidized bed electrode in seawater desalination

Kim, E.H.,Jung, Y.G.,Lee, J.H.,Yeo, J.G.,Yang, S.C.,Choi, J. Elsevier Sequoia 2014 Surface & Coatings Technology Vol.260 No.-

Active carbon particles have been coated with cation-exchanged polymer for the fabrication of core-shell particles, to be used as a fluidized bed electrode in seawater desalination. To adequately utilize the features of the core-shell particles, the polymer should be uniformly coated on the surface of independent active carbon particles. To do that, the active carbon particles prior to the polymer coating were modified with an acid for individual separation without agglomeration between particles, producing a more effective coating of polymer on the carbon particles. The modified carbon particles were well dispersed in an aqueous solution with cation-exchanged polymer by the hydrophilic groups generated on the carbon chain, resulting in the homogeneous coating of polymer on the surface of individual carbon particles. This means that the core-shell particles prepared with heterogeneous materials could be applicable to a fluidized bed electrode in seawater desalination.

저탁도 해수를 이용한 해수 담수화 전처리에서 응집-MF 공정의 적용에 관한 연구

이윤건 ( Yoon-geon Lee ),배상대 ( Sang-dae Bae ) 한국환경기술학회 2014 한국환경기술학회지 Vol.15 No.1

본 연구에서는 저탁도 해수를 이용한 해수담수화 전처리에서 응집-MF 공정의 적용으로 해수 원수는 기장군 앞 바다의 수심 5m 지점의 해수를 채취하여 사용하였다. 사용된 해수는 여름에 수온이 20℃까지 상승하며 겨울에는 5℃까지 낮아지고, pH는 7.9∼8.3로 일정하고, 탁도는 1 NTU 이하로 낮은 편이다. 응집-MF 공정의 flux는 응집제 주입농도를 3, 6, 10 ㎎/L(as FeCl₃), pH 8.0 조건에서 응집제 주입농도가 증가할수록 해수원수의 flux보다 52.5, 70.1, 76.2%로 증가하였다. 완속교반 5분의 경우도, 응집제 주입농도가 증가할수록 해수원수 flux 보다 70.7, 82.1, 98.4% 증가하였다. 또한 pH 6.5 경우에도 응집제 주입농도가 증가할수록 해수원수의 flux보다 57, 64.5, 71% 증가하였다. pH 8.0과 pH 6.5의 잔류 철 농도는 0.05 ㎎/L 이하로 조사되었고 pH 8.0의 SDI₁₅값은 약 2 정도로 양호하게 나타났다. pH 6.5 조건에서 SDI₁₅ 값이 0.3∼0.53 범위로 일부 증가하는 경향이 있지만 RO 공급수의 SDI를 낮추기 위한 전처리 공정으로 MF 공정은 적합하다고 판단된다. 결론적으로 MF 막에 대한 최적의 응집 조건을 조사하고 그에 따른 flux 특성을 관찰하여 RO 전처리 공정으로써 MF 공정 적용 시 기초 운전 자료로 활용하고자 한다. Gijang-offshore seawater from a depth of 5m was used as raw seawater for the experiments in this study that were conducted to explore the applicability of a coagulation-microfiltration(MF) process to the pretreatment step in desalination of low-turbidity seawater. The temperature of collected seawater rises up to 20℃ in summer and falls down to 5℃ in winter, with constant pH values ranging between 7.9 and 8.3 and constantly low turbidities of ≤ 1 NTU. The experiments in which the concentrations of coagulant injected varied among 3, 6, and 10 ㎎/L (as FeCl₃) under the pH condition of 8.0 resulted in the finding that the flux rate in the coagulation-MF process increased by 52.5, 70.1, and 76.2%, respectively, as the concentration of coagulant injection increased in comparison with the flux rate of feed water. Like wise, in the 5-min slow-stirring experiments, the flux rate in the coagulation-MF process increased by 70.7, 82.1, and 98.4%, respectively, as the concentration of coagulant injection increased in comparison with the flux rate of feed water. The same proportional increase of the flux rate in the coagulation-MF process applied at a pH value of 6.5 demonstrates increases of 57, 64.5, and 71 %, respectively, compared to that of feed water. The residual iron was found to be ≤ 0.05 ㎎/L at both pH values of 8.0 and 6.5. The SDI15 value at pH 8.0 was verified to be good approximately 2. The SDI₁₅ value tended toward partial increase at pH 6.5, ranging from 0.3 to 0.53; however, the MF process is considered adequate as pretreatment for reducing the SDI of reverse osmosis(RO) feed water. The results of this study, which investigated the optimal coagulation condition for MF membranes and the corresponding flux characteristics, will serve as useful basic data for operating an MF process as RO pretreatment.

