ACRYLIC ACID, WATER-ABSORBENT POLYMER STRUCTURES BASED ON RENEWABLE RESOURCES AND METHOD FOR PRODUCING SAID STRUCTURES

1 . A process for production of acrylic acid, comprising at least the following steps:

a. dehydrating glycerine to a dehydration product comprising acrolein;

b. gas phase oxidation of the dehydration product comprising acrolein to obtain a monomer gas comprising an acrylic acid;

c. bringing into contact the monomer gas with a quench means to obtain a quench phase comprising acrylic acid; and

d. processing of the quench phase comprising acrylic acid to obtain a monomer phase comprising acrylic acid.

2 . The process according to claim 1 further including the step of:

E. radical polymerization of the monomer phase.

3 . The process according to claim 2 , wherein the polymer is a water-absorbing polymer structure.

4 . The process according to claim 3 , wherein the water-absorbing polymer structure is obtainable by a process comprising the following process steps:

i) polymerizing the acrylic acid in the presence of a crosslinker to form a polymer gel;

ii) optionally comminuting the polymer gel;

iii) drying of the comminuted polymer gel to obtain a water-absorbing polymer structure; and

iv) optionally surface post-crosslinking of the water-absorbing polymer structure.

5 . The process according to claim 2 , wherein the acrylic acid is present to at least about 20 mol %, based on the monomer, as a salt.

6 . The process according to claim 1 , wherein the glycerine is obtained from the saponification of fats.

7 . The process according to claim 1 , wherein glycerine is generated in the generation of liquid fuels from natural raw materials.

8 . The process according to claim 1 , wherein the dehydration occurs at least partially in a liquid phase.

9 . The process according to claim 1 , wherein the dehydration occurs at least partially in a gas phase.

10 . The process according to claim 1 , wherein the glycerine is used in aqueous phase.

11 . The process according to claim 1 , wherein a dehydration catalyst is used.

12 . The process according to claim 11 , wherein the dehydration catalyst is in contact with a carrier x.

13 . The process according to claim 12 , wherein the carrier x is a solid with a total pore volume according to DIN 66133 within a range from about 0.1 to about 1.5 ml/g.

14 . The process according to claim 11 wherein the dehydration catalyst is an inorganic acid.

15 - 23 . (canceled)

24 . A device for production of acrylic acid comprising being connected with each other in fluid-conveying fashion:

1a. a dehydration reactor,

2a. a gas phase oxidation reactor,

3a. a quench unit, and

4a. a processing unit.

25 . The device of claim 24 further comprising

5a. a polymerization unit.

26 . The device according to claim 24 , wherein the dehydration reactor comprises

a compound reservoir, followed by

a reaction area accepting a catalyst, followed by

a quencher with a line to the gas phase oxidation reactor.

27 . The device according to claim 26 , wherein an evaporator is provided after the compound reservoir and before the reaction area.

28 . (canceled)

29 . The device according to claim 27 , wherein the reaction area comprises an upper product outlet which leads into the quencher.

30 - 32 . (canceled)

33 . A water-absorbing polymer structure based to at least about 25 wt. % upon optionally partially neutralized acrylic acid, wherein the water-absorbing polymer structures are characterized by a sustainability factor of at least about 80%.

34 . The water-absorbing polymer structure according to claim 33 , wherein the polymer structures are based to at least about 25 wt. %, based upon the total weight of the water-absorbing polymer structure, upon natural, biodegradable polymers.

35 . A water-absorbing polymer structure according to claim 33 characterized by the following properties:

(β1) the polymer structure is based to at least about 25 wt. % on acrylic acid, whereby at least about 80 wt. % of the acrylic acid monomers used in the preparation of the water-absorbing polymer structures has been obtained by a synthesis process which starts from non-fossil, renewable organic material,

(β2) the polymer structure has a biodegradability determined according to the modified Sturm Test according to Appendix V of Guideline 67/548/EWG after 28 days of at least about 25%; and

(β3) the polymer structure has a CRC value determined according to ERT 441.2-02 of at least about 20 g/g.

36 . A water-absorbing polymer structure according to claim 33 based to at least about 10 wt. %, based upon the polymer structure, upon acrylic acid and which is characterized by the following properties:

(ε1) the polymer structure has a sustainability factor of at least about 10;

(ε2) the polymer structure has a biodegradability determined according to the modified Sturm Test according to Appendix V of Guideline 67/548/EWG after 28 days of at least about 25%; and

(ε3) the polymer structure has a CRC value determined according to ERT 441.2-02 of at least about 20 g/g.

37 . A composite comprising a water-absorbing polymer structure according to claim 33 and a substrate.

38 - 39 . (canceled)

40 . A hygiene article comprising an upper sheet, a lower sheet and an intermediate sheet arranged between the upper sheet and the lower sheet, which comprises water-absorbing polymer structures according to claim 33 .

41 - 42 . (canceled)