Amorphous and humidity caking: A review

Caking of products is a common and undesired phenomenon in food, chemical, pharmaceutical, and fertilizer industries which leads to extra cost and irregular quality. In general, caking processes could be identified as amorphous caking or humidity caking. In this review, history of studying caking, formation, methods, and prospects of these two caking processes are summarized and discussed. The relevant studies from the 1920 s to today are mentioned briefly. According to the different properties(i.e. hygrocapacity, hygrosensitivity, mechanical properties, and diffusion behavior) of amorphous powders and crystals, the conditions and mechanisms of amorphous and humidity caking are discussed. It is summarized that glass transition, moisture sorption, quantitative methods characterizing caking, accelerated caking tests, and simulation of caking behaviors are the main aspects that should be studied for a caking process. The methods for these five aspects are reviewed. Potential research points are proposed including caking of mixed particles, caking with phase transition or polymorph transition,non-homogenous caking, and simulation of caking.

Experimental and mechanistic study on chemical looping combustion of caking coal

Under high-temperature batch fluidized bed conditions and by employing juye coal as the raw material,the present study determined the effects of the bed material,temperature,OC/C ratio,steam flow and oxygen carrier cycle on the chemical looping combustion of coal.In addition,the variations taking place in the surface functional groups of coal under different reaction times were investigated,and the variations achieved by the gas released under the pyrolysis and combustion of Juye coal were analyzed.As revealed from the results,the carbon conversion ratio and rate were elevated significantly,and the volume fraction of the outlet CO_(2)remained more than 92%under the oxygen carriers.The optimized reaction conditions to achieve the chemical looping combustion of Juye coal consisted of a temperature of 900℃,an OC/C ratio of 2,as well as a steam flow rate of 0.5 g·min^(-1).When the coal was undergoing the chemical looping combustion,volatiles primarily originated from the pyrolysis of aliphatic-CH_(3)and-CH_(2),and CO and H_(2)were largely generated from the gasification of aromatic carbon.In the CLC process,H_(2)O and CO_(2)began to separate out at 270℃,CH4 and tar began to precipitate at 370℃,and the amount of CO_(2)was continuously elevated with the rise of the temperature.

Synergistic reaction behavior of pyrolysis and reduction of briquette prepared by weakly caking coal and metallurgical dust

Co-carbonization of weakly caking coal and zinc-containing dust to prepare highly reactive ferro-coke and collaboratively recover zinc powder is one of the feasible ways for steel enterprises to recycle zinc-containing dust.The pyrolysis mass loss behavior of adding blast furnace dust with different zinc contents to different ferro-coke materials was systematically studied by thermogravimetry and differential thermogravimetry analysis,and the kinetic mechanism of pyrolysis-reduction reaction of hybrid briquette was explored.The results of thermogravimetric curve analysis show that the addition of zinc oxide to the sample has no significant effect on the mass loss rate of the sample below 580℃,and the pyrolysis mass loss of zinc oxide mainly occurs between 800 and 1000℃.Kinetic analysis results show that the pyrolysis of zinc-containing samples is controlled by chemical reactions below 580℃.The reaction at 580–700℃ is controlled by the nucleation and growth model,and that above 700℃ is mainly controlled by diffusion.The results of X-ray diffraction analysis show that the pyrolysis process can effectively remove zinc oxide from ferro-coke.

Modification mechanism of caking and coking properties of Shenmu subbituminous coal by low-temperature rapid pyrolysis treatment

Shenmu(SM)subbituminous coal without caking property was treated by low-temperature rapid pyrolysis(LTRP)to modify its caking and coking properties.The treated samples were characterized by Fourier transform infrared spectrometry,vitrinite reflectance,and X-ray diffraction to determine the modification mechanism.Moreover,caking index(G)and coking indices(mechanical strength,coke reactivity,and coke strength after reaction)were employed to evaluate caking and coking properties,respectively.The results showed that SM coal was gradually upgraded with increasing processing temperature.Furthermore,the G values for the treated samples were significantly higher than that for SM coal,and G reached the maximum value at 450℃,implying the modification of caking property and the existence of an optimum temperature(450℃).Additionally,laboratory coking determinations showed that LTRP increased the mechanical strength of coke and coke strength after reaction and decreased coke reactivity when the treated coals were used in the coal blends instead of raw SM coal.Overall,LTRP treatment is effective to improve the caking and coking properties of SM coal.A mechanism was proposed for the modification.Suitable upgrading degree with suitable molecular masses and some releasable hydrogen-rich donor species present within the coal,which dominate the development of caking property,is important.

