Study on the catalytic degradation of sodium lignosulfonate to aromatic aldehydes over nano-CuO:Process optimization and reaction kinetics

As one of the few renewable aromatic resources,the research of depolymerization of lignin into highvalue chemicals has attracted extensive attention in recent years.Catalytic wet aerobic oxidation(CWAO)is an effective technology to convert lignin like sodium lignosulfonate(SL),a lignin derivative,into aromatic aldehydes such as vanillin and syringaldehyde.However,how to improve the yield of aromatic aldehyde and conversion efficiency is still a challenge,and many operating conditions that significantly affect the yield of these aromatic compounds have rarely been investigated systematically.In this work,we adopted the stirred tank reactor(STR)for the CWAO process with nano-CuO as catalyst to achieve the conversion of SL into vanillin and syringaldehyde.The effect of operating conditions including reaction time,oxygen partial pressure,reaction temperature,SL concentration,rotational speed,catalyst amount,and NaOH concentration on the yield of single phenolic compound was systematically investigated.The results revealed that all these operating conditions exhibit a significant effect on the aromatic aldehyde yield.Therefore,they should be regulated in an optimal value to obtain high yield of these aldehydes.More importantly,the reaction kinetics of the lignin oxidation was explored.This work could provide basic data for the optimization and design of industrial operation of lignin oxidation.

Catalytic depolymerization of calcium lignosulfonate by NiMgFeO_x derived from sub-micron sized NiMgFe hydrotalcite prepared by introducing hydroxyl compounds

A new method for regulating the synthesis of Ni Mg Fe hydrotalcites(NMF LDHs) with the addition of hydroxyl compounds was proposed. A series of NMF LDHs were prepared by the above method, and then were calcined to obtain the Ni Mg FeOx(NMFOx) samples. The NMFOxsamples were characterized by XRD,SEM, TG-DTG, XPS and CO2-TPD, respectively. The catalytic performance of NMFOxfor depolymerizing calcium lignosulfonate(CLS) was evaluated by hydrothermal reaction. The results showed that the addition of hydroxyl compounds favored reducing the particle sizes of NMF LDHs. For the depolymerization of CSL, the yield of liquid product increased from 45% to 75.8% with the addition of NMFOx-ethanol(NMFOxET). The liquid products were mainly phenolics, aromatics, ketones and esters. The total selectivity of oxy-containing compounds was over 90.6%, among them, the phenolics were approximately 35.2%. The valence of Ni and Fe, crystalline phase and basicity almost remained unchanged. The NMFOx-ET samples were recycled for the depolymerization of CLS, moreover, the NMFOx-ET samples had high activity and stability after 4 cycles.

Hemoglobin-biocatalyzed Synthesis of Conducting Molecular Complex of Polyaniline and Lignosulfonate

A new biocatalyst route for the synthesis of a conducting polyaniline （PANI）/ lignosulfonate （LGS） complex was presented.Four different catalysts such as hemoglobin （Hb）,5,10,15,20-tetrakis （meso-hydroxyphenyl） porphyrin,iron （II） tetrasulfophthalocyanine and ferric chloride were used to polymerize aniline in the presence of a natural polyelectrolytes template LGS.The experimental results show that Hb is an effective catalyst in this case and the synthesis is simple,and the conditions are mild in that the polymerization may be carried out in lower pH （1.0-4.0） buffered solution and optimal pH of 2.0.Varying concentrations of aniline,LGS and H2O2 in feed the favorable conditions for the production of PANI were determined.UV-vis absorption,FTIR,elemental analysis,conductivity,cyclic voltammetry and thermogravimetric analyses confirm the formation of thermally stable and electroactive PANI.

