Soluble asymmetric bismaleimide with low molten viscosity and its high glass transition temperature polymer

Three novel bismaleimide monomers (MBA‐BMI, EBA‐BMI, and PBA‐BMI) with unsymmetrical backbone and different pendant groups were synthesized using asymmetric diamine and maleic anhydride as the precursors. The prepared bismaleimide monomers show good solubility in common organic solvents such as acetone and tetrahydrofuran. The EBA‐BMI melt treated at 180 °C also shows low viscosity about 190–934 mPa s at the temperature range of 160–139 °C below its melting point (166 °C). In addition to the good processability, all three cured bismaleimides show high storage moduli at high temperatures (2.0 GPa at 400 °C), high glass transition temperatures over 400 °C, and good thermal stability with the 5% weight loss temperatures around 470 °C under nitrogen atmosphere. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43491.     

Development of a Stimuli-Responsive Gemini Zwitterionic Viscoelastic Surfactant for Self-Diverting Acid

A Gemini zwitterionic viscoelastic surfactant named self diverting acid - gemini sulfonated surfactant (SDA-GS), which has double quaternary ammonium groups, double sulfonate groups, and two hydrophobic tails, was synthesized from oleylamidopropyl dimethylamine, 1,3-propanesultone, and 2, 2-bis(bromomethyl)propane-1, 3-diol. The viscosity of an SDA-GS aqueous solution varies with acid and calcium chloride concentrations. With a decrease in the HCl concentration, the viscosity of the acid solution prepared with SDA-GS increases to a maximum value, followed by a decrease, which results from the aggregation of the surfactant into wormlike micelles and the following disaggregation. Calcium ions generated by the reaction of acid and calcium carbonate can enhance the aggregation of the surfactant to increase the peak viscosity of the acid solution. The peak viscosity of the acid solution prepared by 5 wt.% SDA-GS without calcium ions could only reach 73.2 mPa.s when the HCl concentration was 4 wt.%, but that of the acid solution with calcium carbonate powder added could reach over 200 mPa.s when the HCl concentration was consumed to 4 wt.% and the calcium chloride concentration 21.6 wt.%. The viscoelastic measurements proved that calcium ions can drive the growth of the wormlike micelle. The acid and Ca²⁺ response of SDA-GS can be applied in self-diverting acid to improve the acid displacement in the heterogeneous reservoir. Experimental evaluation showed that the acid solution prepared by SDA-GS and the selected corrosion inhibitor showed a good corrosion inhibition performance and a viscosity variation that makes it an efficient self-diverting acid. The spent acid (21.6 wt.%) with 4 wt.% HCl retained high viscosity over 80 mPa.s at a 170 s⁻¹ shearing rate and at 120°C after 90 min. The parallel core flood tests to simulate in situ application of SDA-GS acid showed that the permeability improvement ratios (K₁/K₀) of the cores could reach 182.3 and 278.4 at 60 and 90°C, respectively.     

Flash pyrolysis of coals: behaviour of three coals in a 20 kg h−1 fluidized-bed pyrolyser

Flash pyrolysis of Loy Yang brown coal, and Liddell and Millmerran bituminous coals has been studied using a fluidized-bed reactor with a nominal throughput of 20 kg h^?1. The apparatus and its performance are described. The yields of tar and hydrocarbon gases are reported for each coal in relation to pyrolysis temperature, as also are analytical data on the pyrolysis products. The peak tar yields for the dry, ash-free Loy Yang and Millmerran coals were respectively 23% wt/wt (at ≈ 580 °C) and 35% wt/wt (at $\text{\$}\text{?}$600 °C). The tar yield from Liddell coal was 31% wt/wt at ≈ 580 °C. Hydro-carbon gases were produced in notable quantities during flash pyrolysis; e.g. Millmerran coal at 810 °C gave 6% wt/wt (daf) methane, 0.9% wt/wt ethane, 6% wt/wt ethylene, and 2.5% wt/wt propylene. The atomic $\text{H}\text{C}$ ratios and the absolute levels of hydrogen in product tars and chars decreased steadily with increasing pyrolysis temperature.     