Valorization of Camellia oleifera oil processing byproducts to value-added chemicals and biobased materials: A critical review

The C.oleifera oil processing industry generates large amounts of solid wastes,including C.oleifera shell(COS)and C.oleifera cake(COC).Distinct from generally acknowledged lignocellulosic biomass(corn stover,bamboo,birch,etc.),Camellia wastes contain diverse bioactive substances in addition to the abundant lignocellulosic components,and thus,the biorefinery utilization of C.oleifera processing byproducts involves complicated processing technologies.This reviewfirst summarizes various technologies for extracting and converting the main components in C.oleifera oil processing byproducts into value-added chemicals and biobased materials,as well as their potential applications.Microwave,ultrasound,and Soxhlet extractions are compared for the extraction of functional bioactive components(tannin,flavonoid,saponin,etc.),while solvothermal conversion and pyrolysis are discussed for the conversion of lignocellulosic components into value-added chemicals.The application areas of these chemicals according to their properties are introduced in detail,including utilizing antioxidant and anti-in-flammatory properties of the bioactive substances for the specific application,as well as drop-in chemicals for the substitution of unrenewable fossil fuel-derived products.In addition to chemical production,biochar fabricated from COS and its applications in thefields of adsorption,supercapacitor,soil remediation and wood composites are comprehensively reviewed and discussed.Finally,based on the compositions and structural characteristics of C.oleifera byproducts,the development of full-component valorization strategies and the expansion of the appli-cationfields are proposed.

Deep bed filtration model for cake filtration and erosion

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. In the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

Measurement and quantification of caking in excipients and food products with emphasis on the non-homogeneous interaction with ambient moisture

Whilst caking occurs via several different mechanisms,absorption and migration of moisture is frequently the most dominant mechanism within the food and pharmaceutical industry.Fully understanding the propensity to cake is important for minimising down-stream process issues,however most characterisation techniques assume that moisture induced caking occurs homogenously through the sample resulting in a uniformly caked powder bed.In this study,the effect of moisture induced caking on powder flowability was investigated using powder rheology.Several materials,including skimmed milk powder(SMP)and sulphated methyl ester(SME)were stored for several days under controlled humidity conditions.The flow energies,a measure of the resistance to flow,were measured at 24 h intervals using an FT4 Powder Rheometer.As the energy is measured as a function of the bed height,variations in the powder bed are also captured.The results demonstrated that caking does not always occur uniformly,instead a caked region(or crust)forms at the air-powder interface and then progresses through the powder bed.Furthermore,the strength of this caked region was shown to increase over several days before stabilising.

Mechanism and inhibition of trisodium phosphate particle caking： Effect of particle shape and solubility

We investigated the influence of particle shape and solubility on the caking behavior of trisodium phosphate by considering the adhesion free energy and crystal bridge theory. Caking of trisodium phosphate during the drying process under static conditions is a two-step process： adhesion followed by crystal bridge formation between particles. The adhesion free energy plays an important role in adhesion. Trisodium phosphate particles cannot adhere to each other and cake when the adhesion free energy is greater than a critical value, which varies with particle shape. Compared with granular particles, cylindrical particles have larger contact area between particles, which results in more crystal bridges forming and a higher caking ratio. Thus, the critical value is about 100 mJ/m^2 for cylindrical particles, but 60 mJ/m^2 for granular particles at 25 ℃. Concerning the solubility, when particles are similar shapes and soluble in the rinsing liquid, the caking ratio has a linear relationship with adhesion free energy. However, if the particles are insoluble in the rinsing liquid, caking can be completely prevented regardless of adhesion free energy because no crystal bridges form during the growth process. Hence, caking of trisodium phosphate particles could be inhibited by screening rinsing liquids, and optimizing the particle shape and size distribution.

