Decreased eggshell strength caused by impairment of uterine calcium transport coincide with higher bone minerals and quality in aged laying hens

Background Deteriorations in eggshell and bone quality are major challenges in aged laying hens.This study compared the differences of eggshell quality,bone parameters and their correlations as well as uterine physiologi-cal characteristics and the bone remodeling processes of hens laying eggs of different eggshell breaking strength to explore the mechanism of eggshell and bone quality reduction and their interaction.A total of 24074-week-old Hy-line Brown laying hens were selected and allocated to a high(HBS,44.83±1.31 N)or low(LBS,24.43±0.57 N)eggshell breaking strength group.Results A decreased thickness,weight and weight ratio of eggshells were observed in the LBS,accompanied with ultrastructural deterioration and total Ca reduction.Bone quality was negatively correlated with eggshell quality,marked with enhanced structures and increased components in the LBS.In the LBS,the mammillary knobs and effective layer grew slowly.At the initiation stage of eggshell calcification,a total of 130 differentially expressed genes(DEGs,122 upregulated and 8 downregulated)were identified in the uterus of hens in the LBS relative to those in the HBS.These DEGs were relevant to apoptosis due to the cellular Ca overload.Higher values of p62 protein level,caspase-8 activity,Bax protein expression and lower values of Bcl protein expression and Bcl/Bax ratio were seen in the LBS.TUNEL assay and hematoxylin-eosin staining showed a significant increase in TUNEL-positive cells and tissue damages in the uterus of the LBS.Although few DEGs were identified at the growth stage,similar uterine tissue damages were also observed in the LBS.The expressions of runt-related transcription factor 2 and osteocal-cin were upregulated in humeri of the LBS.Enlarged diameter and more structural damages of endocortical bones and decreased ash were observed in femurs of the HBS.Conclusion The lower eggshell breaking strength may be attributed to a declined Ca transport due to uterine tissue damages,which could affect eggshell calcification and lead to a weak ultrastructure.Impaired uterine Ca transport may result in reduced femoral bone resorption and increased humeral bone formation to maintain a higher mineral and bone quality in the LBS.

Adjusting phosphate feeding regimen according to daily rhythm increases eggshell quality via enhancing medullary bone remodeling in laying hens

Background Body phosphorus metabolism exhibits a circadian rhythm over the 24-h daily cycle.The egg laying behavior makes laying hens a very special model for investigating phosphorus circadian rhythms.There is lack of information about the impact of adjusting phosphate feeding regimen according to daily rhythm on the phosphorus homeostasis and bone remodeling of laying hens.Methods and results Two experiments were conducted.In Exp.1,Hy-Line Brown laying hens(n=45)were sampled according the oviposition cycle(at 0,6,12,and 18 h post-oviposition,and at the next oviposition,respectively;n=9 at each time point).Diurnal rhythms of body calcium/phosphorus ingestions and excretions,serum calcium/phosphorus levels,oviduct uterus calcium transporter expressions,and medullary bone(MB)remodeling were illustrated.In Exp.2,two diets with different phosphorus levels(0.32%and 0.14%non-phytate phosphorus(NPP),respectively)were alternately presented to the laying hens.Briefly,four phosphorus feeding regimens in total(each included 6 replicates of 5 hens):(1)fed 0.32%NPP at both 09:00 and 17:00;(2)fed 0.32%NPP at 09:00 and 0.14%NPP at 17:00;(3)fed 0.14%NPP at 09:00 and 0.32%NPP at 17:00;(4)fed 0.14%NPP at both 09:00 and 17:00.As a result,the regimen fed 0.14%NPP at 09:00 and 0.32%NPP at 17:00,which was designed to strengthen intrinsic phosphate circadian rhythms according to the findings in Exp.1,enhanced(P<0.05)MB remodeling(indicated by histological images,serum markers and bone mineralization gene expressions),elevated(P<0.05)oviduct uterus calcium transportation(indicated by transient receptor potential vanilloid 6 protein expression),and subsequently increased(P<0.05)eggshell thickness,eggshell strength,egg specific gravity and eggshell index in laying hens.Conclusions These results underscore the importance of manipulating the sequence of daily phosphorus ingestion,instead of simply controlling dietary phosphate concentrations,in modifying the bone remodeling process.Body phosphorus rhythms will need to be maintained during the daily eggshell calcification cycle.

