Band 5, Heft 1

The influence of temperature and pressure on the non-catalytic partial oxidation and reforming of natural gas in an entrained-flow reactor under non-equilibrium conditions has been investigated experimentally in pilot scale.As thermochemical equilibrium suggests, the methane conversion increases drastically with temperature, but does not reach equilibrium in the investigated range of parameters (Tmax = 1450 °C; 30 bar (3 MPa) < p(g) < 100 bar (10 MPa), 5 s < ? < 20 s). A practical method to describe the non-equilibrium state of a partial oxidation product gas at high temperatures due to kinetic limitations and/or mixing conditions within a reactor is by calculating apparent equilibrium temperatures Teq,ap for the main global kinetic reactions from the measured concentrations of the gas. The temperature difference between Teq,ap and the measured reactor outlet temperature Tex results in the temperature differental approach (?TApp = Teq,ap - Tex).In this paper, typical parameters influencing ?TApp for the methane reforming reaction (temperature T, pressure p, residence time ?) were examined. ?TApp was found in the range between -300 K and -50 K in non-catalytic partial oxidation. Its absolute value decreases with increasing pressure and decreasing ratio of steam to fuel carbon H2O : Cf , but is just weakly dependent on the reactor temperature Tex in a range from 1100-1450 °C. The results were used for the evaluation and further development of a model combining kinetics and residence time behaviour of the non-catalytic partial oxidation and reforming of natural gas.For comparison, results from catalytic autothermal reforming of natural gas and non-catalytic partial oxidation of liquid hydrocarbons are also presented.

A transient three-dimensional, two-fluid computational fluid dynamics (CFD) model is developed in the Eulerian framework to predict the hydraulics of sieve trays, especially with gas maldistribution. For this purpose, an algorithm is developed to explain the hole-gas velocity and pressure drop terms along the liquid flow path length. An important modification to the previous CFD works is the use of variable, position dependent, gas superficial velocity for calculation of interphase drag term along the tray. The flow path length of tray was divided into a number of sections; gas-superficial velocity, hydraulic parameters and drag coefficient were obtained for each section. This modification has an important effect on the simulation results and causes faster convergence and better predictions of tray hydraulics. The results are in good agreement with experimental data. Model results obtained in this study have revealed that the effect of hydraulic gradient is significant for high liquid path length and may create non-uniform gas flow. This paper describes how the inlet flow maldistributions can be included in CFD simulation of sieve trays. The results of simulations with non-uniform gas velocity distributions are presented, and compared against experimental data from literature. The results are in good agreement with experimental data.

The sorption isotherm, permeation time lag, and steady state permeability of a noble gas, argon, were measured on a CMS membrane at different temperatures and a range of permeation pressures. It is found that Ar permeation present strong diffusion anomalies (The deviation to the traditional Darken relation). The degree of the anomalies was found approximately same for the transient permeation time lag and the steady state permeability. Comparison studies with other permeation gases further reveals that the permeation behaviors are related to their molecular properties.

The drying characteristics of plaster of paris (POP) under microwave conditions at different microwave power input, initial moisture content, sample thickness and drying time were studied. Further the experimental data on moisture ratio of POP for different operating conditions were obtained and calculations were made using nine basic drying model equations. The appropriate model with modified constants and coefficients to represent the drying kinetics of POP was found through the analysis of the statistical analysis. The effective moisture diffusivity of the drying process was also computed for different experimental conditions and a relationship between the drying rate constant and the effective moisture diffusivity was obtained. The energy consumption for microwave drying of plaster of paris at different experimental conditions were also computed.

In the present work, crab shell was used as the biosorbent to remove copper from aqueous solution. Batch experiments were performed at different initial copper concentration of copper solutions (1-40 g/l), initial pH (2-9), temperature (20-400°C), and biosorbent dosages (2-10 g/l). The maximum removal of copper using crab shell occurred at a pH of 3 and at a temperature of 400°C using an optimum biosorbent dosage of 5 g/l. A mathematical model was proposed to identify the effects of the individual interactions of these variables on the biosorption of copper. The results have been modeled using response surface methodology using a Box-Behnken design. The response surface method was developed using three levels (-1, 0, +1) with the above mentioned four factors. The second order quadratic regression model fitted the experimental data with Prob > F to be < 0.0001. The experimental values were found to be in good agreement with the predicted values, with a satisfactory correlation coefficient of R2 = 0.9999.

