Chembrane Research and Engineering Inc.

East Newark, NJ, United States

Chembrane Research and Engineering Inc.

East Newark, NJ, United States

Time filter

Source Type

Qin Y.,Chembrane Research and Engineering Inc. | Liu R.,Tianjin University | Li X.,Tianjin University | Liu L.,Chembrane Engineering and Technology Inc. | Zhang Y.,Chembrane Engineering and Technology Inc.
AIChE 2012 - 2012 AIChE Annual Meeting, Conference Proceedings | Year: 2012

It is well known that hydrochloric acid (HCl) is usually used as pickle liquor to remove surface oxide in a steel production industry. When pickling cannot be accomplished effectively and the quality of the treated metal surface deteriorates, the pickle liquor is discharged from the pickling tank, and the pickling tank is replenished with fresh acid solution. According to the data provided by the World Steel Association in 2011, the total world crude steel production was 1,490.1 million tonnes. And about 60 kg of spent pickle liquor was generated with the production of each ton of steel, and thus annual emission of spent pickle liquor was up to several million tons. As an example, 1000 ton of pickle liquor is being produced daily in a steel plant in north China, which contains 7% HCl and 15% FeCl2. The spent pickle liquor usually contains 2-8 wt% hydrochloric acid and is considered a hazardous waste. The spent pickle liquor from steel processes is usually neutralized with lime and disposed in a landfill, which results into the following problem: high-salinity wastewater and sludge volume, the remaining salt residue processing difficulties, and most importantly, the acid unrecoverable. Therefore, there is an urgent need to recover and enrich hydrochloric acid to achieve economical and ecological benefits. Since the 1960s, hydrochloric spent pickling liquor is often treated in a hydrochloric acid regeneration system such as ion-retardation, diffusion dialysis and electro-dialysis, which recovers some of the hydrochloric acid and ferric oxide. Nevertheless, these regeneration processes produce lots of dilute hydrochloric acid solution. Thus, there still needs a novel and efficient technology to concentrate the recovered dilute HCl solution for further use. In the last few years, numerous studies have been performed to test the application of membrane distillation for concentrating dilute HCl solution. However, the high thermal energy consumption of the traditional MD process is one of the biggest barriers in its industrialization. In the present study, multiple-effect membrane distillation (MEMD) based on AGMD module with function of internal heat recovery has been developed. This kind of MEMD process combines the advantages of MD process and conventional MSF process, avoids the disadvantages of MSF such as evacuation operation, and can provide a high PR value. The effects of feed-in concentration, cold feed-in temperature (Tc), hot feed-in temperature (Th) and feed-in volumetric flow rate (F) on the performance of MEMD process were studied. The permeation flux (N) and energy efficiency, performance ratio (PR), and the average selectivity of water over HCl (βavg) are the most important indicators for module performance evaluation. N indicates the productivity of this device; PR (performance ratio) is usually used to determine the thermal efficiency of evaporation-based process, which is defined as the amount of latent heat needed for evaporation of the produced water and the amount of heat provided to the system from an external energy source; βavg is represents the measure of the preferential transport of water. The results showed that MEMD process could be used successfully for concentrating dilute HCl solution with the advantage of energy saving. The experimental data indicated that all N, PR and βavg decreased with the increase of feed concentration. When the feed concentration was below 12 wt%, PR could achieve 6.0∼9.6, and βavg was about 10~190. As the concentration of HCl achieved 18 wt%, the values of PR and βavg were still about 4.4 and 2.3, respectively. However, βavg sharply decreased to a value around 1.0 when feed was further concentrated. It is also found that there exists trade-off phenomenon between N, PR and βavg under experimental ranges, that is, the maximum N will be obtained with high temperature Th, low temperature Tc and high flow rate F while the maximum PR is obtained with high temperatures Th and Tc, as well as low flow rate F. the lowest βavg will be obtained with low temperature Th, low temperature Tc and low flow rate F. During an operational stability test lasting for 30 days, the performance of MEMD modules was kept in good condition.


