scholarly journals Effect of Process Parameters on Catalytic Incineration of Solvent Emissions

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Satu Ojala ◽  
Ulla Lassi ◽  
Paavo Perämäki ◽  
Riitta L. Keiski
Keyword(s):  
Laboratory Experiments ◽  
Butyl Acetate ◽  
Space Velocity ◽  
Optimal Operation ◽  
Process Conditions ◽  
Statistical Experimental Design ◽  
Operation Conditions ◽  
A Minor ◽  
Increasing Temperature ◽  
By Products

Catalytic oxidation is a feasible and affordable technology for solvent emission abatement. However, finding optimal operation conditions is important, since they are strongly dependent on the application area of VOC incineration. This paper presents the results of the laboratory experiments concerning four most central parameters, that is, effects of concentration, gas hourly space velocity (GHSV), temperature, and moisture on the oxidation of n-butyl acetate. Both fresh and industrially aged commercial Pt/Al2O3catalysts were tested to determine optimal process conditions and the significance order and level of selected parameters. The effects of these parameters were evaluated by computer-aided statistical experimental design. According to the results, GHSV was the most dominant parameter in the oxidation of n-butyl acetate. Decreasing GHSV and increasing temperature increased the conversion of n-butyl acetate. The interaction effect of GHSV and temperature was more significant than the effect of concentration. Both of these affected the reaction by increasing the conversion of n-butyl acetate. Moisture had only a minor decreasing effect on the conversion, but it also decreased slightly the formation of by products. Ageing did not change the significance order of the above-mentioned parameters, however, the effects of individual parameters increased slightly as a function of ageing.

scholarly journals On the Nature of Hydrodynamic Cavitation Process and Its Application for the Removal of Water Pollutants

2019 ◽  
Vol 12 ◽  
pp. 117862211988048 ◽  
Author(s):  
Erick R Bandala ◽  
Oscar M Rodriguez-Narvaez
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
High Energy ◽  
Optimal Operation ◽  
Hydrodynamic Cavitation ◽  
Radical Scavenger ◽  
Process Conditions ◽  
Cavitation Process ◽  
Operation Conditions ◽  
Hydroxyl Radical Scavenger

Cavitation is considered a high energy demanding process for water treatment. For this study, we used a simple experimental setup to generate cavitation at a low pressure (low energy) and test it for hydroxyl radical production using a well-known chemical probe as a hydroxyl radical scavenger. The conditions for generating the cavitation process (eg, pressure, flow velocity, temperature, and other significant variables) were used to degrade model contaminants, an azo dye and an antibiotic. The amount of hydroxyl radicals generated by the system was estimated using N,N-dimethyl-p-nitrosoaniline (pNDA) as hydroxyl radical scavenger. The capability of hydrodynamic cavitation (HC) to degrade contaminants was assessed using Congo red (CR) and sulfamethoxazole (SMX) as model contaminants. Different chemical models were analyzed using UV-visible spectrophotometry (for pNDA and CR) and high-performance liquid chromatography (HPLC) (for SMX) after HC treatment under different process conditions (ie, pressure of 13.7 and 10.3 kPa, and flow rates of 0.14 to 3.6 × 10−4 m3/s). No pNDA bleaching was observed for any of the reaction conditions tested after 60 minutes of treatment, which suggests that there was no hydroxyl radical generation during the process. However, 50% degradation of CR and 25% degradation of SMX were observed under the same process conditions, comparable with previously reported results. These results suggest that the process is most likely thermally based rather than radically based, and therefore, it can degrade organic pollutants even if no hydroxyl radicals are produced. Hydrodynamic cavitation, either alone or coupled with other advanced water technologies, has been identified as a promising technology for removing organic contaminants entering the water cycle; however, more research is still needed to determine the specific mechanisms involved in the process and the optimal operation conditions for the system.

scholarly journals Optimization of the Enzymatic Synthesis of Pentyl Oleate with Lipase Immobilized onto Novel Structured Support

Fermentation ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 48 ◽  
Author(s):  
Valeria Cavallaro ◽  
Gabriela Tonetto ◽  
María Luján Ferreira
Keyword(s):  
Enzymatic Synthesis ◽  
Reaction Times ◽  
Value Added ◽  
Inhibitory Effects ◽  
Molar Ratios ◽  
Operation Conditions ◽  
Ping Pong ◽  
Experimental Findings ◽  
Increasing Temperature ◽  
By Products

