# US 4,399,012 A · Nitrogen fixation method and apparatus

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- Number: US 4,399,012 A
- Document ID: US4399012A
- Status: Granted
- Kind: A
- Application number: 06/291,899
- Filed: 1981-08-11
- Granted: 1983-08-16
- Earliest claimed: 1981-08-11
- Inventors: Hao-Lin Chen
- Web page: https://patentgrep.com/patent/US4399012A

## CPC

- B01J 19/088: {giving rise to electric discharges (for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00)}
- C01B 21/24: Nitric oxide (NO) {(C01B21/203 takes precedence)}
- 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 method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

## Claims

### Claim 1

A method of nitrogen fixation, comprising:
providing an electric discharge chamber which produces a substantially equal volumetric electron discharge therein;
maintaining said discharge chamber at a voltage to pressure ratio of about 5 to 15 kV/atm of O.sub.2 /cm;
introducing air into said discharge chamber;
passing an electrical discharge through said discharge chamber while air is disposed therein;
forming O and vibrationally excited N.sub.2 in said discharge chamber;
interacting O and vibrationally excited N.sub.2 within said discharge chamber to form NO and N;
interacting N and O.sub.2 within said discharge chamber and form NO and O; and
removing NO from said discharge chamber prior to its decomposition.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
introducing NO from said discharge chamber into an oxidation chamber;
introducing O.sub.2 into said oxidation chamber;
interacting the NO and O.sub.2 within said oxidation chamber and
forming oxides of nitrogen having a higher oxidation state than NO.

### Claim 3 (depends on 2)

The method according to claim 2, further comprising:
removing the higher oxidation state oxides from said oxidation chamber;
introducing the higher oxidation state oxides into a separation chamber; and
separating the higher oxidation state oxides from all other gases in said separation chamber.

### Claim 4 (depends on 3)

The method according to claim 3, comprising:
lowering the temperature of said separation chamber after the higher oxidation state oxides have been introduced therein;
solidifying the higher oxidation state oxides in said separation chamber;
evacuating any gases remaining within said separation chamber;
raising the temperature of said separation chamber sufficiently to form gases of the solidified higher oxidation state oxides; and
removing the gaseous higher oxidation state oxides from said separation chamber.

### Claim 5 (depends on 1)

The method according to claim 1, wherein said voltage to pressure ratio in said discharge chamber is about 10 kV/atm of O.sub.2 /cm.