Flow-Induced Clogging in Microfiltration Membranes: Numerical Modeling and Parametric Study

Microfiltration membrane technology has been widely used in various industries for solid-liquid separation. However, pore clogging remains a persistent challenge. This study employs (CFD) and discrete element method (DEM) models to enhance our understanding of microfiltration membrane clogging. The models were validated by comparing them to experimental data, demonstrating reasonable consistency. Subsequently, a parametric study was conducted on a cross-flow model, exploring the influence of key parameters on clogging. Findings show that clogging is a complex phenomenon affected by various factors. The mean inlet velocity and transmembrane flux were found to directly impact clogging, while the confinement ratio and cosine of the membrane pore entrance angle had an inverse relationship with it. Two clog types were identified: internal (inside the pore) and external (arching at the pore entrance), with the confinement ratio determining the type. This study introduced a dimensionless number as a quantitative clogging indicator based on transmembrane flux, Reynolds number, filtration time, entrance angle cosine, and confinement ratio. While this hypothesis held true in simulations, future studies should explore variations in clogging indicators, and improved modeling of clogging characteristics. Calibration between numerical and physical times and consideration of particle volume fraction will enhance understanding.

Valorization of Griffonia simplicifolia Seed Oil for Biodiesel Production: A Sustainable Alternative

Bio-derived oxygenated hydrocarbons, such as mixtures of fatty acid methyl esters (biodiesel), are promising alternatives for alleviating the adverse effects of fossil fuel consumption on climate change and preventing petroleum resource depletion. However, the selection of a viable feedstock for competitive biodiesel production remains challenging. Recent studies focusing on Griffonia simplicifolia seeds, the sole plant industrially exploited for 5-hydroxy- tryptophan (5-HTP) extraction, have shown that G. simplicifolia seed oil (GSO) can be solvent-extracted directly from ground seeds or the remaining seed cakes obtained after 5-HTP extraction with quantitative yields. This work documents the conversion of GSO into biodiesel through homogeneous base-catalyzed transesterification. The refractive index and density of the obtained methyl ester mixtures decreased with increasing oil-to-methanol molar ratio, reaction temperature, and time. Under specific conditions, 1.43 wt% FFA oil, 63.5C, 60 min, and 1:9 oil/MeOH molar ratio with 1.2 wt% NaOH or 1.3 wt% KOH as catalysts, optimal reaction conditions were reached. There were no significant differences in the potential for diminution of the refractive index and density between the NaOH and KOH catalysts. The predicted fuel properties based on the fatty acid composition determined by GC-MS showed that G. simplicifolia biodiesel exhibited a cetane index of 50.29, volumetric energy density of 34.97 MJ/L, cloud point of -1.03°C, kinematic viscosity of 4.07 mm2/s, and oxidative stability of 0.65 h. Apart from its unfavorable oxidative stability and slightly lower energy density compared to petrodiesel, all other calculated parameters met the current standards. The valorization concept proposed in this study should be integrated into the 5-HTP extraction process, preferably using the remaining dry seed cakes as raw materials to maximize revenue in a bioeconomic and sustainable approach.

中秋月饼考

关于中秋月饼产生的时间和原因,有多种说法。经过文献考证可知,中国饼食的制作有古远的历史,而月饼的前身是汉代以来的胡饼。关于中秋月饼产生于唐代和宋代的说法都是没有确凿依据的。有充分资料证明,作为中秋节节令食品的月饼正式出现于明代,开始它是拜月的供品,后来才演变为节令食品。

Hygroscopic Behavior of Lyophilized Powder of Grugru Palm (<i>Acrocomia aculeata</i>)

The objective of this study was to determine adsorption isotherms and hygroscopic behavior of lyophilized powder from grugru palm. The powders of grugru palm were obtained by lyophilization process without maltodextrin (T1) and with 8% matodextrin (T2). The experimental data were obtained through the static gravimetric method at temperatures (25℃, 30℃, 35℃ and 40℃), with different saturated solutions of salts. The models of GAB, BET, Henderson and Oswin were fitted to experimental data. The values obtained for hygroscopicity were 7.68% and 6.86% and the degrees of caking were 0.33% and 0.09% for T1 and T2, respectively. Mathematical models of adsorption isotherms for grugru palm powders can be classified as Type III. The GAB and Oswin models represented better the behavior of isotherms for T1 and T2. Grugru palm powder showed an increase in the humidity of the monolayer Xm along with increasing temperature. The grugru palm powder demonstrated to be a non-hygroscopic product, non-caking features.