The term biorefinery is related to the sustainable production of value-added bioproducts and bioenergy from biomass. Esters from fatty acids are important compounds synthesized from by-products of the oleochemical industry. In agreement with the biorefinery concept, it is important to search for catalysts that reduce the consumption of energy and water, using moderate operation conditions and low reaction times. In this work, response surface methodology (RSM) was used to optimize the enzymatic synthesis of pentyl oleate using Candida antarctica lipase B (CALB) immobilized on a polyethylene-aluminum structured support. A factorial design was employed to evaluate the effects of several parameters on the ester yield. To obtain a model with a good fit, an approach to reaction mechanism and enzyme kinetics was taken into consideration. Experimental findings were correlated and explained using equations of a ping-pong bi-bi kinetic model and considering the inhibitory effects of both substrates. The developed model was consistent with the experimental data predicting an increase in pentyl oleate production with increasing temperature and a decrease with higher oleic acid amounts and alcohol to acid molar ratios. This model could be useful in a future industrial application of CALB/LLDPE/Al to minimize the costs in oleochemical biorefineries.

Calibration 7" – Cutthroat Flume as New Size for Discharge Measurement at Free Flow Condition

2020 ◽  
Vol 38 (12A) ◽  
pp. 1783-1789
Author(s):  
Jaafar S. Matooq ◽  
Muna J. Ibraheem
Keyword(s):  
Steady State ◽  
Flow Condition ◽  
Laboratory Experiments ◽  
Free Flow ◽  
Experimental Program ◽  
Steady State Flow ◽  
Empirical Formulas ◽  
State Flow ◽  
Operation Conditions ◽  
Throat Width

 This paper aims to conduct a series of laboratory experiments in case of steady-state flow for the new size 7 ̋ throat width (not presented before) of the cutthroat flume. For this size, five different lengths were adopted 0.535, 0.46, 0.40, 0.325 and 0.27m these lengths were adopted based on the limitations of the available flume. The experimental program has been followed to investigate the hydraulic characteristic and introducing the calibrated formula for free flow application within the discharge ranged between 0.006 and 0.025 m3/s. The calibration result showed that, under suitable operation conditions, the suggested empirical formulas can accurately predict the values of discharge within an error ± 3%.

scholarly journals Fish heating tolerance scales similarly across individual physiology and populations

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicholas L. Payne ◽  
Simon A. Morley ◽  
Lewis G. Halsey ◽  
James A. Smith ◽  
Rick Stuart-Smith ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Tropical Species ◽  
Acclimation Temperature ◽  
Tight Coupling ◽  
Abundance Patterns ◽  
Biological Responses ◽  
In The Wild ◽  
Demographic Processes ◽  
Climate Vulnerability ◽  
Increasing Temperature

AbstractExtrapolating patterns from individuals to populations informs climate vulnerability models, yet biological responses to warming are uncertain at both levels. Here we contrast data on the heating tolerances of fishes from laboratory experiments with abundance patterns of wild populations. We find that heating tolerances in terms of individual physiologies in the lab and abundance in the wild decline with increasing temperature at the same rate. However, at a given acclimation temperature or optimum temperature, tropical individuals and populations have broader heating tolerances than temperate ones. These congruent relationships implicate a tight coupling between physiological and demographic processes underpinning macroecological patterns, and identify vulnerability in both temperate and tropical species.

scholarly journals Formation of C-A-S-H phases from the interaction between concrete or cement and bentonite

Clay Minerals ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 223-235 ◽  
Author(s):  
Raúl Fernández ◽  
Ana Isabel Ruiz ◽  
Jaime Cuevas
Keyword(s):  
Calcium Silicate Hydrate ◽  
Laboratory Experiments ◽  
Pore Scale ◽  
Lime Mortar ◽  
Cement Interface ◽  
Argillaceous Rocks ◽  
Deep Geological Disposal ◽  
Engineered Barriers ◽  
High Level ◽  
Increasing Temperature

