Removing hydrogen chloride from air in a direct-flow sprayer and Venturi tube system

A technological scheme is given for removing hydrochloric acid vapor from air together with the parameters of the plant operation with Venturi tubes and air flow up to 76000 m³/h. With an initial content of hydrochloric acid in air of 250 mg/liter, the final content is as follows: with the solution in the etching bath at 60–70°C it is 1.5 mg/m³, while at 80°C it is not more than 5 mg/m³. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 4, pp. 33–34, April, 2006.     

超重力场下络合铁法脱硫过程传质模型研究

H_2S是一种有毒有害气体,故天然气在使用之前必须进行脱硫处理。而超重力旋转填料床因其在巨大的剪切力作用下强化了传质,大大增加了设备的生产能力,且装置尺寸远远小于传统塔设备。超重力技术与氧化还原法结合在天然气脱硫领域具有较好的应用价值。因此,建立一个实用可靠的传质系数模型,对超重力技术脱硫的研究具有重要意义。用CH_4和H_2S的混合气模拟含硫天然气,并在某中试装置上用络合铁氧化还原法进行脱硫。根据所得的数据及旋转填料床中气液接触的特性,包括气体流量、液体流量、转子转速对体积传质系数的影响,采用Matlab进行相关数据拟合分析,得到传质系数经验模型。对经验模型进行分析对比,根据超重力装置气液传质的特性对经验模型进行了改进,得到最终的传质系数经验模型。最后,将建立的传质系数经验模型与实验得到的数据进行对比验证。经分析对比,模型与实验数据吻合程度较高,平均偏差仅为0.12%,且该模型可以外推到其他体积与该超重力装置近似的装置,但气体流量应为1~10 m~3/h,液体流量为0.1~1 m~3/h,转速为100~1 500r/min。     

Photochemical oxidation of thiophene by O<Subscript>2</Subscript> in an organic two-phase liquid-liquid extraction system

Photochemical oxidation products and the kinetics of thiophene in an n-octane/acetonitrile extraction system using O₂ as an oxidant was studied. The results could be used as a reference for the oxidative desulfurization of gasoline because thiophene is one of the main components containing sulfur in a fluid catalytic cracking (FCC) gasoline. Thiophene dissolved in n-octane was photodecomposed and removed into the water phase at an ambient temperature and atmospheric pressure. A 500-W high-pressure mercury lamp (main wavelength 365 nm, 0.22 kW m⁻²) was used as the light source for irradiation and air was introduced by a gas pump to supply O₂. Thiophene could be photooxidized to SO₄ ²⁻ and CO₂. The desulfurization yield of thiophene in n-octane is 65.2% for a 5-h photoirradiation under the conditions of air flow at 150 m min⁻¹ and V(n-octane): V(acetonitrile) = 1:1. It can be improved to 96.5% by adding 1.5 g L⁻¹ artificial zeolite, which is an absorbent for O₂. Under such conditions, the photooxidation kinetics of thiophene with O₂ is of the first order with an apparent rate constant of 0.6297 h⁻¹ and a half time of 1.10 h. The sulfur content can be depressed from 800 to 28 ppm. The text was submitted by the authors in English.     

Hybrid resin composite membrane for oil & gas produced water treatment

In this work, a hybrid resin composite membrane was successfully synthesized from a phenyl epoxy/poly (vinyl pyrrolidone)/Fe₃O₄ resin composite and characterized using a scanning electron microscope (SEM). Performance characteristics such as concentration factor, the flow rate, and permeate flux of the synthesized hybrid resin membrane were investigated. The concertation factor was changed through the experiment from 1 to 1.6. The flow rate changed from 2.5 l/h at the beginning of the experiment to 1.05 l/h by the end of the experiment. The permeate flux was equal to 8.9 l/(m²h) at the beginning of the investigation. It was noticed that the permeate flux decreased over time to 3.76 l/(m²h). In addition, the hybrid resin composite membrane was efficiently used for treating petroleum-produced water (PPW) as an alternative to chemical scale inhibitors. The results showed that the proposed treatment system could successfully remove most scale-forming cations and anions from the PPW. Combining the new prepared resin with membrane could remove several cations and anions from OFPPW at rates ranging from 75% (for Strontium) to 97% (for Barium), while the Iron was 100% removed. Thus, the treated water effluent could be reused safely as injection water in the petroleum production process without concern for forming Barium sulfate and Dolomite scales in the used water.     

