Process Intensification and Integration: an assessment

A considerable number of studies have been performed for improving the efficiency of production processes, of energy supply and utilisation, while reducing emissions of greenhouse gases, volatile organic compounds and other pollutants. This has been a very important task which this journal has been targeting. As a response to these industrial and societal requirements considerable research effort has been targeted to process integration and process intensification. This article has made an attempt for a short assessment of those advanced engineering approaches.     

A systematic technique for cost-effective CO<Subscript>2</Subscript> emission reduction in process plants

There has been growing interests to reduce the environmental impact caused by greenhouse gas emissions from process plants through various energy conservation strategies. CO₂ emissions are closely linked to energy generation, conversion, transmission and utilisation. Various studies on the design of energy-efficient processes, optimal mix of renewable energy and hybrid power system are driven to reduce reliance on fossil fuel as well as CO₂ emissions reduction. This paper presents a systematic technique in the form of graphical visualisation tool for cost-effective CO₂ emission reduction strategies in industry. The methodology is performed in four steps. The first step involves calculating the energy consumption of a process plant. This is followed by identification of potential strategies to reduce CO₂ emissions using the CO₂ management hierarchy as a guide. In the third step, the development of “Investment” versus “CO₂ Reduction” (ICO₂) plot is constructed to measure the optimal CO₂ emission reductions achieved from the implementation of possible CO₂ reduction strategies. The Systematic Hierarchical Approach for Resilient Process Screening (Wan Alwi and Manan in AIChE J 11:3981–3988, 2006) method is used in the fourth step via substitution or partial implementation of the various CO₂ reduction options in order to meet the cost-effective emission reduction within the desired investment limit or payback period (PP). An illustrative case study on a palm oil refinery plant has been used to demonstrate the implementation of the method in reduction of CO₂ emissions. The developed graphical tool provides an insight-based approach for systematic CO₂ emission reduction in the palm oil refinery considering both heat and power energy sources. Result shows that 31.2 % reduction in CO₂ emissions can be achieved with an investment of USD 38,212 and PP of 10 months based on the present energy prices in Malaysia.     

The localized corrosion of Cr-Ni stainless steel

The kinetics of localized corrosion of Cr-Ni stainless steel is characterized by the quadratic time dependence of the total current density, by the linear increase in the number of pits and by the decrease of the current density in the pits. The pits have a shape of a rotary ellipsoid. The Tafel slope of the metal dissolution in the pits is 0.50 V. The dissolution rate is the highest on the pit bottom and the lowest at the mouth of the pit. The different rate of metal dissolution is caused by the different concentration of chloride ions over the pit surface.     

The influence of structure order on the kinetics of dehydroxylation of kaolinite

The structural order of kaolinite is an important factor that shows a substantial effect on the processes which take place during the thermal treatment of kaolin. The influence of structural order on the dehydroxylation process was investigated by simultaneous thermogravimetry and differential thermal analysis (TG-DTA). The thermal analysis was performed on the samples with gradually decreasing structural order prepared by milling procedure. The apparent activation energy of dehydroxylation process decreases with decreasing structural order according to the exponential function. The extrapolation of experimental data leads to the estimation of apparent activation energy of 76.6 kJ mol^?1 and of frequency factor of 0.12 × 10⁴ s^?1 related to completely disordered form of kaolinite, while the ordered form shows the apparent activation energy of 216.17 kJ mol^?1 and the frequency factor of 9.26 × 10⁴ s^?1. The relationships between features such as the infrared pattern of treated material, the degree of structural order and the apparent activation energy were established.     

Some Properties of Nickel-Cobalt Alloys Electrodeposited from Sulphosalicylate Solutions

An uncommon electrolyte, based on sulphosalicylic acid, was used for nickel-cobalt deposition. Some mechanical properties (internal stress and microhardness) and structural properties of the deposits have been presented. High microhardness (nearly 800 HM) with simultaneous low internal stress (about 50 MPa) can be reached.     