This work aims to present a detailed study on a commercial double-effect tomato paste evaporation system. The modeling equations formulated for process simulation belong to backward feeding arrangement. Open-loop process dynamics has been studied by rigorous simulation of the model structure. In the next, three multi-loop control schemes, namely conventional proportional integral (PI), gain-scheduled PI (GSPI) and nonlinear PI (NLPI), have been synthesized for the sample process. Finally, several simulation experiments have been conducted to investigate the comparative closed-loop performance based on set point tracking and disturbance rejection.

The control structure problem which has been considered the central issue in modern process control has attracted large research attentions in the last three decades. There are various methods which have been developed but only a handful of them can really provide a practical solution to such an open-ended problem. The concept of partial control structure which has long been adopted in process industries has to a certain extent provided the engineers with sound theoretical foundation upon which this issue can be tackled in a systematic way. One major limitation of partial control preventing its effective adoption to solving this problem is due to its heavy reliance on engineering experiences and process knowledge in finding the dominant variables. In this paper, we propose a novel PCA-based technique to identify the dominant variables, which avoids the need for extensive experience and process knowledge. Various criteria and conditions forming the backbone of the technique are also proposed. The effectiveness of the technique is demonstrated based on its application to the continuous extractive alcoholic fermentation system.

This work deals with the problem of the search for optimal design of multiproduct batch chemical plants found in a chemical engineering process with uncertain demand. The aim of this work is to minimize the investment cost and find out the number and size of parallel equipment units in each stage. For this purpose, it is proposed to solve the problem in two different ways: the first way is by using Monte Carlo Method (MC) and the second way is by Genetics Algorithms (GAs). This GAs consider an effective mixed continuous discrete coding method with a four- point crossover operator, which take into account simultaneously, the uncertainty on the demand using Gaussian process modeling with two criteria maximization the Net Present Value (NPV) and Flexibility Index (FI). The results (number and size of equipment, investment cost, production time (Hi), NPV, FI, CPU time and Idle times in plant) obtained by GAs are better than the MC. This methodology can help the decision makers and constitutes a very promising framework for finding a set of "good solutions."

There is an increasing awareness of the impact of spilled crude oil and its refined products on human health and environment. The potential of using groundnut husk, agro-based waste, which is not only ubiquitous but indiscriminately littered around Nigerian urban areas, as an adsorbent in removal of oil spilled on water was investigated. Groundnut shell, a waste generated in local vegetable oil processing plants, has been converted into a low cost adsorbent. The groundnut husk was treated and meshed to adsorb crude oil from water at various experimental conditions. Investigations include the effects of sorbent dosage, particle size, contact time and temperature on the adsorption of crude oil. Meshed groundnut shell, especially less than 150 µm, exhibited high affinity for oil adsorption with time. The optimum adsorption temperature range lies between 25 – 45°C. The adsorption data indicates that a pseudo-second-order equation could be used to study the adsorption kinetics and the correlation coefficient of 0.9985 indicates that the sorption process is dominated by adsorption process. The results demonstrate that crude oil removal by adsorption onto this abundantly available low cost and readily biodegradable material is feasible. With high affinity for oil and low water pick up, meshed groundnut shell adsorbent could be said to be oleophilic or hydrophobic.

Limitations of the recently developed Adomian solution for the reaction-diffusion process in a porous catalyst slab have been demonstrated and an improved solution, overcoming these restrictions, has been proposed by using a novel scheme of Restarted Adomian method coupled with orthogonal polynomials. The results obtained from this approach have been compared with those obtained by Adomian and other methods and are found to be superior to them. The present results are commendable in the sense that not only the primary but the derived quantities as well, match accurately with their exact numerical counterparts. The scheme is attractive since short analytical expressions with impressive accuracy can be obtained without generating higher Adomian polynomials which are difficult to form; besides, this scheme is also applicable to other similar problems. This validates the general and effective nature of the present approach.