Mechanism of calcium lignosulfonate in apatite and dolomite flotation system

Since the physical and chemical properties of apatite and dolomite can be similar,the separation of these two minerals is difficult.Therefore,when performing this separation using the flotation method,it is necessary to search for selective depressants.An experimental research was performed on the separation behavior of apatite and dolomite using calcium lignosulfonate as a depressant,and the mechanism by which this occurs was analyzed.The results show that calcium lignosulfonate has a depressant effect on both apatite and dolomite,but the depressant effect on dolomite is stronger at the same dosage.Mechanism analysis shows that the adsorptive capacity of calcium lignosulfonate on dolomite is higher than that of apatite,which is due to the strong reaction between calcium lignosulfonate and the Ca sites on dolomite.In addition,there is a hydrogen bond between calcium lignosulfonate and dolomite,which further prevents the adsorption of sodium oleate to dolomite,thus greatly inhibiting the flotation of dolomite.

Isolation of lignosulfonate with low polydispersity index

Lignosulfonate with low polydispersity index of 1.178-1.210 was isolated by gel column chromatography of Sephacryl S-100 eluted with 0.2 mol/L of NaNO3 aqueous solution,whereas nearly monodisperse ligosulfonate fraction with polydispersity of 1.0(57 can be obtained after chromatographic separation twice.This method provides an available approach to investigate the structure and characteristics of lignosulfonate.

Study of sodium lignosulfonate prepare low-rank coal-water slurry:Experiments and simulations

The effect of sodium lignosulfonate(SL)as additive on the preparation of low-rank coal-water slurry(LCWS)was studied by experiments and molecular dynamics(MD)simulation s.The experimental results show that the appropriate amount of additives is beneficial to reduce the viscosity of LCWS and increase the slurry concentration.Adsorption isotherm studies showed that SL conforms to single-layer adsorption on the coal surface,andΔG_(ads)^(0) was negative,proving that the reaction was spontaneous.Zeta potential measurements showed that SL increased the negative charge on coal.FTIR scanning and XPS wide-range scanning were performed on the coal before and after adsorption,and it was found that the content of oxygen functional groups on coal increased after adsorption.Simulation results show that when a large number of SL molecules exist in the solution,some SL molecules will bind to hydrophobic hydrocarbon groups on coal.The rest of the SL molecule s,their hydrophobic alkyl tails,come into contact with each other and aggregate in solution.The agglomeration of SL molecules and the surface of coal with static electricity will also produce electrostatic interaction,which is conducive to the even dispersion of coal particles.The results of mean square displacement(MSD)and self-diffusion coefficient(D)show that the addition of SL reduces the diffusion rate of water molecules.Simulation results correspond to experimental results,indicating that MD simulation is accurate and feasible.

Preparation and Characterization of Lignosulfonate Intercalated Layered Double Hydroxides and Their Application in Improving Ultraviolet Aging Resistance for Bitumen

In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxides(LDHs), then the LS intercalated LDHs(LS-LDHs) were applied to improve UV aging resistance of bitumen. With the characterization of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, chemical analysis and scanning electron microscopy(SEM), LS was successfully intercalated into the galleries of LDHs. The ultraviolet and visible(UV-vis) absorbance curves showed LS-LDHs had excellent UV absorptive ability from 200 to 400 nm. Thermogravimetry and differential scanning calorimetry(TG-DSC) indicated LS-LDHs could have a good thermal stability during the processing of bitumen. Compared with the LDHs, the LS-LDHs exhibited better performance in UV aging resistance of bitumen.

Effects of Calcium Lignosulfonate(CaLS)on Growth Performance,Slaughter Performance and Antioxidant Function of Meat Duck

[Objective]The paper was to study the effects of calcium lignosulfonate(CaLS)on feed processing performance,growth performance,slaughter performance and antioxidant function of cherry valley duck.[Method]A total of 48010-day-old cherry valley ducks were selected and randomly divided into four treatments,10 replicates each treatment and 12 meat ducks each replicate(half male and half female).The ducks in control group were fed with basal diet,and those in experimental groups were fed with the basal diet adding 0.2%,0.4%and 0.6%CaLS,respetively.The trial lasted 28 d.[Result](1)CaLS significantly reduced feed pulverization rate of meat duck(F<0.05),and significantly increased PDI and starch gelatinization degree(F<0.05);adding CaLS had no significant impact on the processing cost(F>0.05),but the granulation electric charge per ton feed could be reduced by 1.06 yuan.(2)CaLS had no significant effect on growth performance,slaughter performance and organ index of meat duck(Q0.05).(3)Compared with the control group,there were no significant differences in serum GSH-Px,T-SOD,T-AOC activities and MDA content of three CaLS groups(F>0.05).[Conclusion]CaLS could improve the processing quality of meat duck feed and reduce the processing cost,hut could not improve the growth performance,slaughter performance and antioxidant function of meat duck.

