Review of thermal efficiency and heat recycling in membrane distillation processes

Desalination and concentration of saline aqueous solutions up to supersaturation by air gap membrane distillation and crystallization fouling

“…As it can be seen in Fig. 12(a) the thermal efficiency increases with the feed temperature [41,42] and it is higher for the membrane TF450 having greater pore size. A similar thermal efficiency value was reported by Liu et al [43], 98%, by using an AGMD system with a flat sheet PTFE membrane of 100 nm as mean pore size, a temperature difference between feed and permeate sides of 55 K, 4 mm of air gap and 228 L/h feed flow rate.…”

Numerical Investigations of Coupling a Vacuum Membrane Desalination System with a Salt Gradient Solar Pond

“…The use of SGSP does not only seem to be the most interesting solution but also allows a high permeate flux to be reached with membrane fed by waters from lower convective zone (LCZ) of the SGSP. The study of different coupling configurations has confirmed the benefits of the membrane module immersion in the solar collector [18,[22][23][24]. This possibility reduces heat loss and has a compact installation, which leads to improved productivity.…”

“…The heat transfer simultaneously occurs with mass transfer whose process influences the rate and coefficients of the heat transfer process, giving birth to a complex heat transfer model [23]. The transfer through the membrane is caused by a partial pressure difference on either side of the membrane.…”

Fouling in direct contact membrane distillation of produced water from unconventional gas extraction

“…The thermal efficiency of separation, which is the same as gain output ratio (GOR) for a system that does not include heat recovery, is defined as the ratio of thermal energy utilized for water evaporation to the total heat flux across the membrane [51]. The specific thermal energy consumption for PTFE 1 during this experiment increased from 2.6 kWh/kg at the beginning of the experiment (feed TDS=92,800 mg/L) to 3.7 kWh/kg at the end (feed TDS=270,000 mg/L), while the thermal efficiency of separation decreased from 51% to 35%.…”