Effect of sulphur compounds on the heptane pyrolysis kinetics

1985 ◽  
Vol 50 (12) ◽  
pp. 2893-2902 ◽  
Author(s):  
Martin Bajus ◽  
Jozef Baxa
Keyword(s):  
Thermal Decomposition ◽  
Stainless Steel ◽  
Carbon Disulphide ◽  
Reaction Times ◽  
Pyrolysis Kinetics ◽  
Sulphur Compounds ◽  
Dithiophosphoric Acid ◽  
Tube Reactor ◽  
Flow Through ◽  
Steel Flow

The effect of 1-didecyl sulphide, diethyl disulphide, p,p'-dichlorodiphenyl disulphide, 1-butanethiol, 0,0'-di-1-butyl dithiophosphate zinc, 0,0'-diethyl dithiophosphoric acid and carbon disulphide, respectively, on the kinetics and selectivity of the thermal decomposition of heptane at 700 °C and 100 kPa was studied in a stainless steel flow-through tube reactor. The sulphur substance content was 0.1-1.0 wt.%. 1-Didecyl sulphide, p,p'-dichlorodiphenyl disulphide, 1-butylthiol, 0,0'-di-1-butyl dithiophosphate zinc and carbon disulphide favour the decomposition of heptane by 5-17%. A decrease in the heptane decomposition rate was observed in the presence of diethyl disulphide (2.8%) and 0,0'-diethyl dithiophosphoric acid (13.9%). The selectivity of decomposition to ethylene is increased by diethyl disulphide, p,p'-dichlorodiphenyl disulphide, carbon disulphide and 1-didecyl sulphide and, in the range of short reaction times, also by 0,0'-diethyl dithiophosphoric acid, 0,0'-di-1-butyl dithiophosphate zinc and 1-butanethiol.

Coke formation during the pyrolysis of hydrocarbons in the presence of sulphur compounds

1985 ◽  
Vol 50 (12) ◽  
pp. 2903-2909 ◽  
Author(s):  
Martin Bajus ◽  
Jozef Baxa
Keyword(s):  
Carbon Disulphide ◽  
Coke Formation ◽  
Steel Tube ◽  
Inhibition Mechanism ◽  
Stainless Steel Tube ◽  
Tube Flow ◽  
Sulphur Compounds ◽  
Dithiophosphoric Acid ◽  
Inhibiting Effect ◽  
Flow Through

The effect of 1-butanethiol, 0,0'-di-1-butyl dithiophosphate zinc, 0,0'-diethyl dithiophosphoric acid and carbon disulphide, respectively, on the formation of coke during the pyrolysis of a reformer raffinate at 820 °C and 100 kPa was studied using a stainless steel tube flow-through reactor. The sulphur compounds were added in amounts of 0.05 to 5.0 wt.%. The coke formation was followed from the beginning of the experiment. The coking rate was lower as compared with the pyrolysis of the pure reformer raffinate; 0,0'-di-1-butyl dithiophosphate zinc, 0,0'-diethyl dithiophosphoric acid and carbon disulphide have a strong inhibiting effect on the coke formation. The coking inhibition mechanism is discussed.

Co-pyrolysis kinetics of sewage sludge and oil shale thermal decomposition using TGA–FTIR analysis

2016 ◽  
Vol 118 ◽  
pp. 345-352 ◽  
Author(s):  
Yan Lin ◽  
Yanfen Liao ◽  
Zhaosheng Yu ◽  
Shiwen Fang ◽  
Yousheng Lin ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Oil Shale ◽  
Ftir Analysis ◽  
Pyrolysis Kinetics ◽  
Kinetics Of

scholarly journals Calibration of Stainless Steel-edged V-Notch Weir Stop Logs for Water Level Control Structures

2019 ◽  
Vol 35 (5) ◽  
pp. 745-749
Author(s):  
L. E. Christianson ◽  
R. D. Christianson ◽  
A. E. Lipka ◽  
S. Bailey ◽  
J. Chandrasoma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Water Level ◽  
Flow Rate ◽  
Subsurface Drainage ◽  
Conservation Practices ◽  
Nutrient Loads ◽  
Level Control ◽  
Control Structures ◽  
Flow Monitoring ◽  
Flow Through

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.

Hydrothermal Synthesis of Walnut-Like α-Ni(OH)2 Architectures and their In Situ Thermal Convention to NiO

2011 ◽  
Vol 412 ◽  
pp. 44-48
Author(s):  
Zhi Rong Suo ◽  
Hui Liu ◽  
Na Wei
Keyword(s):  
Thermal Decomposition ◽  
Polyethylene Glycol ◽  
Hydrothermal Synthesis ◽  
Formation Process ◽  
Hydrothermal Reaction ◽  
Reaction Times ◽  
Thermal Decomposition Process ◽  
Similar Morphology ◽  
Microwave Assisted

The walnut-like α-Ni (OH)2 architectures have been successfully synthesized through a microwave-assisted hydrothermal method using urea as a hydrolysis-controlling agent and polyethylene glycol (PEG) as a surfactant. The NiO architectures with similar morphology were obtained by a simple thermal decomposition process of the precursor α-Ni (OH)2. The as-obtained products were well characterized by XRD, SEM, TEM, and FTIR. The experimental results shown that walnut-like α-Ni (OH)2 architectures with a diameter of 2-6 μm. The formation process of Ni (OH)2 architectures was observed by SEM via different hydrothermal reaction times.

