Adsorptive removal of nitrogen compounds from fuel oil by a poly ionic liquid PVIm-PXDC

ABSTRACT

A poly ionic liquid, poly(1-vinyl imidazole)-p-xylylene dichloride (PVIm-PXDC), was synthesized and used for fuel oil denitrogenation. The structure of PVIm-PXDC was characterized and the denitrogenation performance was investigated. Results indicate that the pseudo-second-order kinetic model and Langmuir model are appropriate to describe the adsorption kinetics and thermodynamics, respectively. The adsorption ability of PVIm-PXDC for different nitrogen compounds follows the order of indole > pyrrole > quinoline > pyridine. The equilibrium adsorption amount decreased about 10% for all the nitrogen compounds after six regeneration cycles and the denitrogenation and regeneration processes have no influence on the structure of PVIm-PXDC.     

Selective removal of nitrogen compounds from shale oil

A solid extraction process for selectively removing nitrogen from alternative refinery feedstock has been developed. It has been demonstrated that solid CuCl₂ · xH₂O can reduce the nitrogen content of shale oils to acceptable levels for some refineries. In a simple single-stage process, the nitrogen content was reduced by more than 85% to levels below 0.2 wt%. The solid extraction process was remarkably selective and produced high oil recovery yields corresponding to ≈98% of the theoretical limit. Experiments with model systems have shown complete selectivity for the nitrogen compounds and have demonstrated that the entire bulk of the solid is involved in the extraction process. Many other solids have been shown to be effective, namely transition metal halides, nitrates, sulphates, acetates, fluoroborates, and phosphates.     

Identification of nitrogen bases in a coker gas oil and influence of catalytic hydrotreat ment on their composition

The investigation of nitrogen bases occurring in a coker gas oil before and after catalytic hydrotreatment has shown important differences in reactivity of azaarenes. Compounds with a low degree of aromaticity are relatively resistant compared with higher benzologues. Particularly stable are α-methylated azaarenes, which are also major nitrogen bases found in crude oils. Alkyl anilines, the last intermediates before denitrogenation, are the most abundant bases in hydrotreated samples.     

混合废塑料与焦化蜡油共催化裂解制取燃料油

以混合废塑料和焦化蜡油为原料,共催化裂解制备燃料油,克服了废塑料裂解中塑料粘稠度大且传热效率低、裂解炉中温度极不均匀、反应时间长、气体和固体收率高、液体收率低和易结焦等难题。详细考察焦化蜡油与混合废塑料质量比和催化剂用量对产物组成的影响以及FCC催化剂的重复使用性能。结果表明,在焦化蜡油与混合废塑料质量比为2、FCC催化剂用量为混合废塑料质量的10%、终温460 ℃并保持4 h条件下,燃料油收率达到96.67%,气体收率和釜残率分别仅有0.27%和1.53%。焦化蜡油的添加使液相产物中重组分增多,轻组分减少。FCC催化剂的重复使用性能好,催化剂重复使用5次,液体收率大于85%。采用混合废塑料与焦化蜡油共催化裂解的工艺不仅为“白色污染”的处理开辟了一条新途径,而且扩大了焦化蜡油的应用范围。     

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy oil from aqueous solution

The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The mesoporous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltrimethylammonium bromide as a template using the sol-gel technique. Four samples were prepared by (1) totally removing the template using the calcination process, (2) partially removing the template via ethanol extraction, (3) partially removing the template via water extraction, and (4) keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric analysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.     

气提法去除油田污水中二氧化碳气体的实验研究

采用氮气气提装置处理油田污水中溶解的CO2气体,考察了气液比、温度、pH及含油量对CO2去除效果的影响。结果表明,气提法去除油田污水中的CO2效果明显,在气液比为5∶1、温度为30℃、pH为5条件下,污水中的CO2去除率可达98%以上;升高温度、降低污水中的含油量有助于增强氮气气提对CO2的去除效果;处理后的污水CO2质量浓度降到2 mg/L,pH升高到7,碳钢的腐蚀速率降到0.02 mm/a以下。     

催化裂化催化剂再生过程中的氮化学进展

从流化催化裂化待生催化剂中含氮化合物的主要类型和生成机制、再生过程中含氮化合物的转化途径以及降低再生过程中氮氧化物排放的相应控制措施等几个方面,综述了流化催化裂化催化剂再生过程中的氮化学研究进展。     

The use of denitrifying bacteria for the removal of nitrogen oxides from combustion gases