Product formulation design has seen an increasing attention because of the rising demand for application-specific products such as paints, adhesives, coating chemicals, detergents, disinfectants, pharmaceuticals, etc. However, new product formulation design is becoming increasingly difficult in today's markets due to tough competition. To survive and succeed, companies should be able to design new products in a short pace. Failure to do so can be very costly, not only in terms of market share lost, but also in the investment made to develop a product. Given that traditional product development methods are very slow, and cannot fulfill today's needs, a methodology is presented here to efficiently design new product formulations based on a combination of experimental designs, neural networks and optimization techniques. The methodology is applied on a case study that involves disinfectants' formulations. The framework takes advantage of all previous experiments for the next product formulation design, and archives experimental results of the existing project and uses them to retrain a model for future projects. The results show that the use of the proposed methodology significantly reduces the time and cost of product formulation. Although the methodology is applied to the case study of disinfectant formulation, it can be easily adopted to the design of other products.

Solid oxide fuel cell (SOFC) has been considered as one of the most efficient power generation devices for the coming decades. There are various physical phenomena appearing in SOFC in multi-length and -time scales, such as multi-component gas-phase species/charge flow, thermal energy and mass transfer. Meanwhile, generation and consumption of gas- and surface-phase species together with electric current production are involved at various active sites. Catalytic reforming reactions of hydrocarbon fuels in SOFC anode are strongly coupled with the transport processes making the physical phenomena more complicated.An effective SOFC electrode design is to correctly balance each of the transport processes and the involved reactions. To deeply understand the multi-scale chemical reactions and transport processes in the anode, a fully three-dimensional numerical calculation method (CFD approach) is further developed and applied. The calculated domain includes the porous anode, fuel gas flow channel and the solid interconnects.By calculating fractions of Ni catalyst vacancies and surface-phase species coverages, the gas-phase species/heat generation and consumption related to the internal reforming reactions of methane and the electrochemical reactions of hydrogen have been implemented. The variable thermal-physical properties and transport parameters of the fuel gas mixture have also been taken into account. Furthermore, the heat transfer due to the fuel gas diffusion is implemented into the energy balance based on multi-component diffusion models. A multi-step heterogeneous steam reforming reaction mechanism based on the micro and detailed reaction mechanisms of Ni/YSZ is employed in this study. The surface reactions include 42 irreversible elementary ones accounting for the steam reforming, the water-gas shift reforming and Boudouard reactions. This microscopic reaction model describes the adsorption and desorption reactions of 6 gas-phase species and surface reactions of 12 surface-adsorbed species.The predicted results show that the catalytic reactions take place at most regions of the porous anode, and a gradual CH4 distribution profile and incomplete CH4 conversion at the anode exit are observed. Transport processes of the fuel gas-phase species and temperature distribution are affected by both the internal reforming reactions and the electrochemical reaction. Parameter studies reveal that both low operating temperature and big permeability can increase the available nickel catalyst surface fraction in the anode. Such detailed reaction scheme is much more complicated to incorporate in SOFC modelling but helpful to predict surface-phase species profiles over Ni-catalyst surfaces.

This paper presents the simulation work on kinetic study for the transesterification reaction between palm oil-based methyl ester with trimethylolpropane to produce biodegradable lubricant base oil. The reaction mechanism involves three stepwise reversible series-parallel elementary reactions. New kinetic modeling approach is needed in this field due to the limitation of the earlier kinetic models developed for this reaction. The earlier kinetic study made use of many assumptions in order to simplify the solutions. In this work, new rate equations were derived from the actual reaction mechanism, and MATLAB was used to obtain the simultaneous solutions of the rate equations. The results obtained were compared with the experimental data used in the earlier study. The new simulation approach was found to describe the experimental values satisfactorily.

This paper presents fault detection and diagnosis methodology for batch/semi-batch processes using a multi-way orthogonal nonlinear PCA approach. In this work, a sequential extracting process of linear and nonlinear correlations from process data is performed. The approach reduces the complexity of the nonlinear PCA model structure, which dramatically improves the model generalization. An orthogonal nonlinear PCA procedure is incorporated to capture the nonlinear characteristics with a minimum number of principal components. A trajectory-boundary-limit crossing point discriminant analysis is proposed to diagnose the process faults. A two-step discriminant analysis is also incorporated to improve the diagnostic performance in the case of isotropically distributed trajectories. The validity of the proposed strategy is demonstrated by the application to an emulsion copolymerization of styrene/MMA semi-batch process.