Numerical study on the spectroscopic ellipsometry of lamellar gratings made of lossless dielectric materials

The spectroscopic ellipsometry of lamellar gratings made of lossless dielectric materials is studied numerically by using the rigorous coupled-wave method with the use of Li's Fourier factorization rules [J. Opt. Soc. Am. A 13, 1870 (1996)], which are known to improve the convergence on the analyses of metallic gratings. Numerical results show that the calculation method also provides fast convergence on lossless gratings, and accurate values of the ellipsometric angles are obtained in very short computation times. Moreover, estimation of grating parameters is investigated by using a cost function defined by the average distance on the Poincaré sphere, and it is shown that the computation required for accurate estimation is possible in reasonable computation time.     

Fabrication of buried microfluidic channels with observation windows using femtosecond laser photoablation and parylene-C coating

We developed an advanced method for fabricating microfluidic structures comprising channels and inputs/outputs buried within a silicon wafer based on single level lithography. We etched trenches into a silicon substrate, covered these trenches with parylene-C, and selectively opened their bottoms using femtosecond laser photoablation, forming channels and inputs/outputs by isotropic etching of silicon by xenon difluoride vapors. We subsequently sealed the channels with a second parylene-C layer. Unlike in previously published works, this entire process is conducted at ambient temperature to allow for integration with complementary metal oxide semiconductor devices for smart readout electronics. We also demonstrated a method of chip cryo-cleaving with parylene presence that allows for monitoring of the process development. We also created an observation window for in situ visualization inside the opaque silicon substrate by forming a hole in the parylene layer at the silicon backside and with local silicon removal by xenon difluoride vapor etching. We verified the microfluidic chip performance by forming a segmented flow of a fluorescein solution in an oil stream. This proposed technique provides opportunities for forming simple microfluidic systems with buried channels at ambient temperature.     

Chemical curing of alkyd resin catalyzed by benzoylferrocene: Performance,kinetics, and thickness effects

Catalytic properties of benzoylferrocene, as a representative of cobalt‐free drier, was investigated on alkyd resin modified with soybean oil. Mechanical tests, performed on alkyd films, revealed promising activity at low metal concentrations. A detailed analysis of time resolved infrared spectra was used for in‐depth investigation of chemical curing in the films. The experiments, performed in transmission mode, enabled determination of kinetic parameters for the autoxidation process. Effects of film thickness were investigated using attenuated total reflectance technique. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46184.     

Lipidomic Study of Precursors of Endocannabinoids in Freshwater Bryozoan Pectinatella magnifica

Freshwater bryozoan Pectinatella magnifica was collected from a sand pit (South Bohemia). The total lipids after extraction from lyophilized bryozoans were analyzed using high‐performance liquid chromatography/high‐resolution negative tandem electrospray mass spectrometry. A total of 19 lipid classes were identified, including N‐acyl‐substituted phospholipids, that is, N‐acylphosphatidylethanolamine and N‐acylphosphatidylserine in their plasmenyl forms. Based on gas chromatography/mass spectrometry of 3‐pyridylcarbonyl (picolinyl) esters, a very unusual fatty acid was identified, namely 24:7n‐3 (all‐cis‐3,6,9,12,15,18,21‐tetracosaheptaenoic acid). The presence of polyunsaturated fatty acids in individual classes is very specific: arachidonic and eicosapentaenoic acids being predominantly bound as amides in N‐acyl phospholipids, that is, diacyl‐N‐acylphosphatidylethanolamines (NAPtdEtn), plasmenyl‐N‐acylphosphatidyl ethanolamines (PlsNAPtdEtn), diacyl‐N‐acylphosphatidylserines (NAPtdSer), and plasmenyl‐N‐acylphosphatidylserines (PlsNAPtdSer). While 24:6n‐3 was identified in the sn‐2 position of several phospholipids, 24:7n‐3 was identified in only two plasmalogens, that is, PlsNAPtdEtn and PlsNAPtdSer. Thanks to the tandem mass spectrometry, we managed to identify the position of all acyl groups in both diacyl‐ and also in alkenyl‐acyl‐(plasmenyl) molecular species of N‐acylphospholipids. The identification of the molecular species of N‐acyl‐substituted phosphatidylethanolamine and phosphatidylserine, including their plasmalogen forms, in the freshwater bryozoan P. magnifica has enabled the identification of endogenous cannabinoid precursors.