scholarly journals A Study on Lithium Hydroxide Recovery Using Bipolar Membrane Electrodialysis

2021 ◽  
Vol 59 (4) ◽  
pp. 223-232
Author(s):  
Yeonchul Cho ◽  
Kihun Kim ◽  
Jaewoo Ahn ◽  
Jaeheon Lee

Bipolar electrodialysis was used in a process of desalting a lithium sulfate solution, converting it to lithium hydroxide and sulfuric acid, and concentrating and recovering them. The effects of the experimental variables such as applied voltage, the concentration of electrode solution, the concentration of raw material solution, volume ratio, and impurity were confirmed. The optimum conditions were investigated by comparing the conversion(%) of lithium hydroxide and sulfuric acid, the process time, and energy consumption. As the applied voltage was increased, the energy consumption tended to increase, but the processing time decreased significantly. As the concentration of lithium sulfate in the raw material solution increased, the conversion(%) of lithium hydroxide decreased. As the concentration of lithium sulfate increased, the energy consumption did not increase linearly, and energy consumption increased significantly. When a raw material solution of 0.5 M Li<sub>2</sub>SO<sub>4</sub> or more is used in the bipolar electrodialysis process, an applied voltage of 25 V is preferable. As the applied voltage increased at a constant process time, the conversion(%) of LiOH and H<sub>2</sub>SO<sub>4</sub> increased. Regarding the effect of the electrode solution concentration, when a 5.0 wt% electrode solution was used rather than a 3.0 wt% electrode solution, energy consumption decreased by more than 10%. When the volume of the raw material solution was increased, the processing time required for desalting increased. By using a low concentration raw material solution, it was confirmed that it was simultaneously possible to recover and concentrate lithium hydroxide and sulfuric acid through volume ratio control. When the raw material solution contained Na as an impurity, it was converted to NaOH with a surface LiOH, and it was not possible to separate the lithium and sodium.

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 851
Author(s):  
Yeonchul Cho ◽  
Kihun Kim ◽  
Jaewoo Ahn ◽  
Jaeheon Lee

In order to manufacture lithium carbonate to be used as a raw material for a secondary lithium battery, lithium sulfate solution is used as a precursor, and the concentration of lithium is required to be 10 g/L or more. Electrodialysis (ED) was used as a method of concentrating lithium in a low-concentration lithium sulfate solution, and multistage concentration (MSC) electrodialysis was used to increase the concentration ratio (%). When MSC was performed using a raw material solution containing a large amount of sodium sulfate, the process lead time was increased by 60 min. And the concentration ratio (%) of lithium decreased as the number of concentration stages increased. In order to remove sodium sulfate, methanol was added to the raw material solution to precipitate sodium sulfate, and when it was added in a volume ratio of 0.4, lithium was not lost. Using a solution in which sodium sulfate was partially removed, fourth-stage concentration ED was performed to obtain a lithium sulfate solution with a lithium concentration of 10 g/L.


FLUIDA ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 65-72
Author(s):  
Rifki Ardiansyah ◽  
Triyoga Meiditama Putra ◽  
Dian Ratna Suminar ◽  
Agustinus Ngatin

ABSTRAK Salah satu upaya untuk menjaga persediaan air yaitu dengan cara menurunkan parameter air laut agar memenuhi parameter air tawar menggunakan metode elektrokoagulasi. Penelitian ini bertujuan untuk mempelajari pengaruh waktu proses elektrokoagulasi terhadap penurunan TDS, kekeruhan, kadar Cl, dan kadar Fe. Selain itu, untuk mengetahui perbandingan antara elektroda Al dan Fe. Air laut diambil dari Pantai Pelabuhan Ratu. Elektroda yang digunakan adalah Al dan Fe dengan ukuran 15x10 cm2. Tegangan yang digunakan yaitu 5 volt atau rapat arus sebesar 0,137 A/dm2 dengan waktu proses 15, 30, 45, dan 60 menit serta volume bahan bakunya 4 Liter. Penelitian dengan waktu proses 30 menit dan proses pengendapan selama satu hari mampu menurunkan kekeruhan hingga 2,28 NTU (55,07%); TDS hingga 1.010 mg/L (3,71%); kadar Cl hingga 271,98 mg/L (3,52%); dan kadar Fe 0,05 mg/L (40,65%). Proses elektrokoagulasi menggunakan elektroda aluminium lebih baik dibandingkan elektroda besi pada waktu proses 30 menit.   ABSTRACT One of the efforts to maintain water supply is by lowering seawater parameters to meet freshwater parameters using the electrocoagulation method. This study aims to study the effect of electrocoagulation process time on the decrease in TDS, turbidity, Cl content, and Fe content. In addition, to determine the comparison between Al and Fe electrodes. Seawater is taken from Pelabuhan Ratu Beach. The electrodes used are Al and Fe with a size of 15x10 cm2. The voltage used is 5 volts or a current density of 0,137 A/dm2 with processing times of 15, 30, 45, and 60 minutes and the volume of the raw material is 4 liters. Research with a processing time of 30 minutes and sedimentation for one day was able to reduce turbidity up to 2,28 NTU (55,07%); TDS up to 1.010 mg/L (3,71%); Cl content up to 271,98 mg/L (3,52%); and Fe content of 0,05 mg/L (40,65%). The electrocoagulation process using aluminum electrodes was better than iron electrodes at a processing time of 30 minutes.