The complex organic wastewater from agrochemical industry consists of a large number of solids and dissolved compounds. For the design and scale-up of any activated sludge reactor, it is desirable to know the kinetics of oxidation, which strongly depends upon the nature of wastewater and the microorganism. In the present work, the kinetics of aerobic biological oxidation of an agrochemical plant waste is investigated, having initial COD of 800-1200 mg/L. Experiments are performed at five different dissolved oxygen (DO) levels; viz. (i) 1.5 to 2.5 mg/L, (ii) 2.5 to 3.5 mg/L, (iii) 3.5 to 4.5 mg/L, (iv) 4.5 to 5.5 mg/L, and (v) 5.5 to 6.5 mg/L. For each DO level five mixed liquor suspended solids (MLSS) are studied in the range of 6000-20000 mg/L. The maximum percentage reduction of COD is 74.1%, 74.8%, 89.9%, 73.3% and 89.6% at different DO levels of 1.5-2.5 mg/L, 2.5 to 3.5 mg/L, 3.5 to 4.5 mg/L, 4.5 to 5.5 mg/L, and 5.5 to 6.5 mg/L and MLSS concentrations from 6000 to 20000 mg/L, respectively. An attempt is made to propose the kinetics of substrate utilization that does not actively support growth of organism. A kinetic model is proposed to understand the effect of DO and MLSS concentration.

Multi-phase superstructure optimization formulations for reactive extraction systems are often difficult to initialize and time consuming and solve. That is why such formulations, which capture detailed reaction and mass transfer phenomena, should only be employed for cases in which reactive extraction turns out to be a promising option. However, in systems with complex kinetics it is often non-obvious whether reactive extraction would enhance the performance of the system. The optimisation efforts can be minimised with the help of high-level models to screen the potential of the reactive extraction option prior to the detailed optimal process synthesis stage. This paper presents a conceptual optimisation formulation to establish the potential of reactive separations prior to complex detailed optimisation tasks. The conceptual approach supports high-level decision-making in early stages of design and allows to identify whether reactive extraction processes constitute promising design options for a given reaction system. The approach is illustrated with two biochemical examples of different complexity.

Majority of the processes available for manufacturing of p-anisic acid (4-methoxy benzoic acid) are pertaining to large-scale production comprising of heterogeneous and homogeneous catalysis. These are involved with hazardous and highly toxic materials, involving complex processes, which are not suitable for small-scale industries. The present work has been conducted in a small-scale industry laboratory. A modified Williamson etherification reaction has been studied through process validation and design of experiments (DOE). It is observed that the yield is affected by the process factors; such as mole ratio, addition temperature, reaction temperature, time of addition (or dosage rate), and agitator speed. The maximum yield can be derived by setting the time of addition (120 min) and agitator speed (300 rpm). This simple process may serve the purpose of small scale industry to derive this important product through less hazardous and toxic chemicals with high yield.

Distillation columns are the core of a refining process. An understanding of their heat and mass transfer is essential to propose modifications of the equipment. A multiphase model is applied to the vacuum tower with the vapor-liquid flow being modeled with an Eulerian-Lagrangian approach. An ideal multicomponent equilibrium model is adopted to represent the thermodynamics in the heat and mass transfer processes. The characteristic time scales are used in the classification and the understanding of the dominant mechanisms in gas-liquid suspensions. This methodology is general, and therefore can be applied to any turbulent gas-liquid flow. The present work applies a simplified multicomponent Fick's law and gamma-phi approach to liquid-vapor equilibrium in an Eulerian-Lagrangian multiphase flow model in order to get multicomponent heat and mass transfer. The simplification proposed here is that the diffusive flux is independent of the other fluxes. This implies that each flux can be calculated without information on the other fluxes. On the other hand, thermodynamic equilibrium takes all components into account. Thus, it is rigorously calculated. The main target of this work is to gather information on vacuum tower fluid dynamics using an Eulerian-Lagrangian model with computational fluid dynamics (CFD) techniques, which is a powerful tool for better understanding the physical phenomena involved in vacuum towers.

