A method for controlling a direct contact membrane distillation (DCMD) system, the method including modeling the DCMD system with differential-algebraic equations (DAEs), wherein the DAEs include process states {tilde over (x)}(t.sub.k) and an input state u(t.sub.k); selecting a value for the input variable u(t.sub.k) for a time t.sub.k; estimating the process states {tilde over (x)}(t.sub.k) based on the DAEs and the input state u(t.sub.k); checking that a boundedness function G applied to the process states {tilde over (x)}(t.sub.k) is smaller than a desired steady-state point ρ.sub.e; and minimizing an objective function, which depends on the process states {tilde over (x)}(t.sub.k) and the input state u(t.sub.k), to determine an updated input state u(t.sub.k+1) for a next time t.sub.k+1. The process states {tilde over (x)}(t.sub.k) include temperatures and heat flow rates.

A device for continuous seawater desalination of and a method thereof. A hydrophobic carbon nanotube composite membrane is made of a hydrophobic polymer and carbon-based materials, and the carbon-based materials are, such as, carbon nanotubes or graphene. The hydrophobic carbon nanotube composite membrane is perforated to obtain the hydrophobic carbon nanotube composite membrane having micrometer-nanometer multi-level pore structure using laser light. Further, a surface is coated with a photothermal-electrothermal responsive polymer to increase electric joule heat and photothermal effects to increase energy utilization efficiencies, and the hydrophobic carbon nanotube composite membrane having multi-level pore structure and electrothermal effects and photothermal effects is finally obtained. A device is designed, a hydrophobic carbon nanotube composite porous membrane is applied to electro-induced and light-induced seawater desalination, and conditions are controlled to enable the hydrophobic carbon nanotube composite porous membrane to generate heat.

Devices and techniques may improve the permeate productivity in membrane distillation separation by modifying the feed and/or coolant sides of a membrane distillation module depending on the membrane distillation configuration. The bubbling of a carrier gas through the feed liquid in the feed liquid side of the module can increase the turbulent dissipation rate and/or enhance mass transfer across the membrane pores.

A membrane distillation apparatus includes a housing and an impeller. The housing includes a hot medium compartment, a cold medium compartment, a permeate gap compartment, a membrane, and a thermally conductive plate. The hot medium compartment includes a hot medium inlet configured to receive a hot medium stream including water. The cold medium compartment includes a cold medium inlet configured to receive a cold medium stream. The membrane defines pores that are sized to allow water vapor originating from the hot medium stream to pass from the hot medium compartment through the membrane to the permeate gap compartment. The thermally conductive plate and the cold medium stream are cooperatively configured to condense the water vapor from the hot medium stream. The permeate gap compartment includes a permeate outlet configured to discharge the condensed water vapor. The impeller is disposed within the permeate gap compartment.

The purpose of the present invention is to provide: a membrane distillation module with excellent stability of water treatment ability over time as a result of wetting being controlled; and a membrane distillation apparatus comprising the same. Provided is a membrane distillation module that comprises a housing and multiple porous hollow fiber membranes, both ends of which are bonded and fixed to the housing, wherein: the water contact angle of the outer surfaces of the porous hollow fiber membranes is at least 90°; and a hydrophobic polymer adheres to at least some of the areas of the porous hollow fiber membranes that are not bonded and fixed.

A desalination device may comprise: a membrane distillation module comprising a water feed chamber, a carrier gas (CG) chamber, and a hydrophobic microporous membrane configured to separate the water feed chamber and the CG chamber; and a bubble column dehumidifier comprising a bubble column inlet, a bubble column gas outlet, and a product outlet, wherein the MD module allows water vapor to translocate to the CG chamber, but not liquid water, and wherein the water feed each chamber has comprises a water feed inlet and a water feed outlet, wherein the CG chamber comprises a CG chamber inlet and CG chamber outlet, wherein the CG chamber outlet is upstream of and connected to the bubble column dehumidifier, and wherein the CG chamber inlet is downstream of and connected to the bubble column dehumidifier so as to cycle a carrier gas through the CG chamber and the bubble column dehumidifier.

Composite polyether block amide (PEBA) copolymer tubes incorporate an ultra-thin PEBA extruded layer that enables rapid moisture transfer and exchange through the tube. An extruded composite PEBA film may include a porous scaffold support and may be formed or incorporated into the composite PEBA tube. An extruded PEBA may be melted into pores of a porous scaffold support. Extruded PEBA may be wrapped on a mandrel or over a porous scaffold support to form a composite PEBA tube. A film layer may be applied over a wrapped composite PEBA film to secure the layers together. A support tube may be configured inside or outside of the PEBA tube.

The invention relates to a modular flow system having a plurality of frame elements (101, 102) configured to be combined together to form a stack for forming a functional member such as in particular a membrane distillation stage, a vapor generator, a condenser, a heat exchanger, a filter and/or a pervaporation stage, wherein the frame elements (101, 102) each include: an outer frame (39) and an inner frame (43), the inner frame (43) encasing a central inner region (40) and being surrounded by the outer frame (39), at least one first passage opening (13 to 16) arranged between the outer frame (39) and the inner frame (43) and separated from the central inner region (40) by a frame wall on a first and/or opposite second frame side of the inner frame (43), and at least one liquid passage (45, 46) provided by the frame wall and configured to distribute a liquid from the first passage opening (13) to a feeding area (40′) and/or to collect a liquid from the feeding area (40) to the first passage opening (16a, 16b)), the feeding area (40′) being aligned with the central inner region (40) but being outside and/or in front of the inner frame (43), wherein the liquid passage extends asymmetrically and/or discontinuously along the first and/or second frame side.

A membrane distillation (MD) system includes a membrane module and reduced graphene oxide-carbon nanotube immobilized membrane for organic solvent separation. The MD module could include a feed inlet and outlet, a sweep gas inlet, and a sweep gas outlet. Thermostats are positioned at the feed inlet and outlet to measure the change in temperature. Preferential sorption of the organic, specifically tetrahydrofuran (THF), on a hybrid reduced graphene oxide-carbon nanotube immobilized membrane contributes to enhanced solvent removal of the MD system.

Described are methods of membrane distillation for processing organic liquids, hydrophobic distillation membranes useful for membrane distillation methods, and methods of preparing the hydrophobic distillation membranes.