低黏度氢化蓖麻油聚氧乙烯(40)醚的合成

以氢化蓖麻油和环氧乙烷为原料,三氟化硼乙醚作催化剂,合成了氢化蓖麻油聚氧乙烯(40)醚。产物为极淡黄色,常温下为透明液体,羟值为70~80 mg KOH/g,皂化值为60~70 mg KOH/g,黏度为1 500~2 000 mPa.s。对影响目标产物黏度、色泽、外观、羟值和皂化值的主要因素进行了优化,得到了适宜的反应条件:w(三氟化硼)=0.8%~1.3%,反应温度100~120℃。用500 L反应釜进行扩试生产,得到的产品色泽为极淡黄色,常温下为透明液体,羟值为70.3 mg KOH/g,皂化值为63.2 mg KOH/g,黏度为1 620 mPa.s。     

Catalytic roles of iron and hydrogen sulphide on hydrogenation of coal

Washed Samla coal was hydrogenated in batches, with and without added sulphur in the presence and absence of hydrated iron oxide as a catalyst, for 3 h at 400 °C under 21.6 MPa hydrogen pressure. Further, hydrogenation of the same coal was studied with varying amounts of hydrated iron oxide in the presence of tar oil as vehicle, keeping the quantity of added sulphur unaltered, at 450 °C under 24.5 MPa pressure for 1.5 h. Comparative roles of iron and H₂S in the catalytic hydrogenation of coal are suggested from the experimental results.     

Oleic acid‐based poly(alkyl methacrylate) as bio‐based viscosity control additive for mineral and vegetable oils

This work described the design of an efficient oleic‐acid based viscosity control additive for lubricating oils as potential alternative to petroleum poly(alkyl)methacrylates (PAMAs) additives. Hence, Poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO) was synthesized by free radical homopolymerization to afford a comb‐like polymer structure similar to common PAMAs. Then, in order to evaluate its efficiency as viscosity control additive, the resulting polymer was mixed at several concentrations from 1%wt to 10%wt with different oil compositions, including a mineral paraffinic oil (MPO) and an organic triglyceride oil (OTO). For all polymer‐solution blends, relative viscosities (RV) measurements showed that addition of PMAEO in MPO had a better contribution on oil viscosity at 100°C than at 20°C (RV = 1.16 at 40°C while RV = 1.25 for 3%wt of PMAEO in MPO). These results were attributed to the coil expansion of polymer chains with increasing temperature. Additionally, rheological studies showed that addition of 3%wt of PMAEO in MPO improved the MPO cold flow properties at ?30°C by decreasing the required yield stress to put the oil in motion from 310 mPa to 42 mPa. These results are in total accordance with the common viscosimetric properties of PAMAs‐based viscosity control additives at low and high temperature in mineral oils. POLYM. ENG. SCI., 59:E164–E170, 2019. © 2018 Society of Plastics Engineers     

Products from rapid heating of a brown coal in the temperature range 400–2300 °C

The devolatilisation behaviour of Yallourn brown coal was investigated under rapid heating conditions using two different flash pyrolysers: a fluid-bed reactor giving coal particle heating rates of 10⁴ °Cs^?1 with a gas residence time of about 0.5 s and a shock tube which generated heating rates of the order of 10⁷ °Cs^?1 and a 1 ms reaction time. Yields of products are reported covering pyrolysis temperatures in the range 400–2300 °C. Hydrocarbon gas yields reached maximum values which were remarkably similar for both reactors although occurring at different temperatures. Carbon oxide production was also similar for both reactors with CO yields reaching 30% wt/wt daf coal. These high yields of CO are very different from those reported for slow heating conditions. It appears that on flash heating, coal decomposition pathways change in a manner which increases CO yields at the expense of H₂0 and to a lesser extent C0₂, resulting in the volatilisation of additional carbon from the coal.     

