Science Letters： Discovery of ultrahigh-T spinel-garnet granulite with pure CO2 fluid inclusions from the Altay orogenic belt, NW China

We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the orthopyroxenes have high XMg and Al2O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88g/cm^3. Based on preliminary mineral paragenesis, reaction textures and petrogenetic grid considerations, we infer that the rock was subjected to UHT conditions. The CO2-rich fluids were trapped during exhumation along a clockwise P-T path following isothermal decompression under UHT conditions.

Experimental Study on Water-rock Reactions with CO2 Fluid in a Deep Sandstone Formation under High Temperature and Pressure

Qiongdongnan Basin has a tectonic geological background of high temperature and high pressure in a deep reservoir setting,with mantle-derived CO2.A water-rock reaction device was used under high temperature and high pressure conditions,in conjunction with scanning electron microscope(SEM)observations,to carry out an experimental study of the diagenetic reaction between sandstone at depth and CO2-rich fluid,which is of great significance for revealing the dissolution of deep clastic rock reservoirs and the developmental mechanism of secondary pores,promoting deep oil and gas exploration.In this study,the experimental scheme of the water-rock reaction system was designed according to the parameters of the diagenetic background of the deep sandstone reservoir in the Qiongdongnan Basin.Three groups of single mineral samples were prepared in this experiment,including K-feldspar samples,albite samples and calcite samples.Using CO2 as a reaction solution,a series of diagenetic reaction simulation experiments were carried out in a semi-closed high temperature and high pressure simulation system.A field emission scanning electron microscope(SEM)was used to observe the microscopic appearance of the mineral samples after the water-rock reaction,the characteristics of dissolution under high temperature and high pressure,as well as the development of secondary pores.The experimental results showed that the CO2-rich fluid has an obvious dissolution effect on K-feldspar,albite and calcite under high temperature and high pressure.For the three minerals,the main temperature and pressure window for dissolution ranged from 150℃to 300℃and 45 MPa to 60 MPa.Scanning electron microscope observations revealed that the dissolution effect of K-feldspar is most obvious under conditions of 150℃and 45 MPa,in contrast to conditions of200℃and 50 MPa for albite and calcite.Through the comparative analysis of experimental conditions and procedures,a coupling effect occurred between the temperature and pressure change and the dissolution strength and calcite.Under high temperature and high pressure,pressure changed the solubility of CO2,furthermore,the dissolution effect and strength of the sandstone components were also affected.The experiment revealed that high temperature and high pressure conditions with CO2-rich fluid has a significant dissolution effect on aluminosilicate minerals and is conducive to the formation of secondary pores and effective reservoirs.Going forward with the above understanding has important implications for the promotion of deep oil and gas exploration.

A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles

The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.

In situ Raman spectroscopic quantification of CH4–CO2 mixture: application to fluid inclusions hosted in quartz veins from the Longmaxi Formation shales in Sichuan Basin, southwestern China

We re-evaluate the Raman spectroscopic quantification of the molar ratio and pressure for CH4–CO2 mixtures.Firstly,the Raman quantification factors of CH4 and CO2 increase with rising pressure at room temperature,indicating that Raman quantification of CH4/CO2 molar ratio can be applied to those fluid inclusions(FIs)with high internal pressure(i.e.,>15 MPa).Secondly,the v1(CH4)peak position shifts to lower wavenumber with increasing pressure at constant temperature,confirming that the v1(CH4)peak position can be used to calculate the fluid pressure.However,this method should be carefully calibrated before applying to FI analyses because large discrepancies exist among the reported v1(CH4)-P curves,especially in the highpressure range.These calibrations are applied to CH4-rich FIs in quartz veins of the Silurian Longmaxi black shales in southern Sichuan Basin.The vapor phases of these FIs are mainly composed of CH4 and minor CO2,with CO2 molar fractions from4.4%to 7.4%.The pressure of single-phase gas FI ranges from 103.65 to 128.35 MPa at room temperature,which is higher than previously reported.Thermodynamic calculations supported the presence of extremely high-pressure CH4-saturated fluid(218.03–256.82 MPa at 200°C),which may be responsible for the expulsion of CH4 to adjacent reservoirs.

