Catalyst for single step conversion of glycerol to acrylic acid and process for the preparation thereof

Patent metadata

Field	Value
Publication number	US-9409847-B2
Application number	US-201314072916-A
Country	US
Kind code	B2
Filing date	Nov 6, 2013
Priority date	Nov 7, 2012
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

The present invention provides a process and a solid catalyst for oxydehydration of glycerol to acrylic acid with H 2 O 2 under mild experimental condition at atmospheric pressure. The process provides a single step liquid phase selective oxidation glycerol to acrylic acid over nanocrystalline Cu supported α-MnO 2 catalyst. The process provides glycerol conversion of 20-78% and selectivity of acrylic acid up to 86%.

First claim

We claim:

1. Nanocrystalline Cu supported α-MnO 2 catalyst comprising Cu in the range of 1 to 5 (wt %) MnO 2 in the range of 99 to 95 (wt %) having a particle size in the range of 25 to 50 nm.

2. A process for the preparation of a nanocrystalline Cu supported α-MnO 2 catalyst as claimed in claim 1 , said process comprising the steps of:
a. mixing Cu(NO 3 ) 2 .3H 2 O and Mn(NO 3 ) 2 .3H 2 O solutions at temperature ranging between 35 to 80° C.;
b. adding a surfactant solution into the solution as obtained in step (a) with stirring, where the molar ratio of elemental Cu to surfactant ranges between 0.005 to 0.1;
c. adding a reducing agent into the solution as obtained in step (b) with stirring to form a gel, where the molar ratio of Cu to reducing agent ranges between 0.5 to 1.5;
d. heating the gel as obtained in step (c) at a temperature in the range of 100 to 200° C. for a period ranging between 12 to 30 hours to obtain a solid followed by washing the solid with water;
e. drying the solid as obtained in step (d) at a temperature in the range of 80 to 110° C. for a period ranging between 6-12 hr; and
f. calcining the solid as obtained in step (e) at a temperature ranging between 300 to 800° C. for a period of 6 to 12 hr to obtain the nanocrystalline Cu supported α-MnO 2 catalyst.

3. The process as claimed in claim 2 , wherein the surfactant used in step (b) is cetyltrimethyl ammonium bromide (CTAB).

4. The process as claimed in claim 2 , wherein the reducing agent used in step (c) is hydrazine.

5. A process for a single step conversion of glycerol to acrylic acid using a nanocrystalline Cu supported α-MnO 2 catalyst having a particle size of from 25 to 50 nm; wherein said process comprising the steps of:
mixing said nanocrystalline Cu supported α-MnO 2 catalyst with an elemental Cu to α-MnO 2 weight ratio in the range of 0.5 to 5%, solvent and glycerol followed by adding H 2 O 2 with a weight ratio of glycerol to catalyst being in the range of 20 to 200, with a molar ratio of glycerol to H 2 O 2 being the range of 1:2 to 1:15, at a temperature in the range of 60 to 120° C., while agitating the reaction mixture for 1 to 30 hr, followed by cooling to a temperature in the range of 25 to 30° C. to obtain acrylic acid.

6. The process as claimed in claim 5 , wherein the molar ratio of elemental Cu to H 2 O 2 is in the range of 1:2.5 to 1:10.

7. The process as claimed in claim 5 , wherein the conversion of glycerol to acrylic acid in the range of 20 to 78 mole %.

8. The process as claimed in claim 5 , wherein the selectivity of the acrylic acid is in the range of 20 to 84 mole %.

Assignees

• Council Scient Ind Res

Inventors

• Bal Rajaram
• Sarkar Bipul
• Singha Rajib Kumar
• Pendem Chandrashekar
• Shankha Shubhra Acharyya
• Ghosh Shilpi

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J37/0018

  Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat) · CPC title