Investigation of Particle Breakdown in the Production of Composite Magnesium Chloride and Zeolite Based Thermochemical Energy Storage Materials

Composite thermochemical energy storage(TCES)represents an exciting field of thermal energy storage which could address the issue of seasonal variance in renewable energy supply.However,there are open questions about their performance and the root cause of some observed phenomena.Some researchers have observed the breakdown of particles in their production phase,and in their use.This study seeks to investigate the underlying cause of this breakdown.SEM and EDX analysis have been conducted on MgCl2 impregnated 13X zeolite composites of differing diameters,as well as LiX zeolite.This was done in order to study the level of impregnation of salt into the zeolite matrix,as well as the effect this impregnation process has on the morphology of the zeolite.Analysis was conducted using ImageJ software to study the effect of the impregnation process on the diameter of the particles.It has been found that a by weight impregnation concentration of magnesium chloride of 11.90%for the LiX zeolite,and 7.59%and 5.26%for the large diameter 13X zeolite and the small diameter 13X zeolite respectively has been achieved.It has been found that the impregnation process significantly affects themorphology of 13X zeolite particles,causing large fissures to form,and eventually resulting in the previously found breakdown of these particles.It has been verified that a primary factor influencing the breakdown of the 13X zeolite particles is the efflorescence and sub-fluorescence phenomena,which leads to a build-up of crystals in the zeolite pores.It has also been found that prolonged impregnation times and the use of high concentration salt solutions in the soaking process can induce significant crystal growth which also leads to the breakdown of these particles.Results demonstrate that LiX zeolite is the optimum host matrix choice in these conditions.These results will allow for the design of more resilient composite TCES particles.

Utilization of Various Analogy of Synthetic Nanoporous Zeolites and Composite of Zeolites for Decontamination/Detoxification of CWA Simulants—An Updated Review

In this review, we summaries the past few year work on the chemistry of CWA’s and their simulants on various heterogeneous surfaces of zeolites, composites of zeolites and doped zeolite with transition metal oxides. This review elaborates an updated literature overview on the degradation of CWA’s and its simulants. The data written in this review were collected from the peer-reviewed national and international literature.

Pore Structure and Catalytic Performance of Steam-Dealuminated ZSM-5/Y Composite Zeolites

For investigating the effect of dealumination on the pore structure and catalytic performance, ZSM-5/Y composite zeolites synthesized in situ from NaY gel were dealuminated by steaming at different temperatures. XRD (X-ray diffraction) characterization indicates that the relative crystallinity of the composite zeolites decreases with the increase in Si/Al ratio after steaming. N2 adsorption-desorption suggests that more mesopores are formed while the BET (Brunauer, Emmett and Teller) specific surface area and the micropore specific surface area decrease as the temperature of steaming rises. Daqing heavy oil was used as feedstock to test the catalytic cracking activity of ZSM-5/Y composite zeolites. The experimental results of the catalytic cracking performance reveal that the distribution of products differs due to the different conditions of hydrothermal treatment. Further hydrothermal treatment leads to an increase in the yield of light oil, and a decrease in the yield of gas products and coke.

Synthesis,characterization and catalytic properties of Y-β zeolite composites

Y-β zeolite composites were hydrotherrnally synthesized by using high silica Y zeolite as the precursor and characterized by XRD, N2 adsorption, SEM and IR spectra of pyridine. The result showed that the N2 adsorption-desorption isotherm of the zeolite composites had a distinct hysteresis loop, and the SEM result showed that the zeolite composites had a different morphology from Y, β and the corresponding physical zeolite mixture. The acid catalytic performance of the zeolite composite catalysts was investigated in the hydrocracking and hydroisomerization of n-octane, and the results showed that the composite materials exhibited an excellent hydrocracking activity and good hydroisomerization performance. The yield of i-C4 over the zeolite composite catalyst was 4.45% higher than that on the corresponding zeolite mixture in the n-octane hydrocracking process at 553 K. The isomerization ability of n-octane over the composite catalyst was 3.6 fold that of the corresponding mixture at 503 K.