AbstractConcrete and bentonite are being considered as engineered barriers for the deep geological disposal of high-level radioactive waste in argillaceous rocks. Three hydrothermal laboratory experiments of different scalable complexity were performed to improve our knowledge of the formation of calcium aluminate silicate hydrates (C-A-S-H) at the interface between the two materials: concretebentonite transport columns, lime mortar-bentonite transport columns and a portlandite- (bentonite and montmorillonite) batch experiment. Precipitation of C-A-S-H was observed in all experiments. Acicular and fibrous morphologies with certain laminar characteristics were observed which had smaller Ca/Si and larger Al/Si ratios with increasing temperature and lack of accessory minerals. The compositional fields of these C-A-S-H phases formed in the experiments are consistent with Al/(Si+Al) ratios of 0.2– 0.3 described in the literature. The most representative calcium silicate hydrate (C-S-H) phase from the montmorillonite–cement interface is Al-tobermorite. Structural analyses revealed a potential intercalation or association of montmorillonite and C-A-S-H phases at the pore scale.

The effects of ultraviolet/H2O2 advanced oxidation on the content and characteristics of groundwater natural organic matter

2014 ◽  
Vol 15 (1) ◽  
pp. 34-41 ◽  
Author(s):  
J. Molnar ◽  
J. Agbaba ◽  
A. Tubić ◽  
M. Watson ◽  
M. Kragulj ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Advanced Oxidation ◽  
Total Content ◽  
Process Conditions ◽  
Water Type ◽  
H2o2 Treatment ◽  
Trihalomethane Formation Potential ◽  
Aromatic Character ◽  
A Minor

This work investigates the effects of ultraviolet (UV)/H2O2 advanced oxidation on the content and characteristics of natural organic matter (NOM) originating from two different groundwaters (3.03–9.69 mg/L total organic carbon (TOC), 2.71–4.31 Lmg−1m−1 specific ultraviolet absorbance (SUVA)). Application of UV irradiation resulted in a minor reduction in the total content of NOM. Using UV/H2O2 advanced oxidation led to a significant reduction of the aromatic character of NOM (SUVA was reduced by up to 80%) and an increase in the hydrophilic character of the residual NOM, with the optimal UV/H2O2 treatment conditions depending on the water type. In addition, fluctuations in trihalomethane formation potential (THMFP) were observed depending on the UV/H2O2 process conditions, with a maximal reduction of about 40% achieved for both waters.

Application of Additives in 1,8-Cineole Purification

2013 ◽  
Vol 634-638 ◽  
pp. 382-385
Author(s):  
Ke Guo Liu ◽  
Li Li Gu ◽  
Hui Guang Hu ◽  
Rong Yang ◽  
Jun Tao
Keyword(s):  
Experimental Studies ◽  
Optimal Operation ◽  
Experimental Results ◽  
Second Step ◽  
Reflux Ratio ◽  
Batch Distillation ◽  
Operation Temperature ◽  
Operation Conditions ◽  
Vacuum Degree

The experimental studies for purification of 1,8-cineole by vacuum batch distillation as well as the application of additives in 1,8-cineole purification were carried out. There were two steps during the purification. In the first step, experimental results showed that the optimal operation conditions for purification of 1,8-cineole were the temperature of the reboiler at about 320.15 K under a certain vacuum degree. In the second step, the optimal operation temperature of the reboiler was 331.15 K. The optimal reflux ratio was generated finally. Vacuum degree was controlled between 1.1 kPa and 1.3 kPa.

scholarly journals Extraction and Characterization of Gelatin from Skin By-Products of Seabream, Seabass and Rainbow Trout Reared in Aquaculture

2021 ◽  
Vol 22 (22) ◽  
pp. 12104
Author(s):  
Jesus Valcarcel ◽  
Carolina Hermida-Merino ◽  
Manuel M. Piñeiro ◽  
Daniel Hermida-Merino ◽  
José Antonio Vázquez
Keyword(s):  
Molecular Weight ◽  
Rainbow Trout ◽  
Raw Materials ◽  
Gel Strength ◽  
Current Trends ◽  
First Case ◽  
Imino Acids ◽  
Increasing Demand ◽  
A Minor ◽  
By Products

