Miscibility of light oil and flue gas under thermal action

The miscibility of flue gas and different types of light oils is investigated through slender-tube miscible displacement experiment at high temperature and high pressure.Under the conditions of high temperature and high pressure,the miscible displacement of flue gas and light oil is possible.At the same temperature,there is a linear relationship between oil displacement efficiency and pressure.At the same pressure,the oil displacement efficiency increases gently and then rapidly to more than 90% to achieve miscible displacement with the increase of temperature.The rapid increase of oil displacement efficiency is closely related to the process that the light components of oil transit in phase state due to distillation with the rise of temperature.Moreover,at the same pressure,the lighter the oil,the lower the minimum miscibility temperature between flue gas and oil,which allows easier miscibility and ultimately better performance of thermal miscible flooding by air injection.The miscibility between flue gas and light oil at high temperature and high pressure is more typically characterized by phase transition at high temperature in supercritical state,and it is different from the contact extraction miscibility of CO_(2) under conventional high pressure conditions.

MISCIBILITY,CRYSTALLIZATION AND MECHANICAL PROPERTIES OF PPC/PBS BLENDS

In this paper, melt blends of poly（propylene carbonate） （PPC） with poly（butylene succinate） （PBS） were characterized by dynamic mechanical analysis （DMA）, differential scanning calorimetry （DSC）, tensile testing, wide-angle X-ray diffraction （WAXD）, polarized optical microscopy and thermogravimetric analysis （TGA）. The results indicated that the glass transition temperature of PPC in the 90/10 PPC/PBS blend was decreased by about 11 K comparing with that of pure PPC. The presence of 10% PBS was partially miscible with PPC. The 90/10 PPC/PBS blend had better impact and tensile strength than those of the other PPC/PBS blends. The glass transition temperature of PPC in the 80/20, 70/30, and 60/40 PPC/PBS blends was improved by about 4.9 K, 4.2 K, and 13 K comparing with that of pure PPC, respectively; which indicated the immiscibility between PPC and PBS. The DSC results indicated that the crystallization of PBS became more difficult when the PPC content increased. The matrix of PPC hindered the crystallization process of PBS. While the content of PBS was above 20%, significant crystallization-induced phase separation was observed by polarized optical microscopy. It was found from the WAXD analysis that the crystal structure of PBS did not change, and the degree of crystallinity increased with increasing PBS content in the PPC/PBS blends.

Miscibility of Semi-flexible Thermotropic Liquid Crystalline Copolyesteramide with Polyamide 66

Liquid crystalline polymer-polyamide 66 (LCP/PA66) blends were compounded by using a Brabender mixing followed by compression moulding. The LCP employed was a semi-flexible liquid crystalline copolyesteramide based on 30% (molar fraction ) of p-amino benzoic acid (ABA ) and 70% (molar fraction) of poly (ethylene terephthalate) (PET). The LCP/PA66 blends were investigated in terms of the thermal and dynamic mechanical properties. It was found that PA66 and LCP components of the blends are miscible in the molten state, but are partially miscible in the solid state. The inclusion of the semi-flexible LCP into PA66 retards the crystallization rate of PA66. Furthermore, the melting temperature and the degree of crystallinity of PA66 are reduced considerably due to the LCP addition.

Microstructure Evolution in a Rapidly Solidified Cu85Fe15 Alloy Undercooled into the Metastable Miscibility Gap

A model has been developed to describe the microstructure evolution in the atomized droplets of Cu-Fe alloy during cooling through the metastable miscibility gap. Calculations have been performed for Cu85Fe15 alloy to investigate the process of liquid-liquid phase transformation. The numerical results indicate that the minority phase droplets are nucleated in a temperature region around the peak of the supersaturation. The average radius of the Fe-rlch droplets decreases and the number density of the minority phase droplets increases with decreasing the atomized droplet size. The simulated results were compared with the experimental ones. The kinetic process of the liquid-liquid phase transformation was discussed in detail.

The impacts of gas impurities on the minimum miscibility pressure of injected CO_2-rich gas–crude oil systems and enhanced oil recovery potential

An effective parameter in the miscible-CO_2 enhanced oil recovery procedure is the minimum miscibility pressure(MMP)defined as the lowest pressure that the oil in place and the injected gas into reservoir achieve miscibility at a given temperature. Flue gases released from power plants can provide an available source of CO_2,which would otherwise be emitted to the atmosphere, for injection into a reservoir. However, the costs related to gas extraction from flue gases is potentially high. Hence, greater understanding the role of impurities in miscibility characteristics between CO_2 and reservoir fluids helps to establish which impurities are tolerable and which are not. In this study, we simulate the effects of the impurities nitrogen(N_2), methane(C_1), ethane(C_2) and propane(C_3) on CO_2 MMP. The simulation results reveal that,as an impurity, nitrogen increases CO_2–oil MMP more so than methane. On the other hand, increasing the propane(C_3)content can lead to a significant decrease in CO_2 MMP, whereas varying the concentrations of ethane(C_2) does not have a significant effect on the minimum miscibility pressure of reservoir crude oil and CO_2 gas. The novel relationships established are particularly valuable in circumstances where MMP experimental data are not available.