Rapid liquefaction of Longkou lignite coal by using a tubular reactor under methane atmosphere

Rapid liquefaction of Longkou lignite coal under methane atmosphere was studied in a novel laboratory scale tubular reactor. Experiments were performed at a temperature ranging from 400 to 800 °C, a residence time ranging from 4.5 to 11.2 s and 10–15 MPa (without catalyst). Reactions were also carried out under a nitrogen gas atmosphere at the same reaction conditions. The results indicate that there are synergistic effects between coal and methane at temperatures higher than 600 °C, and the temperature and residence time are the main factors influencing the coal conversion and products distribution. The oil yields reach a maximum of 21.97 (wt.% daf) at 750 °C during 9.0 s.     

Effect of catalyst distribution in coal liquefaction

The effect of the mode of catalyst addition in the liquefaction of eastern Kentucky Elkhorn #2 coal was studied in a continuously stirred tank reactor. Particulate addition of iron in the form of pyrite significantly catalyzed the liquefaction reaction; coal conversion increased, and oil yield was greater by more than a factor of two, both at 825 and 850°F (714 and 728 K, respectively). Although pyrite concentration had a negligible effect on product distribution, the mode of catalyst addition was significant. Impregnation and molecular dispersion with 1 wt. % iron based on coal gave either similar or improved product distribution compared to the addition of 3.5 wt. % iron in the form of particulate pyrite. Significantly lower hydrocarbon gas make and hydrogen consumption were noted with impregnation and molecular dispersion than with particulate addition. SRC sulfur content was marginally higher with impregnation, but was lower with molecular dispersion. Solvent hydrogen content increased with particulate addition, but decreased with impregnation and molecular dispersion.     

三种双生磷酸酯表面改性剂改性碳酸钙表面性质的研究

将三种合成产物分别用于轻质碳酸钙的表面改性.研究了改性后轻质碳酸钙的饱和吸水率、吸油量、粘度等性能.结果表明:此类表面活性剂改性的碳酸钙表面性能显著优于其他常用表面活性剂改性的碳酸钙.用相对于碳酸钙质量分数1％的HDP-2Na改性的碳酸钙与未改性碳酸钙相比,其室温下的饱和吸水率由1.14％降低到0.61％,吸油量由68 mL/100g降到18 mL/100 g,粘度由790 mPa·s降低到240 mPa·s,效果明显优于其他表面改性剂,是一种具有良好应用前景的碳酸钙表面改性剂.     

Low-temperature—long-time,high-temperature—short-time liquefaction of coal (Hokudai process): 2. Effect of reaction conditions

A vitrinite-rich Australian subbituminous coal (77 wt %) was subjected to two-stage hydrogenation (low-temperature-long-time, high-temperature-short-time) using several different catalysts with or without donor solvent and with the temperature range and time of the first hydrogenation stage varied. The condition used in the first stage did not significantly affect the final results of the hydrogenation and ≈ 30 wt % always remained as an undistillable fraction. The use of donor solvent or higher pressure improved the distillate yield and the use of active catalyst had a significant effect. In the best case (450 °C-60 min and 500 °C-20min, under 12 MPa initial hydrogen pressure, using Co-Mo catalyst) 54 wt % of oil boiling up to 325 °C and 68 wt % of total distillable oil boiling up to 500 °C were obtained.     

Upgrading of low rank coal with solvent

In this study, thermal upgrading of low-rank coal with solvent at 380–440 °C under an initial nitrogen pressure of 2 MPa was studied as a possible method for producing clean solid fuel with a high heating value and less spontaneous ignition behavior. Upgrading of Buckskin coal (USA, subbituminous coal) in the presence of t-decalin (non hydrogen-donor solvent) at 440 °C gave 11.4 wt.% of gas, 5.3 wt.% of oil and 74.1 wt.% of upgraded solid product with a small amount of water. The gaseous product consisted mainly of carbon dioxide (67 wt.%), methane, carbon monoxide, hydrogen and a trace of C₂ and C₃ hydrocarbon gases. The oil product from coal contained BTX, phenol, and their alkyl-derivatives. The heating value of the upgraded solid product from the Buckskin coal increased to 31.0 MJ/kg in dry base as compared to the heating value of wet base of the untreated raw coal, which was 19.3 MJ/kg. Spontaneous ignition behavior was greatly reduced by the upgrading. The effect of catalyst and additives on the upgrading was investigated in terms of product distribution and the quality of the solid product. Taiheiyo (Japan, subbituminous) and Yallourn (Australia, brown) coals were also studied.     