丁香精油的超临界CO2和溶剂回流萃取及其GC-MS分析

研究了超临界CO2流体萃取技术(SFE)和溶剂回流法萃取丁香精油,所得精油经气相色谱(GC)-质谱(MS)分析。结果显示:溶剂回流法宜采用正己烷为溶剂,最佳工艺条件为:料液比(g∶mL)1∶15、回流温度80℃、回流时间30min;SFE最佳工艺条件为:萃取温度45℃、萃取压力12MPa、解析温度50℃、萃取时间90min。验证试验显示:SFE法收油率达到21.04%,高于溶剂回流法(17.401%),所得精油色泽和流动性较优。经GC-MS分析显示:所得精油的组成相似,但含量不同,溶剂回流法除β-石竹烯的含量略高外,3种主要活性物质丁香酚、乙酰基丁香酚、β-石竹烯的的含量和提取率均低于SFE法提取的精油。SFE法是提取丁香精油值得推广和有前景的一种方法。

超临界CO2萃取三七总皂苷

三七总皂苷为药材三七的主要生物活性物质,已有的提取方法虽技术成熟,但存在提取率低、高污染等诸多缺点。该文以三七主根为原料,先采用粉碎工艺或轧胚工艺对其预处理,然后在超临界CO2中试设备中,分别考察了原料的两种预处理方法及提取工艺条件对三七总皂苷提取率的影响,通过正交实验对工艺条件进行了优化:粉碎工艺适宜的萃取温度45℃,压力38 MPa,CO2流量23 kg/h,夹带剂300 mL,萃取时间3.0 h,提取率7.97%;轧胚工艺适宜的萃取温度45℃,压力35 MPa,CO2流量20 kg/h,夹带剂350 mL,萃取时间2.5 h,提取率9.98%。该文报告工作的新颖性,已为教育部科技查新工作站(Z12)2007年10月10日出具的第ZDT 2007106号《科技查新报告》所证实。

罗勒子油的超临界CO2提取工艺及其成分分析

研究萃取温度、萃取压力、萃取时间对超临界CO_2萃取罗勒子油得率的影响,进行了工艺的优化。结果表明,影响超临界CO_2萃取罗勒子油得率的因素主次顺序为A(压力)>C(时间)>B(温度),最佳工艺条件为萃取压力300 Pa,萃取温度45℃、萃取时间为3 h。在此工艺条件下,罗勒子油得率为17.05%。罗勒子油脂肪酸组成主要为亚麻酸(85.76%)、棕榈酸(8.54%)和硬脂酸(5.1%),其中不饱和脂肪酸含量为86.35%。

海拉尔盆地乌尔逊凹陷无机CO2充注驱油的流体包裹体证据

CO2充注驱油是一种普遍的地质现象,对揭示油气藏中油气的动态成藏规律具有重要的指示意义。海拉尔盆地乌尔逊凹陷含片钠铝石砂岩既示踪了CO2充注,又记录了油气充注,是进行CO2充注驱油研究的理想岩石类型。通过岩石学和流体包裹体地球化学研究,确定了含片钠铝石砂岩的成岩共生序列、油气充注历史和CO2充注驱油的微观证据。研究表明,该区油气充注是一个连续的过程,开始于石英次生加大早期（120 Ma）,在片钠铝石沉淀前（105-95 Ma）达到充注高峰。CO2充注晚于大规模油气充注,充注之后形成的自生矿物组合为片钠铝石与铁白云石。片钠铝石中首次发现一定数量的原生油气包裹体,为CO2充注驱油提供了重要的微观证据。

亚临界CO2萃取不同产地八角果实化学成分的GC—MS分析。

采用亚临界CO2萃取法萃取广西4个八角主产区八角的挥发油，对其进行气相色谱-质谱联用（GC-MS）分析，以期得到不同产区八角挥发性成分的更真实信息，筛选出最佳原料产地，促进八角资源的合理开发利用。结果表明：在防城港、玉林、那坡和金秀所产八角果实的挥发油中分别鉴定出82、70、70和69种化合物，其峰面积分别占总峰面积的98．96％、91．83％、99．56％和97．77％；4个产区果实挥发性成分均是以芳香族化合物为主，分别占总量的94．31％、90．59％、95．32％、97．60％；4个产区八角果实挥发油中反式茴香脑的相对含量分别为91．2178％、86．2760％、89．3585％和87．9586％，其中防城港所产八角的挥发油中反式茴香脑的含量最高，八角品质最好。

超临界CO2萃取法和乙醇回流提取法提取大高良姜中1＇-乙酰氧基胡椒酚乙酸酯的比较

本实验采用CO2超临界流体萃取法(CO2-SFE)和乙醇回流法提取大高良姜的有效成分1'-乙酰氧基胡椒酚乙酸酯(ACA),通过硅胶柱纯化前后TLC图谱、HPLC图谱、有效成分ACA的含量及萃取物的物理指标为指标评价两种方法。结果表明:CO2-SFE提取物所含杂质较少,萃取的挥发油中ACA的含量达72.11%。CO2-SFE法得到ACA的净含量是乙醇回流法的5.6倍。用CO2-SFE提取大高良姜中的ACA明显优于乙醇回流法。