The partitioning of bovine serum albumin (BSA) was investigated in polyethylene glycol (PEG) 4000-sodium citrate system at 308K and 318K with varying pHs and tie line lengths (TLL). The systems were prepared at a pH of 5.2, 7.1 and 9.2 with different TLL compositions. The affinity of the BSA for the lower phase increases with an increase in pH, which is due to an increase of trivalent to divalent citrate ions in the two phase system. The affinity of the BSA to the upper phase increases with an increase in TLL, which is due to the increase in available free volume in the upper phase. As the temperature increases, the partition coefficient of BSA shows increment.

In the present work simulation studies were carried out focusing on the separation of a mixture of chlorinated hydrocarbons of an industrial process stream by batch distillation process. The effect of different process variables on the performance of the batch separation process was evaluated. Based on the simulation results, it was observed that the column pressure has a significant effect on the condenser operation, indicating that operating pressure equal to 3 bar is more favorable to the process. It was shown that high values of the reboiler heat duty lead to a decrease in the operation time necessary to attain the steady state regime. Regarding the influence of the column reflux, it was also observed that reflux values exceeding 1.0 reduce the separation process performance, leading to a poor recovery of the components in the product tank. It was illustrated the occurrence of multiple steady states as a consequence of nonlinear response of the process to the reboiler holdup, characterized by complex nonlinear phenomena.

This work presents the dynamic modeling of drying behavior of polymer solutions in an infrared-convective oven. Two study cases were considered for the drying process. The first one deals with the drying of a coated polymer solution on a fixed substrate while the second one includes drying of the same solution on a moving substrate in an infrared (IR) oven. Both models involve simultaneous heat and mass transfer equations that describe changes in the solvent concentration and the polymer temperature during the drying process. The set of partial differential equations (PDEs) arising from the mass and energy balances constitute a highly nonlinear system due to inter-dependence of the thermodynamic and transport properties of polymer solutions. The models were numerically solved and were validated using published experimental data. The models were employed to simulate the drying of a polyvinyl acetate coating (in toluene) on a polyester substrate. Results obtained from the derived model demonstrated the importance of parameters such as web velocity, heater temperature, and inlet air velocity in the IR drying process. In general, high temperature and air velocity cause rapid drying of the polymer coating, while high substrate velocity resulted in drying. This model can be applied on any industrial applications that include continuous IR drying process of polymer-coated layers to predict the drying behavior of the coated product.

This paper describes a computer program that increases the productivity of petrochemical scientists conducting research on Fischer-Tropsch synthesis. FTSlurry integrates Fortran 90 simulation codes with a graphical front end and various visualization tools developed in Delphi. The software serves to evaluate operating process conditions and reaction kinetics on the product distribution of Fischer-Tropsch synthesis carried out on slurry reactors. The software allows for full parameter analysis and study of factor effects. A detailed description of the system architecture and a typical scenario of usage are presented, along with parameter analysis and visualization features.

A numerical study on the steady state flow of an incompressible Newtonian fluid past a square cylinder confined in a rectangular channel by two plates has been carried out using CFX 10.0. Computations were carried out for two different boundary conditions of moving and stationary plates for a Reynolds number range between 0.1 to 200 and a blockage ratio ? in the range 0.0125 to 0.65. The flow parameters such as drag coefficient, length of recirculation zone were determined. From the results obtained it was found that drag coefficient decreased with an increase in Re for a fixed value of ?. For a given value of ?, the length of recirculation increases as the Re increases. An expression has been developed for the relation between drag coefficient and ?.

Bubble column bioreactors used to perform aerobic fermentations consist of a liquid medium containing microorganisms that uptake oxygen for metabolic reactions and gas bubbles that supply this oxygen. Mass transfer rate from gas to liquid phase is a crucial factor for the performance of bioreactors because microorganisms’ life and metabolic reactions depend directly upon it. The maximum transfer rate of oxygen from gas bubbles to the liquid medium is a function of two important parameters: the specific interfacial area and the mass transfer coefficient. These two parameters are lumped into the volumetric specific transfer coefficient. Since size of gas bubbles is not constant along the bioreactor, gas-liquid mass transfer rate changes continuously. In order to optimize mass transfer rates, it is essential to know the bubble size distribution and the interfacial phenomena in each particular system at different operating conditions. Due to the complexity of hydrodynamics and bubble interphase characteristics, the current state of the problem does not consider a universal model to evaluate mass transfer rates in gas-liquid systems; moreover, information about bubble size and its distribution is often neglected. This work presents a model to evaluate axial distribution of values of volumetric mass transfer coefficients considering changes in bubble size and its influence on bubble area along the reactor in homogeneous regime. Simultaneously, this model evaluates changes of volumetric mass transfer coefficient and its effect on the fermentation kinetics, which influences performance of the bioreactor.