2020 ◽  
Vol 13 (1) ◽  
pp. 158
Author(s):  
Sishen Wang ◽  
Hao Wang ◽  
Pengyu Xie ◽  
Xiaodan Chen

Low-carbon transport system is desired for sustainable cities. The study aims to compare carbon footprint of two transportation modes in campus transit, bus and bike-share systems, using life-cycle assessment (LCA). A case study was conducted for the four-campus (College Ave, Cook/Douglass, Busch, Livingston) transit system at Rutgers University (New Brunswick, NJ). The life-cycle of two systems were disaggregated into four stages, namely, raw material acquisition and manufacture, transportation, operation and maintenance, and end-of-life. Three uncertain factors—fossil fuel type, number of bikes provided, and bus ridership—were set as variables for sensitivity analysis. Normalization method was used in two impact categories to analyze and compare environmental impacts. The results show that the majority of CO2 emission and energy consumption comes from the raw material stage (extraction and upstream production) of the bike-share system and the operation stage of the campus bus system. The CO2 emission and energy consumption of the current campus bus system are 46 and 13 times of that of the proposed bike-share system, respectively. Three uncertain factors can influence the results: (1) biodiesel can significantly reduce CO2 emission and energy consumption of the current campus bus system; (2) the increased number of bikes increases CO2 emission of the bike-share system; (3) the increase of bus ridership may result in similar impact between two systems. Finally, an alternative hybrid transit system is proposed that uses campus buses to connect four campuses and creates a bike-share system to satisfy travel demands within each campus. The hybrid system reaches the most environmentally friendly state when 70% passenger-miles provided by campus bus and 30% by bike-share system. Further research is needed to consider the uncertainty of biking behavior and travel choice in LCA. Applicable recommendations include increasing ridership of campus buses and building a bike-share in campus to support the current campus bus system. Other strategies such as increasing parking fees and improving biking environment can also be implemented to reduce automobile usage and encourage biking behavior.


Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 261-271
Author(s):  
Ashley L. Kaiser ◽  
Dale L. Lidston ◽  
Sophie C. Peterson ◽  
Luiz H. Acauan ◽  
Stephen A. Steiner ◽  
...  

Aligned carbon nanotube (CNT) array adhesion strength evolves with CNT process time, decreasing and then increasing during growth and annealing, as captured by models relating CNT diameter, array effective modulus, and CNT–substrate work of adhesion.


2021 ◽  
Vol 13 (14) ◽  
pp. 7572
Author(s):  
Gigliola D’Angelo ◽  
Marina Fumo ◽  
Mercedes del Rio Merino ◽  
Ilaria Capasso ◽  
Assunta Campanile ◽  
...  

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hossein Ahmadvand ◽  
Fouzhan Foroutan ◽  
Mahmood Fathy

AbstractData variety is one of the most important features of Big Data. Data variety is the result of aggregating data from multiple sources and uneven distribution of data. This feature of Big Data causes high variation in the consumption of processing resources such as CPU consumption. This issue has been overlooked in previous works. To overcome the mentioned problem, in the present work, we used Dynamic Voltage and Frequency Scaling (DVFS) to reduce the energy consumption of computation. To this goal, we consider two types of deadlines as our constraint. Before applying the DVFS technique to computer nodes, we estimate the processing time and the frequency needed to meet the deadline. In the evaluation phase, we have used a set of data sets and applications. The experimental results show that our proposed approach surpasses the other scenarios in processing real datasets. Based on the experimental results in this paper, DV-DVFS can achieve up to 15% improvement in energy consumption.