天然气中酸性组分含量升高的脱硫系统优化研究

针对近年来天然气中酸性组分含量升高导致的产品气气质下降、设备故障频繁等问题,利用Aspen HYSYS软件对MDEA溶液循环量提高后的脱硫系统进行了流程模拟。结果表明,当原料气中酸性组分CO2和H2S的体积分数分别由5.280%和0.028%增至6.280%和0.052%时,为了保证产品气符合国家标准,需将系统中的MDEA溶液循环量由63.25m3/h逐渐提高至102.85m3/h。使用Tray Rating、HTRI Xchanger Suite软件对不同MDEA溶液循环量下的塔器和换热器等重要设备进行了一系列优化。经计算,胺液吸收塔和再生塔的流体力学性能均符合要求;胺液贫富液换热器在MDEA溶液循环量提高时可串联1台同型号换热器,同时更换换热管规格,以满足系统需要并缓解堵塞;优化后的二级闪蒸装置能够较大程度地缓解装置频繁波动的情况,而在其入口处加装高效波纹板除沫器则可有效避免系统发泡。     

Universal system for injection feed of feedstock and air into a vacuum resid oxidation reactor

A universal system was developed for injection feed of feedstock and air into an oxidation reactor which ensures its efficient operation in a wide range (15–40 m³/h) of output in feedstock: production of oxidized asphalts of improved quality, reduced specific air flow and oxygen content in oxidation gases. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 4, pp. 13–16, July–August, 2008.     

Development and validation of an accurate and rapid LC-ESI-MS/MS method for the simultaneous quantification of aflatoxin B1, B2, G1 and G2 in lotus seeds

An accurate and rapid LC-ESI-MS/MS analytical method was developed and validated for the simultaneous determination of aflatoxin B₁, B₂, G₁ and G₂ in lotus seeds. The samples were firstly extracted with methanol-water solution (80:20, v/v), and then cleaned up by immunoaffinity columns. The mass spectrometer was operated in the positive ionization electrospray (ESI+) mode using multiple reaction monitoring (MRM) for analysis of four aflatoxins. The transitions of m/z 313 → 285 (AFB₁, CE 33 eV), m/z 315 → 259 (AFB₂, CE 37 eV), m/z 329 → 243 (AFG₁, CE 37 eV) and m/z 331 → 257 (AFG₂, CE 37 eV) were used to quantify these four aflatoxins, respectively. The limits of detection (LODs) of aflatoxin B₁, B₂, G₁ and G₂ were 0.007, 0.005, 0.003 and 0.005 μg kg^?1 based on a signal-to-noise ratio of 3:1, respectively. The limits of quantification (LOQs) of aflatoxin B₁, B₂, G₁ and G₂ were 0.02, 0.015, 0.01 and 0.015 μg kg^?1 based on a signal-to-noise ratio of 10:1, respectively. Recoveries for samples of spiked lotus seeds were all above 66% with relative standard deviation all below 15% for all compounds. Nineteen out of twenty batches of lotus seeds collected from different drug stores or markets in China were found to be contaminated with aflatoxins at different levels ranging from 0.02 to 688.4 μg kg^?1.     

CT6-4B和CT6-8B催化剂在硫磺回收装置的应用

针对广西石化公司6×10^4 t/a硫磺回收装置排放烟气中SO 2质量浓度高的问题,采用多种手段排查分析,确定原因是一级转化器制硫催化剂的有机硫水解率下降,引起过程气中有机硫含量升高。将其更换为中国石油西南油气田公司天然气研究院自主研发生产的制硫催化剂CT6-4B和CT6-8B后,结果表明,有机硫水解率得到大幅提高,排放烟气中SO 2质量浓度从接近400 mg/m^3降至120 mg/m^3以下,满足GB 31570-2015《石油炼制工业污染物排放标准》中对于广西地区排放烟气中SO 2质量浓度低于400 mg/m^3的排放限值。     

Optimization of HPLC conditions for quantitative analysis of aflatoxins in contaminated peanut

