Dynamic real-time optimization for a CO2 capture process

Growing awareness of climate change has led to increased focus on new energy processes that mitigate generation of CO₂, or provide for its efficient capture. To enable the development of these processes, advanced modeling and optimization platforms have been created. New capabilities among platforms include efficient solution strategies for online optimization problems. For real time, dynamic optimization of CO₂ capture processes, we demonstrate the application of the Python-based Pyomo platform to facilitate realization of Moving Horizon Estimation and Nonlinear Model Predictive Control, through novel nonlinear optimization and sensitivity strategies. This capability allows large scale, first principle models to be applied for online optimization. Here, we introduce the Control and Adaptation with Predictive Sensitivity Enhancements (CAPRESE) framework to demonstrate this framework for advanced energy processes. Moreover, we present two case studies: profile tracking with detailed tray-by-tray distillation models and Bubbling Fluidized Bed reactors for CO₂ capture. © 2018 American Institute of Chemical Engineers AIChE J, 65: e16511 2019     

Characteristics of microbial biofilm on wooden vats ('gerles') in PDO Salers cheese

The purpose of this study was to characterize microbial biofilms from 'gerles' (wooden vats for making PDO Salers cheese) and identify their role in milk inoculation and in preventing pathogen development. Gerles from ten farms producing PDO Salers cheese were subjected to microbial analysis during at least 4 periods spread over two years. They were distinguished by their levels of Lactobacillus (between 4.50 and 6.01 log CFU/cm(2)), Gram negative bacteria (between 1.45 and 4.56 log CFU/cm(2)), yeasts (between 2.91 and 5.57 log CFU/cm(2)), and moulds (between 1.72 and 4.52 log CFU/cm(2)). They were then classed into 4 groups according their microbial characteristics. These 4 groups were characterized by different milk inoculations (with either sour whey or starter culture, daily or not), and different washing procedures (with water or whey from cheese making). The farm gerles were not contaminated by Salmonella, Listeria monocytogenes or Staphylococcus aureus. Only one slight, punctual contamination was found on one gerle among the ten studied. Even when the milk was deliberately contaminated with L. monocytogenes and S. aureus in the 40 L experimental gerles, these pathogens were found neither on the gerle surfaces nor in the cheeses. Using 40 L experimental gerles it was shown that the microbial biofilms on the gerle surfaces formed in less than one week and then remained stable. They were mainly composed of a great diversity of lactic acid bacteria (Leuconostoc pseudomesenteroides, Lactococcus lactis, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus hilgardii,…), Gram positive catalase positive bacteria (Curtobacterium flaccumfaciens, Curtobacterium oceanosedimentum Citrococcus spp., Brachybacterium rhamnosum, Kocuria rhizophila, Arthrobacter spp.…) and yeast (Kluyveromyces lactis, Kluyveromyces marxianus). In less than 1 min, even in a 500 L farm gerle, the gerle's microbial biofilm can inoculate pasteurized milk with micro-organisms at levels superior to those in raw milk.     

Switchable surfaces from highly hydrophobic to highly hydrophilic using covalent imine bonds

The formation of materials with switchable wettability is extremely important for various applications such as in separation membranes or liquid transportation. Here, we report for the first time the use of imine bonds in order to prepare switchable hydrophobic/hydrophilic surfaces. Based on a poly(3,4‐ethylenedioxythiophene) surface bearing amino groups, imination reaction allows for reversible functionalization of surfaces with various carbonyl groups. Here, surfaces functionalization induces high hydrophobic properties while the surface structures are preserved. This reaction can be a choice method to prepare switchable surfaces for a large range of applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43130.     

A dual mode 2.4-GHz CMOS low noise amplifier employing body biasing

This paper presents a dual mode CMOS low noise amplifier (LNA) suitable for Worldwide Interoperability for Microwave Access applications, at 2.4?GHz. The design concept is based on body biasing. An off chip Digital to Analog Converter is used to generate the proper body bias voltage to control the LNA gain and linearity. Measurement results show that in the high gain mode, for V _BS?=?0.3?V, the cascode LNA, implemented in a 0.13???m CMOS standard process, exhibits a 14?dB power gain, a 3.6?dB noise figure (NF) and ?4.6?dBm of third order intercept point (IIP3) for a 4?mA current consumption under 1?V supply. Tuning V _BS to ?0.55?V, switches the LNA into the low gain mode. It achieves 8.6?dB power gain, 6.2?dB NF and 6?dBm IIP3 under a constrained power consumption of 1.7?mW.     

Cosmic ray sonification: the COSMOPHONE

The Cosmophone is an attempt to show the close connections existing between the infinitely small and the infinitely large in sensory terms by detecting and imaging the continuous flow of elementary particles (cosmic rays) originating from our entire galaxy.     

Corrosion of ceramics for vinasse gasification in supercritical water

Supercritical water gasification (SCWG) is a very efficient process to convert wet biomass into energetic gases. Unfortunately, SCWG reactor may strongly corrode due to the addition of temperature, pressure and the presence of corrosive species. In the present paper, the corrosion of various ceramic materials in subcritical and supercritical water (SCW) gasification process was studied in a batch reactor. We compare the corrosion in distillated water and the corrosion in sugar beet slurry that will be gasified under supercritical conditions. The experimental temperatures were 350 °C and 550 °C and the pressure was 25 MPa. Technical ceramics (SiC, alumina, Y stabilized zirconia, Si₃N₄, BN, aluminosilicate, cordierite-mullite) show poor capability to sustain corrosion whereas graphite and glassy carbon are the highest performance materials in our working conditions.