Development of Eggshell Waste Incorporated with a Porous Host as a Humidity Adsorption Material

The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment.The calcium oxide(Ca O)and calcium chloride(CaCl_(2))as the calcium-based desiccants were prepared from eggshell waste.The Ca O desiccant derived from the eggshell waste sintering at 1300℃,while the CaCl_(2)desiccant was extracted from eggshell waste with the hydrochloric(HCl)solution at difierent concentrations from 5 to 30 wt%.The yield percentage of CaCl_(2)desiccant increased with increasing the HCl concentration to 25 wt%.The humidity adsorption behavior were investigated in the range of 75%-5%relative humidity.The results show the CaCl_(2)desiccant has the highest hydration rate.The porous host from the kaolin was sintered at different temperatures from 200 to 1000℃and incorporated with 30%w/v concentrations of CaCl_(2).The physical properties and the humid-adsorption capacity of all porous host conditions were investigated.The porous host at sintering temperature 800℃has the highest specific surface area.Moreover,the porous host at sintering temperature 800℃with the 30%w/v concentration of CaCl_(2)desiccant has the highest humid-adsorption capacity.

Comparisons of microstructure and elemental composition of eggshells among wild plover populations

Reproduction investment is a prominent trade-off in life-history theory and is subject to strong selection pressure.The avian eggshell,as a crucial barrier between the bird embryo and the surrounding environment,undergoes optimization under different environmental selection regimes to ensure the successful development of embryos,which can be linked to local adaptation.Therefore,understanding the variation in eggshell microstructure and composition in wild bird populations living in contrasting ambient environments is of great significance.In this study,we utilized electron microscope ultrastructure measurement and elemental analyses to measure and compare the microstructure and element composition of eggshells from three wild plover populations(Charadrius alexandrinus and C.dealbatus)residing in heterogeneous habitats across varied climatic zones.These populations include the high-altitude Qinghai Lake population,the temperate coastal Tangshan population,and the tropical coastal Zhanjiang population.Our findings revealed that the palisade layer was thinner in the Qinghai Lake population compared to its lowland populations.This difference might be attributed to hypoxia which facilitates the hatching process by allowing chicks to easily break through their shells.Additionally,the variations in the elemental composition of the eggshells among populations well reflected the distribution of element content in different geographical regions.The Qinghai Lake population displayed low zinc and low manganese levels but high calcium levels,while the Zhanjiang population exhibited high zinc,high iron,high manganese,and high phosphorus levels.Furthermore,these variations in elemental composition could also account for the observed microstructural differences among populations.Collectively,we propose that the dissimilarities in eggshell microstructure and elemental composition among populations could be attributed to adaptations to different environmental conditions.Our findings lay the groundwork for future research to explore the mechanisms behind the variations in eggshell characteristics among wild bird populations,and contribute to a broader understanding of biodiversity mechanisms.

Chicken Eggshell as an Innovative Bioflocculant in Harvesting Biofloc for Aquaculture Wastewater Treatment

Implementation of biofloc technology(BFT)system in aquaculture industry shows high productivity,low feed conversion ratio,and an optimum culture environment.This study was divided into two phases.The first phase involved maintaining the water quality using the optimum carbon-to-nitrogen ratio by manipulating pH in culture water.The second phase examined the performance of harvesting biofloc(remaining phytoplankton and suspended solids in the system)using chicken eggshell powder(CESP).This study showed that pH 7 to 8 were the best biofloc performance with high removal percentage of ammonia(>99%)with a remaining ammonia concentration of 0.016 mg L^(−1)and 0.018 mg L^(−1),respectively.The second phase of this study was performed to determine the optimal formulation and conditions of using CESP as a bio-flocculant in harvesting excess biofloc.The use of eggshell showed a higher harvesting efficiency of more than 80%under the following treatment conditions:0.25 g L^(−1)of eggshell dosage;with rapid and slow mixing rates of 150 and 30 rpm,respectively;30 min of settling time;settling velocity of 0.39 mm s^(−1)and pH of 6 to 7.Therefore,the results indicated that biofloc would be the best green technology approach for sustainable aquaculture wastewater and the CESP is an organic matrix that environmental-friendly bio-coagulant for biofloc harvesting.

