Kinetics and Inhibition of Ferrous Sulfide Nucleation and Precipitation

2014 ◽  
Author(s):  
Qiliang ‘Luke’ Wang ◽  
Zhang Zhang ◽  
Amy Kan ◽  
Mason Tomson
Keyword(s):  
Flow Reactor ◽  
Production Systems ◽  
Batch Reactor ◽  
High Surface ◽  
Plug Flow ◽  
Oil Production ◽  
Rate Equations ◽  
Precipitation Kinetics ◽  
Severe Problem ◽  
Ferrous Sulfide

Abstract Ferrous sulfide (FeS) precipitation is a severe problem and the significance of this problem is increased in the shale gas and oil production due to the potentially increasing biologically and thermally induced sulfide production. Although FeS scale is ubiquitous, little is understood about its precipitation and inhibition properties due to experimental difficulties. In conventional research, we used a batch reactor to study the precipitation kinetics and inhibition of FeS formation. In order to assess scaling risk in pipes, a new plug flow reactor was developed under anoxic condition at different ionic strength (IS), pH and temperature to enable more reliable study of FeS precipitation kinetics at high surface to solution ratio. The precipitation kinetics of FeS is successfully fitted by a second/pseudo-first order rate equations for batch/plug flow systems. The rate of precipitation increases with increasing pH and temperature, and decreases with increasing IS. Commercial scale inhibitors, citrate, EDTA and other chelating agents have been tested for their inhibition effects on FeS precipitation. The new plug flow apparatus not only adds reliable data to the limited database of scaling kinetics in realistic flowing pipes, but also supplies a new method to study the effect of inhibitors in oil production systems. The research outcomes will contribute to the prediction of FeS scaling risk under different brine composition and well conditions.

Modeling the Formation of Pollutant Emissions in Large-Bore, Lean-Burn Gas Engines

2017 ◽  
Author(s):  
Anamol Pundle ◽  
David G. Nicol ◽  
Philip C. Malte ◽  
Joel D. Hiltner
Keyword(s):  
Partial Oxidation ◽  
Flow Reactor ◽  
Batch Reactor ◽  
Plug Flow ◽  
Chemical Reactor ◽  
Chemical Kinetic ◽  
Pollutant Emissions ◽  
Lean Burn ◽  
Reciprocating Engines ◽  
Stroke Engine

This paper discusses chemical kinetic modeling used to analyze the formation of pollutant emissions in large-bore, lean-burn gas reciprocating engines. Pollutants considered are NOx, CO, HCHO, and UHC. A quasi-dimensional model, built as a chemical reactor network (CRN), is described. In this model, the flame front is treated as a perfectly stirred reactor (PSR) followed by a plug flow reactor (PFR), and reaction in the burnt gas is modeled assuming a batch reactor of constant-pressure and fixed-mass for each crank angle increment. The model treats full chemical kinetics. Engine heat loss is treated by incorporating the Woschni model into the CRN. The mass burn rate is selected so that the modeled cylinder pressure matches the experiment pressure trace. Originally, the model was developed for large, low speed, two-stoke, lean-burn engines. However, recently, the model has been formatted for the four-stroke, open-chamber, lean-burn engine. The focus of this paper is the application of the model to a four-stroke engine. This is a single-cylinder non-production variant of a heavy duty lean-burn engine of about 5 liters cylinder displacement Engine speed is 1500 RPM. Key findings of this work are the following. 1) Modeled NOx and CO are found to agree closely with emission measurements for this engine over a range of relative air-fuel ratios tested. 2) This modeling shows the importance of including N2O chemistry in the NOx calculation. For λ = 1.7, the model indicates that about 30% of the NOx emitted is formed by the N2O mechanism, with the balance from the Zeldovich mechanism. 3) The modeling shows that the CO and HCHO emissions arise from partial oxidation late in the expansion stroke as unburned charge remaining mixes into the burnt gas. 4) Model generated plots of HCHO versus CH4 emission for the four-stroke engine are in agreement with field data for large-bore, lean-burn, gas reciprocating engines. Also, recent engine tests show the correlation of UHC and CO emissions to crevice volume. These tests suggest that HCHO emissions also are affected by crevice flows through partial oxidation of UHC late in the expansion stroke.

scholarly journals Continuous-Flow Process for Glycerol Conversion to Solketal Using a Brönsted Acid Functionalized Carbon-Based Catalyst

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 609 ◽  
Author(s):  
Vanesa Domínguez-Barroso ◽  
Concepción Herrera ◽  
María Ángeles Larrubia ◽  
Rafael González-Gil ◽  
Marina Cortés-Reyes ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Batch Reactor ◽  
High Surface ◽  
Molar Ratio ◽  
Fuel Additive ◽  
Flow Process ◽  
Glycerol Conversion ◽  
Structured Catalyst ◽  
Carbon Based

The acetalization of glycerol with acetone represents a strategy for its valorization into solketal as a fuel additive component. Thus, acid carbon-based structured catalyst (SO3H-C) has been prepared, characterized and tested in this reaction. The structured catalyst (L = 5 cm, d = 1 cm) showed a high surface density of acidic sites (2.9 mmol H+ g−1) and a high surface area. This catalyst is highly active and stable in the solketal reaction production in a batch reactor system and in a continuous downflow reactor, where several parameters were studied such as the variation of time of reaction, temperature, acetone/glycerol molar ratio (A/G) and weight hourly space velocity (WHSV). A complete glycerol conversion and 100% of solketal selectivity were achieved working in the continuous flow reactor equipped with distillation equipment when WHSV is 2.9 h−1, A/G = 8 at 57 °C in a co-solvent free operation. The catalyst maintained its activity under continuous flow even after 300 min of reaction.