Removal of Pb(II) from simulated wastewaters using a stainless-steel wool cathode in a flow-through cell

2006 ◽  
Vol 36 (6) ◽  
pp. 677-683 ◽  
Author(s):  
Luiz H.S. Gasparotto ◽  
Nerilso Bocchi ◽  
Romeu C. Rocha-Filho ◽  
Sonia R. Biaggio
Keyword(s):  
Stainless Steel ◽  
Steel Wool ◽  
Flow Through

Preparation of Magnetite Nanoparticles by Thermal Decomposition of Hematite Powder in the Presence of Organic Solvent

2007 ◽  
Vol 998 ◽  
Author(s):  
Chun-Rong Lin ◽  
Ray-Kuang Chiang ◽  
Chih-Jung Chen ◽  
Hsin-Yi Lai ◽  
Igor S. Lyubutin ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Reaction Time ◽  
Magnetite Nanoparticles ◽  
Magnetic Measurements ◽  
Spinel Phase ◽  
Reaction Times ◽  
Transformation Process ◽  
Verwey Transition ◽  
Magnetite Particles ◽  
Xrd Patterns

ABSTRACTMagnetite nanoparticles have been synthesized by thermal decomposition of hematite (Fe2O3) powder in the presence of high boiling point solvent. The mixture of hematite and 1- octadecene solvent was heated and stirred in nitrogen gas at the temperature of 320 °C for the desired time (∼2 to 28 hrs). The influence of the reaction time on transformation process was analyzed with X-ray diffraction (XRD), Mössbauer spectroscopy (MS), and magnetic measurements. XRD patterns show that the phase of intermediate was composed of spinel phase and corundum phase (α-Fe2O3). The 57Fe Mössbauer spectra show that the spinel phase originated from the magnetite particles. The structure transformation proportion of hematite to magnetite strongly depends on reaction times. After reflux for 28 hrs the hematite-magnetite transformation was complete. The mean crystallite size of pure phase of magnetite particles is about 40 nm. The saturation magnetization increases with the reaction time, which corresponds to an increase of concentration of magnetite in the samples. A pronounced feature of the Hc and σr/σs observed in samples is the steplike change which appears at 125 K and is characteristic of the Verwey transition. The hyperfine parameters of Mössbauer spectrum measured at low temperature also indicate that the Verwey phase transition occurs. In other words, the Verwey transition is an indication that the magnetite particles exactly grew up in the synthesized compounds. This thermal decomposition process provided a method to prepare pure magnetite as well as magnetite/hematite nanocomposites useful for various magnetic applications.

Thermal processing of sewage sludge by drying, pyrolysis, gasification and combustion

2001 ◽  
Vol 44 (10) ◽  
pp. 333-339 ◽  
Author(s):  
P. Stolarek ◽  
S. Ledakowicz
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Kinetic Parameters ◽  
Thermal Processing ◽  
Combustion Process ◽  
Order Kinetic ◽  
Municipal Sludge ◽  
Pyrolysis Kinetics ◽  
Exponential Factor ◽  
First Order

Thermal processing of sewage sludge including drying, pyrolysis and gasification or combustion may be an alternative to other ways of utilising it. In this paper thermogravimetric analysis (TGA) was employed in the investigation of thermal decomposition of sewage sludge. The kinetic parameters of drying, pyrolysis and gasification or combustion of sewage sludge have been determined in an inert-gas (argon) and additionally some series of the sludge decomposition experiments have been carried out in air, in order to compare pyrolysis and combustion. The pyrolysis char has been gasified with carbon dioxide. A typical approach to the kinetics of thermal decomposition of a solid waste is to divide the volatile evolution into a few fractions (lumps), each of which is represented by a single first-order reaction. If these lumps are assumed to be non-interacting and evolved by independent parallel reactions the first-order kinetic parameters such as activation energy Ei and pre-exponential factor Ai can be determined from mathematical evaluation of TG or DTG curves. The object of our investigations was a municipal sludge from the two wastewater treatment plants (WTP) in Poland. The experiments have been carried out in the thermobalance Mettler-Toledo type TGA/SDTA851 LF, in the temperature range 30-1,000°C. Five different values of heating rate have been applied β = 2, 5, 10, 15 and 20 K/min. The values of Ei and Ai have been determined for all recognised lumps of gaseous products. The method employed has also revealed its usefulness for the determination of kinetic parameters for municipal sludge, that possess an undefined content. An alternative route to combustion of sewage sludge is its gasification, which significantly increases the gaseous product (pyrolytic gas + syngas). Besides pyrolysis kinetics, gasification or combustion process kinetics have also been determined.

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