The main objective of present study was to investigate the effect of HPLC conditions namely mobile phase composition (X₁), flow rate (X₂) and temperature (X₃) on peak area of four target aflatoxins (i.e. B₁ (Y₁), B₂ (Y₂), G₁ (Y₃) and G₂ (Y₄)) from the spiked peanut. The significant nonlinear response surface models with high coefficient of determinations (R²) ranging from 0.958 to 0.995 were fitted to evaluate the detection value of target aflatoxins as a function of HPLC variables. Flow rate had the most significant (p < 0.05) effect on quantification value of target aflatoxins. The highest quantification value for target aflatoxins could be obtained under the following HPLC conditions: the mobile phase composition of ACN/H₂O/MeOH: 8/54/38, temperature of 24 °C and flow rate of 0.4 mL/min. The recommended optimum HPLC conditions provided higher peak area for all target aflatoxins by 1–2.5 fold compared to two other conditions (A: mobile phase (ACN/H₂O/MeOH: 23/54/23), ambient temperature (28–32 °C), flow rate 1 mL/min; B: mobile phase (ACN/H₂O/MeOH: 17/54/29), temperature 30 °C, flow rate 1 mL/min).     

Optimization of air jet impingement drying of okara using response surface methodology

Okara is a byproduct from the process of soybean foods, and is rich in proteins, fatty acids and dietary fibers. Drying of wet okara is essential for long-term storage and its value-added applications. This study applied response surface methodology and synthetic evaluation method to optimize the drying process of okara in an air jet impingement drier (AJID). Air temperature (50–70 °C), air velocity (1.3–2.3 m/s), and sample loading density (3–4 kg/m²) were considered as treatment factors in the optimization, while drying rate, color, trypsin inhibitor activity, soy isoflavone content and antioxidant activity were evaluated as responding quality parameters. All treatment variables showed significant effects on the drying rate and soy isoflavone content (P < 0.05). Higher temperature, higher air velocity and lower loading density contributed to higher drying rate. Temperature and air velocity showed quadratic and interactive effect on the antioxidant activity of okara. The optimum conditions for AJID of okara were identified as 70 °C, 2.3 m/s air velocity, and 3 kg/m² loading density. This process control study provided baseline data for developing effective drying of okara using AJID.     

SVDS脱硫技术在硫磺回收装置的工业应用

为了满足GB 31570-2015《石油炼制工业污染物排放标准》的规定,提升区域环境质量,对广泛应用于催化烟气的脱硫技术进行了适应性改造,增加了气-气换热器和高效除雾器等设备,形成适合硫磺回收装置的文丘里脱硫技术(SVDS),并在独山子石化硫磺回收装置进行了工业应用。改造后,排放烟气中SO₂质量浓度从300 mg/m³降至30 mg/m³以下,满足GB 31570-2015中特别排放限值地区SO₂质量浓度的排放要求。在文丘里脱硫技术运行过程中,先后出现气-气换热器压降升高及碱液泵泵壳和叶轮腐蚀的问题,并制定了相应的解决措施,保证了碱洗设施的长周期运行。      

孔径双峰分布γ-Al2O3负载NiMoP催化剂的制备及对蜡油加氢催化性能

在氢氧化铝干胶挤条成型时,调节纳米炭黑的加入量和水/粉质量比,制备了孔径呈双峰分布、具有较大孔容和比表面积的γ-Al2O3载体。当炭黑加入质量分数为13%、水/粉质量比1.15时,制备的孔径呈双峰分布的γ-Al2O3载体的孔容为0.80mL/g、比表面积为309m2/g,4～10nm和10～15nm孔径分别占总孔容50.8%和35.1%(体积分数),采用该载体制备的NiMoP/γ-Al2O3催化剂的孔径呈明显的双峰分布。在反应温度370℃、氢分压10MPa、氢/油体积比700、体积空速1.5h-1的条件下,制备的NiMoP/γ-Al2O3催化剂可使减压和焦化混合蜡油的硫质量分数由25600μg/g降至2070μg/g,脱硫率为91.9%,而参比催化剂仅可使减压和焦化混合蜡油硫质量分数降至3450μg/g,脱硫率为86.5%。     