Adsorption of Chromium （Ⅵ） from Aqueous Solution Using Zeolite/Chitosan Hybrid Composite

This study investigated the adsorption ability of ZCHC （zeolite/chitosan hybrid composite） as adsorbent for chromium （Cr（Ⅵ））, ZCHC was prepared with sol-gel method by mixing zeolite and chitosan. Adsorption experiment from aqueous solutions containing known amount of Cr（Ⅵ） using zeolite, chitosan and ZCHC was explored to evaluate the efficiency of ZCHC as adsorbent for Cr in a batch system. The amount of Cr（Ⅵ） adsorbed at different pH values, initial concentrations, adsorbent dosages, and contact times were determined by ICP-AES （inductively coupled plasma-atomic emission spectrometry） in order to determine the optimum conditions for Cr（Ⅵ） adsorption. Furthermore, the adsorption mechanism of Cr（Ⅵ） by zeolite, chitosan and ZCHC was investigated by applying Langmuir and Freundlich isotherm equations to the data obtained. In addition, the rates of adsorption were found to conform to pseudo-second order kinetics.

Structural characteristics of zeolite/TiO-2 composite and photocatalysis of toluene degradation

Zeolite/TiO-2 composite photocatalysts were prepared by adding a certain amount of mordenite in TiO-2, and degradation experiments on toluene through photocatalytic reactions were implemented. In this paper, these photocatalysts were characterized by using SEM, IR, RAMAN, XRD and UV-Vis to shed light on the microstructure and photocatalytic performance of the composite photocatalysts. The results indicated that the structural hydroxy of zeolite can participate in bonding reaction with TiO-2, the addition of zeolite can greatly reduce the diameter of nanometer TiO-2 particles in the composite photocatalysts, and enhance the ultraviolet light absorptance of the composite photocatalysts. When the percentage content of zeolite reached 20%, the photocatalytic performance of this catalyst would be highest, with the toluene conversion rate up to {94.58%}.

SYNTHESIS AND PROPERTIES OF A NOVEL COMPOSITE ZSM-5 ZEOLITE/VERMICULITE CATALYST

The composite ZSM—5 zeolite/vermiculite catalyst,in which tiny ZSM—5 zeolite parti- cles embedded in the vermiculite substrate,has been synthesized by hydrothermal method with vermiculite as silicon source.The catalytic behavior of resulting catalyst for xylene isomerization,propylene aromatization and toluene disproportionation is better than that of HZSM—5 zeolite.

Mechanistic insights into the synergetic remediation and amendment effects of zeolite/biochar composite on heavy metal-polluted red soil

Red soil,the most critical soil resource in tropical/subtropical regions worldwide,faces tremendous threats,including nutrient deficiency,acidification,and heavy metal contamination.There is a great demand for multifunctional eco-materials capable of modifying this situation.Herein,we used widely distributed soil and biomass to develop a zeolite/biochar composite for synergistic red soil remediation and amendment.With the composite material,the Pb^(2+) and Cd^(2+) remediation efficiencies reached 92.8%and 92.9%,respectively,in stems under optimal conditions.Moreover,the acidity and nutrient deficiency conditions of red soil significantly improved.The atomic-scale interaction mechanism during the remediation and amendment process was elucidated with complementary characterization methods,which revealed that in the zeolite/biochar composite material,zeolite contributes to longterm heavy metal remediation effects.Simultaneously,biochar is responsible for soil quality amendment and short-term heavy metal remediation.Furthermore,for the first time,single-atom heavy metal ions were observed on biochar during the remediation process,indicating the broad distribution of single atoms in the natural environment.

Synthesis of MOR/SAPO-11 Composite Molecular Sieve via Seed Crystallization for n-Alkane Hydroisomerization

