A systematic approach for synthesizing a low-temperature distillation system

In this paper, by combining a stochastic optimization method with a refrigeration shaft work targeting method,an approach for the synthesis of a heat integrated complex distillation system in a low-temperature process is presented. The synthesis problem is formulated as a mixed-integer nonlinear programming(MINLP) problem,which is solved by simulated annealing algorithm under a random procedure to explore the optimal operating parameters and the distillation sequence structure. The shaft work targeting method is used to evaluate the minimum energy cost of the corresponding separation system during the optimization without any need for a detailed design for the heat exchanger network(HEN) and the refrigeration system(RS). The method presented in the paper can dramatically reduce the scale and complexity of the problem. A case study of ethylene cold-end separation is used to illustrate the application of the approach. Compared with the original industrial scheme, the result is encouraging.

Trifunctional strategy for the design and synthesis of a Ni-CeO_(2)@SiO_(2)catalyst with remarkable low-temperature sintering and coking resistance for methane dry reforming

In this study,a trifunctional strategy was developed to prepare a confined Ni-based catalyst(Ni-CeO_(2)@SiO_(2))for dry reforming of methane(DRM)of two main greenhouse gases-CO_(2)and CH_(4).The Ni-CeO_(2)@SiO_(2)catalyst was fabricated by utilizing the confinement effect of the SiO_(2)shell and the synergistic interaction between Ni-Ce and the decoking effect of CeO_(2).The catalysts were systematically characterized via X-ray diffraction,N_(2 )adsorption/desorption,transmission electron microscopy,energy dispersive X-ray spectroscopy,hydrogen temperature reduction and desorption set by program,oxygen temperature program desorption,Raman spectroscopy,thermogravimetric analysis,and in situ diffuse reflectance infrared Fourier transform spectroscopy measurements to reveal their physicochemical properties and reaction mechanism.The Ni-CeO_(2)@SiO_(2)catalyst exhibited higher activity and stability than the catalyst synthesized via the traditional impregnation method.In addition,no carbon deposition was detected over Ni-CeO_(2)@SiO_(2)after a 100 h durability test at 800℃,and the average particle size of Ni nanoparticles(NPs)in the catalyst increased from 5.01 to 5.77 nm.Remarkably,Ni-CeO_(2)@SiO_(2)also exhibited superior low-temperature stability;no coke deposition was observed when the catalyst was reacted at 600℃ for 20 h.The high coking and sintering resistance of this confined Ni-based DRM catalyst can be attributed to its trifunctional effect.The trifunctional strategy developed in this study could be used as a guideline to design other high-performance catalysts for CO_(2)and CH4 dry forming and accelerate their industrialization.

Effects of process parameters on pore structure of semi-coke prepared by solid heat carrier with dry distillation

The semi-coke was prepared by solid heat carrier with dry distillation in single factor method. The pore structures of raw coal and semi-coke were characterized by Brunauer-Emmett-Teller (BET) and scanning electron microscope (SEM). The results show that the adsorption and desorption isotherm of semi-coke are not coincident. There was a wide pore distribution on the semi-coke, in which mesopores and micropores account for a considerable proportion. Also there are many more secondary pores. With the increase of the final temperature of heat carrier and constant temperature, as well as the decrease of volume ratio of coal and hot carrier reactor, specific surface area and pore volume of semi-coke increased rapidly first and then decreased and finally increased, along with the rapidly reduction of average pore size. SEM photos show that the surface of semi-coke becomes increasingly rough and glossy.

Low-temperature dry reforming of methane tuned by chemical speciations of active sites on the SiO_(2) and γ-Al_(2)O_(3) supported Ni and Ni-Ce catalysts