Eggshell 49对蛋鸡蛋壳质量的影响

将 4 0 0羽 5 9周龄海兰褐壳蛋鸡随机分成实验组和对照组 ,每组 2 0 0羽 .实验组在千克基础日粮中添加Eggshell 4 91g,试验持续 70 d.结果表明 :实验组的不合格蛋率比对照组下降 1.3% ;实验组的蛋质量 (蛋壳厚度、蛋壳强度、哈氏单位、蛋密度 )、血 Zn、血 Mn和碱性磷酸酶活性均显著高于对照组 (p <0 .0 5 ) ;蛋的受精率、孵化率及血 Ca、血 P、蛋壳成分 (Ca、P、Zn、Mn)及蛋重 ,两组无显著差异 (p>0 .0 5 ) ;蛋壳结构电镜观察表明实验组蛋壳乳突较小、大小一致 ,乳突与壳膜连结紧密 ,壳膜纤维交织密度高 ,而对照组蛋壳乳突较大、大小不一致 ,乳突与壳膜连接不紧密 ,壳膜纤维交织密度稀 .可见 ,在产蛋后期日粮中添加具有生物活性的 Zn。

New ratite eggshell material from the Miocene of Inner Mongolia,China

Some Miocene ratite eggshell fragments from Gashunyinadege (about 17.5 Ma) and Baogedawula (7.11 ± 0.48 Ma), Inner Mongolia, China, are described. The outer surfaces of eggshell fragments from Gashunyinadege are smooth with a sting pore pattern, while their entire thickness is around 2.12 mm. In a cross-sectional view, the surface crystal layer is very thin and the ratio of cone layer to the those from Gashunyinadege, but seem much thinner and have a lower pore density. Both characteristics fit aepyornithid-type eggshells, implying that the distribution of aepyornithid-type eggshells can be extended to East Asia. The sediments at Gashunyinadege date to approximately 17.5 Ma, implying that the specimens from this locality are relatively early examples of aepyornithid-type eggshells. Aepyornithidtype eggshells seem to have appeared in Eurasia much earlier than struthionid-type eggshells. The faunal compositions in the two localities reflect gradual drying of the Mongolian plateau during the Miocene. A reduction in the number of pores 10 Ma ago, probably occurred in response to this drying process.

Removal of heavy metals using waste eggshell

The removal capacity of toxic heavy metals by the reused eggshell was studied. As a pretreatment process for the preparation of reused material from waste eggshell, calcination was performed in the furnace at 800℃ for 2 h after crushing the dried waste eggshell. Calcination behavior, qualitative and quantitative elemental information, mineral type and surface characteristics before and after calcination of eggshell were examined by thermal gravimetric analysis （TGA）, X-ray fluorescence （XRF）, X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. After calcination, the major inorganic composition was identified as Ca （lime, 99.63%） and K, P and Sr were identified as minor components. When calcined eggshell was applied in the treatment of synthetic wastewater containing heavy metals, a complete removal of Cd as well as above 99% removal of Cr was observed after 10 rain. Although the natural eggshell had some removal capacity of Cd and Cr, a complete removal was not accomplished even after 60 rain due to quite slower removal rate. However, in contrast to Cd and Cr, an efficient removal of Pb was observed with the natural eggshell rather than the calcined eggshell. From the application of the calcined eggshell in the treatment of real electroplating wastewater, the calcined eggshell showed a promising removal capacity of heavy metal ions as well as had a good neutralization capacity in the treatment of strong acidic wastewater.

Eggshell and environmental bacteria contribute to the intestinal microbiota of growing chickens

Background: The initial intestinal microbiota acquired from different sources has profound impacts on animal health and productivity. In modern poultry production practices, the source(s) of the establishing microbes and their overall contribution during development of gastrointestinal tract communities are still unclear. Using fertilized eggs from two independent sources, we assessed the impact of eggshell-and environmental-associated microbial communities on the successional processes and bacterial community structure throughout the intestinal tract of chickens for up to 6 weeks post-hatch.Results: Culturing and sequencing techniques identified a viable, highly diverse population of anaerobic bacteria on the eggshell. The jejunal, ileal, and cecal microbial communities for the egg-only, environment-only, and conventionally raised birds generally displayed similar successional patterns characterized by increasing community richness and evenness over time, with strains of Enterococcus, Romboutsia, and unclassified Lachnospiraceae abundant for all three input groups in both trials. Bacterial community structures differed significantly based on trial and microbiota input with the exception of the egg-exposed and conventional birds in the jejunum at week 1 and the ileum at week 6. Cecal community structures were different based on trial and microbiota input source, and cecal short-chain fatty acid profiles at week 6 highlighted functional differences as well.Conclusion: We identified distinct intestinal microbial communities and differing cecal short-chain fatty acid profiles between birds exposed to the microbiota associated with either the eggshell or environment, and those of conventionally hatched birds. Our data suggest the eggshell plays an appreciable role in the development of the chicken intestinal microbiota, especially in the jejunum and ileum where the community structure of the eggshellonly birds was similar to the structure of conventionally hatched birds. Our data identify a complex interplay between the eggshell and environmental microbiota during establishment and succession within the chicken gut.Further studies should explore the ability of eggshell-and environment-derived microbes to shape the dynamics of succession and how these communities can be targeted through interventions to promote gut health and mitigate food-borne pathogen colonization in poultry.