He J.,Tianjin University | Zhang L.,Tianjin University | Zhang K.,Tianjin University | Qin Y.,Tianjin University | And 2 more authors.
Chemical Engineering Research and Design | Year: 2015

In order to remove and recover urea from its dilute aqueous solutions, e.g., wastewater drained from urea synthesis plants, continuous-effect membrane distillation (CEMD) process providing an extremely high thermal efficiency was investigated to concentrate aqueous solution containing urea. By using an air-gap membrane distillation module fabricated with both porous hydrophobic hollow fibers and dense-wall hollow fibers, the CEMD operation-mode can easily realize the direct recovery of condensation heat of the permeate to preheat the cold feed in situ within a single module. A series of experiments were conducted to evaluate the performance of CEMD process in terms of permeation flux (Jw), gain output ratio (GOR) and rejection factor (Rf) under various operating conditions, such as the feed-in concentration, cold feed-in temperature, heated feed-in temperature and feed flow rate. The maximum values of GOR=14.0, Jw=6.8Lh-1m-2 and Rf=99.99% were achieved respectively. When a feed solution of 1.0wt% urea was used as a sample wastewater, the feed could be at least concentrated to 40wt% with high values of GOR, Jw and Rf. The experimental data showed that the mild operation condition could also help to avoid the urea loss from its thermal hydrolysis. A brief theoretical model was introduced and used to discuss experimental results. © 2015 The Institution of Chemical Engineers.


Qin Y.,Chembrane Research and Engineering Inc. | Wu Y.,Chembrane Research and Engineering Inc. | Liu L.,Chembrane Engineering and Technology Inc. | Cui D.,Chembrane Engineering and Technology Inc. | And 6 more authors.
10AIChE - 2010 AIChE Annual Meeting, Conference Proceedings | Year: 2010

Membrane distillation (MD) is a separation method in which a nonwetting, microporous membrane is used with a liquid feed phase on one side of the membrane and a condensing, permeate phase on the other side. Separation by membrane distillation is based on the relative volatility of various components in the feed solution. The driving force for transport is the partial pressure difference across the membrane. Separation occurs when vapor from components of higher volatility passes through the membrane pores by a convective or diffusive mechanism. Membrane distillation systems can be classified broadly into three categories: direct-contact membrane distillation (DCMD), vacuum membrane distillation (VMD) and air-gap membrane distillation (AGMD). Potential advantages of membrane distillation over traditional evaporation processes include operation at ambient pressures, lower temperatures as well as ease of process scale-up, and avoid of corrosion as a result of inertness of hydrophobic polymer membrane material. Although MD has been extensively and intensively studied for nearly 40 years, it is still not use in commercial scale. As matter of a fact, MD is with extremely low thermal efficiency, even if the researcher on MD always declaimed that MD only need a heat resource with low temperature. For example, when VMD occurs, nearly 1 ton of pure water can be produced when 1 ton of steam is used to heat a cold feed; when DCMD occurs, only 0.3 - 0.6 ton of pure water can be produced when 1 ton of steam is used to heat a cold feed. As a comparison, when traditional multi-effect distillation (MED) or multi-stage flash (MSF) is used for desalination, 1 - 15 ton of pure water can be produced when 1 ton of steam is used to heat a cold feed. Therefore, if a term of performance ratio (PR) is used to characterize the thermal energy utility, while the value of PR for MED and MSF is between 1 - 15, unfortunately the value for traditional MD process is only 0.3 - 1.0. Another problem with MD is wetting or fouling of microporous membrane surface, which leads to the decrease of permeate flux and leakage; leakage further leads to the contamination of the permeate product by the impurities in the feed. Wetting or fouling is a more grievous problem in a DCMD or VMD process, since the intimate contact of the permeate with the membrane in DCMD or the large trans-membrane pressure difference in VMD. On the other hand, the scale AGMD module was rarely reported in literature. Recently, MD process with multi-effect characteristics were reported by using hollow fiber or flat sheet membrane, even though the concept of multi-effect membrane distillation was not directly used as a term. In the present study, multi-effect membrane distillation (MEMD), a new membrane distillation process, has been developed, which combines the advantages of both membrane distillation (MD) and multistage flash (MSF) by equipping air gap membrane distillation (AGMD) with internal heat recovery. A novel separation device in the form of hollow fibers is fabricated to test its separation performance, which is identified as MEMD module. Several MEMD modules with different configurations were fabricated in our company since 2005. The water vapor flux (J) and energy efficiency in term of performance ratio (PR) and thermal efficiency (η) are the most important indicators for evaluation of DCMD module performances. J indicates the productivity of the membrane module; PR tells how much energy is recovered by internal configuration and η shows how much energy is lost due to conduction according to the second law of thermodynamics. Experiments were conducted using aqueous solution of salt NaCl to investigate the influences of operating variables including inlet temperatures of two sets of different fibers and flow rate on these above three performance parameters. The value of J was usually 3 - 10 kg/m2hr; the value of η was usually more than 0.9; and the value of PR varied between 3 and 15, which mainly depended on the characteristics of the hollow fiber used, and salt species and concentration, and the operation temperature. Flux decline together with reduction of PR and the decrease of ç were observed with the increased salt concentration (up to about 220g/L) mainly because of its high viscosity and reduction of water vapor pressure with the increase of salt concentration. Even so, the value of J and PR at a NaCl concentration of 20wt% is 50% of the value at a NaCl concentration of 3wt%. Such a MEMD operation for further concentration of 20% salt solution was operation at mild temperature (less than 100°C) and ambient pressure. It must be noted that it is impossible to further concentrate a feed of 20% by reverse osmosis, and high temperature and evacuation must be used when MED or MSF is used for the further concentration of 20% salt solution. Therefore, MEMD can be potentially used to further concentrate the brine by-produced during the routine desalination plant by using RO, MSF, or MED, to produce drainable water and salt. Since 2006, MEMD has been tested in pilot-scale for desalination of real seawater and for the deep concentration of bring from the RO unit for the treatment of wastewater drained from a refinery plant. No leakage or decline of operation performance was observed during the 4-month long test period. MEMD can also used to separate volatile semi-volatile and non-volatile solutes from their aqueous solution. The system tested was aqueous solution of the following solutes: variety of non-volatile salts, sugars, urea, sodium hydroxide, sulfuric acid, hydrochloric acid, hydrofluoric acid, hydrobromic acid, phosphorous acid, phosphoric acid, nitric acid, acetic acid, chloroacetic acid, dichloroacetic acid, oxalic acid, succinic acid, glutaric acid, adipic acid, fluosilicic acid, ammonia, alkyl monoamines with low molecular weight, aminoglucose, amino acids, glycerol, ethylene glycol, propylene glycol, formaldehyde, ethanol, acetone, formamide, dimethylformamide, dimethyl sulfone, solfulane, hydrogen peroxide, hydrazine hydrate, ethanolamine, diethanolamine, diamines or polyamines, ammonium carbonate, ammonia sulfide, or several practical aqueous solutions containing two or three solutes, such as hydrochloric acid + glucose, hydrochloric acid + aminoglucose, sulfuric acid + glycerol, phosphorous acid + formaldehyde, fluosilicic acid + hydrofluoric acid + nitric acid, nitric acid + oxalic acid, hydrochloric acid + ferrum(II) chloride, and so on. The currently performing pilot-scale test is the concentration of fruit juices, and the water production from the wastewater streams strained from the deionized water production unit in a power plant. The test results demonstrated MEMD can effectively concentrate aqueous solution of non-volatile salt, most of inorganic acids, non-volatile or semi-volatile organic compounds with a boiling point of more than 180 °C, or solutes with extremely strong association with water such as hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydrazine, formaldehyde from their aqueous solution. However, MEMD does not provide a high selectivity for aqueous solution containing a volatile organic compounds or a semi-volatile compound with a boiling point less than 180 °C. The techno-economic analysis demonstrated that MEMD process is a strong competitor for desalination or concentration of aqueous solutions to RO, MSF and MED.