Lignosulfonate and Its Derivatives for Oil-well Drilling:A Concise Review

Lignosulfonate,a byproduct of the pulp and paper industry,has been used in the oil-well drilling industry for a significant amount of time.Lignosulfonate and its derivatives serve different roles in the oil-well drilling industry because of their unique structures and properties.This review summarizes lignosulfonate and its derivatives,including lignosulfonate complexed with metal ions,lignosulfonate graft copolymers,lignosulfonatetannin complexes,and other lignosulfonate-containing composites,in terms of their preparation,properties,and potential applications in oil-well drilling industry.It provides readers with a quick review of existing studies in this area and some inspirations for future studies pertaining to the utilization of lignosulfonate-based materials in the oil-well drilling industry.

不同钙源EICP溶液改良路基黄土动力特性研究

由于黄土地区路基基床强度低,在长期动态压力下黄土会发生不均匀沉降、滑坡或坍塌等工程问题。为了使动荷载作用下的黄土强度更符合实际工程需要,有必要进一步研究不同钙源EICP溶液对黄土动强度的改良效果。本工作以陕西某基坑黄土为研究对象,在胶凝液中引入环保型木钙代替传统钙源进行技术改进,结合室内动三轴试验在不同围压下比较三种钙源EICP溶液对黄土的固化效果。结果表明:EICP溶液能显著提高黄土的动强度;同一围压下,黄土试样动应力和阻尼比随应变的增大逐渐升高,而动剪切模量随应变的增大逐渐降低;围压较小时,乙酸钙源EICP溶液对黄土动强度的改良效果较好,而当围压较大时,木钙源EICP溶液对黄土动强度的改良效果较好;同一试样所受围压越大,动强度和动剪切模量越大,阻尼比越小。

减水剂对固化土强度影响的研究

为了探究聚羧酸、木质磺酸钙(木钙)两种减水剂对固化土强度的影响规律,在不同养护龄期下,对添加不同掺量减水剂的固化土开展了一系列无侧限抗压强度试验,从水化产物角度阐述了固化土强度随两种减水剂掺量的演变机理。试验结果表明:掺有两种减水剂的固化土强度均随着龄期的增加而增加,前期强度增长速度快,后期强度增长缓慢。固化土的强度随着聚羧酸掺量的增加呈现先增加后缓慢减小的趋势,当聚羧酸掺量为0.4%时,固化土强度达到最大值;固化土的强度随木钙掺量的增加逐渐减小,木钙减水剂提升强度的效果弱于聚羧酸减水剂。

高强度速分散硅钙颗粒制备及团聚机理研究

以钙硅粉体为原料,添加木质素磺酸钙-壳聚糖有机黏结剂,通过圆盘造粒技术制备硅钙球团颗粒,考察黏结剂、木质素磺酸钙、壳聚糖添加量以及干燥温度等对硅钙球团颗粒抗压性能及速散性的影响,并对造粒工艺条件进行优化;借助于XRF、XRD、FTIR等技术对原料及样品进行表征,探究硅钙粉体团聚成粒的机理。结果表明,最佳成型造粒条件为:木质素磺酸钙添加量3.75%,壳聚糖1.25%,干燥温度115℃,颗粒团聚紧密,平均抗压强度为34.4 N,亲水基团加速了水分子向颗粒内部渗透,静水实验结果显示,51 s内样品可完全崩解。