Synthesis and Optimization of 2-ethylhexyl Ester as Base Oil for Drilling Fluid Formulation

A stable ester was synthesized to overcome the ester hydrolysis problem during the drilling of oil or gas wells using a conventional ester-based drilling fluid. The thermal and hydrolytic stability of the produced ester was high owing to the transesterification method employed in this study. The reaction was performed using 2-ethylhexanol and methyl laureate esters in the presence of sodium methoxide as a catalyst. In order to obtain the optimum synthesis conditions, a response surface methodology (RSM) was appraised based on the central composite design (CCD). The optimum conditions were determined as follows: 0.6 wt.% catalyst, 70°C reaction temperature, 1:1.5 molar ratio, and 11.5 min of reaction time. The results of 77 wt.% 2-ethylhexyl ester (2-EH) illustrated a high agreement between the experimental and RSM models. The reaction product contained 77 wt.% 2-EH and 23% 2-ethylhexanol. The kinematic viscosity was 5 mm²/s at 40°C and 1.5 mm²/sec at 100°C; the specific gravity was 0.854, flash point was 170°C, and pour point was ?7°C. The produced product showed similar properties to the available commercial product. However, it was observed that the mud formulation using the synthesized base oil had superior rheological properties at 121°C.     

On fingering of steam chambers in steam‐assisted heavy oil recovery

Western Canadian oil sands reservoirs are among the largest petroleum accumulations in the world. Given original oil viscosity up to 5,000,000 mPa‐s, these oils are currently recovered from these reservoirs using steam which heats the oil to ～250°C with reduced viscosities <10 mPa‐s. A key issue faced by thermal recovery processes is the uniformity of the steam chamber within the reservoir. Nonuniformities of the chamber arise from multiphase flow instabilities in the porous media where fingering has been explained by penetration of low viscosity steam into viscous oil. Here, fine‐grid thermal reservoir simulation reveals that fingering takes place in the gas phase beyond the chamber edge in a zone created by gas exsolution due to elevated temperature beyond the edge of the steam chamber. The results suggest that nonuniform chambers will occur in perfectly homogeneous reservoirs which implies that uniform chambers along wells may be impossible to achieve. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1364–1381, 2016     

基于分子模拟的新型油溶性降黏剂的制备及性能优化

为了解决胜利油田稠油黏度高、开采困难等问题,通过分子模拟指导,以马来酸酐、甲基丙烯酸十八酯、N-乙烯基吡咯烷酮及苯乙烯进行四元共聚,获得了适合原油特性的降黏剂。以降黏率为考察指标,探讨了单体投料比例、最佳反应条件等对降黏效果的影响。结果表明,马来酸酐、甲基丙烯酸十八酯、N-乙烯基吡咯烷酮及苯乙烯投料摩尔比为4∶13.5∶8∶3、引发剂加量为1%（质量分数）、链转移剂用量为0.5%（质量分数）、80℃反应8h时,合成的降黏剂效果最好,且在降黏剂用量为0.3%（质量分数）时,可将原油黏度从1100mPa·s（50℃）降至403mPa·s,降黏率达到63.3%,原油凝点可从38.5℃降低至33.2℃,通过红外及氢谱等进行了表征,与预想分子结构一致。     

Viscosity changes in coal paste during hydrogenation

Using a viscometer that operates up to a maximum pressure of 29.4 MPa and a maximum temperature of 550 °C, the viscosity of coal paste and its changes with temperature were investigated, and also some effects of: type of vehicle oil, coal to vehicle oil ratio, coal particle size, atmosphere, pressure, catalyst and coal rank. In the viscosity-temperature curve for the paste from high rank bituminous coals, a peak was observed near 300 °C, which is considered to be due to the extractive disintegration of the coal by the vehicle oil. Under hydrogenation with high pressure hydrogen and hydrogenation catalyst, the extractive disintegration of coal was promoted, and the viscosity was higher than that in nitrogen atmosphere. The viscosity behaviour of the coal paste from low rank coals was the same as that of the vehicle oil alone.     