n-Alkane isomerization is a critical reaction that can affect parameters in oil refining, such as the gasoline octane number and diesel oil solidifying point. In this study, a catalyst support, mordenite (MOR)/silicoaluminophosphate (SAPO)-11 composite zeolite with core/shell structure, was synthesized by hydrothermal method with MOR acting as the seed for crystallization. The crystal structure, elemental composition, surface area, pore volume, and acidity of the catalyst was thoroughly characterized. In addition, the catalytic performance of the as-obtained Pt/MOR/SAPO-11 in the hydroisomerization of n-dodecane was tested. The results indicated that the properties and catalytic performance of the composite molecular sieve were quite different from those of the pure zeolites and physical mixture of MOR and SAPO-11 (MOR+SAPO-11). Compared with the physical mixture, MOR and SAPO-11 were more tightly bound in MOR/SAPO-11 because of chemical bonding. Moreover, the acidity and pore structure were favorable to the catalytic hydroisomerization of n-dodecane. Pt/MOR/SAPO-11 exhibited higher isomerization activity than the Pt-loaded pristine MOR and MOR+SAPO-11. Thus, the core-shell composite molecular sieve has promising industrial applications as the catalyst support.

Solvent Recovery from Soybean Oil/Hexane Miscella by PDMS Composite Membrane

Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be reduced greatly.In this work,two kinds of membrane,PDMS(polydimethylsiloxane) composite membrane and Zeolite filled PDMS membrane were prepared,in which asymmetric microporous PVDF(polyvinylidenefluoride) membrane prepared with phase inversion method was functioned as the microporous supporting layer in the flat-plate composite membrane.The different function compositions of the PDMS/PVDF composite membranes were characterized by reflection Fourier transform infrared(FTIR) spectroscopy.The surface and section of PDMS/PVDF composite membranes were investigated by scanning electron microscope(SEM).The PDMS NF(nanofiltration) membranes were then applied in the recovery of hexane from soybean oil/hexane miscellas(1:3,mass ratio).The effects of pressure(0.5-1.5 MPa),cross-linking temperature and PDMS layer thickness on membrane performances were investigated.The results indicated that both two kinds of NF membranes were promising for solvent recovery,and zeolite filled in PDMS NF membrane could enhance the separation performance.

ZSM-5/MAPO Composite Catalyst for Converting Methanol to Olefins in a Two-Stage Unit with a Dimethyl Ether Pre-Reactor

A ZSM-5/MAPO composite catalyst was prepared by adding ZSM-5 zeolite powder to a conventional molecular sieve synthesis system, followed by modification with NH_4H_2PO_4. The samples were characterized by XRD, SEM, IR, NH_3-TPD, and BET analyses. The catalytic property of the samples toward the methanol-to-olefin(MTO) reaction was evaluated in a connected in series two-stage unit equipped with a continuous flow(once-through) fixed-bed tubular reactor similar to an industrial reactor. The first reactor mainly converted methanol into dimethyl ether and water, followed by being subject to continuous reaction in the second reactor, in which DME was converted to hydrocarbons. The composites exhibited the typical framework topology of MFI, AEI and AFI, which represented the ZSM-5 zeolite, the molecular sieves AlPO-18 or SAPO-18, AlPO-5 or SAPO-5, respectively. The composites showed several advantages for optimizing the zeolite acidity, enhancing the mass transfer, and restraining the side reactions. Catalytic reaction results showed that the composites exhibited higher selectivity to light olefins(84.0%) and lower selectivity to C_2―C_4 alkanes and C_5^+ hydrocarbons than pure ZSM-5. Moreover, the composite zeolite loaded with 3% of P demonstrated improved catalytic activity and stability for the conversion of methanol to propylene, because the coking rate was obviously suppressed.

Synthesis and Characterization of ZSM-5 Molecular Sieve Made from Kaolin/Urea Intercalation Composite

In this paper,the kaolin/urea intercalation composites prepared by direct intercalation method and the catalysis composites containing ZSM-5 molecular sieve synthesized based on the kaolin/urea intercalation composites by an in-situ crystallization technique were investigated.The effects of the intercalation ratios and de-intercalation rate and the amounts of added kaolin/urea intercalation composite on the synthesis of the catalysis composites containing the ZSM-5 molecular sieve were studied.The samples were characterized by X-ray diffraction,FT-IR,TG-DTA,N2 adsorption-desorption,and SEM,respectively.The results showed that the structure of the samples prepared by kaolin/urea intercalation composite was pure ZSM-5 molecular sieve.The crystallinity of ZSM-5 molecular sieve increased at first and then decreased with the increase of intercalation ratio of kaolin/urea intercalation composite.When the intercalation ratio was 62%,the crystallinity of ZSM-5 molecular sieve was lower.When the amount of added kaolin/urea intercalation composite with an intercalation ratio of 22%was 3%,the crystallinity of ZSM-5 zeolite was improved to reach 65%.Compared to the crystallization product formed without adding kaolin/urea intercalation composite,the crystallinity of ZSM-5 molecular sieve has increased by 54.8%.The catalytic composites containing ZSM-5 molecular sieve had better thermal stability with a wide pore structure,featuring a particle diameter of about 2.5μm,a BET specific surface area of 236 m^2/g,and a pore size of 10.6 nm.

