Ultrasound assisted extraction of nano calcium from waste eggshell: a preliminary study on crystal violet dye removal

Extraction of bio-based calcium carbonate (CaCO3) nanoparticles from eggshell waste materials assisted by horn-type ultrasonic generator was studied. Chicken eggshells (CS) and duck eggshells (DS) were cleaned and ground using pestle and mortar, and further treated with acetone and dichloromethane (DCM) to remove impurities. The treated eggshells were then ultrasonic irradiated for 5 to 20 min, before sending to Dynamic Light Scattering (DLS) for particle size distribution measurement. Results shown that, nano calcium with approximately 300 nm was being recovered successfully. The recovered nano calcium is later subjected to Crystal Violet (CV) dye removal testing and has recorded a high removal efficiency of up to 87.90 % and 83.06 % for DS and CS, respectively. The high removal efficiency is basically due to the large surface area on calcium nanoparticles created by ultrasonic cavitation, as confirmed by Scanning Electron Microscopy (SEM) analysis

Wastewater System Integration: A Biogenic Waste Biorefinery Eco-Industrial Park

In recent years, great interest has been shown in the utilization of biogenic wastes in biorefineries as part of the concept of a circular bioeconomy. However, various challenges arise including the availability, cost and characteristics of the biogenic wastes in ensuring consistent biorefinery production processes. This work presents an optimization-based approach of a biogenic waste biorefinery eco-industrial park (BWB EIP). An indirect integration scheme is presented with a wastewater treatment plant (WWTP) acting as a centralized utility hub to treat the biogenic wastes generated from the participating plants and to supply volatile fatty acid (VFA) demanded by the participating plants through the WWTP interceptors. The objective of minimizing the VFA demanded by the participating plants from external sources is achieved. To further assess the influence of a future increase in VFA demand for one of the participating plants which is the polyhydroxyalkanoate (PHA) plant on the integration network, a sensitivity analysis is conducted. The results indicated that two WWTP interceptors are required with a 32.8% and 27.4% reduction in fresh VFA from external sources achieved through the integration network before and after sensitivity analysis. This work provides an insight into developing the framework for other BWB processes

Wastewater System Integration: A Biogenic Waste Biorefinery Eco-Industrial Park

In recent years, great interest has been shown in the utilization of biogenic wastes in biorefineries as part of the concept of a circular bioeconomy. However, various challenges arise including the availability, cost and characteristics of the biogenic wastes in ensuring consistent biorefinery production processes. This work presents an optimization-based approach of a biogenic waste biorefinery eco-industrial park (BWB EIP). An indirect integration scheme is presented with a wastewater treatment plant (WWTP) acting as a centralized utility hub to treat the biogenic wastes generated from the participating plants and to supply volatile fatty acid (VFA) demanded by the participating plants through the WWTP interceptors. The objective of minimizing the VFA demanded by the participating plants from external sources is achieved. To further assess the influence of a future increase in VFA demand for one of the participating plants which is the polyhydroxyalkanoate (PHA) plant on the integration network, a sensitivity analysis is conducted. The results indicated that two WWTP interceptors are required with a 32.8% and 27.4% reduction in fresh VFA from external sources achieved through the integration network before and after sensitivity analysis. This work provides an insight into developing the framework for other BWB processes

A two-stage optimization approach for the synthesis of an integrated pulp and paper biorefinery

AbstractPulp and paper mills (PPMs) generate large amount of wastewater with high chemical oxygen demand (COD) concentration. Recently, anaerobic digestion receives much attention for the treatment of PPM wastewater. Through anaerobic digestion treatment, biogas can be generated and converted to bioenergy via combined heat and power (CHP). However, there are limited studies on the systematic allocation of bioenergy from CHP to wastewater treatment (WWT) and PPM to form an integrated pulp and paper biorefinery (IPPB). Therefore, the current work explores the potential of energy integration in an IPPB through a two-stage optimization approach. In the first stage, an optimal cost effective WWT for the treatment of PPM wastewater is synthesized. Next, the generated biogas from WWT is converted into four different forms of bioenergy. The detail allocation of the generated bioenergy is then determined in the second stage optimization. A case study is solved to illustrate the proposed approach

Optimization of chilled and cooling water systems in a centralized utility hub

Process cooling is widely applied in various petrochemical and chemical industries. A chilled/cooling water system (CCWS) consists of a set of operations which usually operate in parallel configuration along with heat exchangers (HE) and chiller/cooling towers. A parallel arrangement of the CCWS would mean the process streams receive cooling utility at the supply temperature while series arrangement allow returned chilled/cooling water to be reused instead of directly sent to chiller/cooling tower. Also, parallel configurations have reduced cooling efficiency from large, thermodynamically unfavorable temperature differences. Previous studies on CCWS have dealt with cooling water and chilled water systems separately. The main aim of this study is to develop a procedure for the synthesis of an integrated CCWS in an eco-industrial park (EIP). A centralized utility hub is proposed to supply the cooling utility to the EIP. Few case studies are used to illustrate the model. Cooling/chilled water at variable supply temperature to accommodate the cooling requirement in different contiguous plants. The integration between cooling towers and chillers provides intermediate re-cooling to the process streams provides dual savings in terms of energy and operating cost. © 2014 The Authors

Data augmentation and machine learning techniques for control strategy development in bio-polymerization process

Machine learning has been increasingly used in biochemistry. However, in organic chemistry and other experiment-based fields, data collected from real experiments are inadequate and the current coronavirus disease (COVID-19) pandemic has made the situation even worse. Such limited data resources may result in the low performance of modeling and affect the proper development of a control strategy. This paper proposes a feasible machine learning solution to the problem of small sample size in the bio-polymerization process. To avoid overfitting, the variational auto-encoder and generative adversarial network algorithms are used for data augmentation. The random forest and artificial neural network algorithms are implemented in the modeling process. The results prove that data augmentation techniques effectively improve the performance of the regression model. Several machine learning models were compared and the experimental results show that the random forest model with data augmentation by the generative adversarial network technique achieved the best performance in predicting the molecular weight on the training set (with an R(2) of 0.94) and on the test set (with an R(2) of 0.74), and the coefficient of determination of this model was 0.74

Superstructural approach to the synthesis of free-cooling system through an integrated chilled and cooling water network

Chillers are major energy consumers in industrial facilities. They are indispensable in such industries as semiconductor fabrication, food processing, and plastics manufacturing, among others. Previous studies aimed at improving the energy efficiency of chilled water systems have focused on optimizing the performance of individual chillers. However, an alternative method to recover energy is to perform system-wide water source/sink integration using a superstructural approach. In our previous study, several schemes for chilled and cooling water systems (CCWS) with hub topology were proposed for energy savings. The main contribution of this study is in the development of a methodology to achieve energy savings by introducing free cooling in an integrated superstructure for CCWS. Two examples are used to demonstrate three different scenarios of CCWS with free cooling. It is shown that the integration of free cooling into chilled water system improve the cost and energy saving significantly, and can avoid the need to invest in a new chiller and/or cooling tower to enhance the energy efficiency of CCWS. © 2015 The Institution of Chemical Engineer