Pt/MCM-41加氢裂化制备航空生物煤油

利用可再生资源制备液体燃料,是国家应当储备的战略技术之一。本试验以生物柴油加氢脱氧得到的生物烷烃为原料,采用Pt/MCM-41介孔分子筛为加氢裂化催化剂,制备出高转化率、较高选择性的航空生物煤油。试验以不同硅铝比MCM-41为载体,负载不同质量铂金属,制备和表征了不同组成Pt/MCM-41的催化剂;考察了不同硅铝比、反应温度、铂负载量对催化剂活性的影响。结果表明,硅铝比、反应温度和铂负载量对反应产物都有很大影响,硅铝比为10的Pt/MCM-41(Pt%=0.7%)催化剂在340℃条件下的转化率达到了98.42%,煤汽比为1.01,收率也达到了89.50%;随着温度的升高,产物转化率逐渐增加,但是煤汽比随着反应温度的升高逐渐减小;随着铂负载量的增加,转化率提高显著,煤汽比在负载量达到0.7%时才提高明显。     

Pt负载于不同载体对蓖麻籽油加氢催化制备生物航油的影响北大核心CSCD

以蓖麻籽油为原料,在Pt负载于不同载体构建的系列催化剂催化作用下,在高温高压反应釜中开展一步加氢催化制备生物航油研究。采用等体积浸渍法制备了Pt基系列催化剂,探究了氢压、反应时间、反应转速、反应温度对催化反应效果的影响。结果表明,加氢催化制备生物航油的最佳反应条件为:氢压4 MPa,反应时间7 h,催化剂Pt/SAPO-11、Pt/ZSM-23反应转速均为1 100 r/min,催化剂Pt/SBA-15反应转速为1 000 r/min,催化剂Pt/SAPO-11和Pt/ZSM-23反应温度均为360℃,催化剂Pt/SBA-15反应温度为340℃。在最佳条件下,催化剂Pt/SAPO-11的转化率为90.79%,C_(8)-C_(16)烷烃选择性为45.86%,C_(8)-C_(16)烷烃异构率为9.87%;催化剂Pt/ZSM-23的转化率为91.04%,C_(8)-C_(16)烷烃选择性为56.98%,C_(8)-C_(16)烷烃异构率为12.11%;催化剂Pt/SBA-15的转化率为46.26%,C_(8)-C_(16)烷烃选择性为12.85%,C_(8)-C_(16)烷烃异构率为4.83%。实验表明,Pt/ZSM-23的3项指标均优于Pt/SAPO-11和Pt/SBA-15,其更适合用于催化制备生物航油。     

柠檬酸改性Pt/Al-MCM-41催化麻疯树籽油 一步加氢制备燃油组分

采用0.25 mol/L柠檬酸浸渍处理Al-MCM-41后负载Pt制备成新型催化剂，并采用XRD、TEM、XRF、NH3-TPD和Py-IR对改性催化剂进行表征。以麻疯树籽油为原料，在微型高压固定床催化剂反应评价装置上，以空速1.0 h-1、氢油比1 000、氢压4 MPa、柠檬酸改性催化剂Pt/Al-MCM-41用量6 mL以及不同温度进行一步加氢催化制备燃油组分，通过GC-MS对产物进行定性定量分析。结果表明：柠檬酸降低了Al-MCM-41分子筛骨架的有序度，部分Al被脱除，催化剂比表面积降低、但提高了催化剂孔容、孔径，形成了微孔，其酸性也有了显著改变；当加氢反应温度为360 ℃时，产物的脱氧率为87.11%，C9~C14烷烃相对含量为5.59%，C15~C16烷烃相对含量为34.55%，C8~C16异构烷烃相对含量为14.12%，C8~C16芳烃相对含量为3.12%，C17~C18烷烃相对含量为60.48%。柠檬酸改性催化剂Pt/Al-MCM-41对催化麻疯树籽油加氢反应的短链烷烃选择性较低。     

