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热煤气一体化净化工艺中的脱硫反应特征 总被引:1,自引:0,他引:1
利用固定床反应器考察了高温煤气脱硫除尘一体化净化工艺中沉积粉尘对高温煤气脱硫剂脱硫性能的影响.结果表明,表面沉积粉尘对脱硫剂初次硫化行为有明显的影响,且与脱硫剂的组成和结构有关.利用钢厂赤泥制备的脱硫剂,含有多种惰性杂质,且具有较大的孔径结构,易于和粗煤气中的粉尘作用,造成脱硫剂硫容的减小.硫化气氛中,H2O的存在造成脱硫剂硫容和脱硫效率的降低,但不会影响因表面沉积粉尘造成的脱硫剂硫容的减小.多次硫化-再生循环实验表明,硫化-再生循环过程有助于减小表面沉积粉尘对脱硫剂脱硫行为的影响.经历一定次数的硫化-再生循环后,粉尘对脱硫剂脱硫行为的影响逐渐消失. 相似文献
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高温煤气铁系脱硫剂的研究 总被引:6,自引:5,他引:6
高温煤气脱硫净化是目前先进洁净煤利用技术之一 ,但是以前高温煤气脱硫剂在多次硫化再生循环过程中出现粉化 ,妨碍脱硫剂进一步使用 .本研究选择钢厂赤泥作为脱硫剂原料 ,添加不同活性组分和防粉化结构助剂 ,制备了氧化铁基高温煤气脱硫剂 .经过 1 0次硫化 /再生循环实验 .结果表明 :1 0次循环累计 1 96.98% ,再生后脱硫活性不发生变化 ,具有较高和较稳定的脱硫活性 .再生后脱硫剂的机械强度高于新鲜样品 ,在使用过程中没有出现粉化现象 ,这为氧化铁基高温煤气脱硫剂的工业化研究提供了可靠的依据 . 相似文献
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煤气的高温脱硫净化是 IGCC 和 DRI 生产的瓶颈,直接影响整个过程的热效率。在50℃、pH值约为9的条件下采用硝酸锰、硝酸铝混合溶液与氨水进行共沉淀,制备了锰含量不同的脱硫剂,在固定床反应器中考察了脱硫剂的硫化及再生性能,并利用XRD、SEM、BET等手段表征了脱硫剂在硫化/再生过程中的物相和结构变化。共沉淀法制备的脱硫剂Mn/Al分散性好,在850℃高温下进行脱硫反应可以定量快速进行。脱硫硫容与脱硫剂锰含量呈正比,Mn-S/Mn-O交换原子比在0.90~0.95之间,改变空速和进口H2S含量并不改变脱硫硫容。采用O2浓度为3%的稀释空气在850℃下再生,再生后的硫容稳定,说明所制备的脱硫剂可用于高温可再生脱硫。 相似文献
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ZnFe2O4高温煤气脱硫剂的还原与硫化 总被引:1,自引:0,他引:1
采用共沉淀法制备了ZnFe2O4高温煤气脱硫剂,并在动态热天平上对其还原和硫化行为进行了研究,分别考察了温度、反应气氛对脱硫性能的影响。低于300℃,还原反应基本不发生:在450℃出现ZnFe2O4脱硫剂的最大还原速率:CO还原能力远不及ZnFe2O4脱硫剂硫化反应速率与浊度、H2S浓度成正比,300℃左右出现ZnFe2O4脱硫剂的最大硫化速率。还原与硫化反应可用等效应粒子模型描述,ZnFe2O4脱硫剂的还原与硫化反应存在控制段的转移。 相似文献
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铁钙混合氧化物脱硫剂的硫化与再生过程研究 总被引:9,自引:0,他引:9
煤炭是世界上最丰富的化石燃料,有效提高煤炭利用效率和控制环境污染是目前面临的重要研究课题。先进的整体煤气联合循环发电(IGCC)和燃料电池(MCFC)技术被认为是煤炭利用的最佳途径。高温脱除燃料 气中的H2S是其中的关键技术,高温脱硫目前存在的问题是脱硫剂使用过程的粉化。本文研制出铁钙混合氧化物脱硫剂,采用固定床反应器,考察了不同配比铁混合氧化物的硫化及再生性能。结果表明,当Fe2O3与CaO等摩尔比时,脱硫剂有良好的硫化和再生性能。用H2O(g) O2进行再生时,先后有H2S和SO2逸出,并伴有单质硫形成。该脱硫剂连续硫化-再生循环稳定,且硫容逐渐增加,脱硫效率和机械强度亦逐步提高。 相似文献
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Bowu CHENG Zhaofei CAO Yong BAI Dexiang ZHANG 《Frontiers of Chemical Engineering in China》2010,4(4):441-444
A series of iron-based sorbents prepared with iron trioxide hydrate, cupric oxide by a novel method was studied in a fixed-bed
reactor for COS removal from syngas at moderate temperature. In addition, the sorbents mixed with various additives in different
ratios were tested. The effects of additive type and ratio on the breakthrough capacity and desulfurization performance, as
well as the influence of operating conditions on sulfidation behavior of the sorbent, were investigated. The simulate gas
contained 1% COS, 5% CO2, 20%–30% CO and 60%–70% H2. The outlet gases from the fixed-bed reactor were automatically analyzed by on-line mass spectrometry, and the COS concentration
before breakthrough can be kept steady at 1 ppmv. The result shows that the breakthrough sulfur capacity of the sorbent is
as high as 25 g-S/100 g. At 700 K and space velocity of 1000 h−1, the efficiency of sulfur removal and breakthrough sulfur capacity of the sorbent increase with the increase of copper oxide
with an optimum value. The result shows that the species and content of additives also affect desulfurization performance
of the sorbent. 相似文献
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Xiurong Ren Weiren Bao Fan Li Liping Chang Kechang Xie 《Frontiers of Chemical Engineering in China》2010,4(4):429-434
A series of iron-manganese-based sorbents were prepared by co-precipitation and physical mixing method, and used for H2S removal from hot coal gas. The sulfidation tests were carried out in a fixed-bed reactor with space velocity of 2000 h−1(STP). The results show that the suitable addition of manganese oxide in iron-based sorbent can decrease H2S and COS concentration in exit before breakthrough due to its simultaneous reaction capability with H2S and COS. Fe3O4 and MnO are the initial active components in iron-manganese-based sorbent, and FeO and Fe are active components formed by