Dibenzothiophene removal from model fuel using an acid treated activated carbon

Sulfur containing compounds are one of the most concerning pollutants in fossil fuels. The increasing rate of fuel consumption around the globe reveals the necessity of further purification of the fuels. In this study, application of adsorption process in removing dibenzothiophene from a model fuel is investigated. A granular activated carbon is treated with aqueous solution of nitric acid and implemented as the sorbent. Treatment of the activated carbon with nitric acid resulted in increasing the adsorption capacity of the activated carbon. Freundlich and TÓth isotherms are capable of sufficiently describing the equilibrium data. Investigation of the kinetics of the process is carried out using the homogeneous surface diffusion model. Internal and external mass transfer coefficients are 9.3917 × 10^-6?m²/min and 1.4153 × 10^-2?m/min for the virgin activated carbon (VAC) and 4.8738 × 10^-6?m²/min and 5.2529 × 10^-2?m/min for acid treated activated carbon (AAC), respectively.     

Co-occurrence of aflatoxins and ochratoxin A in spices commercialized in Italy

A total of 130 spice samples coming from India, China, South America, USA, Northern Africa, Europe and Sub-Saharan Africa were collected in different stores of Northern Italy. They were analysed for aflatoxins (AFs: AFB₁, AFB₂, AFG₁, AFG₂) and ochratoxin A (OTA) content by liquid chromatography with mass spectroscopy and positive electrospray ionization (LC/ESI-MS/MS), and HPLC with fluorescence detector (FLD), respectively. The analysis showed that 20 (15.4%) and 31 (23.8%) out of 130 samples were contaminated with AFs and OTA, respectively. A low level of total AFs contamination was found in the positive samples, the average concentration was 0.64 ng g⁻¹, far below the maximum threshold admitted by the European legislation (5 ng g⁻¹ for AFB₁, and 10 ng g⁻¹ for total aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂). A higher incidence of OTA was found in chili (60.0%) more than in pepper (13.3%), ranging from 2.16 to 16.35 ng g⁻¹, and from 1.61 to 15.85 ng g⁻¹, respectively. Moreover, three spice samples (2.3%) contaminated by OTA trespassed the threshold admitted by the European Regulation (EC, 2010). The co-occurrence of OTA and AFs in spices was detected in 6 out of 130 samples (4.6%), ranging from 1.61 to 15.85 ng g⁻¹ and from 0.57 to 3.19 ng g⁻¹, respectively.     

炼油厂硫磺回收工艺及催化剂的改进和优化

中国石油宁夏石化分公司炼油厂5000 t/a硫磺回收装置改造前采用两级克劳斯+低温加氢还原吸收工艺,加氢后的尾气经过MDEA吸收,其排放烟气中SO_2质量浓度为500～800 mg/m~3。其中,溶剂再生系统采用集中再生。根据中国石油西南油气田公司天然气研究院的设计工艺,工厂进行了全新的工艺改造,即采用天然气研究院生产的钛基催化剂增强水解和双段吸收工艺,成功解决了硫磺回收装置烟气中SO_2质量浓度达标排放的问题,排放烟气中SO_2质量浓度约50 mg/m~3,可为小型硫磺回收装置,尤其是碱液碱渣处理困难的工厂的尾气达标排放提供技术思路及解决方案。     

炼油厂硫磺回收装置尾气SO2达标排放技术工业应用

针对硫磺回收装置尾气SO_2达标排放问题,开发了SO_2超低排放核心技术。通过在克劳斯段采用有机硫水解性能优良的CT6-8钛基硫磺回收催化剂、在尾气加氢反应器中采用CT6-11新型尾气低温水解催化剂和在加氢尾气脱硫系统采用CT8-26加氢尾气H_2S深度脱除溶剂,达到了降低装置排放尾气中SO_2质量浓度的目的。该技术在塔河炼化公司和中金石化公司成功进行了工业应用,实现了排放烟气中SO_2质量浓度分别低至50 mg/m~3和31 mg/m~3以下的超低排放水平。     

