Premix membrane emulsification

Premix membrane emulsificatio

Oscillating membrane emulsification

Oscillating membrane emulsificatio

Production of silica particles by membrane emulsification

Production of silica particles by membrane emulsificatio

Polycaprolactone multicore-matrix particle for the simultaneous encapsulation of hydrophilic and hydrophobic compounds produced by membrane emulsification and solvent diffusion processes

Co-encapsulation of drugs in the same carrier, as well as the development of microencapsulation processes for biomolecules using mild operating conditions, and the production of particles with tailored size and uniformity are major challenges for encapsulation technologies. In the present work, a suitable method consisting of the combination of membrane emulsification with solvent diffusion is reported for the production of multi-core matrix particles with tailored size and potential application in multi-therapies. In the emulsification step, the production of a W/O/W emulsion was carried out using a batch Dispersion Cell for formulation testing and subsequently a continuous azimuthally oscillating membrane emulsification system for the scaling-up of the process to higher capacities. In both cases precise and gentle control of droplet size and uniformity of the W/O/W emulsion was achieved, preserving the encapsulation of the drug model within the droplet. Multi-core matrix particles were produced in a post emulsification step using solvent diffusion. The compartmentalized structure of the multicore-matrix particle combined with the different chemical properties of polycaprolactone (matrix material) and fish gelatin (core material) was tested for the simultaneous encapsulation of hydrophilic (copper ions) and hydrophobic (α-tocopherol) test components. The best operating conditions for the solidification of the particles to achieve the highest encapsulation efficiency of copper ions and α-tocopherol of 99 (±4)% and 93(±6)% respectively were found. The multi-core matrix particle produced in this work demonstrates good potential as a co-loaded delivery system

Using statistical and artificial neural networks to predict the permeability of loosely packed granular materials

Well-known analytical equations for predicting permeability are generally reported to overestimate this important property of porous media. In this work, more robust models developed from statistical (multivariable regression) and Artificial Neural Network (ANN) methods utilised additional particle characteristics [‘fines ratio’ (x50/x10) and particle shape] that are not found in traditional analytical equations. Using data from experiments and literature, model performance analyses with average absolute error (AAE) showed error of ~40% for the analytical models (Kozeny–Carman and Happel–Brenner). This error reduces to 9% with ANN model. This work establishes superiority of the new models, using experiments and mathematical techniques

A toilet system based on hydrothermal carbonization

We are developing a toilet system that converts faecal material to an aqueous suspension of carbonised material that is safe to handle, and readily separated from the remaining liquid. It will also extract useful salts from the liquid. The system is aim to be the new generation universally appealing toilet and it will be of particular and urgent interest to areas where no (or very crude) sanitation exists. The system is designed to be self-sufficient in terms of energy input and to scale for a number of users in the range a few tens to a thousand or more. In parallel with our engineering development we are designing the system to provide users with a positive and comfortable experience. Hydrothermal carbonisation (HTC) has received attention recently as a way to convert biomass - including sewerage - into coal like material. It involves heating the start material in water at high temperatures and pressures. Depending on the conditions used the process can produce hydrocarbon gases or liquids or coal like particles. Most HTC work involving sewerage treatment is currently aimed at replacing established large-scale treatment plants i.e. for places with well-developed sewerage services. Our system, using HTC, is aimed at bringing the process at a decentralized household ( including combination of households) level so that the new generation toilet become accessible to all and particularly to those areas where none currently exists. Using HTC for toilets on continuous basis for such a small scale is the key innovation of our proposed system. We will describe our work to characterise the energetics of the HTC process in order to optimise the process in terms of total energy input and how we have used this information to develop a continuous system based on a plug flow reactor. The material produced by the system can be easily separated from the remaining liquid and used to generate heat and power (via a generator including solar) in order to maintain the process. The solids are safe to handle, and look, feel and smell much like coffee grounds. In situations where electrical (or renewable energy like solar) power is available the solid material can be used either as a fuel for heating and cooking, as a soil conditioner and possibly for carbon capture. We will discuss the possibility of including other waste material (food, sanitary waste etc.) into the system. In order to minimize the amount of water required to flush material away from the toilet bowl and to help maintain high sanitary standards we have been investigating anti-fouling coatings for the system. We will describe the results of studies of a nano-coating based on a responsive polymer that significantly enhances the rate at which water flushes away material that adheres to the toilet surface

Stability and deformation of oil droplets during microfiltration on a slotted pore membrane

This article was published in the Journal of Membrane Science [© Elsevier] and the definitive version is available at: http://dx.doi.org/10.1016/j.memsci.2012.01.034The effect of interfacial tension between two fluids, on the passage and rejection of oil droplets through slotted pore membranes is reported. A mathematical model was developed in order to predict conditions for 100% cut-off of oil droplets through the membrane as a function of permeate flux rate. Good agreement of theoretical predictions with experimental data shows that the model can be applied to the filtration of deformable droplets through slotted pore membranes. At high interfacial tension (40 mN/m) with lower flux (200 l m−2 hr−1)droplets of crude oil (27 API) were 100% rejected at droplet diameter 4.3 μm using a 4 μm slotted pore membrane. At lower interfacial tension (5 mN/m), with the same flux rate, 100% rejection occurred at 10 μm droplet diameter using the same membrane. It was also found that the droplet rejection efficiency below the 100% cut-off was roughly linear with drop size, down to zero rejection at zero drop diameter. Hence, the model, coupled with this approximate correlation, can be used to predict dispersed oil drop concentration from a known feed drop size distribution

Shear enhanced microfiltration and rejection of crude oil drops through a slotted pore membrane including migration velocities

This article was published in the Journal of Membrane Science [© Elsevier] and the definitive version is available at: http://www.sciencedirect.com/science/article/pii/S0376738812004991Shear enhanced microfiltration of crude oil/water emulsion is investigated and the effect of an applied shear rate on the rejection of droplets by the membrane is reported. Applying vibration provides shear rate at the membrane surface leading to shear-induced migration and an inertial lift of drops/particles. Both phenomena tend to move the droplets away from the membrane surface. The shear-induced migration and inertial lift increase with increasing of the shear rate. A mathematical model is presented to account for the presence of both phenomena. The developed model is used for theoretical prediction of 100% cut-off of crude oil droplets by the membrane with, and with-out, vibration applied. A satisfactory agreement of the model predictions with experimental data shows that the model can be successfully used for a theoretical prediction of 100% cut-off of droplets by slotted pore membranes. Rejection of droplets increased with applying shear rate: at 8000 s-1 shear rate and 200 l m-2 hr-1 flux rate 3 to 4 μm radius droplets were almost completely rejected reducing 400 ppm of crude in the feed to 7 ppm in the permeate