Solid state fermentation of rapeseed cake with Aspergillus niger for degrading glucosinolates and upgrading nutritional value

Background： Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances, such as glucosinolates （GIs）, phytic acid, tannins etc. In the present study, a solid state fermentation （SSF） using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake （RSC）. The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake （FRSC） were investigated, and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined. Results： After 72 h of incubation at 34℃, a 76.89% decrease in GIs of RSC was obtained in solid medium containing 70% RSC, 30% wheat bran at optimal moisture content 60% （w/w）. Compared to unfermented RSC, trichloroacetic acid soluble protein （TCA-SP）, crude protein and ether extract contents of the FRSC were increased （P〈 0.05） 103.71, 23.02 and 23.54%, respectively. As expected, the contents of NDF and phytic acid declined （P〈 0.05） by 9.12 and 44.60%, respectively. Total amino acids （TAA） and essential amino acids （EAA） contents as well as AA in vitro digestibility of FRSC were improved significantly （P 〈 0.05）. Moreover, the enzyme activity of endoglucanase, xylanase, acid protease and phytase were increased （P 〈 0.05） during SSF. Conclusions： Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.

Comparison of membrane fouling during short-term filtration of aerobic granular sludge and activated sludge

Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared （FTIR） spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.

Combination Patterns and Depositional Characteristics of Ordovician Carbonate Banks in the Western Tarim Basin,China

The combination patterns and depositional characteristics of the carbonate banks are investigated based on outcrop sections, thin sections, and carbon isotopes of Ordovician in the western Tarim Basin, China. Four carbonate bank combination patterns are deposited in the Ordovician, western Tarim Basin, including： Reef-Bank Complex （RBC）, Algae-Reef-Bank Interbed （ARBI）, Thick-Layer Cake Aggradation Bank （TLCAB）, and Thin-Layer Cake Retrogradation Bank （TLCRB）. All combination patterns show clear periods vertically. The RBC is mainly composed of reefs and bioclastic banks, and the dimension of the RBC depends on the scale of the reefs. Bioclastic banks deposits surround the reefs. The range of the ARBI is determined by the scale of algae-reefs, algae peloid dolomite microfacies and algal dolomite microfacies deposit alternating vertically. TLCAB and TLCRB are deposited as layer-cakes stacking in cycles and extending widely with cross bedding developed. The grains of TLCAB and TLCRB are diverse and multi-source. With the impacting of relative sea level change, biological development and geomorphology, the ARBI, TLCAB or TLCRB, RBC are successively developed from the Lower Ordovician Penglaiba Formation to the Middle Ordovician Yijianfang Formation. The depositional environment analysis of Ordovician indicates that the RBC and ARBI can form effective oil and gas reservoirs, and the TLCAB and TLCRB have the potential to form the huge scale oil and gas reservoirs and to be the crucial targets of exploration for the Ordovician carbonate banks in the future.

Down-regulation of tyrosinase,TRP-1,TRP-2 and MITF expressions by citrus press-cakes in murine B16 F10 melanoma

Objective:To investigate the suitability of citrus-press cakes,by-products of the juice industry as a source for the whitening agents for cosmetic industry.Methods:Ethylacetate extracts of citrus-press cakes(CCE)were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese,tyrosinase-related protein-1(TRP-1),TRP2,and microphthalmia-associated transcription factor(MITF)proteins.To apply the topical agents,citrus-press cakes was investigated the safety in human skin cell line.Finally flavonoid analysis of CCE was also determined by HPLC analysis.Results:Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern.The CCE inhibited tyrosinase,TRP-2,and MITF expressions in a dose-dependent manner.To test the applicability of CCE to human skin,we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells.The CCE exhibited low cytotoxicity at 50μg/mL.Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin,narirutin,and hesperidin.Conclusions:Considering the anti-melanogenic activity and human safety,CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.

