U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Icon_funbox Bizarre Patents

Patent No. 6205950

Pet Toilet-Like Water Disk and Food Storage

One pet-friendly inventor patented "a device for watering pets, e.g., a dog or cat." The device, he helpfully noted, "has the general shape of a toilet."

Newsletter  PatentStorm News

Make the Most of Our Site

See this month's Top Inventors and Most Cited Patents.

Stay on top of the latest innovations by subscribing to an RSS feed.

Registered users: Manage your profile.

 

Class 203/78 - And returning distillation product to a previous distillation zone


Subclass of Class 203 - Distillation: processes, separatory
Definition: Processes in which a product from a later distillation operation
No. of patents: 219
Last issue date: 08/26/2008


1            
NumberTitleIssue Date
7416645Continuous process for recovering acetone from a waste stream resulting from acetone purification
The present invention provides a continuous process for recovering acetone from a waste stream from an acetone purification stage. The waste stream contains mesityl oxide and optionally acetone. The process for recovering acetone includes separating the waste stream...
08/26/2008
7410556Purification of aqueous solutions of organic acids
The invention relates to a method and a device for the purification of an aqueous solution of an organic acid having a boiling point at atmospheric pressure of less than 450° C., which further has approximately 275 g carboxylate ions/1 or less, preferably 250 g car...
08/12/2008
7384518Method for purifying lactams
A method and a plant are disclosed for purifying lactams, particularly lactams obtained by cyclizing hydrolysis of aminonitrile. The purification of ε-caprolactam obtained by cyclizing hydrolysis of aminocapronitrile is described which includes eliminating the ammo...
06/10/2008
7351311Method for purifying tetrahydrofuran by distillation
Crude water-containing tetrahydrofuran is purified by passing the crude tetrahydrofuran through three distillation columns, withdrawing water from the bottom of the first column, recycling water-containing tetrahydrofuran from the top of the second column into the f...
04/01/2008
7339088Alkylbenzene refining process and apparatus
Improved processes and apparatus use a finishing column with a mid-cut that provides alkylbenzene products of high purity containing less than about 1 ppmw benzene and less than about 50 ppmw heavies while accommodating enhancements in the efficiencies and the capac...
03/04/2008
7329330Method and device for the distillative processing of 1,6-hexanediol, 1,5-pentanediol and caprolactone
A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by di...
02/12/2008
7309403Method for avoiding corrosion
The invention relates to a method of avoiding corrosion in the separation of methylamine from a product stream (10) which is obtained in the preparation of methylamines by gas-phase reaction of methanol and ammonia and includes monomethylamine, dimethylamine,...
12/18/2007
7169268Color stabilization of amines
The present invention concerns a process for providing tertiary amine products which are color-stable, and have a greatly reduced tendency to take on color during their storage. According to the invention, an ethyleneamine derivative is added to the distillation pot...
01/30/2007
7169267Method and device for carrying out the distillative separation of C cuts
A process is proposed for the separation of C5+ cuts by distillation into a low-boiler (A), a medium-boiler (B) and a high-boiler fraction (C) in one or more dividing-wall columns (TK), in which a dividing wall (T) is arranged in the longitudinal directio...
01/30/2007
7157610Process for recovering methanol
A process for recovering methanol from mixtures containing methanol and water, comprising multistage evaporation with heat integration, wherein the pressure is reduced from each stage to the next, and a downstream series of distillation stages with heat integration,...
01/02/2007
7147757Method for separating an azepine derivative out of a mixture containing an amine an azepine derivative
The invention relates to a method for separating by distillation a portion or the entirety of an azeptine derivative (III), which is selected from the group consisting of aminohexylidene imine, tetrahydroazepine, hexylhexahydroazepine and of aminohexylhexahydroazepi...
12/12/2006
7128813Process for manufacturing high purity methacrylic acid
A process for the high yield production of high purity glacial methacrylic acid (“HPMAA”) with minimization of decomposition of hydroxy isobutyric acid (HIBA). The HPMAA is substantially pure, specifically 99% pure or greater with a water content of 0.05% or les...
10/31/2006
7105078Method for producing an aqueous hydroxylamine solution devoid of salt