木质素磺酸钙增强花岗岩残积土微生物固化效果研究

为提升微生物固化花岗岩残积土的效果,综合考虑木质素磺酸钙的特点和MICP(Microbial-induced calcite precipitation)作用过程的环境条件,设计进行木质素磺酸钙增强MICP固化花岗岩残积土试验,综合宏观物理力学试验和微细观检测,系统分析木质素磺酸钙对微生物固化花岗岩残积土的增强效果及增强机制。结果表明:①木质素磺酸钙能够显著提高花岗岩残积土微生物加固过程中的胶结物产量,木钙掺量在4.00%左右达到最佳,与常规MICP相比,胶结物生成量提高了48.86%;②木质素磺酸钙的掺入,显著提高了固化体的抗压强度和抵抗变形能力,2.00%~8.00%掺量下固化体的抗压强度提升了4.75%~41.20%,破坏时应变增加16.24%~38.55%;③掺入木质素磺酸钙后,固化体的孔隙大小及孔隙率均有不同程度降低,孔隙率降低了12.97%~37.38%,固化体的整体密实性进一步增强;④木质素磺酸钙的掺入,改善了残积土的孔隙结构,为后续微生物加固提供更好的环境条件;⑤在微生物固化花岗岩残积土过程中掺入木质素磺酸钙后,改善了微生物生长的酸碱环境,丰富了MICP作用过程中的钙源,提升了固菌率,促进了MICP反应,同时改善了碳酸钙沉淀颗粒的大小、性状及排列形式,使得胶结物产量进一步提升,从而提升固化体的整体固化效果。

改性木质素磺酸钠沥青乳化剂的合成及应用性能

为提高木质素磺酸钠的乳化性能,以H2O2/Vc构成的氧化还原体系作为引发剂,采用接枝聚合制备了一种改性木质素磺酸钠沥青乳化剂,探讨了反应条件对其低温延度的影响,并采用傅里叶变换红外光谱对改性前后木质素磺酸钠的分子结构进行表征,测试了其乳化性能,使用激光粒度仪对乳化沥青的粒径进行测试。结果表明,当n(丙烯酸)∶n(三乙烯四胺)=1∶1、m(丙烯酰胺类单体)∶m(木质素磺酸钠)=1∶1、引发剂用量占单体总质量的1%时,制备的改性木质素磺酸钠效果最佳,由其制备的乳化沥青低温延度达72.3 cm,5 d贮存稳定性达1.2%,相较于未改性前有较大的提升。

不同相对分子质量木质素磺酸钠-石墨烯量子点的结构及性能研究

相对分子质量是影响聚合物性能的重要因素,以不同相对分子质量木质素磺酸钠和柠檬酸为原料制备了4种木质素磺酸钠-石墨烯量子点(SL/GQDs)。将相对分子质量不定、5000、10000、50000时,制备的SL/GQDs溶液分别标记为SL/GQDs1~SL/GQDs4。利用紫外可见光谱、红外光谱、透射电镜和荧光光谱对4种复合量子点进行了光学性能、结构与形貌的比较分析。研究结果表明:制备的SL/GQDs表面富含羰基、羟基等亲水基团,SL/GQDs1~SL/GQDs4的平均粒径分别为1.34、1.78、2.13和2.26 nm。相对分子质量50000的复合量子点SL/GQDs4总体性能最优,光致发光效应最强,对其进行金属离子检测,发现SL/GQDs4对不同金属离子均具有良好的选择性和灵敏性,在不同金属离子的共存体系中仍可检测Fe^(3+),可以作为检测Fe^(3+)的荧光探针。SL/GQDs4由于Fe^(3+)的加入,产生了荧光猝灭效应,当Fe^(3+)浓度在10~400μmol/L范围内,Fe^(3+)浓度与荧光强度(F/F0)存在良好负相关关系,通过数据拟合得Stern-Volmer线性回归方程F/F0=0.89366-0.00119C(Fe^(3+)),R2为0.98。

