Thermophysical properties of new working fluid systems for absorption processes

Refractive index and heat capacity of 1-butyl-3-methylimidazolium bromide and 1-butyl-3-methylimidazolium tetrafluoroborate, and vapor pressure of binary systems for 1-butyl-3-methylimidazolium bromide + trifluoroethanol and 1-butyl-3-methylimidazolium tetrafluoroborate + trifluoroethanol

“…Various organic chemicals as alternatives to the conventional working fluids such as lithium bromide+water (LiBr + H 2 O) and ammonia + water (NH 3 + H 2 O) have been reported. These organic working fluids-mainly consisting of fluoroalcohol refrigerants and their partner organic absorbents-can surmount the difficulties of classical working fluids, but they have simultaneously given rise to new problems such as thermal instability, the volatility of the absorbent, and the low process efficiency [15][16][17][18][19][20].…”

Isothermal Vapor–Liquid Equilibrium of HFC-161 + DMETrEG within the Temperature Range of 293.15–353.15 K and Comparison for HFC-161 Combined with Different Absorbents

“…Flow diagram of vapor–liquid equilibrium experimental apparatus: , 1, thermostatic bath; 2, equilibrium cell; 3, vapor phase circulation pump; 4, liquid phase circulation pump; 5, vapor six-way valve; 6, liquid six-way valve; 7, gas chromatograph; 8, computer; 9, digital multimeter; 10, pressure sensor; 11, vacuum pump; 12, thermometer (for temperature measurement); 13, heater; 14, thermometer (for temperature controlling); 15, stirrer; 16, evaporator; 17, refrigerating system; 18, temperature controller.…”

“…The phase behaviors of HFC-161 with different absorbents need to be fully studied so that a better absorbent will be selected to match HFC-161. Meanwhile, polyethylene glycol dimethyl ethers, such as DMEDEG, DMETrEG, and DMETEG (tetraethylene glycol dimethyl ether), are good choices as absorbents for several refrigerants because of good thermal and chemical stability, and the working pairs have been applied in absorption engines . The pressure–density–temperature ( p ρ T ) of DMETrEG and the VLE of systems of DMETrEG with refrigerant (HFC-134a or HCFC-22) have been studied. − ,− …”

“…Meanwhile, polyethylene glycol dimethyl ethers, such as DMEDEG, DMETrEG, and DMETEG (tetraethylene glycol dimethyl ether), are good choices as absorbents for several refrigerants 18 because of good thermal and chemical stability, and the working pairs have been applied in absorption engines. 19 The pressure−density− temperature (pρT) of DMETrEG 18 and the VLE of systems of DMETrEG with refrigerant (HFC-134a or HCFC-22) have been studied. 5−7,20−24 So far, the isothermal vapor−liquid equilibrium data of HFC-161 with several absorbents, such as DMAC, NMP, DMF, and DMEDEG, have been given.…”

Excess Properties of Some Methanol + Amide Systems Proposed as Working Fluids for Absorption Machines

“…In the present work we have chosen some amides, N-formylmorpholine (NFM), N-methyl-2-pyrrolidine (NMP), and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone also called 1,3-dimethylpropyleneurea (DMPU), as absorbents (Nowaczyk and Steimle, 1992), to study different thermodynamic properties of the mixtures formed by these compounds with methanol (as refrigerant). We report the excess molar enthalpies and excess molar volumes at 298.15 K and atmospheric pressure of these mixtures.…”