Improving the processability of coke water slurries for entrained flow gasification

Jampolski, L.; Sänger, A.; Jakobs, Tobias; Guthausen, Gisela; Kolb, Thomas; Willenbacher, Norbert

doi:10.1016/j.fuel.2016.07.102

Cited by 27 publications

(15 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This effect can be used as a simple method to tune the flow behavior of suspensions that would otherwise require the addition of rheology control agents, surfactants or other additives [7]. Capillary suspensions can be used for various applications such as precursors for ceramic or glass filters with high porosity and simultaneously small pore size [8–10], porous polymeric or hybrid membranes [11, 12] improved polymer blends [13–15], slurries for battery electrodes or printable electronics with accurately molded edge shape, good charge transfer properties and reduced resistivity [16–18], crack-free films [19], thermal interface materials [20], carbon slurries from renewable sources used for energy generation [21], the preparation of novel food products [22, 23] or as 3D printing paste formulations [24, 25].…”

Section: Introductionmentioning

confidence: 99%

Fractal approaches to characterize the structure of capillary suspensions using rheology and confocal microscopy

Bossler

Maurath

Dyhr

et al. 2018

Journal of Rheology

Self Cite

View full text Add to dashboard Cite

The rheological properties of a particle suspension can be substantially altered by adding a small amount of a secondary fluid that is immiscible with the bulk phase. The drastic change in the strength of these capillary suspensions arises due to the capillary forces, induced by the added liquid, leading to a percolating particle network. Using rheological scaling models, fractal dimensions are deduced from the yield stress and from oscillatory strain amplitude sweep data as function of the solid volume fraction. Exponents obtained using aluminum-oxide-based capillary suspensions, with a preferentially wetting secondary fluid, indicate an increase in the particle gel's fractal dimension with increasing particle size. This may be explained by a corresponding relative reduction in the capillary force compared to other forces. Confocal images using a glass model system show the microstructure to consist of compact particle flocs interconnected by a sparse backbone. Thus, using the rheological models two different fractal dimensionalities are distinguished - a lower network backbone dimension ( = 1.86-2.05) and an intrafloc dimension ( = 2.57-2.74). The latter is higher due to the higher local solid volume fraction inside of the flocs compared to the sparse backbone. Both of these dimensions are compared with values obtained by analysis of spatial particle positions from 3D confocal microscopy images, where dimensions between 2.43 and 2.63 are computed, lying between the two dimension ranges obtained from rheology. The fractal dimensions determined via this method corroborate the increase in structural compactness with increasing particle size.

show abstract

Section: Introductionmentioning

confidence: 99%

Fractal approaches to characterize the structure of capillary suspensions using rheology and confocal microscopy

Bossler

Maurath

Dyhr

et al. 2018

Journal of Rheology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Capillary suspensions can be used for various applications such as precursors for ceramic or glass filters with high porosity and simultaneously small pore size,10, 11, 12 improved polymer blends,5, 13, 14 slurries for printable electronics with accurately molded edge shape, good charge transfer properties and reduced resistivity 15, 16, 17,. thermal interface materials,18 slurries of renewable carbon sources used for generation of energy19 or the preparation of novel food products 20…”

Section: Introductionmentioning

confidence: 99%

Influence of mixing conditions on the rheological properties and structure of capillary suspensions

Bossler

Weyrauch

Schmidt

et al. 2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

The rheological properties of a suspension can be dramatically altered by adding a small amount of a secondary fluid that is immiscible with the bulk liquid. These capillary suspensions exist either in the pendular state where the secondary fluid preferentially wets the particles or the capillary state where the bulk fluid is preferentially wetting. The yield stress, as well as storage and loss moduli, depends on the size and distribution of secondary phase droplets created during sample preparation. Enhanced droplet breakup leads to stronger sample structures. In capillary state systems, this can be achieved by increasing the mixing speed and time of turbulent mixing using a dissolver stirrer. In the pendular state, increased mixing speed also leads to better droplet breakup, but spherical agglomeration is favored at longer times decreasing the yield stress. Additional mixing with a ball mill is shown to be beneficial to sample strength. The influence of viscosity variance between the bulk and second fluid on the droplet breakup is excluded by performing experiments with viscosity-matched fluids. These experiments show that the capillary state competes with the formation of Pickering emulsion droplets and is often more difficult to achieve than the pendular state.

show abstract

“…Based on morphology, the breakup regimes of slurry jet can be classified into different modes: Rayleigh-type breakup, fiber-type breakup, superpulsating breakup, and atomization [113,118,119]. The particles in slurry will make membrane breakup very fast, so the membrane structure is not obvious in slurry atomization as shown in Figure 5.…”

Section: Complex Fluidsmentioning

confidence: 99%

Breakup Morphology and Mechanisms of Liquid Atomization

Zhao¹,

Liu²

2020

Environmental Impact of Aviation and Sustainable Solutions

View full text Add to dashboard Cite

Fuel atomization, the transformation of bulk liquid into sprays, is of importance in jet engines. In this chapter, we will introduce the latest research advances on breakup morphology and mechanism of liquid atomization. On primary atomization, based on the morphological difference, the twin-fluid atomization could be classified into different regimes. The influence of Kelvin-Helmholtz and Rayleigh-Taylor instability on breakup morphology and fragment size is great and nonmonotonic. On secondary atomization, Rayleigh-Taylor instability is considered as the main driving mechanism in different bag-breakup modes; for higher Weber number, it will be in concurrence with the shear instability. Based on ligamentmediated spray formation model, ligament breakup is found to be well represented by the gamma distributions. Atomization of complex fluids has special characteristics and mechanisms. There are also a lot of research advances recently in this field.

show abstract

Improving the processability of coke water slurries for entrained flow gasification

Cited by 27 publications

References 30 publications

Fractal approaches to characterize the structure of capillary suspensions using rheology and confocal microscopy

Fractal approaches to characterize the structure of capillary suspensions using rheology and confocal microscopy

Influence of mixing conditions on the rheological properties and structure of capillary suspensions

Breakup Morphology and Mechanisms of Liquid Atomization

Contact Info

Product

Resources

About