A process for preparing a salt-free aqueous hydroxylamine solution by reacting an aqueous solution of a hydroxylammonium salt with a base to give a mixture and separating from said mixture by distillation a salt-free aqueous hydroxylamine solution, involving using a...
09/12/2006
7029557Method for producing an aqueous hydroxylamine solution devoid of salt
The invention relates to a method for producing a highly pure, aqueous hydroxylamine solution by distilling an aqueous solution, devoid of salt, of a hydroxyl ammonium salt in a plate column comprising at least two mechanical plates. Said method is characterised in ...
04/18/2006
6998026Method for producing tertiary C-C-alkyl esters of (meth)acrylic acid
A tert-C4–C8-alkyl (meth)acrylate is prepared by reacting (meth)acrylic acid with an olefin of the formula where R1 and R2, which may be i...
02/14/2006
6986833Process for fractionating water-containing crude amine mixtures from amine synthesis
An amine-containing mixture containing one or more amines, water, low-boilers and optionally high-boilers is fractionated by a process having the steps (iii) and (iv) and optionally the steps (i), (ii) and (v): (i) a (first) low-boiler fraction is separ...
01/17/2006
6982026Azeotropic distillation process for producing organic acids or organic acid amides
Disclosed herein are methods for the recovery of at least one of an organic acid or an organic acid amide, such as a heat stable lactic acid or lactamide, from a feed stream which contains the organic acid and/or organic acid amide. The feed stream is mixed with at ...
01/03/2006
6972075Method for removing 6-aminocapronitrile from mixtures that contain 6-aminocapronitrile, adipodinitrile and hexamethylenediamine
The invention relates to a method for removing, by distillation, 6-aminocapronitrile from mixtures that contain 6-aminocapronitrile, adipodinitrile and hexamethylenediamine, by a) removing the hexamethylenediamine from the mixture while obtaining a mixture (I) that ...
12/06/2005
6969446Method for producing concentrated nitric acid and installation for carrying out a method of this type
Process for producing a nitric acid of a concentration from 75 to 99.9% from a more diluted nitric acid, wherein a nitric acid of a concentration of about 45 to 70% is rectified in contact with a liquid extraction medium to prevent the formation of a nitric acid-wat...
11/29/2005
6955743Method for producing furfural, acetic acid and formic acid from spent pulp-cooking liquor
The invention relates to a process for recovering and producing chemicals in a pulp production process where organic chemicals, such as formic acid and acetic acid, are used as cooking chemicals. The process of the invention is based on regeneration of cooking acids...
10/18/2005
6953499Equipment for physical refining and deodorization of edible oils and fats
Equipment for use in the physical refining and deodorization of edible oils and fats, including a shell containing a number of superimposed trays for degassing, heating, cooling and deodorization purposes. The equipment also includes a scrubber that is located at th...
10/11/2005
6946060Purification of N,N-dimethylacetamide
A method to purify N,N-dimethylacetamide (DMAc) from an aqueous solution containing acetic acid as a contaminant. Two fractional distillation columns are arranged in a series. The solution containing the contaminant is provided to the first column with a temperature...
09/20/2005
6942762Method for the production of a salt-free aqueous hydroxylamine solution
A process for preparing a salt-free aqueous hydroxylamine solution by distilling an aqueous solution of a hydroxylammonium salt and a base in a tray column having at least two mechanical trays, wherein random or structured packings are located above at least one tra...
09/13/2005
6913674Process for fractionating water-containing crude amine mixtures from amine synthesis
A mixture containing one or more amines, water, low-boilers and high-boilers, is fractioned in a process wherein (i) low-boilers are separated from the mixture by distillation, (ii) high-boilers are separated from the mixture by distillatio...
07/05/2005
6896772Method for separating ammonia from solutions containing caprolactam and ammonia
A process for distillative removal of ammonia from solutions (I) which include a lactam and ammonia comprises effecting said removal in a distillation apparatus (a) at an absolute pressure of less than 10 bar. ...
05/24/2005
6863778Separation of tertiary butyl alcohol from diisobutylene
A process for the separation of diisobutylene from tertiary butyl alcohol utilizing pressure swing azeotropic distillation to achieve the desired separation. The pressure swing azeotropic distillation takes advantage of the fact that different azeotropes are formed ...
03/08/2005
6849162Method for the production of propylene oxide
A process for the preparation of propylene oxide in the presence of methanol, in which propylene oxide is separated from a mixture propylene oxide and methanol, and the resultant methanol containing mixture is worked up, including seperating methanol from a mixture ...
