Integration Of Membrane Separation Research Articles

Benzoxazine/ thermoplastic polyurethane nanofibrous membranes with superior mechanical properties for efficient oil-water separation

The integration of membrane separation and electrospinning technologies has significantly advanced oil-water separation processes. However, enhancing the mechanical robustness, corrosion resistance, and durability of oil-water separation membranes remains a challenge. In this paper, we utilized the electrospinning technique to fabricate a micro-nanostructured nanofibrous (NFs) membrane by blending benzophenone monomer (BPAF-an) with thermoplastic polyurethane elastomer (TPU). By optimizing the solid content, the mass ratio of compounds to polymers, and the solvent composition in the spinning precursor solution, we determined the optimal electrospinning parameters for fabricating the TPU/BPAF-an NFs membrane. The incorporation of BPAF-an, known for its low surface energy, significantly enhanced the hydrophobicity of the nanofiber membrane. The TPU/BPAF-an NFs membrane demonstrated excellent mechanical properties, exhibiting a tensile strength of 7.38 MPa and an elongation at break of 292 %. The membrane had good hydrophobicity and its water contact Angle is up to 145.2°. It also displayed exceptional separation efficiency, exceeding 99 % for oil-in-water emulsions and various oil-water mixtures. Even in harsh environments such as strong acids, alkalis and salts, they have prominent hydrophobicity, lipophilicity and chemical stability. In addition, the membrane maintained a high flux rate of 1995.37 L m−2 h−1 and a separation efficiency of 96 % even after 100 cycles of oil-water separation. Consequently, the TPU/BPAF-an NFs membrane, with its superior mechanical properties and cycle stability, holds substantial promise for application in oil-water separation.

Integration of Membrane Separation with Nonthermal Plasma Catalysis: A Proof-of-Concept for CO2 Capture and Utilization

Carbon dioxide (CO2) capture and utilization (CCU) plays an important role in abating carbon emissions, mitigating global warming, and converting CO2 as feedstock to value-added fuels and chemicals...

The mOxy-CaL Process: Integration of Membrane Separation, Partial Oxy-combustion and Calcium Looping for CO2 Capture

CO2 capture and storage (CCS) is considered as a key strategy in the short to medium term to mitigate global warming. The Calcium-Looping process, based on the reversible carbonation/calcination of CaO particles, is a promising technology for post-combustion CO2 capture because of the low cost and non-toxicity of natural CaO precursors and the minor energy penalty on the power plant in comparison with amines capture based technologies (4-9 % compared to 8-12 %). Another interesting process to reduce CO2 emissions in power plants is oxy-combustion, which is based on replacing the air used for combustion by a highly concentrated (~95 % v/v) O2 stream. This work proposes a novel process (mOxy-CaL) for post-combustion CO2 capture based on the integration of membrane separation, partial oxy-combustion and the Calcium-Looping process. An oxygen-enriched air stream, which is obtained from air separation by using highly permeable polymeric membranes, is used to carry out partial oxy-combustion. The flue gas exiting partial oxy-combustion shows a CO2 concentration of ~30 % v/v (higher than 15 % v/v typical in coal power plants). After that, the flue gas is passed to the CaL process where the CO2 reacts with CaO solids according to the carbonation reaction. Thermogravimetric analysis show that the multicycle CaO conversion is enhanced as the CO2 concentration in the flue gas stream is increased. Process simulations show that the mOxy-CaL process has a high CO2 capture efficiency (~95%) with lower energy consumption per kg of CO2 avoided than previously proposed post-combustion CO2 capture technologies. Moreover, the overall system size is significantly lower that state-of-the-art CaL systems, which allows for an important reduction in the capital cost of the technology.

Integration of membrane separation and Fenton processes for sanitary landfill leachate treatment

ABSTRACTThe appropriate treatment of sanitary landfill leachate is one of the greatest challenges nowadays due to the large volumes of solid waste generated. Thus, the aim of this study is to evaluate the performance of different routes involving the integration of advanced oxidation processes based on Fenton’s reagents (AOP-Fenton) and microfiltration (MF) and nanofiltration (NF) membrane processes for the treatment of landfill leachate. MF module configuration (submerged or sidestream) and MF and NF recovery rate were evaluated. The combination of AOP-Fenton, MF and NF proved to be an effective treatment for landfill leachate. High removal efficiencies of chemical oxidation demand (94–96%) and colour (96–99%) were obtained. The configuration named route 3, composed of MF of raw landfill leachate (MF1), POA-Fenton-MF2 of the MF1 concentrate and NF of both MF1 and MF2 permeates, showed a higher global water recovery and was responsible for lower waste generation. It was considered the best one in terms of environmental, technical and economical aspects.

Development of large-scale applications in organic solvent nanofiltration and pervaporation for chemical and refining processes

New membrane, modules, and systems are under development for large-scale organic/organic separations. Practical applications are envisioned in the refining, chemical, pharmaceutical, and polymer industries. A large-scale organic solvent nanofiltration (OSN) process is MAX-DEWAX™ for solvent recovery in lube dewaxing. A commercial installation has been in operation since 1998 at a feed rate of 5800 m 3/day (36,000 barrels/day). A pervaporation process, S-Brane™, is also available for comparable large-scale operations. S-Brane selectively removes sulfur containing hydrocarbon molecules from fluidized catalytic cracking (FCC) and other naphtha streams. A 300 barrels/day demonstration plant has been run on-stream using FCC light and intermediate cat naphthas. S-Brane reduces the overall capital and operating cost for clean fuel compliance, and also provides a means for preserving octane value in hydrotreating based technology. There are several key steps in the development of a robust membrane process that can be moved from lab-scale to pilot plant trials to a demonstration unit on-line at a refinery. These steps expand in complexity and size as process development moves forward. Both MAX-DEWAX and S-Brane are presented as examples of applications that have moved through this progression. Since these processes are large-scale and relatively low capital cost compared to conventional technologies, gains in yield, quality, or energy savings are found to offer significant economic benefits. Experimentally, it appears that high-pressure nanofiltration and low-pressure pervaporation are governed by the principles found in solution-diffusion models. Data taken in OSN mode is used to estimate pervaporation performance. Choice of membrane operating systems is dependent on the composition of the feed stream and the required product quality. In some cases, the high throughput for OSN outweighs the higher selectivities gained in pervaporation, since OSN is inherently a lower cost process to operate. Further investigations of new applications include toluene recovery from a toluene disproportionation unit, lowering benzene levels in gasoline feedstocks to <1%, and integration of membrane separation with aromatics reformer or distillation operations.