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添加剂种类对活性炭纤维的中孔结构的影响 总被引:7,自引:0,他引:7
纺制了含不同种类添加剂(金属氧化物,聚合物及炭素颗粒)的PAN原丝,经预氧化,炭化活化,制得了中孔含量不同的活性炭纤维,考察了添加剂种类对活性炭纤维中孔结构的影响,发现金属氧化物TiO2,MgO,聚合物PVA,PVAc及炭黑均可明显提高最终活性炭纤维的中孔率。 相似文献
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以重质沥青为原料,采用空气热聚合法-物理活化法协同制备重质沥青基活性炭。通过正交设计法系统研究了预氧化升温速率、恒温温度、恒温时间、活化时间、活化温度、炭化时间、炭化温度等因素对重质沥青基活性炭的影响。利用扫描电镜、碘吸附值等对活性炭的表面形态及吸附特性进行表征。结果表明,空气热聚合法-物理活化法协同制备重质沥青基活性炭的优化条件为:预氧化升温速率为2℃/min、预氧化恒温温度为300℃、预氧化恒温时间为1 h、炭化温度为500℃、炭化时间为120 min、活化温度为850℃、活化时间为90 min,该工艺条件下制备的活性炭具有较为发达的微孔结构,碘吸附值为689.33 mg/g。 相似文献
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在煤基球形活性炭的制备过程中,生球预氧化条件很大程度上决定了球形炭的球形度和物化特性。以山西柳林华晋焦煤集团焦煤为原料,研究了活性炭制备过程中预氧化、炭化、活化等工艺参数对活性炭质量的影响。结果表明:预处理温度为200℃,预处理时间3 h,炭化终温700℃,炭化升温速率4℃/min,活化温度800℃,活化时间7 h时,制得的活性炭球形度完整,物化性能优良,活性炭的碘值为770.18 mg/g,亚甲基蓝值为64.24 mg/g。随着预处理时间的增加,活性炭的强度和产率都增大。试验结果对煤基球形活性炭的生产具有一定的指导意义。 相似文献
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炭化温度对酚醛基活性炭纤维孔结构的影响 总被引:2,自引:0,他引:2
从酚醛纤维出发,经过炭化和KOH活化制备了酚醛基活性炭纤维(PACF),并对不同温度下炭化样品的比表面积、孔结构以及表面形态之间的关系进行了探讨。采用氮气(77K)吸附法测定PACF活性炭纤维的孔结构和比表面积。结果表明:用KOH在900℃对低于500℃炭化纤维进行活化,不能保持纤维形态,只能得到碳收率低、比表面积高的粉状物,而高于500℃炭化样品则可保持纤维形态。随着炭化温度的升高,所有样品的整体孔径分布范围基本相同,而平均孔径,比表面积和孔容逐渐缩小。 相似文献
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介绍了活性炭生产过程中炭化设备及工艺的基本情况,通过设备改造及工艺改进,研发了外热式氧化、炭化设备及工艺,分析了炭化工艺运行过程中的影响因素。实践证明,在炭化工艺前采用适当的热空气预氧化处理,可大幅度提高活性炭制品的性能,同时加快活化反应速率,提高活化炉的生产效率。采用自主研发的外热式回转炉作为预氧化和炭化工艺的设备,通过设计炉体内部结构,改变加热方式,有效解决了内热式回转炉存在的温度难以控制及影响产品质量的问题。采用新疆地区弱黏结性煤生产的压块料,通过入口温度、升温速率、炭化最终温度的控制,提高炭化料和活性炭产品质量。 相似文献
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《高科技纤维与应用》2001,(6)
硼酸活化法制备 活性炭纤维的工艺 本发明涉及一种活性炭纤维制备方法。采取硼酸作为碳化活化剂浸泡纤维素纤维原料,取出干燥后,置于加热炉中碳化活化一定时间,得到活性炭纤维。木发明方法操作方便,产品得率高,生产成本低,杂质含量低。专利申请号:99116239;公开号:1238395 旋转逆流式预氧化炉 生产碳纤维毡的旋转逆流式预氧化炉,它在由炉外层、保温层、炉内层、炉门、测温孔、排气孔构成的炉体内设置狭隙层,位于炉腔上部的电阻丝沿圆周均匀分布构成加热系统,设置于加热系统上方的送风系统由主轴装配风叶构成,该… 相似文献
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超级球形活性炭制备的研究 总被引:1,自引:0,他引:1
以煤沥青为主要原料采用悬浮法制备含致孔剂的煤沥青球后进行预氧化、炭化和活化,最终得到沥青基球形活性炭(PSAC)。借助扫描电子显微镜(SEM)和BET测试,所制得的PSAC球形度好、孔径分布范围窄,是一种高性能的炭质吸附材料。探讨了煤沥青球的预氧化、炭化和活化等工艺条件对PSAC的碘、苯和亚甲基蓝吸附值影响规律。结果表明:当分散荆、水溶液和沥青的吡啶溶液体积比为0.1:0.8:1时,适宜的成球温度为90℃、搅拌速度为200rpm及搅拌时间为20min,由此可制备出平均球形度大于0.9和平均粒径为25μm的煤沥青球;将所制备的煤沥青球经过预氧化温度280℃、预氧化时间6小时和炭化温度700℃、炭化时间40min及升温速率5℃/min,KOH与煤沥青的质量比为3:1的条件下,制备出煤沥青基球形活性炭的比表面积为3365m^2/g,碘、苯和亚甲基蓝吸附值分别达到2256mg/g、1068mg/g和390mg/g,微孔径主要集中分布在2~3nm左右的球形活性炭。 相似文献
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中间相沥青微球的活化 总被引:5,自引:0,他引:5
用KOH为活化剂,在不同活化条件下对中间相青微球进行活化,制备出比表面积为3182m^2/g,总孔容为2.45mL/g,苯吸附值为1320mg/g的高比表面积活性炭微球。研究了了KOH配比、活性温度和活化时间对活性炭微球的收率、比表面积和苯吸附值的影响。研究表明:随着KOH配比量或活化温度的提高,活化收率下降,活性炭微球的比表面积和七吸附值升高到一定值后下降;延长活化时间使活化反应进行完全,活性炭微球的活化收率、比表面积和苯吸附值仅有轻微变化。 相似文献
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以酚醛树指为原料,氢氧化钾为活化剂,制备酚醛树脂基超高比表面积活性炭。采用正交实验考查了制备工艺中炭化温度,碱炭比,活化温度和活化时间对活性炭吸附性能的影响,确定了超高比表面积活性炭的制备最佳工艺。利用TG—DTA对热解过程中树脂的炭化活化行为进行了探讨;通过N2-BET对活性炭比表面积和孔结构进行了表征,并简单分析了成孔机理。结果表明:炭化温度400℃,碱炭比为5:1,活化温度为750℃,活化时间为100min时,制备的酚醛树脂基活性炭比表面积为3013m^2·g^-1,孔容1.609ml/g,平均孔径2.135nm,亚甲基蓝吸附值为592mg·g^-1。 相似文献