Description and Phylogenetic Position of Dinosaur Eggshells from the Luanchuan Area of Western Henan Province,China

Here, we examine 145 dinosaur eggshells from a new fossil locality in the Qiupa Formation （Upper Cretaceous） of the Luanchuan area in western Henan Province, China. The eggshells display elongatoolithid macro- and microstructures, including ridges and nodes on the outer surface, two ultrastructurai layers, and an undulatory boundary between the mammillary and continuous layers. A phylogenic analysis shows that the Luanchuan eggshells belong to the ooclade Elongatoolithidae. Within Elongatoolithidae, the thickness ratio of the mammillary layer to the entire eggshell, and the porosity of the Luanchuan eggshells are comparable to the oogenera Macroolithus and Elongatoolithus. There is no direct evidence for the taxonomic identity of the Luanchuan eggshells; however, they were likely laid by oviraptorids based on their phylogenetic position and their similarities with known oviraptorid eggs.

Observation on Ultra-micro Structure of Eggshell and Analysis of Composition of Eggshell and Feather in Great Bustard

Ultra-micro structure of eggshell was observed and compositions of eggshell and feather were analyzed. The results showed that the structure of eggshell has special characters besides common structure. The content of poisonous elements in wild great bustard(Otis talda) eggshell and feather is significant lower than that in eggshell of crested foes(Nipponis nippon) and in feather of red crown crane(Grus japonesis) because of less disturbance by people. The contents of 14 elements of female’s feather all are higher than those of male’s.

Adsorption Kinetics of Matter Contained in a Leachate Using Eggshell and Activated Carbon

The generation of highly polluting leachate from Sanitary Landfills has prompted the development of technologies applicable to treatment of these liquids. The aim of this study was to determine the kinetics of adsorption of organic and inorganic matter contained in pre-treated leachate (by advanced oxidation by the Fenton reaction);after two adsorbents were used, first eggshell and then activated carbon. To determine the content of organic and inorganic matter COD was measured;this was the parameter for monitoring the kinetics. The leachate was subjected to advanced oxidation treatment by the Fenton reaction, then the adsorption process was conducted by batch, in two consecutive steps, the first step was the use of eggshell and the second step activated carbon. Due to the oxidation treatment the pH value decreased to 2, after the adsorption eggshell the pH increased to 6.9 and this was maintained in the treatment with activated carbon. The kinetics of adsorption of organic and inorganic matter on eggshell was evaluated by models pseudo-first-order and pseudo-second-order, the better fitting was the latter. The adsorption process was adjusted to the model of Langmuir. The negative value of △Hads indicated that the adsorption process was exothermic, spontaneous and favorable. The separation factor RL of Langmuir Isotherm values indicated that the adsorption of the matter on the eggshell was favorable at different temperatures. Finally, the activated carbon adsorption of liquid obtained from treatment with eggshell was favored with the kinetic model of pseudo second order. With the oxidation process, eggshell adsorption and activated carbon adsorption, the removal COD was 98.6%. The final COD value was fulfilled with the Mexican standard NOM-001-SEMARNAT-1996.