STUDY ON THE MISCIBILITY OF DYNAMICALLY VULCANIZED EPDM/PP BLEND BY POSITRON ANNIHILATION SPECTROSCOPY

Positron annihilation spectroscopy (PAS) was utilized to investigate the relationship between the free-volume hole properties and miscibility of dynamically vulcanized EPDM/PP blend. The results showed that the noncrystalline region of PP and EPDM in the blend was partially miscible and the miscibility of the blend became worse when the weight percent of EPDM was <50%. This was also demonstrated by DMTA and mechanical properties of the blends with various compositions.

Miscibility of Poly(hydroxybutyrate)/Poly(vinyl alcohol)Melt Blends Plasticized With Glycerol

Poly(hydroxybutyrate)/poly(vinyl alcohol)(PHB/PVA)blends plasticized with glycerol were prepared by melt blending of PHB and glycerol plasticized PVA.The PHB/PVA-glycerol compositions were 90:10,75:25 and 50:50 w/w,being the concentration of glycerol in the PVA mixture of 10 wt%.The blends were characterized by infrared spectroscopy,dynamic-mechanical thermal analysis,and scanning electron microscope of the fragile fractured surface.The results showed one single phase blend,indicating miscibility corroborated by the presence of a single glass transition temperature.The blending method proved to be an efficient way to tune PHB properties keeping its biodegradable nature since both PVA and glycerol are fully biodegradable materials.

STUDIES ON MISCIBILITY OF POLY (ε-CAPROLACTONE) AND ALIPHATIC POLYCARBONATE BLENDS AND DETERMINATION OF THEIR INTERACTION PARAMETER

In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.

Study on the Miscibility and Phase Behavior of Polyoxymethylene with Novolak

The miscibility and phase behavior of the blends of polyoxymethylene (POM)/Novolak were investigated by the cloud point method, which showed that the POM/Novolak blends exhibited a lower critical solution temperature. The melting point of POM decreased when diluted with Novolak. From the melting temperature depression of POM, a negative interaction parameter (x) between POM and Novolak was obtained. The IR spectrum revealed that the miscibility between POM and Novolak was caused by the specific interaction between the OH groups of Novolak and the ether oxygen atoms of POM. The morphology of the blends investigated by polarized light microscopy showed that the size of spherulites of POM was sharply decreased by its mixing with Novolak. This suggests that Novolak be used as a compatibilizer for POM.

TIME-TEMPERATURE-MISCIBILITY AND MORPHOLOGY OF POLYOLEFIN BLENDS

Miscibility and crystallization have been studied for polypropylene-polyethylene and polyethylene-polyethyleneblends. In the case of the polypropylene blends the composition of interest is 20% polypropylene. At this composition thepolypropylene has been found to be soluble in linear low density polyethylene but insoluble in high, low and very lowdensity polyethylenes. The miscibility has been concluded from the crystallization kinetics and polarised optical microscopywith a hot stage. Polyethylene-polyethylene blends have been formed from polymers with similar average branching contentbut where they have different melting temperatures. Important consequences are to introduce long branches into apolyethylene that only has short branches, and to modify the morphology of a polyethylenes so that haze, gloss and strainhardening are improved. Polyethylene blends must be developed after careful consideration of the branch content anddistribution within each of the constituents. It is not sufficient to simply blend polyethylenes, with the desired range ofproperties, without regard to the miscibility of the blend composition.

Investigation of the stable and the metastable liquidus miscibility gaps in Fe–Sn and Fe–Cu binary systems

Two kinds of experimental methods were tried in the present work:(i)the powder metallurgy method combined with differential thermal analysis(DTA)to determine the metastable liquidus miscibility gap for a Fe–Cu binary system and(ii)the high-temperature melting method combined with isothermal treatment to determine the stable liquidus miscibility gap for a Fe–Sn binary system.The experimental method was adopted according to the characteristics of the liquidus miscibility gap of the specific system.Using the powder metallurgy method,a uniform microstructure morphology and chemical composition was obtained in the DTA specimen,and the phase-separation temperature of the supercooled metastable liquid was measured.The isothermal treatment was applied for the samples inside the stable liquidus miscibility gap;here,equilibrated compositions were reached,and a layered morphology was formed after rapid cooling.The liquid miscibility gaps of the Fe–Cu and Fe–Sn binary systems were measured,and the peak temperatures of the corresponding miscibility gaps were determined to be about 1417°C at x(Cu)=0.465 at%and 1350°C at x(Sn)=0.487 at%,respectively.On the basis of the experimental results,both the Fe–Cu and the Fe–Sn binary systems were thermodynamically assessed.

Miscibility, Thermal Stability, Rheological and Mechanical Properties of Blends Derived from Polysulfone Oligomer and Poly (phthalazinone ether sulfone ketone)

Poly (phthalazinone ether sulfone ketone) (PPESK) was melt blended with bisphenol-A polysulfone oligomer (O-PSF) to produce a thermoplastic polymer blends. The miscibility, thermal stability, rheological and mechanical properties of the blends were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and capillary rheometry. The blends showed single Tg over the composition range and possess homogeneous microstructure. The addition of O-PSF slightly affected the thermal properties of the blends. PSF oligomer, as a processing aid, could markedly improve the processability of the PPESK. In addition, the mechanical properties of the blends were increased, to some degree, by adding O-PSF.