He J.,Tianjin University | Liu H.,Tianjin University | Shan P.,Tianjin University | Zhang K.,Tianjin University | And 3 more authors.
Chemical Engineering Science | Year: 2016

The removal and enrichment of aliphatic amines with low molecular weights from their individual aqueous solutions was investigated theoretically and experimentally via a hollow-fiber supported-gas-membrane (SGM) process. Aqueous solutions containing 200-5000mgL-1 amine were tested as feed, and an aqueous solution of 10wt% sulfuric acid was used as an absorbing solution. Amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine, as well as ammonia, were tested in the SGM process. The experimental data demonstrated that the overall mass transfer coefficient was a strong function of the polarity of the amine or amine/water volatility and was not a simple function of the molecular weight or boiling point of amines; the order was determined to be trimethylamine>ammonia>triethylamine>diethylamine>ethylamine>dimethylamine>methylamine. The influences on mass transfer coefficients of the feed-in temperature, feed-in concentration, feed flow rate, and the concentration of NaOH pre-added to the feed were also investigated. Among these operating factors, the feed-in temperature and NaOH concentration were crucial; increasing the feed-in temperature and the NaOH concentration led to a significant increase in the mass transfer coefficient, especially when the amine concentration in the feed was low. Mathematical models incorporating laminar flow, ion and molecular diffusion, dissociation equilibrium and vapor-liquid equilibrium were established and solved numerically. When the surface tension of the feed solution was >45mNm-1, the SGM process demonstrated good stability during a test period of at least 30 days. Greater than 95% of the amine was recovered, and the amine could be enriched by >20 times in the absorbing solution. Thus, this SGM-based separation process is suitable to remove, recover, and concentrate amines from their aqueous solutions. © 2015 Elsevier Ltd.