The cognition of active sites in the Ni-based catalysts plays a vital role and remains a huge challenge in improving catalytic performance of low temperature CO_(2) dry reforming of methane(LTDRM).In this work,typical catalysts of SiO_(2) and γ-Al_(2)O_(3) supported Ni and Ni-Ce were designed and prepared.Importantly,the difference in the chemical speciations of active sites on the Ni-based catalysts is revealed by advanced characterizations and further estimates respective catalytic performance for LTDRM.Results show that larger[Ni0-]particles mixed with[Ni-O-Sin])species on the Ni/SiO_(2)(R)make CH_(4) excessive decomposition,leading to poor activity and stability.Once the Ce species is doped,however,superior activity(59.0%CH_(4) and 59.8%CO_(2) conversions),stability and high H_(2)/CO ratio(0.96)at 600℃ can be achieved on the Ni-Ce/SiO_(2)(R),in comparison with other catalysts and even reported studies.The improved performance can be ascribed to the formation of integral([Ni0_(n))]-[CeⅢ-□-CeⅢ])species on the Ni-Ce/SiO_(2)(R)catalyst,containing highly dispersed[Ni]particles and rich oxygen vacancies,which can synergistically establish a new stable balance between gasification of carbon species and CO_(2) dissocia-tion.With respect to Ni-Ce/γ-Al_(2)O_(3)(R),the Ni and Ce precursors are easily captured by extra-framework Al_(n)-OH groups and further form stable isolated([Ni0_(n))]-[Ni-O-Al_(n)])and[CeⅢ-O-Al_(n)]species.In such a case,both of them preferentially accelerate CO_(2) adsorption and dissociation,causing more car-bon deposition due to the disproportionation of superfuous CO product.This deep distinguishment of chemical speciations of active sites can guide us to further develop new efficient Ni-based catalysts for LTDRM in the future.

Replacement of Forage Fiber Sources with Dried Distillers Grains with Solubles and Corn Germ Meal in Holstein Calf Diets

This study was carried out to determine the effect of replacement of forage fiber sources from alfalfa and Leymus chinensis with nonforage fiber sources（NFFS） from dried distillers grains with solubles and corn germ meal on calves growth, rumen development and blood parameters. 48 female and 12 male calves（（110.55±15.36） kg of body weight and 12 wk of age） were assigned randomly to four dietary treatments（15 calves/treatment） in a completely randomized design. Experimental diets were： 0% NFFS（control）, 9% NFFS（group 1）, 18% NFFS（group 2）, 27% NFFS（group 3）, and contained equivalent neutral detergent fiber and total digestible nutrients, respectively. The dry matter intake was similar among diets, averaging 3.33 kg d-1, and no differences were detected for body weight, withers height, body length and heart girth. In addition, the development of rumen, reticulum, omasum and abomasum also were similar among diets. Dry matter, crude protein, and neutral detergent fiber digestibilities increased with the increasing levels of NFFS in the experimental diets, but had no significant effect. Blood urea nitrogen, total protein and glubulin were not affected by the dietary treatment, but group 3 resulted in the highest（P〈0.05） concentrations of glucose and the lowest（P〈0.05） concentrations of triglycerides and albumin. In conclusion, dried distillers grains with solubles（DDGS） and corn germ meal（CGM） were available and alternative fiber sources for Holstein calf diets.

Amino acid digestibility of heat damaged distillers dried grains with solubles fed to pigs

The primary objective of this experiment was to determine the effects of heat treatment on the standardized ileal digestibility （SID） of amino acids （AA） in corn distillers dried grains with solubles （DDGS） fed to growing pigs. The second objective was to develop regression equations that may be used to predict the concentration of SID AA in corn DDGS. A source of corn DDGS was divided into 4 batches that were either not autoclaved or autoclaved at 130℃ for 10, 20, or 30 min. Four diets containing DDGS from each of the 4 batches were formulated with DDGS being the only source of AA and CP in the diets. A N-free diet also was formulated and used to determine the basal endogenous losses of CP and AA. Ten growing pigs （initial BW： 53.5 ＋ 3.9 kg） were surgically equipped with a T-cannula in the distal ileum and allotted to a replicated 5 x4 Youden square design with 5 diets and 4 periods in each square. The SID of CP decreased linearly （P〈 0.05） from 77.9% in non-autoclaved DDGS to 72.1, 66.1, and 68.5% in the DDGS samples that were autoclaved for 10, 20, or 30 min, respectively. The SID of lysine was quadratically reduced （P〈 0.05） from 66.8% in the non-autoclaved DDGS to 54.9, 55.3, and 51.9% in the DDGS autoclaved for 10, 20, or 30 min, respectively. The concentrations of SID Arginine, Histidine, Leucine, Lysine, Methionine, Phenylalanine, or Threonine may be best predicted by equations that include the concentration of acid detergent insoluble N in the model （r2 = 0.76, 0.68, 0.67, 0.84, 0.76, 0.73, or 0.54, respectively）. The concentrations of SID Isoleucine and Valine were predicted （r2 = 0.58 and 0.54, respectively） by the Lysine：CP ratio, whereas the concentration of SID Tryptophan was predicted （r2 = 0.70） by the analyzed concentration of Tryptophan in DDGS. In conclusion, the SID of AA is decreased as a result of heat damage and the concentration of SID AA in heat-damaged DDGS may be predicted by regression equations developed in this experiment.

