Equipment for product recovery and purification

Production of lignocellulosic ethanol still suffers the drawback of high production cost. Methods for making the process more cost efficient are therefore of high importance for commercialising large-scale production. One way of improving the process economics is to ensure efficient heat integration within the process, thereby reducing process energy costs. Another opportunity to improve production costs is to design the process for high solids loading in the bioreactors. By operating the process with higher solids concentrations (so-called high-gravity), water flows through the process will be reduced, which would enable smaller equipment and lower energy demand for downstream separation and purification of the ethanol product. However, problems with pumping and mixing are also likely to occur due to higher viscosities. Furthermore, the yield will be lower due to increased concentration of inhibitors. In addition, the opportunities for heat integration within the process will be affected. In this paper, the effect on heat integration opportunities of the high gravity concept is investigated for ethanol production in a stand-alone process in which fractionation of the softwood raw material is assumed to be achieved with steam explosion. Estimations of how the process economics will be affected are also provided.

Oxygen separation from air by PSA: modelling and experimental results

Optimum structured adsorbents for gas separation processes

Chromatographic method development for preparative targets is a time-consuming and subjective process. This can be particularly problematic because of the use of valuable samples for isolation and the large consumption of solvents in preparative scale. These processes could be improved by using statistical computations to save time, solvent and experimental efforts. Thus, contributed by ESI-MS, after applying DryLab software to gain an overview of the most effective parameters in separation of synthesized celecoxib and its co-eluted compounds, design of experiment software that relies on multivariate modeling as a chemometric approach was used to predict the optimized touching-band overloading conditions by objective functions according to the relationship between selectivity and stationary phase properties. The loadability of the method was investigated on the analytical and semi-preparative scales, and the performance of this chemometric approach was approved by peak shapes beside recovery and purity of products.

SIMULATION OF CRYOGENIC DISTILLATION OF ATMOSPHERIC AIR USING ASPEN HYSYS

Engineering of Online Optimizing Control - A Case Study: Reactive SMB Chromatography

Itaconic acid is a promising biobased organic acid that can be industrially produced in an eco-friendly way by aerobic fungal fermentation. It has many applications, e.g. in biopolymers, and has the potential to help replace or facilitate the green production of other similar but fossil-based chemicals. Nowadays, its production costs are still relatively high, partly due to the multistep product recovery process from the fermentation broth. In this study, a reduced number of downstream processes were evaluated to recover itaconic acid from model and real fermentation effluents. To the best of our knowledge, this is the first time the whole procedure is presented from the substrates to the solid and pure product, including fermentation, electrodialysis with bipolar membrane, evaporation and optimized crystallization. Based on the fermentation temperature and elevated pH, a synergistic effect was observed that intensified certain mass transfer mechanisms. Consequently, a significant amount of water (400 cm3) and itaconic acid (15 g) was transported into the alkaline concentrate. Moreover, novel outcomes about the condition, decolorization and process enhancements of the membrane (product recovery: 65–80 %, current efficiency: 42–76 %, product purity: 99 %) were recorded. Based on the results, our group is one step closer to the final concept of a continuously operated fermentation-electrodialysis integrated system.

Isothermal suspension conversion is presented as a suitable method for the manufacture of pure cocrystal products once the ternary phase diagram (TPD) for the cocrystal system in the desired solvent is available. One:one and 3:2 cocrystals of p-toluenesulphonamide/triphenylphosphine oxide were produced in acetonitrile and dichloromethane using this method. Eight individual batches of product were prepared with complete conversion to pure product achieved in seven batches. Product recovery (77–99%), reaction conversion (17–89%), and volumetric productivity (0.03–0.63 g/cm3) were calculated for each product batch. These parameters are essentially determined by the batch operating mass fraction composition selected from the TPD, allowing for tailoring of processing conditions to suit process requirements and capabilities by careful selection of the optimum operating mass fraction composition.

Multi-Component Fractionation in SMB Chromatography for the Purification of Active Fractions from Protein Hydrolysates

Multi-objective optimization of sequential simulated moving bed for multi-component separation based on multi-parameter modeling and its determination

Since the middle of the last century, discussion about the operation of discontinuous fractionation to meet multifarious goals, such as product purity and recovery rate, by monitoring process variables including reflux or/and heat duty, is been on. The engineering practice showed intolerable events to occur; hereof the operation must be supervised, which makes it difficult to be in agreement with the batch distillation objectives. Hence, to uphold the effectuation of new operating policies into the industrial “know-how” techniques, different optimal control strategies can be conceived. The objective of this work is to offer a literature survey on the investigations of optimal control functioning for selected simple distillation column configurations employed in batch/semibatch distillation of homogeneous/reactive mixtures, as well as the approaches used in this regard. Available optimal control schemes have been reviewed in detail, emphasizing its major assets.

Membrane-assisted natural gas liquids recovery: Process systems engineering aspects, challenges, and prospects

This work presents a generic modeling framework for the separation of gas mixtures using multibed pressure swing adsorption (PSA) processes. Salient features of the model include various mass, heat, and momentum transport mechanisms, gas valve models, complex boundary conditions, and realistic operating procedures. All models have been implemented in the gPROMS modeling environment and a formal and user-friendly automatic procedure for generating multibed configurations of arbitrary complexity has been developed. The predictive power of the developed modeling framework for various PSA multibed configurations has been validated against literature and experimental data. The effect of various operating conditions on the product purity and recovery is systematically analyzed. Typical trade offs between capital and operating costs are revealed.

Five-zone Simulating Moving Bed (SMB) system, designed for ternary separation, is a modified form of standard four-zone SMB which is only effective in binary separation. It was reported in literature that the five-zone SMB separates the extract-II stream with a lower purity value than that of raffinate and extract-I streams. To address this issue, five zone SMB was designed, using safety margin method for the separation of a ternary amino acid mixture comprises of methionine, phenylalanine and tryptophan having linear isotherms values. The operating conditions at fixed zone-I flow rate were calculated by using triangle theory and the developed mathematical model was run for the simulation studies with Aspen Chromatography vis 12.1. (2004) simulator. The simulation results of the 2-extract five-zone SMB system were illustrated for the effect of change in zone safety factor ( �2, �3 and �4) values on the separation performance (product purity and recovery) and on solutes band propagation behavior at cyclic steady state.

The dynamic response of an air rectification column to interruptions of the feed flow