Yao K.,Tianjin University | Qin Y.,Chembrane Research and Engineering Inc. | Liu L.,Chembrane Engineering and Technology Inc. | Yuan Y.,Tianjin University | Liu D.,Chembrane Engineering and Technology Inc.
10AIChE - 2010 AIChE Annual Meeting, Conference Proceedings | Year: 2010

Bioethanol production is generally regarded as a promising alternative way to substitute the traditional petroleum-based liquid fuels. Lignocelluloses, which are abundant in nature and independent of the market for food and cattle feed, are preferable to conventional starch or sugar containing feedstocks as raw materials for large scale production. The reported concentration of fermentable sugars in the cellulosic hydrolysate prior to fermentation is relatively low because of some process restraints during hydrolysis to obtain high sugar yield. However, in order to decrease the size of footprint of the entire processing plant and also energy consumption in downstream separation/purification, the feed to fermentation requires high concentration of sugars. To resolve this contradiction, an economically efficient and well performed preconcentration unit is necessary to added between the hydrolysis and fermentation step. In the present study, multi-effect membrane distillation (MEMD), a new membrane based distillation process, has been developed, which combines the advantages of both membrane distillation (MD) and multistage flash (MSF) by equipping air gap membrane distillation (AGMD) with internal heat recovery. A novel separation device in the form of hollow fibers is fabricated to test its separation performance, which is identified as MEMD module. The water vapor flux (J) and energy efficiency in term of performance ratio (PR) and thermal efficiency (η) are the most important indicators for evaluation of module performance. J indicates the productivity of the membrane module; PR tells how much energy is recovered by internal configuration and η shows how much energy is lost due to conduction according to the second law of thermodynamics. Experiments were conducted using the dilute salt aqueous solution as a tracer to investigate the influences of operating variables including inlet temperatures of two sets of different fibers (Th:70-90°C and Tc: 25-45Å°C) and flow rate (F:16-48L/h) on these above three performance parameters. During the experiment, no leakage is detected and the distillate is of good quality which means the separation efficiency is almost 100%. It is found that the most important determinant parameter is flow rate and there exists trade-off phenomenon between flux (J) and energy efficiency (PR and η) under experimental ranges, that is, the maximum flux will be obtained with high temperature Th, low temperature Tc and high flow rate F while the maximum PR or η is obtained with high temperatures Th and Tc, as well as low flow rate F. Two kind of modules with different hollow fiber diameter and length (M1 and M2 fabricated in Chembrane, China) are also compared. Response surface method (RSM) is carried out to build an empirical quadratic model for prediction of the separation performance and optimization, which agrees well with the experimental results. In general, the typical measured water permeation flux in this study is around 2.0 - 9.0L/m2 h and the value of PR is 4 - 12 and the value of η is 0.80 - 0.95. Flux decline together with reduction of PR and the decrease of η were observed with the increased sugar concentration (up to about 500g/L) mainly because of its high viscosity and there existed slightly differences among three sugars (glucose, xylose and sucrose). But it should be noted that the performance of this new device is still appreciated even at higher concentration. This MEMD process was successfully applied in preconcentrating sucrose aqueous solution from 150g/L to 600g/L and also obtains 14-fold of initial concentration of model cellulosic hydrolysate (mixture of glucose and xylose aqueous solution) in a very efficient way.


Zhang K.,Tianjin University | Qin Y.,Tianjin University | Qin Y.,Chembrane Research and Engineering Inc. | He F.,Chembrane Research and Engineering Inc. | And 3 more authors.
Separation and Purification Technology | Year: 2015

In the present work, continuous-effect membrane distillation (CEMD) process with a function of in-situ internal latent-heat-recovery was applied to concentrate aqueous glycerol solution by using a hollow fiber air-gap membrane distillation module. Compared with other conventional membrane distillation processes, the CEMD process enabled higher energy efficiency and lower operational cost, and thus greater potential commercializing application. The deep-concentrating experiments revealed that a feed of 10 g/L could be successfully concentrated up to about 400 g/L with a rejection efficiency still greater than 99.9%. The maximum value of gain output ratio (GOR) experimentally obtained could reach 16.2, and even though the glycerol concentration was up to about 350 g/L, the GOR value could still be 5.3, which corresponded to the energy efficiency of a conventional seven-effect evaporator. When the feed was concentrated up to around 300 g/L, the GOR and the trans-membrane flux (Jw) decreased sharply. The increment of glycerol viscosity and the reduction of water vapor pressure resulted from the increase of feed concentration were the critical reasons that led to deterioration in GOR and Jw. Four-factor two-level full factorial analysis showed that for a certain feed-in concentration, the heated feed-in temperature was the most significant factor to obtain higher GOR and Jw. The value of GOR and Jw basically maintained invariable in the long-term stability test lasting for 60 days, which demonstrated that CEMD process was suitable for concentrating aqueous glycerol solution in a high-efficiency and energy-saving way. © 2015 Elsevier B.V. All rights reserved.


