Developments in Chemical Engineering and Mineral Processing 

About: Developments in Chemical Engineering and Mineral Processing is an academic journal. The journal publishes majorly in the area(s): Combustion & Particle. Over the lifetime, 456 publications have been published receiving 2518 citations.

Heterogeneous Photocatalysis in Environmental Remediation

Abstract: Semiconductor-based photocatalytic processes have been studied for nearly 15 years due to their many intriguing advantages in environmental remediation and other areas. In this paper, underlying principles and mechanism of the photocatalytic degradation process were discussed, followed by thermodynamics, kinetics, mass transfer effects were discussed. The kinetics of photocatalytic degradation was analysed with the aim of determining the favourable conditions to obtain high quantum yield. Primary parameters that influence the process such as catalyst loading, dissolved oxygen, pH, temperature, light intensity, crystalline structure, etc. have been discussed in detail. Different types of photocatalytic reactors, process efficiencies and applications in environmental engineering as well as in other areas have also been mentioned. The main barrier to the commercialization of the processes is the low quantum yield. However, it is expected that large-scale applications could be achieved with significant progress by improvement of process performance.

Fluid Flow through 90 Degree Bends

Abstract: Pressure drop measurement and prediction in curved pipes and elbow bends is reviewed for both laminar and turbulent single-phase fluid flow. For curved pipe under laminar flow, the pressure loss can be predicted both theoretically and using empirical relations. The transitional Reynolds number can be predicted from an empirical relation. Turbulent flow in curved pipes can only be theoretically predicted for large bends but there are a large number of empirical relations that have proved to be accurate. Elbow bends have proven to be difficult to both measure and represent the pressure loss. Methods of overcoming such problems are outlined. There was no reliable method of theoretically predicting pressure drop in elbow bends. Experimental measurements showed considerable scatter unless care was taken to eliminate extraneous effects. Reliable data are highlighted and an empirical method is proposed for calculation of pressure drop in elbow bends.

The Production and Characterisation of Activated Carbons: A Review

Abstract: The uses of active carbons and carbon chars for liquid and gas phase applications has been presented. Their application for decolourising, water treatment, solvent recovery, military uses, nuclear industry, air purification, domestic uses, precious metal recovery and catalysis, have been outlined. A detailed review of the production and manufacture of activated carbons from a wide range of carbonaceous sources is given. Methods of activation are discussed based on a range of chemicals and how these chemicals influence surface activity, pore size and pore distribution. The techniques for characterising activated carbons are reviewed in detail and include porosimetry, sorptometry, topography, pore size distribution, isotherms and surface area measurements. The specific results of some active carbons derived from lignocellulosic materials (peat and lignite) are also presented.

A Tutorial on Model Predictive Control: Using a Linear Velocity‐Form Model

Abstract: Model Predictive Control (MPC) has a long history in the field of control engineering. It is one of the few areas that has received on-going interest from researchers in both industry and universities. It has been recognised that there are three major branches of MPC algorithms consisting of step-response model based design: Dynamic Matrix Control (DMC); transfer function model based design: Generdised Predictive Control (GPC); and a general state space model based design. The DMC and GPC algorithms can also be cast in the state space framework. Along the general lines of state space methods, there are two mainstreunts: one solves for the optinzal control signal while the other solves for the increment of the optimal control signal. The latter can be implemented in a velocity form analogous to the implementation of a PID controller on an industrial plant. Motivated by this advantage. and that integral action is naturally embedded in the algorithm, this tutorial paper focuses on an introduction to Model Predictive Control based on the state space approach using a linear velocity-form model.