餐厨废油和醇/酮添加物共裂化制备生物基燃料油

以HY、HZSM-5、MCM-41分子筛为催化剂,通过向餐厨废油中添加5%的乙醇或丙酮进行共裂化反应制备生物基燃料油,对液体产物的品质指标进行了测定,并对其成分进行了GC-MS分析。结果表明:在HY和MCM-41催化条件下,添加醇/酮后裂化反应优化效果明显,液体产物密度、酸值、皂化值均降低,产率升高,催化剂结焦率和产气量均降低,而在HZSM-5催化条件下,优化效果不明显;GC-MS分析表明,在添加乙醇后液体产物中烷烃含量增加到24.93%,添加丙酮后液体产物中芳香烃含量增加到70.27%,含氧化合物含量降低至2.38%。研究表明催化裂化时加入醇/酮可以在不同程度上改善生物基燃料油的产品品质,并对生物基燃料油的成分种类起到很强的选择性。     

基于改性Pt/SAPO-11催化废猪油制备航空煤油的工艺优化

使用经柠檬酸改性的Pt/SAPO-11催化废猪油一步加氢制备航空煤油。在单因素实验的基础上,采用响应面实验进行工艺优化,得到改性Pt/SAPO-11催化废猪油一步加氢制备航空煤油的最佳工艺条件为反应温度290.63℃、反应时间3.94 h、转速148.55 r/min、反应氢压3 MPa、油料比10∶1 (废猪油与催化剂质量比),在此条件下C8~C16烷烃含量为71.34%,烷烃异构率为8.94%。产品经后续精馏等工序处理,可达到国标3号航空煤油标准。     

固体碱KF/CeO2催化大豆油制备生物柴油的研究

以硝酸铈铵为铈源，采用水热法制备CeO₂载体，浸渍法制备KF/CeO₂固体碱催化剂，并采用X射线衍射(XRD)、扫描电镜(SEM)和比表面积(BET)对催化剂进行表征。结果表明：KF/CeO₂固体碱对大豆油制备生物柴油有催化作用；催化剂的最佳制备条件为KF负载量40%、焙烧温度500℃、焙烧时间3 h;制备生物柴油的最佳反应条件为催化剂用量为大豆油质量的3.0%、醇油摩尔比9∶1,在该条件下生物柴油的最高产率为86.7%。     

超声辅助KNO_3/MCM-41催化酯交换制备生物柴油

以浸渍法制备KNO3/MCM-41催化剂,并在超声辅助作用下,以此催化大豆油与甲醇酯交换反应制备生物柴油。考察反应条件对酯交换反应影响,实验表明,在超声功率150 W、醇油质量比8:1、催化剂加入量为原料油质量3.5%、反应温度65℃、反应时间50 min条件下,生物柴油产率可达92%,且所得生物柴油性能基本达到国外生物柴油标准。     

Ru/MCM-41催化葡萄糖加氢制备山梨醇的研究

以MCM-41分子筛为载体,采用甲醛还原法制备Ru/MCM-41催化剂,将其用于葡萄糖氢化制备山梨醇。考察了反应温度、反应时间以及Ru/MCM-41催化剂循环使用次数对山梨醇产率和选择性的影响。实验结果表明：在葡萄糖浓度为10%、催化剂用量为20%（以葡萄糖用量计）,反应温度为120℃时,反应1.5h后,葡萄糖转化率达到100%,而山梨醇产率可达94.43%。同时,催化剂循环使用研究表明,Ru/MCM-41是一种较理想的催化剂,可循环使用3～4次。     

Pt/SAPO-11催化麻疯树油一步加氢制备生物航空煤油工艺条件的研究

以麻疯树油为原料,在Pt/SAPO-11双功能催化剂作用下一步加氢制备生物航空煤油,考察了不同反应温度、空速、压力和氢油比对产物脱氧率、C_8~C_(16)比率及C_8~C_(16)烃异构率的影响。结果表明:高温、高压会促进二次裂化反应的发生,使C_8~C_(16)比率下降;空速增大导致平均停留时间缩短,使脱氧率下降。综合考虑脱氧率、C_8~C_(16)比率及C_8~C_(16)烃异构率指标得到最佳工艺条件为反应温度670 K、空速1.2 h~(-1)、压力5 MPa、氢油比1 000∶1,在此条件下脱氧率为99.24%,C_8~C_(16)比率为71.16%,C_8~C_(16)烃异构率为37.92%。该研究为新能源的开发及其在航空领域的应用提供了理论依据。     