scholarly journals Kinetics and Product Selectivity (Yield) of Second Order Competitive Consecutive Reactions in Fed-Batch Reactor and Plug Flow Reactor

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Subash Chandra Bose Selvamony
Keyword(s):  
Flow Reactor ◽  
Batch Reactor ◽  
Plug Flow ◽  
Second Order ◽  
Plug Flow Reactor ◽  
Effect Of Temperature ◽  
Product Selectivity ◽  
Fed Batch ◽  
Consecutive Reaction ◽  
Consecutive Reactions

This literature compares the performance of second order competitive consecutive reaction in Fed-Batch Reactor with that in continuous Plug Flow Reactor. In a kinetic sense, this simulation study aims to develop a case for continuous Plug Flow Reactor in pharmaceutical, fine chemical, and related other chemical industries. MATLAB is used to find solutions for the differential equations. The simulation results show that, for certain cases of nonelementary scenario, product selectivity is higher in Plug Flow Reactor than Fed-Batch Reactor despite the fact that it is the same in both the reactors for elementary reaction. The effect of temperature and concentration gradients is beyond the scope of this literature.

A stochastic model for two-station hydraulics exhibiting transient impact

1997 ◽  
Vol 36 (5) ◽  
pp. 19-26 ◽  
Author(s):  
J. L. Jacobsen ◽  
H. Madsen ◽  
P. Harremoès
Keyword(s):  
Parameter Estimation ◽  
Flow Reactor ◽  
Deterministic Model ◽  
Plug Flow ◽  
Stochastic Methods ◽  
Sewer System ◽  
Statistical Tool ◽  
Water Level Variation ◽  
Deterministic Description ◽  
Linear Reservoir

The objective of the paper is to interpret data on water level variation in a river affected by overflow from a sewer system during rain. The simplest possible, hydraulic description is combined with stochastic methods for data analysis and model parameter estimation. This combination of deterministic and stochastic interpretation is called grey box modelling. As a deterministic description the linear reservoir approximation is used. A series of linear reservoirs in sufficient number will approximate a plug flow reactor. The choice of number is an empirical expression of the longitudinal dispersion in the river. This approximation is expected to be a sufficiently good approximation as a tool for the ultimate aim: the description of pollutant transport in the river. The grey box modelling involves a statistical tool for estimation of the parameters in the deterministic model. The advantage is that the parameters have physical meaning, as opposed to many other statistically estimated, empirical parameters. The identifiability of each parameter, the uncertainty of the parameter estimation and the overall uncertainty of the simulation are determined.

Efficient Production of Light Olefin Based on Methanol Dehydration: Simulation and Design Improvement

2020 ◽  
Vol 23 ◽  
Author(s):  
S. Majid Abdoli ◽  
Mahsa Kianinia
Keyword(s):  
Dimethyl Ether ◽  
Flow Reactor ◽  
New Technology ◽  
Plug Flow ◽  
Light Olefins ◽  
Efficient Production ◽  
Actual Process ◽  
Light Olefin ◽  
Aspen Hysys ◽  
Improved Design

Background: Ethylene, propylene, and butylene as light olefins are the most important intermediates in the petrochemical industry worldwide. Methanol to olefins (MTO) process is a new technology based on catalytic cracking to produce ethylene and propylene from methanol. Aims and Objective: This study aims to simulate the process of producing ethylene from methanol by using Aspen HYSYS software from the initial design to the improved design. Methods: Ethylene is produced in a two-step reaction. In an equilibrium reactor, the methanol is converted to dimethyl ether by an equilibrium reaction. The conversion of the produced dimethyl ether to ethylene is done in a conversion reactor. Changes have been made to improve the conditions and get closer to the actual process design done in the industry. The plug flow reactor has been replaced by the equilibrium reactor, and the distillation column was employed to separate the dimethyl ether produced from the reactor. Result and Conclusion: The effect of the various parameters on the ethylene production was investigated. Eventually, ethylene is

Enhancing Fenton-like oxidation of crystal violet over Fe/ZSM-5 in a plug flow reactor

2021 ◽  
Author(s):  
Sara Modarresi-Motlagh ◽  
Fatemeh Bahadori ◽  
Mohammad Ghadiri ◽  
Arash Afghan
Keyword(s):  
Crystal Violet ◽  
Flow Reactor ◽  
Plug Flow ◽  
Plug Flow Reactor

scholarly journals The Effect of Mg and Zn Dopants on Pt/Al2O3 for the Dehydrogenation of Perhydrodibenzyltoluene

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 490
Author(s):  
Rudaviro Garidzirai ◽  
Phillimon Modisha ◽  
Innocent Shuro ◽  
Jacobus Visagie ◽  
Pieter van Helden ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Flow Reactor ◽  
Plug Flow ◽  
Optical Emission ◽  
Catalytic Performance ◽  
Emission Spectrometry ◽  
Hydrogen Yield ◽  
X Ray ◽  
Temperature Programmed

The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT.

Anaerobic digestion of pineapple pulp and peel in a plug-flow reactor

2012 ◽  
Vol 110 ◽  
pp. 40-47 ◽  
Author(s):  
Pimjai Namsree ◽  
Worakrit Suvajittanont ◽  
Chureerat Puttanlek ◽  
Dudsadee Uttapap ◽  
Vilai Rungsardthong
Keyword(s):  
Anaerobic Digestion ◽  
Flow Reactor ◽  
Plug Flow ◽  
Plug Flow Reactor ◽  
Pineapple Pulp
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