Effects of dietary replacement of soybean meal with dried distillers grains with solubles on the microbiota occupying different ecological niches in the rumen of growing Hu lambs

Background:Diet has a profound impact on the rumen microbiota,and the impact can vary among the different rumen ecological niches(REN).This study investigated the effects of dietary replacement of soybean meal(SBM)with dried distillers grains with solubles(DDGS)on the rumen microbiota occupying different REN of growing Hu lambs.After a 9-week feeding trial,6 lambs from each dietary treatment(SBM vs.DDGS-based diets)were slaughtered for sample collection.The microbiota of the rumen solid,liquid,and epithelium fractions was examined using amplicon sequencing analysis of bacterial 16S rRNA gene,functional prediction,and qPCR.Results:No interaction of dietary protein source(PS)and REN were detected for virtually all the measurements made in this study.The DDGS substitution resulted in very limited influence on bacterial community structure.However,the metabolic pathways predicted from 16S rRNA gene sequences varied greatly between SBM-and DDGS-based diets.The populations of rumen total bacteria,fungi,sulfate-reducing bacteria(SRB),and methanogens were not influenced by DDGS substitution,but the population of protozoa was reduced.The bacterial communities in rumen solid(RS)and liquid(RL)were similar in taxonomic composition but were different in relative abundance of some taxa.In contrast,the bacterial composition and relative abundance of rumen epithelium(RE)were greatly distinct from those of the RS and the RL.In alignment with the bacterial relative abundance,the metabolic pathways predicted from 16S rRNA genes also varied greatly among the different REN.The populations of total bacteria,protozoa,and methanogens attached to the RE were smaller than those in the RS and RL,and the fungal population on the rumen epitheliumwas smaller than that in the RS but similar to that in the RL.On the contrary,the SRB population on the RE was greater than that in the RS and RL.Conclusions:Substitution of SBM with DDGS had greater impact to the protozoa than to the other microbes,and the microbial community structure and functions at different REN are distinct and niche-adapted.

Amino acid digestibility in low-fat distillers dried grains with solubles fed to growing pigs

The objective of this experiment was to determine the standardized ileal digestibility（SID） of amino acids（AA） in 3sources of distillers dried grains with solubles（DDGS） with different concentrations of fat.Twelve growing barrows（initial body weight：76.1 ± 6.2 kg） were randomly allotted to a replicated 6×4 Youden square design with 6 diets and 4 periods.The fat content of the 3 sources of DDGS were 11.5,7.5,and 6.9%respectively.Diets contained 60%DDGS and fat concentration of the diets were 7.5,52,and 5.2%,respectively.Two additional diets containing the 2sources of DDGS with 75 and 6.9%fat were also formulated,and corn oil was added to these diets to increase the concentration of fat in the diets to levels that were calculated to be similar to the diet containing conventional DDGS with 11.5%fat.A N-free diet was also formulated to calculate endogenous losses of crude protein（CP） and AA from the pigs.Pigs were fed experimental diets during four 7-d periods.The first 5 d of each period were an adaptation period and ileal digesta were collected on d 6 and 7 of each period.The apparent ileal digestibililty（AID） and SID of CP and all indispensable AA,except AID Pro and SID of Trp,were greater（P 〈 0.01） in conventional DDGS than in the 2 sources of DDGS with reduced fat.Adding oil to the diets containing the 2 sources of DDGS with reduced fat did not consistently increase SID of AA.In conclusion,conventional DDGS has greater SID values for most AA compared with DDGS that contains less fat and inclusion of additional oil to diets containing low-fat DDGS does not increase AID or SID of AA.The lower AA digestibility in low-fat DDGS could not be overcome by the inclusion of additional fat to the diets.