响应面法优化Pt/SAPO-11催化废弃猪油一步加氢制备生物航空煤油工艺

以废弃猪油为原料,Pt/SAPO~(-1)1为催化剂,在高压固定床催化剂反应评价装置上研究一步加氢制备生物航空煤油工艺。在单因素实验的基础上,采用响应面法优化废弃猪油制备生物航空煤油的工艺条件。结果表明:最优工艺条件为反应温度409. 96℃、压力5 MPa、空速1. 24 h~(-1),在此条件下C8～C16烃异构率为34. 58%。回归方程验证结果表明,回归方程模拟值与实际值基本吻合,模型具有一定意义。     

Polysaccharides reduce in vitro IgG/IgE-binding of β-lactoglobulin after hydrolysis

We investigate the influence of charged polysaccharides such as gum arabic and low methylated pectin (LMP), and of un-charged polysaccharides such as xylan, on the in vitro digestibility of β-lactoglobulin (β-lg) and on the in vitro IgG- and IgE-binding of its digestion products. β-Ig was hydrolyzed by pepsin, and then by a trypsin/chymotrypsin mixture, in dialysis bags. SDS–PAGE electrophoresis was used to determine protein hydrolysis and immunoblotting in the presence of cow’s milk, and rabbit or human antibodies were used to assess the in vitro IgG- and IgE-binding of the digestion products. The results showed that polysaccharides influenced protein digestibility. The IgG- and IgE-bound hydrolysis products were dependent on the enzymatic hydrolysis and on the presence of polysaccharides. In all cases, IgG-binding was lower in the presence of any of the polysaccharides, and IgE-binding was non-existent or considerably reduced with LMP and xylan. In this study, LMP and xylan were the polysaccharides that most effectively reduced the immuno-reactivity of the hydrolysis products. The eventual reduction of in vivo allergenicity of milk-based food products has to be confirmed.     

利用FTIR/ATR快速测定大豆油的过氧化值

利用傅里叶变换衰减全反射红外光谱法(FTIR/ATR)简单快速地测定大豆油的过氧化值.采用偏最小二乘法(PLS)建立光谱数据与化学测定值之间的校准模型.油样根据过氧化物值分为高过氧化值(10 ～ 90 mmol/kg)和低过氧化值(0～ 10 mmol/kg),然后根据分组波谱及全部波谱分别建模.选择合适的波长范围以及预处理方法,用验证样品集对定标方程进行验证,获得验证相关系数分别为0.999 9、0.996 0,定标集预测标准差(SEC)分别为0.27、0.21,验证集预测标准偏差(SEP)分别为0.58、0.25.FTIR/ATR法的变异系数和相对偏差均优于化学法.因此模型具有较高的精密度和良好的稳定性,研究开发的FTIR/ATR法分析油脂过氧化物值具有快速、准确环境友好等优点.     

Effect of membranes with various hydrophobic/hydrophilic properties on lipase immobilized activity and stability

In this study, three membranes: regenerated cellulose (RC), glass fiber (GF) and polyvinylidene fluoride (PVDF), were grafted with 1,4-diaminobutane (DA) and activated with glutaraldehyde (GA) for lipase covalent immobilization. The efficiencies of lipases immobilized on these membranes with different hydrophobic/hydrophilic properties were compared. The lipase immobilized on hydrophobic PVDF-DA-GA membrane exhibited more than an 11-fold increase in activity compared to its immobilization on a hydrophilic RC-DA-GA membrane. The relationship between surface hydrophobicity and immobilized efficiencies was investigated using hydrophobic/hydrophilic GF membranes which were prepared by grafting a different ratio of n-butylamine/1,4-diaminobutane (BA/DA). The immobilized lipase activity on the GF membrane increased with the increased BA/DA ratio. This means that lipase activity was exhibited more on the hydrophobic surface. Moreover, the modified PVDF-DA membrane was grafted with GA, epichlorohydrin (EPI) and cyanuric chloride (CC), respectively. The lipase immobilized on the PVDF-DA-EPI membrane displayed the highest specific activity compared to other membranes. This immobilized lipase exhibited more significant stability on pH, thermal, reuse, and storage than did the free enzyme. The results exhibited that the EPI modified PVDF is a promising support for lipase immobilization.     