2011 ◽  
Vol 396-398 ◽  
pp. 75-87
Author(s):  
Zai Fu Yang ◽  
Xiao Jing Yang ◽  
Li Hong Sun ◽  
Lian Lian Xu

ABSTRACT: Cation adsorbent was prepared from the Solidago Canadensis(which are abandoned agricultural land of alien invasive plants)by Sulfuric acid esterification modified , isoamyl alcohol as reaction medium. Design L934 orthogonal experiment, the Solidago canadensis cation exchange adsorbent, the optimal preparation conditions. Experimental results show that at 15°C, concentrated sulfuric acid and amyl alcohol volume ratio of 5:6 obtained under conditions of Solidago canadensis cation exchange adsorbent for Pb(II) exchange best. The experimental results of Pb(II) adsorption onto the Solidago Canadensis based cation adsorbent showed that the best conditions are: the initial pH 5, the concentration of Pb(II) 300mg/L,the dosage of cation adsorbent 1.2mg/L and adsorption time 3h. The adsorption data were analyzed by using pseudo-first-order and pseudo-second-order kinetic models were found to follow the pseudo-second-order kinetic model.


2011 ◽  
Vol 314-316 ◽  
pp. 2071-2075
Author(s):  
Jia Hai Wang ◽  
Wen Tao Gong

Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.Discrete machine manufacture enterprises have to induce new low-carbon manufacturing model in order to solve a dilemma of mutual restraint between development and electric energy consumption. The paper presents an approach to solve JSP with the objective of minimizing the energy consumption by shortening the distance between electricity peak and valley according to theory of load shifting in electricity. The mathematical model is proposed for JSP with objective of minimizing the energy consumption and processing time of entire batch, then the idea of time division is introduced, and a solving method based on GA built-in eM-Plant is employed to verify the model and get satisfactory scheduling results.


2013 ◽  
Vol 789 ◽  
pp. 522-530 ◽  
Author(s):  
Latifa Hanum Lalasari ◽  
Rudi Subagja ◽  
Akhmad Herman Yuwono ◽  
Florentinus Firdiyono ◽  
Sri Harjanto ◽  
...  

lmenite (FeO.TiO2) ore from Bangka island-Indonesia is a potential raw material for synthesizing titanium dioxide (TiO2), which can be used further as pigmen and photocatalyst. The fabrication of TiO2 particles from ilmenite can be carried out through the solvent extraction using sulfuric acid route. Therefore, the solubility of the ilmenite ore in sulfuric acid environment is one of the key factors to obtain the desired TiO2 particles. The current research is aimed at comparing the solubility of pristine Bangka ilmenite ore with that of precedingly decomposed by sodium hidroxide (NaOH) in pressurized and atmospheric reflux reactors. The dissolution of both precursors was carried out in those reactors under various temperatures of 75, 100, 125, 150 and 175°C. The results showed that the optimum dilution was achieved at 150°C. The obtained recovery of ilmenite was 88.8 % for the pressurized reactor and 75.5% for the atmospheric reflux reactor. The solubility of titanium (Ti) element increased steadily to reach a recovery of 68% at 150°C and decreased significantly afterwards. It was also found that the increase of iron (Fe) element solubility was proportional to the increase of processing temperatures.


2012 ◽  
Vol 524-527 ◽  
pp. 965-968 ◽  
Author(s):  
Dan Liu ◽  
Shu Ming Wen ◽  
Yong Jun Xian ◽  
Hai Ying Shen ◽  
Shao Jun Bai ◽  
...  

A technology of “arsenic removing- sulfuric acid producing- residuals for ironmaking” is proposed for comprehensive utilization of pyrite with high content of arsenic. The effect of roasting temperature and time on arsenic removing was investigated. The arsenic removed residuals obtained under the optimal arsenic removed conditions, was used to be proceeded for sulphur volatilization test. The results demonstrate that final residuals with 63.53% of Fe can be used for steel industry. This technology can be used to fully utilize sulphur and produce high quality concentrate as iron-bearing feed for steel industry, which will help to reduce the pollution of arsenic and extend raw material sourcing for Chinese steel industry.


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