Water/Rock Interactions and Changes in Chemical Composition During Zeolite Mineralization

Systematic analysis and comparative study of the chemical compositions of rocks and ores from the main types of zeolite deposits in the surroundings of the Songliao Basin have shown that the process of formation of zeolite from volcanic and pyroclastic rocks is generally characterized by the relative purification of SiO\-2, i.e., SiO\-2/Al\-2O\-3 ratios tend to increase, alkali earth elements (CaO+MgO) and H\-2O are relatively enriched, and the alkali metals (K\-2O+Na\-2O) are depleted in their total amount. The alkali metals K and Na follow different rules of migration and enrichment during the formation of mordenite and clinoptilolite. In the process of formation of mordenite more Na\++ will be imported and K\++ will be lost remarkably. On the contrary, in the process of formation clinoptilolite more K\++ will be incorporated and Na\++ will become obviously depleted.

核壳结构的Beta-Y复合分子筛的合成与表征

采用两种不同的水热晶化法合成Beta-Y复合分子筛,并采用XRD、SEM-EDS、FT-IR、N2吸附-脱附技术对其进行表征。结果表明,以Beta分子筛为唯一硅源合成的sample A具有Y和Beta分子筛两种晶型结构,为机械混合形式;而以Beta分子筛母液为前躯体合成的sample B为核壳结构的复合分子筛,具有Y和Beta分子筛两种晶型结构,其核相为Beta分子筛,壳层为Y型分子筛,其晶体中具有介孔结构,并且介孔孔径比较集中。

煅烧沸石粉对硫氧镁水泥耐水性的影响

为提高硫氧镁水泥(MOSC)的耐水性,以煅烧沸石粉为掺合料制备MOSC,研究了煅烧前后沸石粉对MOSC凝结时间、力学性能、耐水性、相组成、微观形貌和孔结构的影响.结果表明:掺入煅烧沸石粉提高了MOSC的力学性能,且煅烧前后的沸石粉均可在MOSC体系中反应形成水化硅酸镁(M-S-H)凝胶,降低了MOSC的总孔隙率,提高了MOSC的耐水性,但掺入煅烧沸石粉的MOSC耐水性更优;MOSC中掺入20%经200℃煅烧、升温速率15℃/min处理的沸石粉后,MOSC的耐水性最优,其28 d抗压和抗折强度保留系数分别可达0.91、0.95.

改性纳米ZSM-5分子筛催化甲醇制对二甲苯的反应性能

通过水热合成的方法合成纳米ZSM-5分子筛,并采用等体积浸渍法制备ZnO,MgO和P_(2)O_(5)复合改性分子筛,用于催化甲醇高选择性制对二甲苯反应中。采用XRD、SEM、氮气吸附-脱附以及NH_(3)-TPD等手段对催化剂进行表征分析,并在固定床微型反应装置上进行甲醇直接制对二甲苯(MTPX)反应性能评价。结果表明:相比于常规微米ZSM-5分子筛,纳米分子筛具有大量晶间介孔,提高总芳烃选择性;Zn改性减少强酸量,增加中强酸酸量,有利于芳烃产物的生成;分子筛上进一步引入适量的MgO和P_(2)O_(5)可以有效覆盖分子筛的部分孔口和外表面的酸性位,对孔道扩散限制产生影响,对位选择性提高至81.1%,对二甲苯选择性提高至23.3%。

