Pyrolysis of unsubstituted bicyclic hydrocarbons and gas oil

1982 ◽  
Vol 47 (7) ◽  
pp. 1838-1847 ◽  
Author(s):  
Martin Bajus ◽  
Jozef Baxa

Pyrolysis of tetraline, decaline, 1,1'-bicyclohexane, cyclohexylbenzene and gas oil was studied in stainless steel and quartz flow tubular reactors at 780 and 800 °C, residence time 0.08 to 0.5 s and at the mass ratio of steam to the raw material changing from 0.5 to 1.5. The effect of reaction temperature, the mass ratio of steam to the raw material, reactor material and of the added elemental sulphur on the yields of individual reaction products is reported. Of bicyclic hydrocarbons, condensed hydrocarbons are more stable than those with noncondensed rings, cyclanoaromates being more stable than bicyclanes. Pyrolysis of gas oil in the stainless steel reactor yields greater amounts of ethylene, propylene, butadiene and smaller amounts of methane and ethane, compared to the pyrolysis carried out under identical conditions in the quartz reactor. Elemental sulphur increases the conversion of gas oil into gaseous pyrolysis products.

1983 ◽  
Vol 48 (9) ◽  
pp. 2666-2675 ◽  
Author(s):  
Martin Bajus ◽  
Jozef Baxa ◽  
Michal Maťaš

Pyrolysis of primary, hydrotreated and hydrogenated kerosene and hydrogenated fraction 160-280 after separation of alkanes was studied in a stainless steel tubular reactor at 800 °C in the presence f steam. Pyrolysis of hydrogenated feedstocks leads to an increased conversion into low molecular olefins and alkanes. The presence of 0.05% of elemental sulphur increases the conversion of primary kerosene into gaseous pyrolysis products. The formation of carbon monoxide is inhibited by the passivation of the reactor wall with hydrogen sulphide. The effect of elemental sulphur on the formation of coke was investigated in the pyrolysis of kerosene in a stainless steel tubular reactor at 800 and 810 °C without steam. In comparison with the pyrolysis of primary kerosene, hydrogenated materials are more inclined to form coke. In the presence of 0.05% sulphur coking decreases.


2017 ◽  
Vol 68 (5) ◽  
pp. 1035-1039
Author(s):  
Maria Mitu ◽  
Elisabeth Brandes

The ignition behaviour at ambient pressure (p0 between 98.0 kPa and 101.3 kPa) of different concentrations of homogenous n-heptane/air mixtures on stainless steel hot surface as well as the composition of the reaction products have been investigated. Although all reaction products are present in each burned n-heptane/air mixture, a correlation between the lowest ignition temperature and the quantitve composition of the reaction products is not obvious.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259
Author(s):  
Sandra Pavón ◽  
Doreen Kaiser ◽  
Robert Mende ◽  
Martin Bertau

The global market of lithium-ion batteries (LIB) has been growing in recent years, mainly owed to electromobility. The global LIB market is forecasted to amount to $129.3 billion in 2027. Considering the global reserves needed to produce these batteries and their limited lifetime, efficient recycling processes for secondary sources are mandatory. A selective process for Li recycling from LIB black mass is described. Depending on the process parameters Li was recovered almost quantitatively by the COOL-Process making use of the selective leaching properties of supercritical CO2/water. Optimization of this direct carbonization process was carried out by a design of experiments (DOE) using a 33 Box-Behnken design. Optimal reaction conditions were 230 °C, 4 h, and a water:black mass ratio of 90 mL/g, yielding 98.6 ± 0.19 wt.% Li. Almost quantitative yield (99.05 ± 0.64 wt.%), yet at the expense of higher energy consumption, was obtained with 230 °C, 4 h, and a water:black mass ratio of 120 mL/g. Mainly Li and Al were mobilized, which allows for selectively precipitating Li2CO3 in battery grade-quality (>99.8 wt.%) without the need for further refining. Valuable metals, such as Co, Cu, Fe, Ni, and Mn, remained in the solid residue (97.7 wt.%), from where they are recovered by established processes. Housing materials were separated mechanically, thus recycling LIB without residues. This holistic zero waste-approach allows for recovering the critical raw material Li from both primary and secondary sources.


2020 ◽  
Vol 56 (4) ◽  
pp. 3444-3454
Author(s):  
Felix Weber ◽  
Markus Rettenmayr

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.


2009 ◽  
Vol 23 (11) ◽  
pp. 5663-5676 ◽  
Author(s):  
Julien Gornay ◽  
Lucie Coniglio ◽  
Francis Billaud ◽  
Gabriel Wild

2014 ◽  
Vol 40 (7) ◽  
pp. 9693-9700 ◽  
Author(s):  
Xiang Zhang ◽  
Guojun Ma ◽  
Yibiao Jin ◽  
Puhong Cheng

2013 ◽  
Vol 30 ◽  
pp. 45-51 ◽  
Author(s):  
Arbind Pathak ◽  
Vinay Kumar Jha

Recently, the demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak which in turn generates a huge amount of construction waste. There are two major types of construction wastes which are burden for disposal namely cement-sand-waste (CSW) and the coal fly ash (CFA). These construction wastes are rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from CSW and CFA using NaOH-KOH and Na2SiO3 as activators. Some parameters like alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process has been carried out using 3-8M KOH/NaOH solutions, Na2SiO3 to CFA and CSW mass ratio of 0.25-2.00 and curing time variation from 5-28 days. The curing temperature was fixed at 40ºC in all the cases. 6M NaOH and 7M KOH solutions were found appropriate alkali concentrations while the ratio of sodium silicate to CSW and CFA of 0.5 and 1.75 respectively were found suitable mass ratio for the process of geopolymer synthesis. The maximum compressive strength of only 7.3 MPa after 15 days curing time with CSW raw material was achieved while with CFA, the compressive strength was found to be 41.9 MPa with increasing the curing time up to 28 days.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9334Journal of Nepal Chemical Society Vol. 30, 2012 Page:  45-51 Uploaded date: 12/16/2013    


2017 ◽  
Vol 62 (3) ◽  
pp. 345-350 ◽  
Author(s):  
José Miguel Hidalgo-Herrador ◽  
Zdeněk Tišler

Two VOx/SBA-15 catalysts and three VOx/SiO2-fumed silica, with 5, 10 and 1, 5, 10 %wt. vanadium content respectively, were tested in a stainless steel continuous flow reactor for the partial oxidation of ethanol. The catalysts were tested at 150 – 300 °C. Products were analyzed by GC-FID, GC-OFID and GC-MS. The aim was exploring the problematics which could be found when more industrial close conditions are used. The total conversion of ethanol and selectivity to acetaldehyde were different than the expected ones. For VOx/SiO2-fumed silica, the total conversion was higher with a lower selectivity to acetaldehyde compared to VOx/SBA-15 catalysts.


2013 ◽  
Vol 658 ◽  
pp. 153-157 ◽  
Author(s):  
Yu Yan Liu ◽  
Song Quan Wu ◽  
Li Li ◽  
Yu Ting Liu ◽  
Guo Hua Shan

The degradation behaviour of an anhydride-cured bisphenol A diglycidyl ether (DGEBA) epoxy resin in near-critical water was studied in this paper. The experiments were performed in a stainless steel reactor (100ml) without stirring. Epoxy resin could be decomposed successfully at 270°C for 30 min. The degradation rate of epoxy resin increased with an increase in reaction temperature and reaction pressure. The degradation reaction products were characterized by gas chromatography-mass spectrometry (GC-MS). The degradation reaction was associated with the scission of ester and ether bonds which further destabilizes the epoxy network.


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