02/01/2005
6849161Process for the production of anhydrous hydrazine and device for its implementation
The present invention relates to a process for preparing anhydrous hydrazine. The process can include distilling an unconcentrated aqueous hydrazine solution into a starting binary solution, distilling the starting binary solution at a pressure where a concentration...
02/01/2005
6846389Method for distillative separation of mixtures containing tetrahydrofuran, γ-butyrolactone and/or 1,4-butanediol
In a process for the continuous fractional distillation of mixtures comprising tetrahydrofuran, γ-butyrolactone and/or 1,4-butanediol to give at least three fractions, the fractionation is carried out in an assembly of distillation columns comprising at least one d...
01/25/2005
6843890Purification and recovery of acetonitrile from waste solvent acetonitrile
A process of treating waste solvent acetonitrile streams which contain at least one water extractable impurity such as isopropyl acetate to remove substantially all of the impurity by distilling the waste solvent acetonitrile in the presence of water for a time suff...
01/18/2005
6835287Apparatus, method for enrichment of the heavy isotope oxygen and production method for heavy oxygen water
An apparatus comprising first to third columns, wherein the outlet of a first column reboiler and the inlet of a second column condenser are connected by a first introduction conduit, and the outlet of a second distillation column reboiler and the inlet of a third c...
12/28/2004
6821382Method and arrangement for cleaning contaminated condensate including a combined stripper/condenser
A method and apparatus for cleaning condensate, produced during the production of cellulose pulp, including evaporation of spent liquor, utilizing a cleaning plant having several condensers, coupled in series. Process steam from the last evaporation stage and unclea...
11/23/2004
6821396Process for fractionating water-containing crude amine mixtures from amine synthesis
A mixture containing mixture one or more amines, water, low-boilers and high-boilers, is fractioned in a process wherein (i) low-boilers are separated from the mixture by distillation, (ii) high-boilers are separat...
11/23/2004
6793777Method for separating and purifying an aqueous mixture that mainly consists of acetic acid and formic acid
The invention relates to a method for separating and purifying an aqueous mixture that mainly consists of acetic acid, formic acid and high-boiling substances by extraction with a solvent in a cyclic process. The inventive method is characterized in that the flow of...
09/21/2004
6758946Recycling hydroxylamine-containing stripper solutions
A process for working up hydroxylamine-containing solutions as obtained in particular in the electronics industry during the cleaning of electronic components is described. According to the invention, the hydroxylamine is stripped from the wastewater with steam. The...
07/06/2004
6695952Method for the separation of and purification of an aqueous mixture consisting of the main components acetic acid and formic acid
A method for the separation and purification of an aqueous mixture of main components, namely acetic acid and formic acid and non-volatiles by extraction, uses a solvent in a circulatory system. A raffinate stream is mixed with the larger proportion of wa...
02/24/2004
6692616Method for purifying trimethylolpropane, which is produced by hydrogenation, by means of continuous distillation
A process is disclosed for the purification, by distillation, of trimethylolpropane originating from the hydrogenation of 2,2-dimethylolbutanal, said process including the following steps: (a) reaction of n-butyraldehyde with formaldehyde in the presence o...
02/17/2004
6689251Cycled-concentration distiller
A distiller (10) that employs a rotary heat exchanger (32) introduces water to be evaporated into evaporation chambers (56). During most of its operation, it collects the water that has passed through the evaporation chamber (56) without evaporating, and ...
02/10/2004
6685802Process and apparatus for removing dissolved and undissolved solids from liquids
This invention relates to a continuous process and an apparatus (1) for removing dissolved and undissolved solids and/or high boiling point liquid contaminants from a mixture of miscible liquids (9). A recycle liquor stream (6) is fed at high velocity thr...
02/03/2004
6679975Process for recovering the methanol contained in a liquid hydrocarbon feed
The present invention aims to isolate the azeotropes formed in a distillation column (B1) by methanol, propane and butane. The azeotropes are then liquefied in heat exchanger (E2) and mixed in contactor (M1) with water in order to dissolve the methanol in...
01/20/2004
1            
 
Sign InRegister
Username  
Password   
forgot password?