Egg recognition in Cinereous Tits(Parus cinereus):eggshell spots matter

Background:Brood parasitic birds such as cuckoos(Cuculus spp.)can reduce their host’s reproductive success.Such selection pressure on the hosts has driven the evolution of defense behaviors such as egg rejection against cuckoo parasitism.Studies have shown that Cinereous Tits(Parus cinereus)in China have a good ability for recognizing foreign eggs.However,it is unclear whether egg spots play a role in egg recognition.The aims of our study were to investigate the egg recognition ability of two Cinereous Tit populations in China and to explore the role of spots in egg recognition.Methods:To test the effect of eggshell spots on egg recognition,pure white eggs of the White-rumped Munia(Lonchura striata)and eggs of White-rumped Munia painted with red brown spots were used to simulate experimental parasitism.Results:Egg experiments showed that Cinereous Tits rejected 51.5%of pure white eggs of the White-rumped Munia,but only 14.3%of spotted eggs of the White-rumped Munia.There was a significant difference in egg recognition and rejection rate between the two egg types.Conclusions:We conclude that eggshell spots on Cinereous Tit eggs had a signaling function and may be essential to tits for recognizing and rejecting parasitic eggs.

Unhatched and Hatched Eggshells of the Chinese Cobra Naja atra

Changes in structure and composition of the eggshell resulting from embryonic mobilization of minerals from the eggshell are found in all oviparous reptiles studied thus far. In this study, we measured samples of unhatched and hatched eggshells of the Chinese cobra Naja atra to determine the percentage of ash and the phase composition of calcium carbonate. The mean percentage of ash was significantly higher in unhatched eggshells （24.6%） than in hatched eggshells （22.3%）. The dominant phase in unhatched eggshells was the calcite form of calcium carbonate. In addition to the peaks of calcite, a few small peaks were found to be caused by the aragonite and vaterite phases of calcium carbonate, implying that there are small amounts of aragonite and vaterite in the eggshell. The concentration of the various phases calculated from the intensity of the X-ray diffraction spectra allowed the estimation that percentages of calcite, aragonite and vaterite were about 92%, 4% and 4%, respectively. Hatched eggshells produced similar spectral characteristics as unhatched eggshells, with one exception. The dominant phase composition in the hatched eggshell was also calcite, but the amount of the aragonite phase had a marked increase. Our study adds evidence that embryonic mobilization of minerals from the eggshell may result in changes in structure of the eggshell.

Reduction of pro-inflammatory cytokines in rats following 7-day oral supplementation with a proprietary eggshell membrane-derived product

NEM&reg;?brand eggshell membrane is a novel dietary supplement that has been clinically shown to alleviate arthritis joint pain and stiffness;however the mechanism of action is not well understood. Preliminary evidence from an?in vitro?study of?NEM&REG;?indicated that the mechanism of action may be based on the reduction of pro-inflammatory cytokines.?In vivo?studies were therefore initiated to evaluate the effects of?NEM&REG;?on pro-inflammatory and anti-inflammatory cytokines following oral administration in rats.?NEM&REG;?was administered daily at doses of 6.13 mg/kg bw/day (Study 1), 10.0 mg/kg bw/day (Study 2), or at doses of 0 (control), 26.0 or 52.0 mg/kg bw/day (Study 3) by oral gavage for 7 consecutive days. Inflammation was induced in the Study 3 rats by intraperitoneal injection of lipopolysaccharide. Changes in plasma cytokine levels from baseline following 7 days of oral supplementation with?NEM&REG;?at 6.13 mg/kg bw/ day (Study 1) were statistically significant at Day 8 for IL-2, TIMP-1 and VEGF, at Day 21 for IL-10, and at Day 35 for MCP-1, MCP-3 and TIMP-1, and at 10.0 mg/kg bw/day (Study 2) were statistically significant at Day 8 for VEGF, at Day 21 for MIP-1β, MIP-2 and VEGF, and at Day 35 for MCP-3, MIP-1β, MIP-2 and VEGF. Changes in serum cytokine levels versus control at 26.0 mg/kg bw/day (Study 3) were statistically significant at all time-points for IL-1β?and at 1.5 hours for IL-10, and at 52.0 mg/kg bw/day (Study 3) were statistically significant at 1.5 hours for IFN-γ, IL-1β?and IL-10, and at 3 hours for IL-1β, and at 24 hours for IL-10. Taken together, these studies demonstrate that oral supplementation with?NEM&REG;?can influence both early-phase pro-inflammatory cytokines like IL-1β?and TNF-α?(Study 3), as well as later-phase cytokines like MCP-1, MIP-1α?&?β, RANTES and VEGF (Study 1 & 2). These studies provide a possible basis for the mechanism of action of?NEM&REG;?in vivo.