Preparation of Nanometer Nd3＋,Y3＋ Co-doped CaF2 Powder by Coprecipitation-azeotropic Distillation Technique

The synthesis of Nd3＋,Y3＋：CaF2 nanopowder was conducted by azeotropic distillation method,which effectively dehydrated hydrous CaF2 and prevented forming hard agglomerates.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,scanning calorimetries-thermalgravimetry（DSC-TG）,Fourier transform infrared spectroscopy（FT-IR） and absorption spectroscopy were performed to characterize the powder properties.The experimental results showed that products obtained by azeotropic distillation were single phased,rather monodispersed,successfully prevented the hard agglomerate formation and effectively removed the residual water inside the as-prepared precipitate than that of the direct drying.The absorption spectra showed a wider and stronger absorption bands around 792 nm,which should be profitable for LD pumping.

化学成分对干白酒糟肉鸡代谢能的影响及其估测模型的研究

本研究旨在研究白羽肉鸡对不同来源干白酒糟的代谢能并建立其估测模型。采用2×11完全随机设计,其中肉鸡饲养阶段设2个阶段,分别为11~14日龄和25~28日龄;试验饲粮设11个饲粮处理,分别为基础饲粮和10个干白酒糟饲粮。在肉鸡11~14日龄,每个试验饲粮处理6个重复,每个重复8只鸡;在肉鸡25~28日龄,每个试验饲粮处理6个重复,每个重复6只鸡。采用全收粪法,以重复为试验单元收集全部排泄物,测定试验饲粮的代谢能,并计算干白酒糟的代谢能。分析干白酒糟的化学成分与代谢能的相关性,并采用逐步回归法建立干白酒糟表观代谢能(AME)和氮校正表观代谢能(AME n)的预测模型。结果表明:1)干白酒糟的粗纤维(CF)含量高(≥20.10%),代谢能低(AME为2.96~6.70 MJ/kg DM),且肉鸡在11~14日龄和25~28日龄对同一个白酒糟样品的代谢能无显著差异(P>0.05)。2)肉鸡在11~14日龄对干白酒糟的AME(r=-0.689,P<0.05)和AME_(n)(r=-0.688,P<0.05)与CF含量呈负相关。肉鸡在25~28日龄对干白酒糟的AME与CF含量呈负相关(r=-0.726,P<0.05);AME_(n)与粗蛋白质(CP)含量呈正相关(r=0.640,P<0.05),与CF(r=-0.776,P<0.05)和酸性洗涤纤维(ADF)含量(r=-0.655,P<0.05)呈负相关。3)肉鸡在11~14日龄对干白酒糟代谢能的估测模型为:AME(MJ/kg DM)=9.52-0.158×CF(%DM)(R^(2)=0.474,RSD=0.84 MJ/kg DM,P=0.028);AME n(MJ/kg DM)=9.12-0.155×CF(%DM)(R^(2)=0.474,RSD=0.82 MJ/kg DM,P=0.028);肉鸡在25~28日龄对干白酒糟代谢能的估测模型为:AME(MJ/kg DM)=-4.43+0.758×总能(GE)(MJ/kg DM)-0.179×CF(%DM)(R^(2)=0.773,RSD=0.62 MJ/kg DM,P=0.006);AME_(n)(MJ/kg DM)=-2.81+0.652×GE(MJ/kg DM)-0.176×CF(%DM)(R^(2)=0.819,RSD=0.51 MJ/kg DM,P=0.008)。由此可见,干白酒糟CF含量是估测肉鸡在11~14日龄时对代谢能最重要的估测因子,CF含量和GE是估测肉鸡在25~28日龄时代谢能的主要估测因子。

Pretreatment of metallurgical sewage via vacuum distillation driven by low-temperature exhausted gas from steel plants