超声波辐照浸渍法制备MnO2/γ-A12O3催化剂及其柴油催化氧化脱硫性能

 分别采用超声波辐照浸渍法和普通浸渍法制备了MnO₂/γ-Al₂O₃催化剂,运用电感耦合等离子体原子发射光谱（ICP-AES）和X射线衍射（XRD）对催化剂进行表征,在空气-异丁醛-MnO₂/γ-Al₂O₃体系中评价其对加氢柴油的氧化脱硫催化性能,并考察了反应温度、异丁醛用量、空气流量、溶剂类型和剂/油体积比对柴油氧化脱硫反应的影响。结果表明,超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂对柴油氧化脱硫的催化性能明显优于普通浸渍法制备的催化剂。最适宜的催化柴油氧化脱硫反应的条件为：乙腈为溶剂、加氢柴油30 mL、温度35℃、异丁醛20 mmol、空气流量0.06 L/min、超声波辐照浸渍法制备的MnO₂/γ-Al₂O₃催化剂0.08 g、剂/油体积比1/6和催化氧化时间10 min。在此条件下可将柴油硫质量分数从542μg/g 降至31μg/g,柴油脱硫率和回收率分别为94.3%和93.3%。     

Antimicrobial efficacy of vacuum impregnation washing with malic acid applied to whole paprika,carrots, king oyster mushrooms and muskmelons

Antimicrobial effect of vacuum impregnation (VI) applied to organic acid washing against Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes on paprika fruit, carrots, king oyster mushrooms and muskmelons was investigated. Samples were treated with intermittent VI with 21.3 kPa and compared with dipping washing in 2% malic acid. The initial sample pathogen levels were approximately 10⁵–10⁷ CFU/cm². Enumerations of the three pathogens on paprika and carrots treated with VI washing were reduced to below the detection limit (= 1 log₁₀ CFU/cm²) after 3–5 min and 15–20 min, respectively. For each time point where populations of the three pathogens were reduced to below the detection limit by VI treatment, populations of 1.2–1.9 log CFU/cm² and 2.5 to 2.8 log CFU/cm² survived on paprika and carrots, respectively, when subjected to dipping treatment. After 20 min of dipping treatment, surviving populations of the three pathogens ranged from 3.5 to 4.1 and 3.3 to 4.4 log CFU/cm² on king oyster mushrooms and muskmelons, respectively. After 20 min of VI treatment, surviving populations of the three pathogens ranged from 3.0 to 3.6 log and 3.1 to 4.1 log CFU/cm², respectively, on king oyster mushrooms and muskmelons. Additionally, there were no significant (P ≥ 0.05) differences in pathogen reductions between dipping and VI treatment for both king oyster mushrooms and muskmelons. King oyster mushrooms (R_a = 6.02 ± 1.65 μm) and muskmelons (R_a = 11.43 ± 1.68 μm) had relatively large roughness values compared to those of paprika (R_a = 0.60 ± 0.10 μm) and carrots (R_a = 2.51 ± 0.50 μm). Scanning electron photomicrographs showed many deep protected sites in king oyster mushrooms and muskmelons with many microbes located deep in these sites following VI treatment. Instrumental color, texture and titratable acidity values of paprika and carrots subjected to VI washing treatment with 2% malic acid for 5 and 20 min were not significantly (P ≥ 0.05) different from those of untreated control samples during 7 day storage.     

硫磺回收装置烟气排放超标原因分析及对策

分析了金澳科技(湖北)化工有限公司2×10~4 t/a硫磺回收装置排放烟气中SO_2含量超标的原因,并采取了相应的改造措施,主要包括:①将液硫池废气由尾气炉改至燃烧炉;②更换更高效的脱硫溶剂;③更换有机硫水解能力更强的催化剂;④在尾气吸收塔后串联1台尾气碱洗塔。在实施①②③及优化工艺参数的前提下,排放烟气中SO_2质量浓度小于100 mg/m~3。     

某高含硫天然气净化厂尾气SO2减排措施探讨

以SO_2排放质量浓度400 mg/m~3为标准,对某高含硫天然气净化厂采用化工模拟软件建立硫磺回收及尾气处理工艺全流程模型,针对采用还原吸收工艺、氧化吸收工艺两种方案进行模拟,模拟结果表明,两种方案均能实现SO_2减排。从工艺成熟度和经济投资两方面进一步分析,氧化吸收工艺具有流程简单、一次性投资低等特点,推荐该天然气净化厂采用氧化吸收工艺进行尾气处理,以达到尾气SO_2减排的目的。