Rheological propertis of coal—oil mixture fuels

The rheological properties of coal—oil mixtures (COM) of a bituminous coal in four types of oil, grade 2, grade 4, light grade 6 and heavy grade 6, have been studied. Variables investigated were the coal concentration (0 – 60 wt.%), coal particle size (10 < d₅₀ < 40 μm), temperature (25 – 90 °C) and time effects (0 – 6 days).

Rheograms were obtained using the Ferranti-Shirley cone and plate viscometer. The COM was classified as a Newtonian fluid at coal concentrations up to 30 wt.% and as a Bingham plastic at higher values. The relative viscosity was found to increase rapidly with coal concentration, reaching 100 for a 60 wt.% of COM.

Both COM viscosity and yield stress decrease with increasing median particle size and decreasing slope of the particle size distribution. This effect is stronger at high solids concentrations.

The COM viscosity is much less sensitive to temperature than the base oil. The COM yield stress increases up to 350 Pa with increasing coal concentration, decreasing temperature and ageing.     

Viscosity of cold lake bitumen and its fractions

New data are presented for the effect of temperature on the viscosity of bitumen fractions, which were obtained by vacuum distillation of a large Cold Lake bitumen sample. The viscosity of these fractions differs by several orders of magnitude; from 4.3 mPa?s for Cut 1 to 430 000 mPa?s for Cut 4 at 30°C. Cut 5 is a glass-like solid at room temperature with a softening temperature of about 100°C, and has a viscosity of 800 000 mPa?s at 120°C. The effect of temperature on the viscosity of each bitumen fraction is modelled very well with a two-parameter correlation that was shown to be valid generally for Alberta bitumens. The results of bitumen viscosity calculations, based on a simple liquid-mixture viscosity formula, are presented and compared with the bitumen viscosity data.     

Nonhydrogenative co-processing of saskatchewan heavy oil and coal

A Saskatchewan heavy oil was processed with coal additives in a tubular reactor packed with procelain berl saddles at 400–480°C and atmospheric pressure. For comparison purposes, blank experiments in the absence of coal additive were also carried out. The results indicate that considerable reduction in viscosity and increased distillate yields can be achieved by processing heavy oil with coal additive. The API gravity of the liquid product is also improved. Increased amounts of gaseous products with changed composition are obtained in the presence of coal. Under certain conditions, significant dissolution of coal occurs even at the relatively mild conditions used.     

Flash pyrolysis of Australian coals: Effects of pre-oxidation and of oxygen in the inlet gases on formation of agglomerated material

Addition of oxygen to nitrogen in the inlet gas during flash pyrolysis at 600 °C reduced the amount of char agglomerate formed from a relatively strongly caking Liddell seam coal and a weakly caking Millmerran seam coal. The reduction of agglomeration was significant over the entire ranges of variables used, viz, oxygen concentrations in the inlet gas of 2.62–10.5% (v/v) and oxygen to coal ratios of 0.02–0.12 (wt/wt). Pre-oxidation at 400 °C with solids residence times below 2 s, inlet concentrations of oxygen up to 10.5% and oxygen to coal ratios up to 0.10 (wt/wt) also effectively reduced agglomeration of Liddell coal. In terms of minimizing the oxygen requirement to obtain essentially nonagglomerating solids, the preferred method was found to be pre-oxidation followed by oxidative pyrolysis. The reduction of agglomeration by oxygen appears to be due to a combination of the extent of coal oxidation and the extents of polymerization and chemical condensation of the coal structure.