苏北盆地黄桥地区富CO2流体对油气储-盖系统的改造作用

查明富CO2流体对储-盖系统的改造作用,对于研究CO2活动与油气成藏效应、CO2储存和CO2驱油提高采收率有着重要意义。选取下扬子苏北盆地黄桥地区和句容地区的二叠系龙潭组储层和大隆组盖层组合,分别作为有无CO2流体活动的对比研究对象。通过薄片观察统计、矿物成分和碳同位素分析,查明了两个地区储层的异同点。黄桥地区储层的自生矿物以石英次生加大边和高岭石充填为主,发育少量片钠铝石,句容地区不发育片钠铝石,且次生石英含量不高;黄桥地区储层孔隙度明显高于句容地区,薄片下观察到大量长石溶蚀孔隙,偶见长石溶蚀孔内生长片钠铝石雏晶,是CO2与长石发生水岩相互作用的直接证据;黄桥地区和句容地区盖层均为黑色块状泥岩,黄桥地区盖层发育微裂隙,但裂隙均已再充填方解石脉,碳同位素数据表明方解石脉为富CO2流体活动结果,在句容地区泥岩盖层中未见大量裂隙和矿物脉。综合研究分析表明,富CO2流体充注引起储层砂岩中长石大量溶蚀,增加了孔隙空间,片钠铝石、次生石英和高岭石自生矿物组合序列沉淀,同时富CO2流体的连续活动导致泥岩盖层发生方解石沉淀,充填盖层裂缝,有利于提高盖层的封盖能力。

超临界CO2萃取芦蒿挥发油的正交试验及GC-MS分析

目的:确定芦蒿挥发油超临界CO2萃取的最佳条件,并对挥发油中化学成分进行分析。方法:采用超临界CO2萃取芦蒿挥发油的正交试验,研究其萃取工艺条件,探讨萃取压力、萃取温度、萃取时间、CO2夹带剂用量对挥发油收率的影响,并用气相色谱-质谱联用技术对其挥发油中化学成分进行分析。结果:确定了超临界CO2萃取芦蒿中挥发油的最佳条件:萃取压力40MPa,萃取温度45℃,萃取时间3h,夹带剂用量1.5ml/g,在最佳条件下芦蒿挥发油的收率为3.12%;气相色谱-质谱联用技术从芦蒿挥发油中共分离出45个峰,确定了其中的37种化合物,经峰面积归一化法测定了各组分的相对百分含量,所鉴定成分占总馏出峰面积的93.12%。主要成分蓝香油薁具有多种较强的生理活性。结论:本研究结果为芦蒿的进一步综合开发利用提供科学依据。

超临界CO2萃取分蘖葱头精油的研究

通过单因素和正交实验研究,对超临界CO2萃取分蘖葱头精油的工艺进行了优化设计。实验结果表明各因素对分蘖葱头精油得率的影响主次顺序是:萃取压力>萃取温度>萃取时间>料液比;最佳萃取实验工艺条件为:萃取压力35MPa,萃取温度50℃,萃取时间3h,料液比(g:mL)1:1.5,分蘖葱头精油的得率为0.4715%。

响应面法优选胡桃醌超临界CO2流体提取工艺

目的优化胡桃醌超临界CO_2流体提取工艺。方法以胡桃醌提取率为考察指标,萃取压力、萃取温度、萃取时间为考察变量,利用响应面分析方法优化最佳工艺参数。结果胡桃醌超临界CO_2流体提取的最佳工艺参数为萃取压力45 MPa,萃取温度为40℃,萃取时间为90 min,95%乙醇为夹带剂,夹带剂流量0.5 mL/min,CO_2流量为2 mL/min胡桃醌提取率可达80.33%。结论优选的工艺稳定可行,可推广使用。

沙葱籽油的超临界CO2萃取及成分分析

以野生沙葱种子为原料,利用超临界CO2流体萃取沙葱籽油。在单因素试验基础上,采用正交试验设计,考察压力、温度、萃取时间、CO2流量4因素对沙葱籽油萃取率的影响。研究得出最佳萃取条件为压力35MPa、温度45℃、萃取时间120min、CO2流量35kg/h,在此条件下油脂萃取率为15.00%。利用GC-MS对沙葱籽油分析,发现沙葱籽油中不饱和脂肪酸主要为亚油酸(63.24%)和油酸(15.99%),占脂肪酸总量的86.65%;饱和脂肪酸以棕榈酸(7.93%)为主,占脂肪酸总量的13.35%。用常规方法对沙葱籽油的理化性质进行测定,结果表明超临界CO2流体萃取法得到的沙葱籽油各项理化指标均良好,产物纯度高、品质好。

