Steam cracking of hydrocarbons 6. Effect of dibenzyl sulfide and dibenzyl disulfide on reaction kinetics and coking

The influence of aromatic sulfides on the kinetics and selectivity of hydrocarbon conversion by steam cracking and on pyrolytic coke formation was investigated in stainless steel tubular reactors with relatively large inner surface.The rate of decomposition of heptane (at 700 ‘C, 100 kPa, and a mass ratio of steam to feed 3:l) increased by 16 to 26 % , and the selectivity toward ethene decreased, if 0.1 to 1 .O % mass of dibenzyl sulfide, relative to heptane, was added. Addiiion of 1 % mass dibenzyl disulfide increased the decomposition rate of heptane by 8 % . Increasing amounts of the title compounds (0.1, 0.5% mass) in the feed decreased coking up to 70% in the pyrolysis of reformer raffinate at 820 OC, without steam. The decreased coking in turn caused an increased aromatic content in the liquid pyrolysis product mixtures. Based on the analytical results, obtained by capillary gas chromatography- mass spectrometry, reaction mechanisms are suggested

Steam cracking of hydrocarbons: 5. effect of thiophene on reaction kinetics and coking

The effect of thiophene on the kinetics and selectivity of the conversion of hydrocarbons by steam cracking was studied in a stainless steel tubular reactor with relatively large inner surface. Heptane was selected as a model and decomposed at 700 OC and 100 kPa with a mass ratio of steam to feed of 3:l. The rate of decomposition increased about 14% if 0.1 and 0.5% mass of thiophene was added, but was unchanged if 1 % was present. The influence of thiophene on the selectivity of the conversion of heptane to ethene appeared to depend on the residence time. The effect of thiophene on the formation of coke was investigated in the pyrolysis of a reformer raffinate in a stainless steel flow reactor at 820 OC, without steam. Coking is lessened with increasing amounts of thiophene in the feed (0.05-0.5 % mass). Reaction mechanisms are suggested

Steam cracking of hydrocarbons: 5. effect of thiophene on reaction kinetics and coking

The effect of thiophene on the kinetics and selectivity of the conversion of hydrocarbons by steam cracking was studied in a stainless steel tubular reactor with relatively large inner surface. Heptane was selected as a model and decomposed at 700 OC and 100 kPa with a mass ratio of steam to feed of 3:l. The rate of decomposition increased about 14% if 0.1 and 0.5% mass of thiophene was added, but was unchanged if 1 % was present. The influence of thiophene on the selectivity of the conversion of heptane to ethene appeared to depend on the residence time. The effect of thiophene on the formation of coke was investigated in the pyrolysis of a reformer raffinate in a stainless steel flow reactor at 820 OC, without steam. Coking is lessened with increasing amounts of thiophene in the feed (0.05-0.5 % mass). Reaction mechanisms are suggested

Zautomatyzowany punkt przesypowy URB/ZS-3

In the KGHM Polska Miedź S.A. mines, excavated material is transported by transport trucks to transfer points and then by belt conveyors to near-shaft storage reservoirs, from where the excavated material is transported to the surface by means of a shaft transport system. Transfer from the means of non-continuous haulage to the continuous transport systems takes place at transfer points, where the excavated material is divided into two fractions: oversized grain and undersized grain. The oversized excavated material (which stays on the grating) is subjected to a process of crushing with the use of jack hammers. The article describes the URB/ZS-3 device for the automatic cleaning of the grating at transfer points, and briefly describes the design and principle of operation of the device. It also presents the purpose of constructing a block-crushing device and the method of its automation.W kopalniach KGHM Polska Miedź S.A. urobek transportowany jest za pomocą wozów transportowych do punktów przesypowych, a następnie przenośnikami taśmowymi do przyszybowych zbiorników retencyjnych, skąd jest wydobywany na powierzchnię transportem szybowym. Przeładunek ze środków odstawy nieciągłej na ciągłe systemy transportowe odbywa się w punktach przesypowych, gdzie urobek dzielony jest na dwie frakcje, nadziarno i podziarno. Nadgabarytowy, pozostający na kracie, urobek poddawany jest procesowi kruszenia z użyciem młotów udarowych. W artykule opisano urządzenie URB/ZS-3 do automatycznego oczyszczania kraty na punkcie przesypowym, skrótowo opisano konstrukcję i zasadę działania. Przedstawiono cel budowy i sposób automatyzacji urządzenia do rozbijania brył