The expansion of fish filleting, driven by the increasing demand for convenience food, concomitantly generates a rising amount of skinning by-products. Current trends point to a growing share of aquaculture in fish production, so we have chosen three established aquaculture species to study the properties of gelatin extracted from their skin: rainbow trout, commonly filleted; and seabass and seabream, marketed whole until very recently. In the first case, trout skin yields only 1.6% gelatin accompanied by the lowest gel strength (96 g bloom), while yield for the other two species exceeds 6%, and gel strength reaches 181 and 229 g bloom for seabass and seabream, respectively. These results are in line with the proportion of total imino acids analyzed in the gelatin samples. Molecular weight profiling shows similarities among gelatins, but seabass and seabream gelatins appear more structured, with higher proportion of β-chains and high molecular weight aggregates, which may influence the rheological properties observed. These results present skin by-products of seabream, and to a minor extent seabass, as suitable raw materials to produce gelatin through valorization processes.

scholarly journals The extraction of total lipids from parsley: Petroselinum crispum (mill.) Nym. Ex. A.W. Hill) seeds

2004 ◽  
Vol 58 (12) ◽  
pp. 563-568 ◽  
Author(s):  
Mihajlo Stankovic ◽  
Nadica Stojanovic ◽  
Nada Nikolic ◽  
Vesna Novkovic
Keyword(s):  
Kinetic Equations ◽  
Optimal Operation ◽  
Petroselinum Crispum ◽  
Optimal Conditions ◽  
Total Lipids ◽  
Operation Conditions ◽  
Lipid Fractions ◽  
Polar Organic Solvents ◽  
Layer Chromatography ◽  
Kinetics Of

The kinetics of extraction of total lipids from ground parsley (Petroselinum crispum (Mill.) Nym. ex. A.W. Hill) seeds with a mixture of ethanol or methanol with non-polar organic solvents, chloroform, carbon tetrachloride, trichloroethylene and petroleum ether, at various temperatures were studied. The maceration technique with reflux was used. The kinetic parameters were determined in extraction kinetic equations, as well as the optimal operation conditions for total lipids extraction. The maximum total lipids yield under optimal conditions was 33.7 g per 100 g of dry parsley seeds. Nine lipid fractions of the total lipids were separated by thin layer chromatography among which were phospholipids, sterol, mono-, di- and triacylglycerol, free fatty acids and carbohydrates.

scholarly journals Reaction Characteristics of Hydrogen-Rich Syngas Production by Sludge/Coal Cogasification Based on the Iron-Based Oxygen Carriers

2022 ◽  
pp. 66-83
Author(s):  
Qingjiao Zhu ◽  
Xintong Guo ◽  
Yanan Guo ◽  
Jingjing Ma ◽  
Qingjie Guo
Keyword(s):  
Wastewater Treatment ◽  
Optimal Operation ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Mass Ratio ◽  
Volume Percentage ◽  
Syngas Production ◽  
Operation Conditions ◽  
Iron Based ◽  
Gasification Reaction

With the acceleration of industrialization and urbanization in China, wastewater treatment is increasing yearly. As a by-product of wastewater treatment, the gasification of sludge with coal in chemical looping process is a clean and efficient conversion technology. To explore the reaction behavior of cogasification of sludge and coal with iron-based oxygen carriers (OCs) for producing hydrogen-rich syngas, the experiment of cogasification using Fe2O3/Al2O3 as OC in a fluidized bed reactor was conducted. The result showed that the volume percentage of hydrogen (H2) and syngas yield is proportional to the amount of sludge added. The optimal operation conditions were: temperature at 900 °C, the mass ratio of OC to coal at 5.80 and mass ratio of sludge to coal at 0.2. Under this operating condition, the volume percentage of H2 and syngas yield in the flue gas was 75.6 vol% and 97.5 L·min-1·kg-1, respectively. Besides, the OC showed a stable reactivity in the sixth redox cycle with added sludge. However, the reactivity of OC significantly declined in the seventh and eighth redox cycles. It was recovered when the ash was separated. The decrease in the specific surface area of the OC caused by ash deposition is the main reason for the decline in its reactivity. The kinetic analysis showed that the random pore model describes the reaction mechanism of sludge/coal chemical looping gasification (CLG). The addition of sludge can reduce the activation energy of coal CLG reaction, accelerate the gasification reaction rate and increase the carbon conversion.

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