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A comparison has been made between the catalytic effects of two groups of elements on the steam gasification of carbon: the alkaline earths and noble transition metals of Group VIII. Spectroscopically pure graphite was selected as a model carbon because it consists of well-defined crystals with a large number of atoms located in basal planes, which, without a catalyst, are of low reactivity. Moreover, foreign atoms which can enhance or inhibit catalysis are eliminated. Local overheating is prevented by the endothermic reaction with steam. It is not possible to distinguish unambiguously reaction-rate increases associated with a lowering of the activation energy and those caused by an increase of the reaction-site density. Thus conclusions about the mode of catalyst action are by necessity tentative. However, evidence from electron micrographs, in connection with elemental maps and theoretical calculations indicates that catalysis in the case of alkaline earths can be explained essentially by an increase of the reaction-site density. A close contact between these catalysts and the carbon surface is preserved during the reaction. In contrast, metals of Group VIII have a tendency to coalesce and to become isolated from the graphite surface. Here a lowering of the activation energy is a distinct possibility due to intercalation of these metals and weakening of the C-C bonds which are to be severed in the carbon gasification. 相似文献
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A comparison has been made between the catalytic effects of two groups of elements on the steam gasification of carbon: the alkaline earths and noble transition metals of Group VIII. Spectroscopically pure graphite was selected as a model carbon because it consists of well-defined crystals with a large number of atoms located in basal planes, which, without a catalyst, are of low reactivity. Moreover, foreign atoms which can enhance or inhibit catalysis are eliminated. Local overheating is prevented by the endothermic reaction with steam.
It is not possible to distinguish unambiguously reaction-rate increases associated with a lowering of the activation energy and those caused by an increase of the reaction-site density. Thus conclusions about the mode of catalyst action are by necessity tentative. However, evidence from electron micrographs, in connection with elemental maps and theoretical calculations indicates that catalysis in the case of alkaline earths can be explained essentially by an increase of the reaction-site density. A close contact between these catalysts and the carbon surface is preserved during the reaction. In contrast, metals of Group VIII have a tendency to coalesce and to become isolated from the graphite surface. Here a lowering of the activation energy is a distinct possibility due to intercalation of these metals and weakening of the C-C bonds which are to be severed in the carbon gasification. 相似文献
It is not possible to distinguish unambiguously reaction-rate increases associated with a lowering of the activation energy and those caused by an increase of the reaction-site density. Thus conclusions about the mode of catalyst action are by necessity tentative. However, evidence from electron micrographs, in connection with elemental maps and theoretical calculations indicates that catalysis in the case of alkaline earths can be explained essentially by an increase of the reaction-site density. A close contact between these catalysts and the carbon surface is preserved during the reaction. In contrast, metals of Group VIII have a tendency to coalesce and to become isolated from the graphite surface. Here a lowering of the activation energy is a distinct possibility due to intercalation of these metals and weakening of the C-C bonds which are to be severed in the carbon gasification. 相似文献