页岩气低伤害超临界CO2凝胶压裂液研究

针对常规水压裂液会对页岩造成伤害,容易产生水锁,不易返排,还造成水资源消耗和污染环境等问题,制备了低伤害二氧化碳凝胶压裂液。将自备的F2EU和F4EU增稠剂加入到超临界CO2基液中,探究两种增稠剂的加入量对CO2凝胶压裂液黏度的影响,综合考虑成本与效果,优选了2%的F4EU增稠剂,可将CO2的黏度增至15.4 mPa·s。研究了温度、压力以及剪切速率对凝胶压裂液黏度的影响。实验结果表明,随着温度升高黏度总体降低,但中间出现一个短暂升高阶段;随着压力上升压裂液黏度增加;随着剪切速率的增加压裂液黏度下降,属于一种典型的剪切变稀的假塑性流体。F4EU超临界CO2凝胶压裂液的平均伤害率为1.39%,远远小于常规压裂液对岩芯的伤害率。实验表明,F4EU超临界CO2凝胶压裂液在页岩气压裂开采中具有良好的应用前景。

小油桐叶超临界CO2萃取物的GC-MS分析

目的对小油桐叶生物活性成分进行分析。方法采用GC-MS技术分析小油桐叶的超临界CO2萃取物。结果超临界CO2萃取后,应用GC-MS分析得到70个峰,确定了其中43种化合物(占61.43%),其中含量占1%以上的有16种化合物,占所有化合物总量的81.36%。含量最为丰富的4种物质依次为:22,23-二羟基豆甾醇,占16.14%;α-维生素E,占15.18%;β-香树素,占7.73%;三十二烷醇,占7.02%。此外,检测出小油桐叶富含γ-维生素E(2.88%),维生素E总相对含量高达18.06%。结论小油桐叶富含多种抗肿瘤、抗病毒、抗真菌及细菌的成分,有较高的开发利用价值。

Comparison of Constituents and Insecticidal Activities of Essential Oil from Artemisia lavandulaefolia by Steam Distillation and Supercritical-CO_2 Fluid Extraction

Essential oil was extracted from Artemisia lavandulaefolia DC.by steam distillation（SD） and supercritical-CO2 fluid extraction（SFE）,respectively.The constituents of the essentil oils extracted with those two methods were analyzed by gas chromatography-mass spectrometry（GC-MS） and insecticidal activities of the essential oils were evaluated,then the results were compared to assess their biological activity.Thirty-one compounds were identified in the essential oil extracted by SD,and its main components were eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol and so on.Twenty-two compounds were identified for the essential oil extracted by SFE,and its main components were cyclodecene,n-hexadecanoic acid and so on.Six chemical compositions were all contained in the essential oils extracted by the two methods,i.e.,eucalyptol,α,α,4-trimethyl-3-cyclohexene-1-methanol,caryophyllene,[3aS-（3aα,3bβ,4β,7α,7aS）]-octahydro-7-methyl-3-methylene-4-（1-methylethyl）-1H-cyclopenta[1,3]cyclopropa-[1,2]benzene,nerolidol and（-）-Spathulenol.The fumigation toxicity of the essential oil obtained by means of SD to the adults of Sitophilus zeamais is significantly higher than that of the essential oil by means of SFE.The contact toxicity of the essential oil obtained by means of SFE to the adults of S.zeamais is higher than that of the essential oil obtained by means of SD,but the difference is not significant.

CO2响应性清洁压裂液的研究与评价

制备了CO2响应性的黏弹性表面活性剂TAV作为清洁压裂液的稠化剂,筛选了反离子盐,得到了压裂液体系的最佳配方,测定了TAV溶液接触CO2质子化前后的油水界面张力,考察了压裂液的流变性、携砂性、破胶与循环性能及其对岩心伤害情况。实验结果表明,CO2响应后的TAV溶液可大幅降低油水界面张力,2.5%(w)的TAV溶液在0.2%(w)KCl助剂下,溶液黏度可达78 mPa·s,在110℃下流变剪切120 min黏度满足要求,体系对20~100目范围内的石英砂具有很好的悬浮性,120 min后仍处于均匀分布的状态;电导率测试证实该体系可重复CO2/N2响应,在40℃时通N2后8 min即可破胶,且对岩心伤害最低达到12.7%。