PREPARATION AND CHARACTERIZATION OF SOLUBLE EGGSHELL MEMBRANE PROTEIN/CHITOSAN BLEND FILMS

Biopolymer chitosan was used to modify the mechanical properties of soluble eggshell membrane protein (SEP) films. The SEP/chitosan blend films were prepared by solution casting from 10% aqueous acetic acid. Tensile strength and elongation at break of the blend films increased with increasing amount of chitosan. Microphase separation was observed by field emission scanning electron microscopy, although interaction between the two components was revealed by FTIR. The biocompatibility of SEP/chitosan blend films containing 10%-50% of chitosan, as demonstrated by cell culture of NIH3T3, was much better than that of pure chitosan.

Production of Bio-Calcium Oxide Derived from Hatchery Eggshell Waste Using an Industrial-Scale Car Bottom Furnace

The valorization of eggshell waste as bio-calcium oxide is crucial for pollution prevention and supporting sustainable development.There are several reports on the thermal conversion of eggshell waste to calcium oxide for the partial or complete substitution of natural lime applications.However,this paper reports the thermal decomposition of large amounts of hatchery eggshell waste on an industrial-scale car bottom furnace for the first time.The hatchery eggshell waste was sundried and placed into five stacked trays in the car bottom furnace.The calcination of the eggshell waste was conducted at 900℃ for 3 and 4 h under an atmosphere of air.Both the physical and chemical properties of the eggshell samples and the bio-quicklime products were carefully examined by TGA,SEM,XRD,FTIR,and XRF.The results demonstrate that the purity of calcium oxide in the quicklime products increased from 79%to 87%upon increasing the calcination time from 3 to 4 h.However,the color of the calcined eggshell samples at the surface of the pile was white while the color of the product beneath the surface was black or dark gray.The purity of the calcium oxide of both the black and white calcined samples was 76.4%and 91.5%,respectively.These results indicate the limited efficacy of the car bottom furnace for thermal decomposition of the large amount of eggshell waste to calcium oxide.Additionally,the production cost of bio-calcium oxide is approximately twice the cost of industrial grade lime.For further industrial applications,the furnace should contain the mixing equipment for improving the thermal decomposition of the large pile of eggshell waste.Furthermore,the oil burner system may be used in order to reduce fuel costs.

Mapping of Quantitative Trait Loci Affecting Eggshell Quality in an F_2 Population Derived from Strong and Weak Eggshell Lines of the White Leghorn Chicken Breed

Broken and cracked eggshells cause major economic losses to the egg production industry. An F2 population of 262 hens obtained by crossing a strong egg shell line with a weak egg shell line of the White Leghorn breed was used for detecting the quantitative trait loci （QTL） affecting eggshell quality. The 2 lines were developed from the same founder population by two-way selection for egg shell strength with nondestructive deformation. Of the 1 014 microsatellite markers tested, 35 were mapped on 10 autosomal linkage groups. There was no informative marker on chromosome Z. The QTLs associated with 7 traits, i.e., body weight, short length of egg, long length of egg, eggshell strength, eggshell thickness （EST）, eggshell weight （ESW）, and egg weight （EW）, were identified. Highly significant （P〈0.01） QTLs associated with EST and ESW and a significant （P〈 0.05） QTL associated with EW were mapped to a region flanking ABR0545 and ABR0362 on chromosome 9. These QTLs are good candidates to be employed in the development of strategies for reducing the number of broken and cracked eggs in commercial layer houses by employing marker assisted selection.

Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

The antibacterial property and biodegradability of soluble eggshell membrane protein （SEP） are reported. Unlike the natural eggshell membrane （ESM）, SEP does not possess antibacterial property against E. coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.

Weakening internal diffusion effect in selective hydrodesulfurization of FCC gasoline by novel designed eggshell CoMoS/Al_2O_3 catalysts

A simple method for preparation of presulfided eggshell CoMoS/γ-Al2O3 catalysts with sharp boundary is developed, through which the eggshell thicknesses of Co and Mo could be easily regulated by controlling the impregnation time. According to the results characterized by EDS, XRD, HRTEM and FT-IR of adsorbed CO, the active component structures, the nature and/or the amount of active sites on the eggshell catalyst are similar to these on the uniform catalyst. The evaluation results of the catalytic performance in selective hydrodesulfurization （HDS） of FCC gasoline show the presence of significant internal diffusion inhibition effect on HDS of S-compounds especially in the uniform catalyst. Compared with uniform catalyst, the eggshell catalyst could remarkably reduce such an internal diffusion inhibition effect due to a shortened diffusion path of the reactants, thus showing higher HDS activity and selectivity.