The metallurgical sewage has very complex component and a significant environmental perniciousness and needs high treatment costs. In addition, too much low-temperature waste heat is emitted owing to the lack of suitable users. Considering these concerns, a low-temperature-driven pretreatment method via vacuum distillation was proposed to treat the sewage from the metallurgical production. It uses the sensible heat carried by low-temperature exhausted gases to drive the distillation of sewage. The distilled water can be reused into the process as new water supply, while the enriched wastewater is discharged into the sewage treatment center for subsequent treatment. Converter dust removal sewage was chosen to perform an experimental observation. The variations of chemical oxygen demand, ammonia nitrogen, suspended solids, electrical conductivity, and pH of the condensate under different vacuum degrees and evaporation rates were mainly investigated. It can be found that the quality of the condensate gets better under certain conditions, which validates the feasibility of the proposed approach. Furthermore, by comprehensively analyzing the water quality indices and their influencing factors, the optimal vacuum degree was suggested to be controlled between 0.07 and 0.09 MPa, and the best evaporation rate was between 40 and 60%.

糟渣复合型饲料对肉牛增重的影响研究

该试验应用低成本的糟渣复合型饲料为突破口,开展饲喂糟渣复合型饲料对肉牛生长的影响,探索肉牛养殖增收的新方法、新材料。在甘肃省武威市的武威顶乐牧业有限公司旗下的牧业二场进行,在牧场选取40头1龄以上的架子育肥牛作为参试牛群,参试育肥牛日龄误差10日龄。试验设对照组和参试组2个组,每个组设参试牛20头,预试期15 d,在这期间,统一测量试验期初犊牛的体重、体高、胸围、体斜长、腹围,开展口蹄疫的免疫接种,做好饲料过渡,参试牛的登记等正试期准备工作;正试期180 d。应用糟渣复合型饲料进行育肥,育肥牛日增重较常规配混合饲料可增加0.17 kg,精饲料料重比可降低0.24,一个育肥期可增收992元,应用糟渣复合型饲料是肉牛生产中降本增效的措施之一。

Quantitative behavior of vibrational excitation in AC plasma assisted dry reforming of methane

Quantitative behavior of non-equilibrium excitation by direct electron impact in low-temperature dry reforming of methane was investigated by integrated studies of experimental validation and kinetic modeling.A plasma chemistry kinetic mechanism incorporating the reactions involving vibrational excitation of CH4,CO2,H2 and CO molecules as well as the low temperature He/CH4/CO2 conversion pathways was developed and validated.The calculation results showed that at lower E/N values(<150 Td)large population of energized electrons generated in a He/CH4/CO2 discharge resulted in an intensification of vibrational excitation.Despite the large generation of vibration,the vibrationally excited molecules in a 0.5/0.25/0.25 of He/CH4/CO2 discharge mixture were easy to relax,due to the strong coupling of the vibration of different molecules in a gas mixture.The results showed that the moderate levels of the vibrational excitation,such as CO2(v10,11,...,18)and CO(v9,10),presented most efficient in the stimulation of species generation including CO,CH2 O,CH3 OH,C2 H4 and C2 H6.Specifically,under conditions of E/N of 108 Td,14.9%of CO formation was estimated from the recombination of CO2(v)with CH3 and H,CO2(v)+CH3→CH3 O+CO,CO2(v)+H→CO+OH.Also,4.8%of C2 H4 formation was from the recombination reaction CH4(v)+CH→C2 H4+H.These results highlight the strong roles of vibrational states in a complex plasma chemistry system.

玉米DDGS蛋白质含量近红外光谱预测模型的建立

为准确测定玉米DDGS中蛋白质含量,采用近红外光谱分析技术结合改进最小二乘回归法(MPLS),以65个不同来源的玉米DDGS为样品,建立玉米DDGS蛋白质含量近红外光谱预测模型。结果显示:预测模型内部交叉验证标准误差(SECV)为0.0957,交叉验证相关系数(1-VR)为0.9888,外部交叉验证相对分析误差(RPDV)为3.60。表明近红外光谱分析模型可准确预测玉米DDGS蛋白质含量。