纽马格／苏拉非织造技术介绍——M＆J费博泰克公司高新无尘纸生产技术

介绍了M＆J费博泰克公司的高新无尘纸生产技术特点、设计经验、供货方式及其与其它技术的结合,并介绍了其研发中心。     

米糠蛋白O/W及W/O/W乳液制备及界面稳定性

为对比不同米糠蛋白质量浓度下O/W及W/O/W乳液的稳定性,以米糠蛋白作为基料,采用双乳化法制备O/W及W/O/W乳液,考察不同米糠蛋白质量浓度下乳液的微观形态和稳定性并探究其界面稳定机理。结果表明：W/O/W乳液的贮存稳定性显著优于O/W乳液;与相同蛋白含量的O/W乳液相比,W/O/W乳液的黏度显著提高;当米糠蛋白质量浓度为0.4 g/100 mL时,W/O/W乳液的稳定性较O/W乳液提高了1 倍以上;乳液内部包裹更多的W/O液滴,W/O/W乳液的粒径较大;而此时静电斥力也较大,起到稳定乳液的目的。同时,米糠蛋白质量浓度不小于0.4 g/100 mL时,O/W及W/O/W乳液中蛋白质的吸附率较高,达到78%以上。本研究为天然米糠蛋白质在食品级乳液中的开发提供参考,为粮食副产物的综合利用提供了新思路。     

An improved LC-MS/MS method for the quantitation of acrylamide in processed foods

An improved liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of acrylamide in processed foods. The homogenized samples, spiked with ¹³C₃-acrylamide as an internal standard, were extracted with water and centrifuged. D₅-3-chloropropanediol as a recovery standard was added to 1-ml aliquots, and the sample was purified with a C₁₈-cartridge column. The extract was directly analyzed using LC-MS/MS without derivatization. The ion transitions of 72–55 m/z (acrylamide), 75–58 m/z (¹³C₃-acrylamide), and 116–98 m/z (d₅-3-chloropropanediol) were found to be the most reliable for the identification and quantification of acrylamide in multiple reaction monitoring. The limit of quantification for acrylamide, defined as a signal-to-noise ratio of 10:1, was 2 μg/kg. The use of d₅-3-chloropropanediol minimized the effects of variation in the sample matrixes and increased the quality of analysis. This method could be applied to the quantification of acrylamide in processed foods.     

人棉细号高密织物上浆工艺探讨

介绍了利用人棉细号纱在有梭织机上织造14.8/14.8 393.5/315 127高密织物的上浆工艺及关键技术措施。     

LC/ESI–MS/MS method for the identification and quantification of spinosad residues in olive oils

This paper reports the use of liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) method for the identification and quantification of residues of the natural insect control agent Spinosad in olive oils. The method determines the active ingredients Spinosyns A and D and two minor metabolites Spinosyns B and K without laborious sample treatment. All four analytes are determined simultaneously in a single injection using positive electrospray ionisation LC–MS with multiple reaction monitoring (MRM). For the quantitative analysis of samples an external calibration curve was built. The calibration curves for each analyte were linear in the concentration range 20–500 ng/mL with a correlation coefficient ranging between 0.995 and 0.999. Results from spike and recovery experiments at levels of 100 and 200 ng/mL gave mean recoveries ranging from 87–116% with satisfactory precision (relative standard deviation (RSD) from 1–8%). The excellent selectivity and sensitivity allows quantification and identification of low levels of Spinosad in olive oils (limits of quantification (LOQs) 0.004–0.073).