reduction during sulfidation. The crystal phases of iron affect obviously their desulfurization capacity. The reducibility
of sorbent changes with the content of MnO in sorbent. S7F3M and S3F7M have bigger sulfur capacities (32.68 and 32.30 gS/100
g total active component), while S5F5M has smaller sulfur capacity (21.92 gS/100 g total active component). S7F3M sorbent
has stable sulfidation performance in three sulfidation-regeneration cycles and no apparent structure degradation. The sulfidation
performance of iron-manganese-based sorbent is also related with its specific surface area and pore volume. 相似文献
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Cerium oxide‐doped ZnFe2O4 sorbents supported on modified semi‐coke (MSC) were prepared to improve the desulfurization efficiency of zinc ferrites. The sulfidation tests of the ZnFe2O4/MSC sorbents with and without Ce were carried out using a fixed‐bed reactor at 450 °C. The effect of the CeO2/ZnFe2O4 molar ratio of the sorbents on the sulfur capacity was studied. The characteristics of the sorbents were analyzed by X‐ray diffraction, N2 adsorption, scanning electron microscopy and X‐ray photoelectron spectroscopy. The results showed that cerium oxide could greatly improve the desulfurization reactivity of the ZnFe2O4/MSC sorbents. The molar ratio of Ce to Zn and Fe influences the desulfurization reactivity, and a good sulfur capacity of the sorbent can be obtained with a Ce/Zn/Fe ratio of 4:4:1. It was also found that the addition of CeO2 could enlarge the surface area and the pore volume, thus improving the dispersion of active components. Ce doping results in an increment of the oxygen adsorbed on the sorbent surface, which facilitates the adsorption of H2S. The Ce ions could act as carriers of the oxidation and reduction reactions and the oxygen transfer could be accelerated during the desulfurization process of coal gas. 相似文献
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Ruizhuang ZHAO Ju SHANGGUAN Yanru LOU Jin SONG Jie MI Huiling FAN 《Frontiers of Chemical Engineering in China》2010,4(4):423-428
Regeneration of a high-temperature coal gas desulfurization sorbent is a key technology in its industrial applications. A
Fe2O3-based high-temperature coal gas desulfurizer was prepared using red mud from steel factory. The influences of regeneration
temperature, space velocity and regeneration gas concentration in SO2 atmosphere on regeneration performances of the desulfurization sorbent were tested in a fixed bed reactor. The changes of
phase and the composition of the Fe2O3-based high-temperature coal gas desulfurization sorbent before and after regeneration were examined by X-ray diffraction
(XRD) and X-ray Photoelectron spectroscopy(XPS), and the changes of pore structure were characterized by the mercury intrusion
method. The results show that the major products are Fe3O4 and elemental sulfur; the influences of regeneration temperature, space velocity and SO2 concentration in inlet on regeneration performances and the changes of pore structure of the desulfurization sorbent before
and after regeneration are visible. The desulfurization sorbent cannot be regenerated at 500°C in SO2 atmosphere. Within the range of 600°C–800°C, the time of regeneration becomes shorter, and the regeneration conversion increases
as the temperature rises. The time of regeneration also becomes shorter, and the elemental sulfur content of tail gas increases
as the SO2 concentration in inlet is increased. The increase in space velocity enhances the reactive course; the best VSP is 6000 h−1 for regeneration conversion. At 800°C, 20 vol-% SO2 and 6000 h−1, the regeneration conversion can reach nearly to 90%. 相似文献
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Ruizhuang Zhao Ju Shangguan Yanru Lou Jin Song Jie Mi Huiling Fan 《Frontiers of Chemical Science and Engineering》2010,4(4):423-428
