公开(公告)号：EP1606240B1

公开(公告)日：2010-10-06

申请号：EP04716587.3

申请日：2004-03-03

Applicant: BASF SE

Inventor： STROEFER, Eckhard ,  LANG, Neven ,  STEINBRENNER, Ulrich ,  HASSE, Hans ,  OTT, Michael ,  GRÜTZNER, Thomas

IPC: C07C45/83 ,  C07C47/04 ,  C07C47/058

CPC classification number: C07C45/002 ,  C07C45/82 ,  C07C47/04

Abstract: The invention relates to a method for producing a highly concentrated, gaseous formaldehyde with a molar ratio CH2O: H2O of = 0.6, from an aqueous formaldehyde solution, by evaporating at least part of said solution, the aqueous formaldehyde solution being heated to an evaporation temperature T and the gas phase formed being drawn off. According to the invention, the following formula holds good for the evaporation temperature T: T [ °C] = T'min [ °C] wherein T'min(c) = A + B x (c/100) + C x (c/100)2 + D x (c/100)3 and A = + 68.759, B = + 124.77, C = - 12.851, and D = - 10.095, c being the actual CH2O content of the aqueous formaldehyde solution during the evaporation in wt. %, amounting to between 20 and 99 wt. %.

公开(公告)号：EP1699537B1

公开(公告)日：2010-09-22

申请号：EP04804129.7

申请日：2004-12-21

Applicant: BASF SE

Inventor： LANG, Neven ,  STROEFER, Eckhard ,  STAMMER, Achim ,  FRIESE, Thorsten ,  SIEGERT, Markus ,  OTT, Michael ,  HASSE, Hans ,  GRÜTZNER, Thomas ,  BLAGOV, Sergej

IPC: B01D3/36 ,  C07D323/06 ,  B01D3/14

CPC classification number: C07D323/06 ,  B01D3/146 ,  B01D3/36 ,  Y02P20/127

Abstract: The invention relates to a method for separating trioxane from a mixture containing formaldehyde, trioxane and water. According to said method: the mixture (1) is distilled in a first distillation stage (7) at a pressure of between 0.1 and 2 bar to obtain a stream (8) containing formaldehyde and a stream (9) containing predominantly trioxane, in addition to water and formaldehyde; the stream (9) is mixed with a recycling stream (19) containing predominantly trioxane, in addition to water and formaldehyde to form a stream (10) containing predominantly trioxane, in addition to water and formaldehyde; the stream (10) is then distilled in a second distillation stage (14) at a pressure of between 0.2 and 10 bar, optionally after the separation of low-boilers from the stream (9) or (10) in an additional distillation stage (11). The pressure in the second distillation stage (14) is at least 0.1 bar higher than the pressure in the first distillation stage (7). Said distillation produces a stream (15) consisting of trioxane and a stream (16) containing predominantly trioxane, in addition to water and formaldehyde. The stream (16) is then distilled in a third distillation stage (17) at a pressure of between 0.1 and 4 bar, to obtain a stream (18) containing predominantly water, in addition to formaldehyde and the recycling stream (19) containing predominantly trioxane, in addition to water and formaldehyde. The resultant stream (18) is optionally distilled in a fourth distillation stage (20), to obtain a stream (21) containing predominantly water and a stream (22) containing predominantly formaldehyde.

公开(公告)号：EP1606241B1

公开(公告)日：2008-03-19

申请号：EP04717071.7

申请日：2004-03-04

Applicant: BASF SE

Inventor： STROEFER, Eckhard ,  LANG, Neven ,  HASSE, Hans ,  GRUETZNER, Thomas ,  OTT, Michael

IPC: C07C47/058

CPC classification number: C07C45/002 ,  C07C45/82 ,  C07C47/04

Abstract: A method for the production of highly concentrated formaldehyde solutions containing ≥ 50 wt. % CH2O from an aqueous formaldehyde solution having a lower CH2O content by evaporating part of said solution (partial evaporation), wherein the aqueous formaldehyde solution is heated to an evaporation temperature T wherein water becomes enriched in a gaseous phase in relation to the liquid phase and the formed gas phase is continuously or discontinuously removed. For the evaporation temperature T: T [ °C]