The potential for using denitrifying bacteria to remove nitrogen oxides from combustion gas streams was investigated. Nitrous oxide was chosen as a model compound and a number of different bacteria were screened for their ability to reduce it to nitrogen. Two strains, Pseudomonas denitrificans ATCC 13867 and Paracoccus denitrificans ATCC 17741, exhibited significantly higher reduction rates than did other bacteria. Maximum reduction occurred at 6gl⁻¹ glucose and 35 °C with Pseudomonas denitrificans, and at 6 g l⁻¹ glucose and 30 °C with Paracoccus denitrificans. The rate of reduction by Pseudomonas denitrificans varied with concentration and was a maximum of ˜0.017 mM h⁻¹ (mg dry biomass)⁻¹ at an initial N₂O concentration of 0.9 mM. Paracoccus denitrificans attained a maximum removal rate of 0.015 mM h⁻¹ (mg dry biomass)⁻¹ at an initial N₂O concentration of 1.6 mM. It was concluded that it may be possible to develop a commercial bioprocess to remove nitrous oxide from combustion gas using either species. However, the ability of these organisms to remove nitrogen oxides in larger-scale systems needs to be assessed.     

废塑料与废机油共催化裂解制取燃料油的研究

以废塑料和废机油为原料,共催化裂解制备燃料油,克服了废塑料裂解因传热差,裂解炉中温度极不均匀、结焦的难题,提高了燃料油得率。实验中考察了裂解温度、不同油固比、萃取剂对燃料油得率和组成的影响。在混合废塑料为PE∶PP∶PS=3∶1.2∶1、裂解温度为420℃、油固比为1.5、ZSM-5/50H分子筛为催化剂的条件下,燃料油得率可达到89%以上,汽、柴油比例达83%。采用络合萃取剂精制裂解产物可显著提高燃料油的安定性。     

Nitrogen compounds characterization in atmospheric gas oil and light cycle oil from a blend of Mexican crudes

The distribution of basic and non-basic nitrogen compounds along the distillation curves of the middle distillates atmospheric gas oil (AGO) and light cycle oil (LCO), used as feedstocks for diesel fuel production, is presented in this paper. For this purpose, the total and basic nitrogen content of true boiling point distillation fractions of AGO and LCO were obtained, followed by nitrogen compounds identification by a GC-MS technique. The ratio of quinoline, indole and carbazole derivatives was determined as 1/0.75/2.5 in AGO. In LCO, a 1/2.3/12.2 ratio of aniline, indole and carbazole derivatives was found. A complete physical and chemical characterization of both AGO and LCO is also presented.     

氨气深度脱除材料与技术研究进展

氨气（NH₃）作为一种危害性碱性有毒气体,不仅危害环境,而且会对人体造成不可逆伤害。在电子信息、能源等行业,极微量的NH₃即可影响产品品质、降低过程性能。因此,NH₃的深度脱除在工业上具有重要的意义。本文综述了近年来NH₃深度脱除的工艺现状,分析了NH₃脱除材料如离子液体、低共熔溶剂、改性活性炭、分子筛、改性氧化铝、金属盐类、金属有机框架材料、多孔有机聚合物、共价有机骨架材料、氧化石墨烯、普鲁士蓝类似物对NH₃的分离性能。总结了深度脱除NH₃的工艺特点和脱氨材料的性能,浅析了该领域发展面临的问题,并对未来的发展方向提出了建议。     

Preparation and gas transport properties of dual‐layer polysulfone membranes for high pressure CO2 removal from natural gas

Permeability, sorption, and plasticization behaviors of dual‐layer composite membrane were studied. Polysulfone containing 10.7 wt % glycerol as additive was used for preparing a microporous membrane support. A thin top selective layer was prepared using diethylene glycol dimethyl ether as casting solvent. The overall performance of the membrane was evaluated using Scanning Electron Microscopy, and permeation and sorption tests at pressure up to 50 bar. The prepared membrane displayed high permeability at low pressure which gradually decreased with increase in pressure. Permeability of CO₂ was determined to be 84.97 Barrer at 2 bar. Membrane did not show any plasticization tendency up to the experimental pressure of 40 bar. Plasticization pressure and permeability at plasticization pressure were estimated to be 41.07 bar and 6.03 Barrer, respectively. The improved performance of the membrane is associated to the synergistic properties of the two layers prepared from different formulations of the same polymer. Thus, the dual‐layer flat sheet configuration displayed a potential in high pressure CO₂ removal from natural gas. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40924.     