Mixing rules play an important part in the ability of an equation of state to accurately model the behavior of various phases at equilibrium. Many mixing rules have been proposed in the literature. However, due to shortcomings of the mixing rules and/or the equation of state, binary interaction parameters have been introduced to improve the accuracy of models. This work proposes an alternative to binary interaction parameters based on a weighting matrix. It is demonstrated that for the Peng-Robinson EOS applied to prediction of the solubility of various species of industrial importance, such as dyes and pharmaceutical products in supercritical CO2, the weighting matrix approach performs slightly better than the binary interaction parameter while providing more flexibility in the model.

In this paper, the three-dimensional flow and characteristics of numerous injections into horizontal flow stream are examined numerically using CFD with the standard k-? turbulence model following side tee mixing experiments. The model has been validated with experimental results in a side tee mixer in which a side stream mixes with a horizontal stream perpendicularly. A good agreement between simulated and experimental results was obtained. The effects of numerous injections are discussed for this configuration. A reasonable decrease in downward mixing length of horizontal pipe is observed. Other factors such as the tee angle, which enhanced mixing in pipes with side tees, do have a similar impact on mixing in this mutiple tee geometry.

The aim is this paper is to study fault diagnosis in a continuous chemical process. An experimental system is built to be the research base and a model is proposed and trained to carry out the fault diagnosis in the process. A Bayesian network model with two-layer nodes structure is designed and Maximum likelihood estimation (MLE) is used to amend the conditional probability table (CPT) given by expert knowledge. Then a Monte Carlo method is applied to simplify the inference rules and the data samples collected from the experimental system has been used to test the model.

Fluoride contamination occurs in a wide range of industrial wastewater that has to be regulated from time to time. In the present study, wastewater from a polybutadiene rubber plant of Indian Petrochemicals Corporation Limited, Vadodara, Gujarat, India with a higher temperature, acidic pH and high level of fluoride concentration is treated with alumina. The contact time between the adsorbent and the adsorbate should be sufficient for the adsorption to be effective. Though synthetic resins have good adsorption capacity for the wastewater, they have some disadvantages; therefore, alumina has been tried. Properties of alumina, such as pH, bulk density, surface area, pore specific volume, and bulk crushing strength, have been found. Adsorption by alumina is found to be favorable. Five equilibrium adsorption isotherms, viz. Freundlich, Langmuir, Temkin, Harkins-Jura and Halsey, have been tested. It is found that the Halsey and Freundlich adsorption isotherms are fitting the data well. Four kinetic models, viz. Lagergren, pseudo-first-order, second-order, pseudo-second-order and Elovich have been used to find the rate constants. Out of the four kinetic models tested, the pseudo-second-order model fitted the data well in the present case. It is found that when the pH of the wastewater is acidic the adsorption capacity is high. It is also seen that as the temperature of the wastewater increases, the capacity of adsorption also increases.

The polyamides used for hot-melt adhesives were synthesized from C36 dimer fatty acids and ethylenediamine under 200 mmHg and atmospheric pressures. The kinetics of the reaction rate at low pressure and the effect on the thermal properties of the produced polyamide adhesive were experimentally investigated. The effects of reaction temperature and catalyst concentration on polyamide melting point, glass transition temperature, sample weight loss and foaming height were studied. The kinetic rate constants were obtained for polymerization reaction carried out at three different reaction temperatures, 115, 120, and 135 °C, fixed mixing rate of 100 rpm and low operation pressure of 200 mmHg. Polymers produced at atmospheric pressure and reaction temperatures 140, 170, 180, and 190 °C where used to investigate the polyamide thermal properties using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal properties such as melting point, glass transition temperature and the temperature at which 5% and 10% weight loss were recorded by TGA at a heating rate of 10 C/min in N2 atmosphere. The effect of foaming height as a function of reaction temperature and catalyst concentration was measured. The analysis makes known that the reaction temperature and catalyst concentration has a noteworthy impact on the glass transition temperature, foam height and melting point and insignificant effect on the sample weight loss.

