Method for breakdown of formates

Abstract

A process for decomposing formates in formate-containing compositions of matter comprises reacting formate-containing compositions of matter in the presence of at least one heterogeneous catalyst comprising lanthanum and at a temperature of from 80 to 180 C. and a pressure of from 0.1 to 60 bar, the formate-containing compositions of matter having a pH of from 6.5 to 10.

Claims

1. A process for decomposing formates in formate-containing compositions of matter, which comprises reacting formate-containing compositions of matter in the presence of at least one heterogeneous catalyst comprising lanthanum and at a temperature of from 80 to 180 C. and a pressure of from 0.1 to 60 bar, wherein the formate-containing compositions of matter have a pH of from 6.5 to 10, the catalyst is a lanthanum oxide/copper/copper oxide/aluminum oxide catalyst, comprising 4 to 15 wt % of lanthanum reckoned as La.sub.2O.sub.3 and based on the total weight of the catalyst, the formate-containing composition of matter comprises carbonyl compounds formed by an aldol reaction of alkanals with formaldehyde and/or their corresponding hydrogenation products, and at least 50 wt % of formate is decomposed.

2. The process as claimed in claim 1, wherein the decomposition of the formates is effected in the presence of hydrogen.

3. The process as claimed claim 1, wherein the decomposition of the formates is effected in the presence of a tertiary amine.

4. The process as claimed claim 1, wherein the formate-containing composition of matter comprises compounds comprising at least two methylol groups.

5. The process as claimed in claim 1, wherein the formate-containing composition of matter comprises hydroxypivalaldehyde and neopentyl glycol.

6. The process as claimed in claim 2, wherein the formate-containing composition of matter comprises hydroxypivalaldehyde and neopentyl glycol.

7. The process as claimed in claim 3, wherein the formate-containing composition of matter comprises hydroxypivalaldehyde and neopentyl glycol.

8. The process as claimed in claim 1, wherein the catalyst consists of: 4 to 15 wt % of lanthanum oxide, 40 to 65 wt % of copper oxide, 15 to 30 wt % of aluminum oxide and 5 to 20 wt % of copper.

9. The process as claimed in claim 6, wherein the catalyst consists of: 4 to 15 wt % of lanthanum oxide, 40 to 65 wt % of copper oxide, 15 to 30 wt % of aluminum oxide and 5 to 20 wt % of copper.

10. The process as claimed in claim 7, wherein the catalyst consists of: 4 to 15 wt % of lanthanum oxide, 40 to 65 wt % of copper oxide, 15 to 30 wt % of aluminum oxide and 5 to 20 wt % of copper.

Description

EXAMPLES

(1) The formate content was in each case determined by ion-exchange chromatography (IC). The Cu/Al.sub.2O.sub.3 catalyst was prepared similarly to WO 95/32171 A1, example E; the lanthanum-containing catalyst according to WO 2007/006719 A1, example 2.

(2) The catalysts were activated before use. This involved heating the catalysts to 180 C. under nitrogen at atmospheric pressure and subsequently admixing 10 vol % of hydrogen to the nitrogen stream. After 2 h, the hydrogen content was increased to 100% by 20% per hour in a step-wise fashion.

(3) Example 1 and also the comparative example were carried out as follows:

(4) The catalyst (87 g, 33 mm tablets) was activated as described above in a tubular reactor (1) (length 10 m) which was subsequently operated in downflow mode at 40 bar and with temperatures increasing from 98 to 105 C. in the downward direction. The hydrogen flow rate was 10 standard liters (L(STP))/hour. The effluent was collected and, once analyzed, post-hydrogenated at 103 C. and 40 bar in a further reactor (2) over the same activated catalyst (87 g) as in the first reactor.

(5) The formate content of the feed was about 1500 weight ppm.

(6) Feed composition (wt %): about 65% NPG, about 5% hydroxypivalaldehyde, about 25% water, pH 8.1. Other components such as isobutyraldehyde, trimethylamine, methanol, formaldehyde, isobutanol sum to less than 5%.

(7) The results are summarized in Table 1.

(8) TABLE-US-00001 TABLE 1 Space Superficial velocity velocity Formate kg of m.sup.3 of HPA content feed/liter feed/ Operating con- weight Catalyst of cat h m.sup.2 h time version ppm Example 1 Reactor (1) Similar to 4.25 19 1 month 88% 1000 Reactor (2) WO 0.90 4 100% 200 2007/006719 Reactor (1) 7.0 32 Further 2 77% 1100 Reactor (2) 1.5 6.5 months 100% 500 Reactor (1) 4.25 19 3 months 87% 1000 Reactor (2) 0.90 4 +1 week 100% 200 Comparative example 1 Reactor (1) Similar to WO 4.25 19 1 month 85% 1500 Reactor (2) 95/32171 0.90 4 100% 1300 Reactor (1) 7.0 32 Further 2 66% 1500 Reactor (2) 1.5 6.5 months 100% 1400 Reactor (1) 4.25 19 3 months 75% 1500 Reactor (2) 0.90 4 +1 week 100% 1500

(9) It can be seen that after 3 months operating time the catalyst not containing lanthanum (comparative example 1) distinctly deactivated and decomposed almost no formate while the lanthanum-containing catalyst used in the process according to the invention retains excellent activity even after 3 months.

(10) The hydrogenation effluents collected from example 1 and the comparative example, comprising 200 ppm and 1300 ppm of formate respectively, were separated into a predominantly water-containing tops fraction and a predominantly NPG-containing bottoms fraction in a distillation. On distillation of the effluents from example 1, the water fraction was found to contain 0.1% of formate in the form of formic acid amine salt and/or NPG formate. On distillation of the effluents from comparative example 1, these were found to contain 1% of formate in the form of formic acid amine salt and/or NPG formate.

Examples 2 and 3

(11) The catalyst (87 g, 33 mm tablets) was activated as described above in a tubular reactor (1) (length 10 m) which was subsequently operated in downflow mode at given pressure and temperatures according to table 2. The hydrogen flow rate was 10 L(STP)/hour. The effluent was collected and, once analyzed, posthydrogenated in a further reactor (2) in each case over the same activated catalyst (87 g) as in the first reactor.

(12) The formate content of the feed was about 1500 weight ppm. Feed composition (wt %): about 65% NPG, about 5% hydroxypivalaldehyde, about 25% water, pH 8.1. Other components such as isobutyraldehyde, trimethylamine, methanol, formaldehyde, isobutanol sum to less than 5%. The results are summarized in Table 2.

(13) TABLE-US-00002 TABLE 2 Space velocity Superficial For- kg of velocity Pres- HPA mate feed/liter m.sup.3 of sure T con- content Catalyst of cat h feed/m.sup.2 h bar C. version ppm Example 2 Reactor (1) Similar to 4.25 19 10 98-105 65% 700 Reactor (2) WO 0.90 4 10 103 100% 20 2007/006719 Example 3 Reactor (1) Similar to 4.25 19 40 120 90% 800 Reactor (2) WO 0.90 4 40 120 100% 50 2007/006719

Example 4

(14) 1 kg of the hydrogenation effluents collected from comparative example 1 and comprising about 1500 ppm of formate were reacted with 200 ml of the activated lanthanum-containing catalyst (prepared according to WO 2007/006719 A1, example 2) at 90 C. in a batch experiment. After 30 min, the hydrogenation effluent was found to contain about 250 ppm of formate in the form of formic acid amine salt and/or NPG formate; after 1 hour, 70 ppm of formate were found to remain.

(15) The aforementioned examples show that the process according to the invention is effective in decomposing the formates to an extent of 50% or more.