Utilizing ultraviolet photooxidation as a pre‐treatment of volatile organic compounds upstream of a biological gas cleaning operation

Laboratory experiments were conducted to evaluate the potential to utilize ultraviolet (UV) photooxidation as a pre‐treatment to render recalcitrant volatile organic compounds into more biodegradable compounds. α‐Pinene was selected due to its low water solubility and low biodegradability. α‐Pinene‐contaminated gaseous streams with inlet loadings between 250 and 2500 g m^?3 h^?1 were passed through an annular reactor equipped with a UV lamp that emitted light at 254 nm and 185 nm wavelengths. The outlet stream containing UV photooxidation intermediates was then sparged through nanopure water that was then analyzed for its total organic carbon (TOC) content and subjected to batch biodegradability tests. UV photooxidation effectively degraded α‐pinene with a maximum removal rate of about 700 g m^?3 h^?1. The removal rate followed first order kinetics at low inlet loadings (less than 1200 g m^?3 h^?1) and approached zero order behavior at higher inlet loadings. The principal oxidizing species in the reactor was ozone. Of the total α‐pinene removed, measured as TOC, 50% was converted to water‐soluble and more biodegradable intermediates. The biodegradability of the resultant intermediates was similar to that of methyl ethyl ketone (MEK), which is 3–30 times more biodegradable than α‐pinene. These results show that the use of UV photooxidation is a promising and effective pre‐treatment technique for enhancing the biodegradability of hydrophobic and recalcitrant organic compounds such as α‐pinene. Copyright © 2004 Society of Chemical Industry     

Preliminary evaluation of polymeric Fe‐ and Al‐modified clays as adsorbents for heavy metal removal in water treatment

This paper assesses the potential of modified montmorillonite clays as low‐cost adsorbents/ion‐exchangers for the removal of trace level heavy metals (Cd, Cu, Ni, Pb and Zn) from potable water. Modification of the montmorillonites resulted in the exchange of the interlayer calcium ions for the polymeric species. One unmodified montmorillonite and three polymeric Fe‐ and Al‐modified montmorillonites have been evaluated with respect to their selectivity and uptake performance. All of the clays are selective for Pb and Cu adsorption from aqueous solutions at the mildly acidic pH range in which the experiments were performed (pH 5.5–6). Polymeric iron‐ and polymeric Al/Fe‐modified clays had comparatively great affinities for all the metals studied, whilst the original and polymeric Al modified clays had relatively lower affinities. Only the uptake of Pb and Cu could be correlated with physical properties such as clay surface area. The metal selectivity could be correlated to the type of intercalated polymeric Fe and Al species of the modified clays. © 2002 Society of Chemical Industry     

DCR评价装置对重油催化裂化催化剂LDC-200的性能评价

采用DCR催化裂化评价装置,通过不同原料油及剂油比对重油催化裂化催化剂LDC-200的反应性能进行评价。结果表明,以中国石油天然气股份有限公司兰州石化公司3 Mt·a-1催化装置所用渣油为原料油,在剂油质量比大于8.4时,催化剂LDC-200裂化能力强,拥有良好的焦炭选择性,且异构化功能显著,明显提高汽油辛烷值。采用3 Mt·a-1催化装置所用渣油与蜡油质量分数各50%配成的原料油,在剂油质量比小于8.4时,能够在确保汽油收率的同时控制焦炭产率。     

Improvement of glycerin removal from crude biodiesel through the application of a sulfonated polymeric adsorbent material

The proposal of suitable processes for glycerin removal from crude biodiesel is an important task for making the overall biodiesel production process environmentally friendly and economically viable. In this article, we propose a dry purification process for biodiesel treatment with different polymeric materials [chitosan, cellulose acetate, poly(vinyl alcohol) (PVA), and sulfonated PVA]. Except for pure PVA, all of the proposed materials were able to reduce the free glycerin content of crude biodiesel from 0.03 wt % to values lower than 0.02 wt %. When the PVA was sulfonated, the glycerin removal increased from 12 to 82% compared that of pure PVA. The glycerin content in the biodiesel sample treated with sulfonated PVA was 0.0055 wt %. Mid‐IR spectrometric analysis showed that the sulfonation of PVA increased the band due to H? O? H stretching vibrations; this enabled greater hydrogen bonding between glycerol and the ? SO₃? groups of the sulfonated adsorbent. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45330.     

Quantitative and qualitative studies of microorganisms involved in full‐scale autotrophic nitrogen removal performance

Autotrophic nitrogen removal systems have been implemented at full‐scale and provide an efficient way for nitrogen removal from industrial and urban wastewaters. Our study present qualitative and quantitative analysis of archaeal and bacterial amoA genes and Candidatus Brocadiales bacteria analyzed in six full‐scale autotrophic nitrogen removal bioreactors. The results showed that ammonium oxidizing bacteria (AOB) were detected in all bioreactors. However, ammonium oxidizing archaea (AOA) were detected only in the non‐aerated technologies. Conversely, different Candidatus Brocadiales phylotypes appeared due to differences in influent wastewater composition and hydraulic retention time (HRT). In the same terms multivariate redundancy analysis confirmed that AOA was positively correlated with temperature, ammonium concentration and low HRT. However, AOB population was positively correlated with pH, temperature, and dissolved oxygen concentration. Our data suggested a correlation between the microorganisms involved in the nitrogen removal performance and the operational conditions in the different full‐scale bioreactors. © 2017 American Institute of Chemical Engineers AIChE J, 64: 457–467, 2018