해양심층수를 이용한 냉동법 담수화시스템 성능 특성

이승원(S.W.Lee),이호생(H.S.Lee,),김현주(H.J.Kim),문덕수(D.S.Moon) 한국해양환경·에너지학회 2012 한국해양환경·에너지학회 학술대회논문집 Vol.2012 No.5

해양심층수, 해수난방시스템에서의 증발 열원으로 이용된 배출수, 해양표층수 등 해수를 열원으로 이용하여 냉동법 담수화 성능 실험을 수행하였다. 냉동법 담수화 실험 장치는 압축기, 응축기, 팽창밸브, 증발기로 구성되었고, 압축기는 3/4 마력이 적용되었으며, 냉동법 답수화 장치에서 해수 내 수분을 얼게 하기 위한 증발기는 20리터 용량의 해수조 형태로 제작되었다. 실험 장치 내 구동 냉매는 R-134a를 적용하였다. 여러 가지 해수를 증발열원으로 하여 냉동법 담수화시스템의 성능 특성을 실험하기 위해 해수조 내 냉매 증발온도를 -15 ~ -5℃,해수조 해수 온도를 5 ~ 26℃, 응축기 열원 온도를 15 ~ 25℃로 변화시켜 실험을 수행하였다. 동일 증발온도에서 4가지 열원의 온도 변화는 거의 비슷하게 나타났고,50분 동안의 장치 구동 후 4가지 해수열원의 해수조 내 온도변화는 거의 일정하였다. 또한, 동일 증발온도에서 해수 열원의 온도가 높아지면 실험 시간이 길어지므로 얼음 생성량 및 생성율이 증가하였으며, 증발 온도가 -5℃일 때, 여름 표층수의 경우 겨울 표층수 및 심층수에 비해 얼음 생성량이 각각 약 17.5%, 20.5% 증가하였고, 해수난방시스템 배출수의 경우 심층수에 비해 얼음 생성량은 평균 약 4.3% 감소되었다. 본 실험 결과는 향후 해수 난방시스템의 배출수를 비롯한 해수를 이용한 냉동법 담수화시스템의 설계를 위한 기초 자료로 활용될 수 있을 것으로 생각된다. The paper presents an experimental study of freezing desalination system using deep seawater. The experimental apparatus is composed of a compressor, a condenser, an expansion valve and an evaporator. The capacity of the compressor is 3/4 horse power and seawater storage tank is 20 liters. R- 134a is applied as a refrigerant. The performance characteristics of freezing desalination system such as ice productivity and seawater temperature variation, etc. were experimented on the -15 ~ -5℃ of evaporating temperature and 5 ~ 26℃ of seawater temperature. The temperature variation of seawater in the storage tank showed the similar values to each other. When the heat source is seawater heat pump discharge, the ice productivity decreased by about 4.3%.

