{"id":323,"date":"2019-05-10T10:57:35","date_gmt":"2019-05-10T10:57:35","guid":{"rendered":"https:\/\/nicl.it\/new\/?p=323"},"modified":"2020-07-31T15:26:45","modified_gmt":"2020-07-31T13:26:45","slug":"alkoxilation-processes-str-and-vlr-models-1","status":"publish","type":"post","link":"https:\/\/nicl.it\/new\/alkoxilation-processes-str-and-vlr-models-1","title":{"rendered":"ALKOXILATION PROCESSES – STR and VLR Models [1]"},"content":{"rendered":"

STR and VLR Models [1]<\/h3>\n

In the VLR, the pumped liquid passes through a nozzle that provides a high velocity jet of fluid to create suction of the gas. In a mixing tube, the high velocity jet attaches itself to the mixing tube wall, resulting in a rapid dissipation of kinetic energy, which creates an intensive mixing with the production of a fine dispersion of gas bubbles. The two-phase mixture that \u201cjets\u201d into the reaction autoclave here also causes intensive mixing. The ejector of VLR in many cases can be considered as a device for the complete saturation of the liquid with gas. This occurs because of a high kLa value, and the concentration variation for the reactions is insignificant due to a short contact time. The holding vessel can be considered as a well-stirred reactor with a very high kLa value. Taking into account that the Hatta number of ethoxylation reactions is <1, a Venturi loop reactor can be simulated by considering it as a well-stirred isotherm reactor.<\/p>\n

Reactors<\/a><\/b><\/p>\n

Comparison of Reactors<\/a> <\/b><\/p>\n

STLR Model<\/a><\/b><\/p>\n

 <\/p>\n

\"\"<\/p>\n

 <\/p>\n

In the case of dodecanol ethoxylaion, for example, To prevent a significant mass-transfer limitation, values of kLa > 0.1-0.2 s-1 are needed. These values can be reached in a stirred reactor with a high stir speed (>1000 rpm), which is not easy to achieve in industrial reactors. In the case of VLR, the required kLa values can, on the contrary, be achieved with a power input per unit volume 10 times less than that for stirred reactors<\/p>\n

1- Industrial & Engineering Chemistry Research (2005), 44(25), 9482-9489.\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

STR and VLR Models [1] In the VLR, the pumped liquid passes through a nozzle that provides a high velocity jet of fluid to create suction of the gas. In a mixing tube, the high velocity jet attaches itself to the mixing tube wall, resulting in a rapid dissipation of kinetic energy, which creates an […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[14],"tags":[],"class_list":["post-323","post","type-post","status-publish","format-standard","hentry","category-subprocesses"],"acf":[],"_links":{"self":[{"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/posts\/323","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/comments?post=323"}],"version-history":[{"count":2,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/posts\/323\/revisions"}],"predecessor-version":[{"id":332,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/posts\/323\/revisions\/332"}],"wp:attachment":[{"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/media?parent=323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/categories?post=323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nicl.it\/new\/wp-json\/wp\/v2\/tags?post=323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}