Studies into methods of using microelectromechanical systems (MEMS) technology for medical and biological application have led to the development of several interesting devices such as microneedles, micropumps, and microreservoirs. Such microsystems featuring controlled transport process are important in laboratory testing of predecessors of implantable smart devices as well as analysis of pharmaceuticals and performing biomedical precision tasks. In the present study dealing with nanodrug delivery, nanofluid flow in a microchannel with various angles of drug injection is considered. The nanofluid is a solid-liquid mixture in which nonmetallic nanoparticles are suspended. A transient 3-D problem of controlled nanodrug delivery has been numerically solved. The velocity profile and dimensionless nanodrug concentration profile for different angles of drug injection were obtained at different axial stations along the length of the microchannel (z = 0.5, 5, and 10mm), with one particle diameter (10 nm) and one Reynolds number ratio (? = 1.69).

Advances in industrial biotechnology offer potential opportunities for economic utilization of agro-industrial residues such as banana peel and corn pith as a substrate for many biochemical reactions. Due to their rich organic nature, they can serve as an ideal substrate for the production of value added products like alpha amylases. In the present work, an attempt was made to optimize different process variables by Taguchi methodology for the production of amylase using banana peel and corn pith by Bacillus subtilis. The orthogonal array design of the experiment was used to study the effects of carbon and nitrogen source, pH, temperature, inoculum size, and incubation time on amylase production. The predicted values of amylase activity by Taguchi S/N ratio methodology were 1799 U/ml for banana peel and 671 U/ml for corn pith. The measured amylase activities at optimal conditions by experimental runs were 1580 U/ml for banana peel and 530.32 U/ml for corn pith, respectively. After ignoring minor effects the deviation between the predicted and measured were further reduced. The predicted results are in good agreement with the experimental values.

In this study, the use of wheat bran as a possible adsorbent has been successfully demonstrated in the removal of Acid blue9 (AB9) from aqueous solution. The effect of different parameters such as temperature, adsorbent dose, contact time, adsorbent size and agitation speed were investigated. The optimum conditions obtained from response surface methodology are: temperature-38.1°C, adsorbent dose (3.1g/L), contact time (206 min), adsorbent size 0.1mm (150mesh), and agitation speed (222rpm). The effect of pH and initial substrate concentration were studied. The pseudo-first order and pseudo-second order kinetics were tested. The sorption equilibrium, expressed by the Langmuir and Freundlich equations, indicated that the process was in compliance with Freundlich isotherm.

This paper aims to fast track the historical development in simulation technology as a powerful tool of computer aided process engineering and discusses versatility of the dynamic process simulators. The focus of this paper is on the application as a dynamic operator training simulator, appreciating the benefits it brings especially in the process safety and operability improvements. Motivations behind the utilization of this enabling tool are thoroughly explored.

Life Cycle Assessment (LCA) is a method used to evaluate the potential impacts on the environment of a product, process, or activity throughout its life cycle. Today’s LCA users are a mixture of individuals with skills in different disciplines who want to evaluate their products, processes, or activities in a life cycle context. This study attempts to present some of the LCA studies on agro-chemical processes, recent advances in LCA and their application on food products and non-food products. Due to the recent development of LCA methodologies and dissemination programs by international and local bodies, use of LCA is rapidly increasing in agricultural and industrial products. The literatures suggest that LCA coupled with other environmental approaches provides much more reliable and comprehensive information to environmentally conscious policy makers, producers, and consumers in selecting sustainable products and production processes. For this purpose, a field study of LCA of biodiesel from Jatropha curcas has been taken as an example in the study. In the past, LCA has been applied primarily to products but recent literature suggests that it has also the potential as an analysis and design tool for processes and services. In general, all primary industries use energy and water resources and emit pollutants gases. LCA is a method to report on and analyze these resource issues across the life cycle of agro-chemical processes. This review has the importance as a first part of a research project to develop a life cycle assessment methodology for agro-chemical industries. It presents the findings of a literature review that focuses on LCA of agriculture and chemical engineering literature.