DDGS粉尘燃爆特性试验研究及热反应分析

为研究饲料加工行业酒精糟及其干燥物(DDGS)粉尘的着火爆炸特性,采用热板炉、G-G炉、哈特曼管和20 L球爆炸装置对实际工段收集的DDGS粉尘进行试验分析;同时,采用热重-红外联用技术进一步分析DDGS受热分解反应过程以及该过程可能产生的可燃气体。研究结果表明:DDGS粉尘的粉尘层着火温度为280℃,粉尘云最低着火温度为460℃;最小点火能为30~100 mJ,粉尘云爆炸下限质量浓度为140 g/m 3,最大爆炸压力为0.68 MPa,爆炸强度属于St1级;DDGS受热分解过程中会产生小分子可燃气体,增加DDGS粉尘爆炸危险性。研究结果可为预防DDGS粉尘爆炸提供数据参考,并为今后进一步研究其热解过程的反应途径提供思路。

Theoretical and Experimental Studies on Low-Temperature Adsorption Drying of Fresh Ginger

The working principle of low-temperature adsorption drying and the advantages of its application for biological materials drying were introduced in this paper. By using fresh ginger as the drying material, the effects of temperature and relative humidity on its drying characteristics were examined. The results show that the drying rate increases with the temperature increasing or the humidity decreasing. The drying time to the equilibrium is almost the same under different humidity conditions, but low equilibrium moisture content can be acquired under low humidity. The shrinkage characteristics of fresh ginger were also studied. The change of its surface appearance during the drying process was characterized by the new Charged Coupled Device （CCD） and the Environmental Scanning Electron Microscopy （ESEM） technique. A mathematical model of drying dynamics was set up according to the experiments.

充氮蒸馏滴定法测定香菇中二氧化硫含量的不确定度评定

为了提高检测结果的准确性,确定影响检测方法的关键因素,对充氮蒸馏滴定法测定干香菇中二氧化硫含量的不确定度进行评定。依据GB 5009.34-2022酸碱滴定法对干香菇中二氧化硫含量进行测定,依据JJF 1059.1-2012建立数学模型,分析影响测定结果的不确定度来源,计算合成不确定度和扩展不确定度。在95%置信区间内,干香菇中二氧化硫含量测定结果为40.9 mg·kg^(-1),扩展不确定度为1.89 mg·kg^(-1)(k=2)。测量结果的不确定度主要由试样重复检验和滴定体积两个不确定度分量引入,其他因素的影响相对较小。

DDGS的营养价值及在动物生产中的应用研究进展

酒精糟及其残液干燥物(DDGS)是工业生产酒精的副产品,因其蛋白含量较高,近年来在畜禽生产中广泛应用,体现出较高的营养价值、经济价值和生态价值。DDGS的营养价值主要表现为高蛋白质含量、高脂肪和可消化纤维以及高有效磷含量。DDGS营养成分变异性较大,而造成其变异的主要原因是生产原料和加工工艺的不同。我国现阶段对于DDGS的研究还远落后于生产,因此急需对DDGS饲料进行深入研究,以推进这一优良蛋白质资源在我国畜牧业中的有效应用。

酒糟主要成分含量的近红外反射光谱快速分析

从全国21个省份收集78个代表性酒糟样品,采用国标方法测定了其成分含量并进行了统计分析,结果显示粗纤维、粗灰分和粗蛋白3种成分质量分数分布范围分别为1.60%～37.54%、0.74%～26.85%和12.01%～38.69%,标准偏差分别为8.33%、5.21%和7.11%,样品成分含量差异较大。利用NIRS建立了其粗纤维、粗灰分和粗蛋白质量分数的定量分析模型,定标决定系数分别为0.98、0.91和0.96,定标标准误差分别为1.19%、1.58%和1.61%,验证决定系数分别为0.98、0.92和0.96,预测标准误差分别为1.20%、1.57%和1.60%,相对分析误差分别为7.38、3.75和4.98,模型预测精度较高,可以用于实际检测分析。

酒精废水处理及资源利用

通过对酒精废水的水质特性、污染情况及治理现状的分析,提出了污水综合治理的工艺流程,包括预处理、二级UASB、好氧活性污泥法。通过一系列的生物及物理化学方法在酒精废水处理工程中的实际应用,COD、BOD5、SS去除率均>99%,达到国家《污水综合排放标准》(GB 8978-1996)二级标准,有效地削减了酒精废水的排放量,减少污染。并且,预处理可回收DDG蛋白饲料,厌氧消化可回收沼气能源,实现了酒精废水的综合治理与资源回收利用,既保护了生态环境,又实现了经济、社会、环境效益的和谐统一。