The use of grass as an environmentally friendly additive in water-based drilling fluids

Excellent drilling fluid techniques are one of the significant guaranteed measures to insure safety, qual- ity, efficiency, and speediness of drilling operations. Dril- ling fluids are generally discarded after the completion of drilling operations and become waste, which can have a large negative impact on the environment. Drilling mate- rials and additives together with drill cuttings, oil, and water constitute waste drilling fluids, which ultimately are dumped onto soil, surface water, groundwater, and air. Environmental pollution is found to be a serious threat while drilling complex wells or high-temperature deep wells as these types of wells involve the use of oil-based drilling fluid systems and high-performance water-based drilling fluid systems. The preservation of the environment on a global level is now important as various organizations have set up initiatives to drive the usage of toxic chemicals as drilling fluid additives. This paper presents an approach where grass is introduced as a sustainable drilling fluid additive with no environmental problems. Simple water- based drilling fluids were formulated using bentonite, powdered grass, and water to analyze the rheological and filtration characteristics of the new drilling fluid. A particle size distribution test was conducted to determine the par- ticle size of the grass sample by the sieve analysis method. Experiments were conducted on grass samples of 300, 90, and 35 μm to study the characteristics and behavior of the newly developed drilling fluid at room temperature. The results show that grass samples with varying particle sizes and concentrations may improve the viscosity, gel strength, and filtration of the bentonite drilling fluid. These obser- vations recommend the use of grass as a rheological modifier, filtration control agent, and pH control agent to substitute toxic materials from drilling fluids.

Rice Bran Oil Extraction by Screw Press Method:Optimum Operating Settings,Oil Extraction Level and Press Cake Appearance

The appearance of rice bran ＇cake＇ or discharge from a screw press corresponds to the level of oil produced in the extraction process. The relationships between operating settings, oil extraction level and cake appearance were studied. Cake characteristics reliably indicate the expected oil recovery extraction level. These conclusions applyed to both Chainat 1 rice bran and parboiled rice bran. Variables were the speed of the screw press （set at five levels from 8.5 to 19.8 r/min） and corresponding clearance distances between the screw and barrel （set between 1.0 and 1.9 cm）. Results showed that the maximum levels of extraction were 4.17% for the rice bran and 8.20% for the parboiled rice bran. At the maximum extraction level, the apparatus continuously discharged cake that were hard, crispy, flaky, shiny and polished on one side but dull and coarse on the other.

Effects of a novel bimetallic catalytic biofilter-based pretreatment technique on the form of ultrafiltration membrane fouling

Pretreatments of influents using bimetallic catalytic biofilter(BC-biofilter)can help reduce transmembrane pressures.For ultrafiltration membranes coupled with a conventional biofilter pretreatment,the cake layer resistance accounts for 25.0%of the total resistance.However,for those coupled with BC-biofilter pretreatment,the cake layer resistance accounts only for 12.5%of the total resistance.Confocal laser scanning microscopy is employed to determine the porosity of cake layer.It is found that ultrafiltration membranes with BC-biofilter pretreatment show a cake layer porosity of up to 0.56 or greater,whereas those with a conventional biofilter pretreatment exhibit a cake layer porosity of only 0.36.This is because micro-flocculation occurs in the effluents of BC-biofilter.The flocs generated through flocculation deposit on membrane surfaces to create highly porous cake layer.Moreover,catalytic reduction can increase the zeta potentials of the biofilter effluents.This makes the deposition of colloidal particles and flocs on membrane surfaces difficult under electrostatic repulsion.Simultaneously,micro-flocculation after BC-biofilter pretreatment can remove colloidal particles with particle sizes of200–350 nm in water.This can effectively prevent the blockage of ultrafiltration membrane pores.Furthermore,compared to conventional biofilter,BC-biofilter pretreatment can more effectively reduce the number of colloidal particles and the van der Waals forces of ultrafiltration membranes.They can also change the action directions of electric double layers and thereby mitigate ultrafiltration membrane fouling.