Oligomerization of 1-Butene in Sulfuric Acid. Mechanisms and Rates

Abstract

The oligomerizstion of liquid 1 -butene catalyzed by concentrated sulfuric acid was studied in an adiabatic, capillary-flow reactor at 17.5" and 25" C. The reaction products were analyzed by gas-liquid chromatography. The maior products were 5-methyl-2-heptene, 5-methyl-1 -heptene, 2,2-dimethyl-3-hexene, and 5-methyl-3-heptene. Butene cgnsumption rates were calculated from axial temperature profiles measured by thermistors. The reaction rates per unit area of the butene drops were 0.98 X lod3 g. mole/ (min.)(sq. cm.) at 17.5" C. and 1.07 X

The Kinetics of Isobutane Alkylation in Sulfuric Acid

“…In a simplified view of alkylation, the reaction of isobutane with butene to form isooctane is the main reaction, and the oligomerization of butenes is the by-product reaction, or at least the first step in the formation of less desirable products. Kinetic studies of 1-butene oligomerization in sulfuric acid in a capillary-flow reactor gave a first-order rate constant of about 3.4 X 104 s_1 at 25 °C based on an estimated solubility and diffusivity (Naworski and Harriott, 1969). However, there was some evidence for a higher reaction order, and the second-order rate constant for oligomerization would be 8.7 X 108 cm3/mol s. Since the main reaction accounts for only about half of the alkylate product when the isobutane-olefin ratio is large (5-20) the effective rate constant for the main reaction is expected to be less than that for oligomerization, say of the order 108 cm3/mol s.…”

“…In this work, the mass transfer resistances for isobutane and butene in the acid phase were allowed for in determining reaction rate constants. The mass transfer area was controlled by generating hydrocarbon drops of uniform size in a reactor similar to that of Naworski and Harriott (1969). The drops did not coalesce and the contact time was kept to a few seconds so that only part of the butene was consumed.…”

Alkylation of Isobutane and 2-Butene by Concentrated Sulfuric Acid in a Rotating Packed Bed Reactor

“…Some side reactions like oligomerization, cracking, and disproportionation could simultaneously occur. Both rate constants of 1-butene oligomerization and alkylation increased, due to the increasing temperature, and oligomerization would generate more components of lower alkylate RON, such as C9+.…”

Über die Trägheitsmessfehler der thermometrischen Methode von reaktionskinetischen Untersuchungen

“…1 dargestellte angewandte Apparatur 2Y = 0.55 betriigt, der Tdigheitsfehler dagegen mit der Funktion aT(t ) = 0.77 e -0"67t --1.77 e -st (37) angegeben werden kann. 19 Sek. 5 dargestellten Verlaufes dieser Funktion folgt, dag der Tr~igheitsmegfehler schon nach Ablauf yon 0.…”

“…Die thermometrische Methode, erstmals von Tschelinzew zur Untersuchung der Bildungskinetik yon Etheroxoniumdibromiden angewandt [1][2][3][4][5], wurde in den letzten Jahren zur Verfolgung der Hydrolyse-und Neutralisationsreaktionen [6][7][8][9][10][11][12] einiger biochemischer Prozesse [13,14], der Oligomerisation und Polymerisation von ungesfittigten Verbindungen [15][16][17][18][19][20][21][22][23][24][25] und anderer chemischer Reaktionen [26,27] Dieser Tatsache verdanken die thermometrischen Methoden ihre zahlreichen Vorteile, wie insbesondere die Einfachheit und Schnelligkeit der Experimente, die M6glichkeit der automatischen Registrierung der Mel3resultate und schliel31ich ihren ausgedehnten Anwendungsbereich hinsichtlich der Reaktionsgeschwindigkeitskonstante.…”