# US 5,348,657 A · Process for the separation of catalyst-free working solution from the hydrogenation circuit of the anthraquinone process for the production of hydrogen peroxide

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,348,657 A
- Document ID: US5348657A
- Status: Granted
- Kind: A
- Application number: 08/061,513
- Filed: 1993-05-17
- Granted: 1994-09-20
- Earliest claimed: 1992-05-25
- Assignees: Degussa AG
- Inventors: Hubert Eickhoff; Rudiger; Schirrmacher; Karl-Heinz Mangartz; Hans-Martin Huber; Ralf Godecke
- Web page: https://patentgrep.com/patent/US5348657A

## CPC

- B01D 61/147: {Microfiltration}
- B01J 8/006: {by filtration}
- C01B 15/023: by the alkyl-anthraquinone process
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

A process is disclosed for the separation of catalyst-free working solution from working solution containing palladium black of the hydrogenation circuit of the anthraquinone process for the production of hydrogen peroxide. The problem addressed was to improve the separation of a catalyst-free working solution from the hydrogenation circuit containing Pd black, which was previously carried out using filter candles, in order to reduce the process costs. This problem is solved by the use of a microfilter operating on the crossflow principle with a filter membrane of ceramic material, more particularly .alpha.-aluminum oxide, or polyolefin with an average pore diameter of 0.1 to 3.0 .mu.m, preferably 0.1 to 1.5 .mu.m, and more preferably 0.5 to 1.5 .mu.m. The crossflow rate is generally 0.5 to 5 m/sec.

## Claims

### Claim 1

A process for the removal of catalyst-free working solution from working solution containing palladium black of the hydrogenation circuit of the anthraquinone process for the production of hydrogen peroxide using a microfiltration filter, the differential pressure between the retentate side and the permeate side being briefly reversed on a periodic basis, said process comprising passing said working solution containing palladium black through a microfilter operated on the crossflow principle with a filter membrane of ceramic material or polyolefin having an average pore diameter of 0.1 to 3 .mu.m.

### Claim 2 (depends on 1)

The process according to claim 1, wherein said filter membrane comprises oxidic ceramic material and the average pore diameter is in the range from 0.1 to 1.5 .mu.m.

### Claim 3 (depends on 2)

The process according to claim 2, wherein said average pore diameter is in the range from 0.5 to 1.5 .mu.m.

### Claim 4 (depends on 2)

The process according to claim 2, wherein said oxidic ceramic material is .alpha.-aluminum oxide.

### Claim 5 (depends on 1)

The process according to claim 1, wherein the flow rate transversely of the filtration direction is between 0.5 and 5 m/sec.

### Claim 6 (depends on 5)

The process according to claim 5, wherein the flow rate transversely of the filtration direction is between 1 and 2 m/sec.

### Claim 7 (depends on 1)

The process according to claim 1, wherein said filter membrane comprises polyolefin and the average pore diameter is in the range from 0.1 to 3.0 .mu.m.

### Claim 8 (depends on 1)

The process according to claim 1, wherein the transmembranal differential pressure is more than 200 and less than 500 kPa and wherein said filter membrane comprises oxidic ceramic material.

### Claim 9 (depends on 3)

The process according to claim 3, wherein said average pore diameter is approximately 1 .mu..

### Claim 10 (depends on 1)

The process according to claim 1, wherein the transmembranal differential pressure is between 150 to 200 kPa and wherein said filter membrane comprises polypropylene.