Miscibility Calculation of GaN1-xPx Ternary Alloys

A theoretical calculation of the miscibility gap with considering the mismatch strain and elastic parameters was performed for the GaN1-xPx ternary alloys on (0001) GaN/sapphire substrates based on the strictly regular solution model. The calculated results show that the boundary of the spinodal isotherm shifts from x=0.06 to x=0.25 at the growth temperature of 1200 K as the strain factor increases from 0 to 1, indicating that the strain in the GaN1-xPx layers can suppress the phase separation. Meanwhile, with the increase of the effective elastic parameters of GaN and GaP, the available maximum P content also increases slightly at the growing temperature.

MISCIBILITY BEHAVIOR AND PRESSURE DEPENDENCE OF THE SYSTEMS POLYSTYRENE/CYCLOPENTANE AND POLYSTYRENE/1-PHENYLDECANE ACCORDING TO A MODIFIED HOLE THEORY

The influence of pressure on miscibility behavior of the systems polystyrene/cyclopentan(?)and polystyrene/1-phenyldecane is studied with a modified hole theory.It is found that the pres-sure dependence of excess volume is responsible for the different kinds of behavior of these two sys-tems.Furthermore,the excess volume is decomposed into two separatc parts,one from the contri-bution of cell volume expansion and the other from the change of hole fraction,and their relation-ship with pressure dependence of the miscibility behavior is analysed.

PRELIMINARY INVESTIGATION ON THE MISCIBILITY OF ISOTACTIC POLYPROPYLENE (iPP) AND SYNDIOTACTIC POLYPROPYLENE (sPP) BLENDS

Experimental miscibility studies were performed on different compositions of iPP/sPP blends, where sPP has a low syndiotacticity （[rrrr] = 81%）. Combining optical microscopy, rheology, and solid state NMR spectroscopy, the miscibility of the blends was investigated at different scales in the traditionally thought to be ＂immiscible＂ iPP/sPP blends. For the composition of iPP/sPP （90/10） blend, it shows to be miscible in the melt, and furthermore, the existence of intermolecular chain interactions between sPP and iPP components was detected in the solid state.

MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF BIODEGRADABLE BLEND OF POLY(β—HYDROXYBUTYRATE)AND POLY(D,L—LACTIDE)—CO—POLY(ETHYLENE GLYCOL)

Studies on the miscibility of PHB/PELA blends showed that PHB and PELA were miscible in amorphous state.The crystallization behavior of PHB in the blend was strongly de- pendent on the addition of PELA component.

MISCIBILITY, THERMAL STABILITY AND RETENTION OF PVP FOR CROSSLINKED PVA/PVP BLENDS

The thermal behavior, miscibility, crystallite conformation and thermal stability ofcrosslinked(CL-) PVA/PVP blends were studied by DSC and TG methods, respectively. DSCresults showed that in the blend, the crystallinity,T_m and T_c of PVA were obviously lower thanthose of pure PVA; the crystal growth changed from three dimensional to two dimensional andonly a single T_g was detected. These facts demonstrated that this crystalline and amorphousblend have good miscibility. TG curves showed that providing the quantity of K_2S_2O_8 added ismore than 3 wt%,in the blends PVA will form a stable CL-network, whose thermal degradationtemperature was near to that of PVP. But crosslinking reaction will not take place for PVP. Theprocesses of thermal degradation of CL-blends are based on combining both the thermaldegradation of PVP and that of PVA crosslinked with corresponding quantity of K_2S_2O_8 CL-agent, respectively. The UV measurements showed that 75 wt% of PVP may be remained in CL-blend hydrogelscrosslinked by adding (3--5 wt% )K_2S_2O_8. This is mainly due to the stable CL-network formed and the good compatibility and properentanglement between the composites in the CL-blends.

Miscibility Gap in the Fe-Cu-Ni System at 1173 K

The isothermal section of the Fe-Cu-Ni ternary system at 1173 K was determined by microprobe analysis and diffusion triple technique. The experimental results show that this isothermal section only contains a miscibility gap region,and the maximal Ni content in the miscibility gap is 44.7 at.-%Ni.

Miscibility of Ethanol in Diesel Fuels

The primary barrier to the use of ethanol in diesel fuel is the poor miscibility at lower temperatures. The miscibilities of ethanol in 19 diesel fuels having a wide variation in compositions were evaluated by testing their phase separation temperatures. The result shows that aromatic contents and intermediate distillate temperatures have a significant impact on miscibility limits. The FCC diesels, which contain up to 50% of aromatics, exhibit different phase behavior trends in comparison with straight-run diesels and other diesel fuels.

MISCIBILITY AND MORPHOLOGICAL STRUCTURE OF BIODEGRADABLE BLEND OF POLY(β—HYDROXYBUTYRATE)AND POLY(D,L—LACTIDE)

The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend exhibited the crystallization change and a certain improvement of the mechanical property.