해수담수 공정의 전력비 평가기준에 관한 연구

심규대(Shim, Kyu Dae),김창용(Kim, Chang Ryong),정준연(Choung, Joon Yeon),김동균(Kim, Dong Kyun) 대한토목학회 2021 대한토목학회논문집 Vol.41 No.5

본 연구에서는 서해에 위치한 대산산업단지 해수담수화 시설에 필요한 전력비를 계산하고, 해수온도 및 염분도 변화에 따른 안전도를 고려한 전력비 기준을 산정하였다. 입력 자료(온도 및 염분도)는 국가해양환경정보통합시스템(MEIS, Marine Environment Information System) 22년 자료(1997~2018년)를 이용하고, 해수공정에서 사용되는 전력량은 RO막 제조사에서 제공되는 프로그램(Q-Plus v3.0)을 활용하였다. 금회연구에서는 해수담수화 시설물 설계시 합리적인 전력비 운영 가이드라인을 제시했다는데 의의가 있다. 해수담수화 역삼투압 공정은 약2.10~2.90 kWh/m³의 전력비가 소요되며, 에너지 안전도 95 % 기준으로 2.80 kWh/m³의 전력비가 해수담수화 시설을 운영할 때 고려되어야 하는 것으로 검토되었다. This study focused on safety aspects surrounding energy consumption in the seawater desalination process in the Daesan Industrial Complex located on the West Sea coast. The safety index for energy consumption was evaluated under different salinities and temperatures of the incoming seawater. Temperature and salinity input data for the 1997-2018 period were obtained from the Marine Environment Information System, and the power required for reverse osmosis (RO) was applied to the program as per the data provided by the RO membrane manufacturer (Q-Plus v3.0). Notably, reasonable energy consumption guidelines were proposed during the design of the desalination facilities; in this regard, the desalination process required approximately 2.10-2.90 kWh/㎥ electrical power. Moreover, the energy safety based on 95 % was estimated to be 2.80 kWh/㎥ when the desalination facility was operated.

신개념 해수담수 플랜트 적용을 위한 장치개발 및 적용기술

이주동(Ju Dong Lee),강경찬(Kyung Chan Kang) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.5

가스하이드레이트 원리를 이용한 신개념의 해수담수화 장치를 제안하였다. 본 연구의 연속식 장치는 하이드레이트를 제조하고, 듀얼실린더의 압축공정에 의해 해수로부터 순수의 하이드레이트 펠릿화가 가능하다. 해수 샘플로부터 용존된 각 이온들의 제거 효율이 유도결합플라즈마분광광도계(ICP-AES)와 이온크로마토그래피(IC)에 의해 분석되었다. 본 연구에서 제안된 방법과 장치를 이용한 해수담수화시 형성된 하이드레이트 결정과 고농도의 염농축액과의 분리에 어려움이 있지만, 이를 해결함으로 좀더 효율적인 해수담수화 공정 적용이 가능할 것으로 판단된다. A new apparatus for seawater desalination, based on the principle of gas hydrates, is suggested. The equipment continuously produces and pelletizes gas hydrates by a squeezing operation in a dual cylinder unit, which is able to extract pure hydrate pellets from the seawater-containing reactor. Desalination efficiency for each dissolved ion from seawater samples was tested by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ion chromatography (IC) analysis. This study demonstrates that the suggested method and the stated apparatus may solve the difficulty of separating hydrate crystals from concentrated brine solutions, and therefore may be applied to improve the efficiency of existing desalination processes.

신개념 해수담수 플랜트 적용을 위한 장치개발 및 적용기술

이주동(Ju Dong Lee),강경찬(Kyung Chan Kang) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

A new apparatus was suggested for seawater desalination using gas hydrate principle. The equipment continuously produces and pelletizes gas hydrates by a squeezing operation of a dual cylinder unit, which is able to extract pure hydrate pellets from the reactor containing seawater. Desalination efficiencies for each dissolved ion from seawater samples was tested by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and Ion Chromatography(IC) analysis. This study illustrates that the suggested method and apparatus may solve the separation difficulty between hydrate crystals and concentrated brine solutions, thus it can be applied for more effective desalination processes.