GB731815A - Improvements in or relating to methods of and apparatus for mixing and contacting liquids - Google Patents

Abstract

<PICT:0731815/IV (b)/1> <PICT:0731815/IV (b)/2> Systems for the alkylation of isoparaffins with an olefin in the presence of a liquid catalyst such as concentrated sulphuric acid, and for isopropanol extraction, employ a method of contacting the materials by injecting opposed streams of the materials into a confined liquid pool through terminally restricted jets (see Group II). Alkylation of isobutane and butylenes in the presence of sulphuric acid having a strength of from 90 to 95 per cent, is carried out at a temperature of from about 30 DEG to 60 DEG F. in a system wherein an emulsion of the reaction materials passes upwardly through each of a series of vessels such as the vessel 1, Fig. 4. Within the vessels 1 are arranged partitions 25 having perforations which receive pairs of conduits 28, 29 terminating in opposed jets 30. Upstream of each partition 25 is a manifold 31 for the supply of fresh olefin feed material. The emulsion, and the fresh feed materials entering through the manifolds 31, pass upwardly through the perforated plates 25 into the conduits 28, 29 and pass out of the jets 30 as opposed streams into the liquid pool constituted by the emulsion in the zones above the partitions 25 whereby the reaction materials are contacted. The system includes means for recycling some of the emulsion discharged from the last vessel 1 of the series and for recycling some of the acid obtained from a separator at the end of the series of vessels 1, from which separator hydrocarbon materials containing the desired alkylation products are passed on to fractionation means, not described. Excess isobutane derived from the fractionation step is recycled to the alkylation system. The Specification describes another example of a typical alkylation operation carried out in an apparatus in accordance with Fig. 4, and steam stripping means are referred to for the recovery of absorbed isobutylene from the acid from the separator, and for recovery of condensed butyl alcohol from the overhead from such regenerator operation. A gas is also recovered which may give a product containing isobutylene. The proportions of the constituents of the feed stock used in the two examples are specified. Several alternative arrangements of the jets are described (see Group II). A process of isopropanol extraction is carried out in a vessel 101, Fig. 2, which is initially filled with water into which kerosene-isopropyl alcohol mixture and water are injected through jets 103a, 104a respectively. Isopropanol extraction is also carried out in the apparatus of Fig. 10 (see Group II).ALSO:<PICT:0731815/III/1> A method of contacting liquid materials consists in injecting opposed streams of the materials into a confined liquid pool through jets consisting of terminally restricted orifices of substantially equal diameter spaced apart by a distance not less than 0.3 and not more than 5 times the diameter of the jets, the injection being carried out so that there is a pressure drop across the jets of from 2 to 20, preferably 6 to 8, pounds per square inch. The method may be used for purposes such as to bring about absorption of one material in another, to bring about chemical reactions between two or more materials alone or in the presence of catalyst materials, or to form emulsions. In an apparatus for the treatment of gas oil for the removal of aromatic mercaptans, a confined liquid pool of oil and caustic soda solution is formed within a vessel 101 and opposed jets 103a, 104a are formed at the termination of inlets 103, 104 for oil and caustic soda solution respectively. The caustic soda solution flowing into the inlet 104 is a mixture of caustic soda solution circulated from the bottom of the vessel 101 by way of a line 106 and fresh caustic soda solution supplied by way of a line 107. Spent caustic soda solution is removed from the vessel 101 by way of a line 108. Treated gas oil from the vessel 101 passes along a line 109 into a line 110 in which it mixes with water supplied by a line 111, which is a mixture of water circulated from the bottom of a vessel 102 and fresh water supplied through a line 114. The line 110 terminates in a pair of opposed jets 110c in the vessel 102 and the water-oil mixture in the line 110 is divided into two separate opposed streams passing through the jets 110c into a confined liquid pool defined by the vessel 102. Water containing extracted residual caustic soda solution is continuously removed from the vessel 102 by way of a line 115. Treated washed gas oil is removed from the vessel 102 by way of a line 116. Several constructions and arrangements of opposed jets are described (see Group II), more particularly for use in apparatus for the alkylation of isoparaffins with an olefin in the presence of sulphuric acid, in which the confined liquid pool contains an emulsion of these materials, and for isopropanol extraction (see Group IV (b)).