He J.,Tianjin University | Shan P.,Tianjin University | Zhang L.,Tianjin University | Qin Y.,Tianjin University | Qin Y.,Chembrane Research and Engineering Inc.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2012

Separation of dimethylamine from the aqueous solution was carried out by using a supported-gas-membrane absorption method with the hollow-fiber membrane modules. In this paper, three experimental conditions affecting mass transfer were investigated trough an orthogonal experiment, and the effects of two factors, including overall mass transfer coefficient and the rate of dimethylamine removal, were evaluated. It can be found that the two evaluation factors increases with increasing the feed temperature, whereas with increasing the feed velocity, the overall mass transfer coefficient increases and the rate of dimethylamine removal decreases. The effect of feed-in concentration of dimethylamine on the overall mass transfer coefficient and the rate of removal are not significant. The best experimental conditions were obtained by single-factor experiments with a feed temperature of 45 °C, a feed velocity of 0.08 m·s -1 and a feed-in concentration of 3000×10 -6. These results demonstrate that among the three experimental conditions, feed temperature is the most influential factor on the separation process, followed by the feed velocity. The feed-in concentration affected the system negligibly. Through a stability test, it can be seen that the properties of the membrane modules still remain very high after 550 hours run over.


Yao K.,Tianjin University | Qin Y.,Tianjin University | Yuan Y.,Tianjin University | Liu L.,Chembrane Research and Engineering Inc. | And 2 more authors.
AIChE Journal | Year: 2013

A continuous-effect membrane distillation (CEMD) process was developed by equipping air gap membrane distillation (AGMD)-based and strictly-parallel hollow fiber module with internal heat recovery. Its performance was indicated by flux, performance ratio and evaporation efficiency. Two kinds of CEMD modules made from different membrane fibers were tested. A face-centered central composite experimental design was conducted to investigate the influences of operating variables including cold-feed temperature, hot-feed temperature, and feed-in flow rate on the performance. Within the studied experimental range, the maximum PR of 13.8 was obtained. A theoretical model based on governing transport equations was established to predict the process performance, and the model described the experimental data fairly well. In light of the model, possible ways to further increase PR were predicted. The dilute aqueous sugar solution was successfully concentrated 12-fold to a final concentration of about 20 wt % by using CEMD process with a final PR of 8.2. © 2012 American Institute of Chemical Engineers (AIChE).


Li X.,Tianjin University | Qin Y.,Tianjin University | Liu R.,Tianjin University | Zhang Y.,Chembrane Research and Engineering Inc. | Yao K.,Tianjin University
Desalination | Year: 2012

Multiple-effect membrane distillation (MEMD) process, by using a hollow fiber-based AGMD module and an external heat exchanger, was studied to concentrate dilute sulfuric acid solution. Latent heat of distillate was in-situ recovered by directly heating the cold feed within the AGMD module of special configuration. Permeation flux (Jw) and performance ratio (PR) parameters were used to characterize the operation performance of MEMD process. PR value obtained in the MEMD process was much higher than that obtained in traditional and the other modified membrane distillation process. The effects of heated feed-in temperature, cold feed-in temperature, feed-in flow rate and feed-in concentration on the MEMD performance were experimentally investigated. The dilute sulfuric acid in 2wt.% could be concentrated up to about 40wt.% by using MEMD process. The maximum value of PR and Jw could reach 11.5 and 5.3L/m2h, respectively. When the feed concentration was up to 20wt.%, the value of PR and Jw could still be 4.9 and 1.9L/m2h, respectively. In a long-term stability test lasting for >30days, the electrical conductivity of the distillate was always less than 150μs/cm, which demonstrated that the performance of MEMD modules was kept in good condition. © 2012 Elsevier B.V.

Loading Chembrane Research and Engineering Inc. collaborators
Loading Chembrane Research and Engineering Inc. collaborators