阳离子季铵盐改性沸石对天然橡胶性能的影响

采用阳离子型季铵盐二甲基二烯丙基氯化铵(DMDAAC)对球磨后的天然沸石进行改性处理,将其等量替代部分炭黑后填充至天然橡胶(NR)中,制备天然沸石或改性沸石/NR复合材料,并对其进行结构表征和性能测试。通过离子交换反应,DMDAAC可以吸附在沸石表面,改变了沸石表面的化学性质,降低了沸石的极性,从而改善了沸石在NR中的分散效果,提升胶料的力学性能。结果表明,当替代量为5份时,硫化胶的抗拉强度可达28.6 MPa、撕裂强度为119.3 kN/m;阿克隆磨耗体积最小,为0.28 cm 3;抗屈挠疲劳效果最好,为31.5万次。当替代量为10份时,硫化胶的断裂伸长率可达491%,同时硫化胶还具有较高的抗湿滑性能和较小的滚动阻力。

沸石/牡蛎壳复合材料的优化制备及吸附性能研究

为实现多种污染物的低能耗、高效率地协同去除,利用正交试验法优化沸石/牡蛎壳(Z-OS)复合材料在不同条件(原料比、试剂用量、焙烧温度、焙烧时间)下对NH4^(+)-N和PO_(4)^(3-)的协同吸附效果。实验得到最优条件:吸附PO_(4)^(3-)材料优选中,m(沸石):m(牡蛎壳)为2:1,ω(乙二醇)为20%,焙烧温度为700℃,焙烧时间为90min;吸附NH4^(+)-N材料优选中,m(沸石):m(牡蛎壳)为2:1,ω(乙二醇)为20%,焙烧温度为600℃,焙烧时间为30min。在最佳吸附条件下,复合材料对PO_(4)^(3-)和NH4^(+)-N的吸附率分别可高达97.27%和83.18%。通过SEM和BET表征发现,Z-OS复合材料表面微观形态粗糙,呈现不规则的团状结构,为典型的介孔结构且孔径集中分布于2.3~7.4 nm。

微@介孔复合分子筛的合成及其加氢裂化性能

研究了微@介孔复合分子筛合成过程中TEOS水解状态、酸种类、核分子筛种类及性质等因素对合成产物性质的影响。结果表明,在适宜酸浓度下搅拌6h静置24h时TEOS可最大程度水解成活性Si物种,在核分子筛表面形成有序介孔壳层。合成过程中酸根阴离子作用不同,Cl^(-)有助于复合分子筛比表面积的增加,C_(2)O_(4)^(2-)和NO_(3)^(-)有利于孔体积的增大。Y分子筛或Beta分子筛为核时,核分子筛自身酸量高、酸性强时有助于壳层介孔结构的生成及核壳结构的完整。以十二烷和甲苯为模型化合物,与含单一的Y或Beta分子筛催化剂相比,含复合分子筛催化剂具有更好的中间馏分油选择性,并且催化剂的加氢性能与酸性质、孔结构匹配越好,对甲苯的转化能力越强。

沸石胶凝增强复合包装板材的制备及性能

目的 为了拓展固废资源化的应用,本研究以生物质废料(秸秆粉、废木屑)为基体,以预处理后的污水污泥焚烧灰作为填料,采用热压成型制备了一种沸石胶凝增强复合包装板材。方法 通过XRD、SEM等方法表征预处理前后填料的元素组成、晶体结构、微观形貌等,并研究预处理填料对制备复合包装板材性能的影响趋势以及增强机制。结果 添加质量分数为22.5%的预处理后的填料制备的复合板材,其弯曲强度为27.73MPa,压缩强度为44.38MPa,在力学性能、隔热性能和吸水厚度膨胀率等方面均明显优于未经过预处理的对照组,满足GB/T7284—2016《框架木箱》、GB/T23898—2009《木托盘用人造板》等国家标准的要求。复合板材性能的增强主要归因于预处理引起填料相组成及结构的变化。由于方沸石晶相的生成,填料对自身和基体的吸附性、易分散性得到极大改善。结论 经过预处理的填料制备的沸石胶凝增强复合包装板材性能优异,在木包装领域及建筑领域具有广阔的应用前景。该研究可为大宗固体废弃物资源化利用提供高附加值的解决方案,还可以为缓解林产资源短缺的现状提供新的思路。