生物基静电纺纳米纤维膜的制备及其抗紫外线性能研究

为缓解塑料造成的白色污染、降低紫外线对紫外光敏产品的影响,选择可生物降解的聚乙烯醇(PVA)作为成膜基材,以去离子水为溶剂,木质素磺酸钠(LS)为抗紫外线剂,采用静电纺丝技术制备了具有紫外线防护功能的可生物降解PVA/LS复合纳米纤维膜。研究了LS对PVA/LS复合纳米纤维膜微观形貌、抗紫外线性能及透光率的影响。结果表明:PVA/LS复合纳米纤维膜的纤维形貌良好无串珠产生;LS添加量为4.5%(质量分数)时,复合纳米纤维膜对中波紫外线(UVB)、长波紫外线(UVA)的屏蔽率分别达到82.3%、65.4%,抗紫外线性能远优于纯PVA纳米纤维膜;PVA/LS复合纳米纤维膜在波长555nm处的透光率均大于70%,在阻挡部分可见光能量的同时保持了良好的透明度。

木质素磺酸钠衍生物对钢筋的阻锈作用研究

钢筋混凝土结构往往因钢筋锈蚀而发生过早破坏,加入阻锈剂可以有效抑制钢筋腐蚀,提高钢筋混凝土结构的耐久性。木质素磺酸盐作为一种绿色高效组分,具有良好的阻锈性能,但其减水效果较差,单独使用无法满足现代混凝土大流动度和高强度技术需求。为此,对木质素磺酸钠进行羟基、羧基接枝改性,合成了木质素磺酸钠衍生物,并将其掺入模拟孔溶液和水泥砂浆中,研究其对钢筋的阻锈作用。结果表明:模拟碱性氯盐环境和砂浆加速腐蚀环境下,木质素磺酸钠衍生物均可增大电荷转移电阻以及减小腐蚀电流密度,起到显著的阻锈作用;在水灰比为0.35时,掺入木质素磺酸钠衍生物的水泥净浆流动度可达350 mm,减水效果接近聚羧酸,可满足混凝土的流动性和强度需求。

木质素磺酸钙对模拟混凝土孔隙腐蚀液中碳钢阻锈作用

钢筋混凝土结构常因钢筋锈蚀而导致过早破坏,加入阻锈剂可以有效抑制钢筋锈蚀,提高钢筋混凝土结构耐久性。在模拟混凝土孔隙腐蚀液中加入不同浓度的木质素磺酸钙,通过开路电位、交流阻抗谱和动电位极化曲线研究其对碳钢的阻锈作用与机理。结果表明:在3.5%Na Cl、p H为12.5的腐蚀液中,木质素磺酸钙可提高开路电位、增大电荷转移电阻以及减小腐蚀电流密度,从而起到阻锈作用。同时,木质素磺酸钙在碳钢表面能够与氯离子竞争吸附,保护钝化膜,抑制腐蚀发展。

木质素磺酸钠对羊毛织物的着色现象

木质素磺酸钠来源于工业生产中的废弃物木质素,在印染行业中经常用做分散剂,但在使用过程中对纤维有沾色现象。文中研究木质素磺酸钠对羊毛的着色情况,从温度、时间、pH值以及浓度等方面对木质素磺酸钠上染羊毛的条件进行探索,并测试染后织物的色牢度、耐洗涤、强力、防紫外线等性能。结果表明,木质素磺酸钠在pH值2.0~4.0、用量大于30.0%、90℃的条件下能将羊毛织物染成深色,着色60min后织物的K/S值在6.00以上;并且着色羊毛织物强力损伤较低,试验范围内不同pH值的染浴得到的织物强力损伤都在10%以内;对紫外线也有较好的过滤效果。

竹子碱法制浆黑液木质素磺酸钠的制备及染料分散性研究

研究了Na_(2)SO_(3)用量、反应温度、pH和反应时间对磺化木质素磺酸基含量和溶解度的影响,并对磺化木质素的磺酸基含量和溶解度影响进行了显著性分析。结果显示,木质素磺酸钠(SL)的最大磺酸基含量为1.93mmol.g^(-1),最佳溶解度为98.48%;最佳磺化条件为:Na_(2)SO_(3)用量3mmol.g^(-1),反应温度160℃,pH值12,反应时间3h。此外,研究表明,具有较高磺酸基含量的SL2(最优磺化条件)在吸附染料后,由于较大的静电排斥力,颗粒得到有效分散,边缘分离距离为1mm。在所有样品中,SL2的粒径最小(27.34μm),且在高温下具有最佳分散性。