Regeneration of a high-temperature coal gas desulfurization sorbent is a key technology in its industrial applications. A Fe2O3-based high-temperature coal gas desulfurizer was prepared using red mud from steel factory. The influences of regeneration temperature, space velocity and regeneration gas concentration in SO2 atmosphere on regeneration performances of the desulfurization sorbent were tested in a fixed bed reactor. The changes of phase and the composition of the Fe2O3-based high-temperature coal gas desulfurization sorbent before and after regeneration were examined by X-ray diffraction (XRD) and X-ray Photoelectron spectroscopy(XPS), and the changes of pore structure were characterized by the mercury intrusion method. The results show that the major products are Fe3O4 and elemental sulfur; the influences of regeneration temperature, space velocity and SO2 concentration in inlet on regeneration performances and the changes of pore structure of the desulfurization sorbent before and after regeneration are visible. The desulfurization sorbent cannot be regenerated at 500°C in SO2 atmosphere. Within the range of 600°C–800°C, the time of regeneration becomes shorter, and the regeneration conversion increases as the temperature rises. The time of regeneration also becomes shorter, and the elemental sulfur content of tail gas increases as the SO2 concentration in inlet is increased. The increase in space velocity enhances the reactive course; the best VSP is 6000 h?1 for regeneration conversion. At 800°C, 20 vol-% SO2 and 6000 h?1, the regeneration conversion can reach nearly to 90%. 相似文献
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范武波刘勇军王维竹郭家秀李建军尹华强 《四川化工》2014,(1):49-53
有色金属冶炼烟气中SO2浓度高、气量波动大。目前还没有特别有效的处理技术脱除有色金属冶炼烟气中高浓度的SO2。本文采用粘胶基活性炭纤维(ACF)为脱硫剂,对脱除模拟有色冶炼烟气中SO2(0.3%-0.8%)的性能进行了研究,考察了水蒸气含量、床层温度、SO2浓度以及体积空速对ACF脱硫性能的影响。研究结果表明:随着水蒸气含量的增加,ACF脱硫效率逐渐提高,随着反应温度的增加,脱硫效率先增加后减小。当烟气中SO2浓度为0.8%时,在水蒸气含量为33.6%、反应温度为100℃及空速为500h-1时,脱硫效果最佳,平台阶段脱硫效率达41%。降低入口SO2浓度和体积空速可进一步提高ACF脱硫的穿透时间、穿透硫容和平台阶段脱硫效率。 相似文献
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分别以硝酸铁和草酸铁分解产物及分析纯氧化铁为活性组分进行脱硫剂制备,在固定床活性评价装置上对其硫化性能进行考察。结果表明,CF750、NF750和F750脱硫剂的孔结构和比表面积相差不大,但以硝酸铁和草酸铁为前驱体分解得到的活性组分粒径小于氧化铁,硝酸铁和草酸铁分解产物制备的脱硫剂对H_2S的脱除活性优于分析纯氧化铁,脱硫剂对硫化过程中出现的COS具有相同的脱除规律,硝酸钾的改性提高了脱硫剂的还原温度,减弱了CO_2与H_2S的竞争吸附能力,抑制了CO的歧化反应,有利于H_2S和COS脱除能力的改善。 相似文献
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Jinxiao Dou Yongqi Zhao Arash Tahmasebi Jianglong Yu 《Korean Journal of Chemical Engineering》2016,33(10):2849-2857
The sulfidation and regeneration properties of lignite char-supported iron-based sorbent for coke oven gas (COG) desulfurization prepared by mechanical stirring (MS), ultrasonic assisted impregnation (UAI), and high pressure impregnation (HPI) were investigated in a fixed-bed reactor. During desulfurization, the effects of process parameters on sulfidation properties were studied systematically. The physical and chemical properties of the sorbents were analyzed by X-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared (FTIR) and BET surface area analysis. The results of desulfurization experiments showed that high pressure impregnation (HPI) enhanced the sulfidation properties of the sorbents at the breakthrough time for char-supported iron sorbents. HPI method also increased the surface area and pore volume of sorbents. Sulfur capacity of sorbents was enhanced with increasing sulfidation temperatures and reached its maximum value at 400 °C. It was observed that the presence of steam in coke oven gas can inhibit the desulfurization performance of sorbent. SO2 regeneration of sorbent resulted in formation of elemental sulfur. HPIF10 sorbent showed good stability during sulfide-regeneration cycles without changing its performance significantly. 相似文献