DE602594C - Cleavage of nitrosyl chloride - Google Patents

Description

Cleavage of nitrosyl chloride The processing and decomposition of nitrosyl chloride into its components and transforming them into recyclable products, from for whom the nitrogen content is particularly valuable, attempts have been made in various ways been. A number of these processes, insofar as they are not of a purely physical nature, go to an oxidative cleavage, which leads to the formation of nitrogen dioxide or Nitric acid leads.

In order to make the nitrogen of the nitrosyl chloride usable by a reduction process, various substances, such. B. Fe, Sri, S, CO and moist coal have been proposed, when used in addition to nitrogen oxide, the corresponding chlorides FeCls, Sn C14, S2 C12, CO Cl. (or CO, and H C1) can be obtained. However, as is well known, the nitrosyl chloride can also be reduced with hydrogen. As far as this process has been investigated so far, a mixture of nitrosyl chloride with hydrogen is very inert under normal conditions, but in the presence of Pt and Pd and Ni a very violent reaction takes place, sometimes even explosively, with the formation of free nitrogen or NH3 or NH4C1 and other hydrogen nitrogen compounds.

Object. In contrast, the present method is to obtain the reaction free of these side reactions and to carry out the economical reduction of Nit.rosylchlori: ds by means of: hydrogen to NO and HCl according to the equation a NOCl + @ H = 2 HCl +: 2 NO. It was found that a lossy formation of nitrogen or NH, C1 does not occur, but an almost complete conversion of the above formula occurs when a mixture of nitrosyl chloride and hydrogen or hydrogen-containing gases is heated to temperatures below 500 °. It has also been found that in the presence of catalysts which accelerate the splitting of NO Cl, the reaction can be carried out well and the reaction temperature can also be reduced considerably. Such catalysts are the oxidic and chlorideic compounds of heavy and light metals, eg. B. A1203, Mn 02, Mn C12, Cr2 03, Si 02 and active charcoal in question; while the easily reducible compounds that lead to the metals that strongly condense hydrogen on their surface, such as Pt, Pd and Ni, are not suitable for this.

It has also been found that the implementation works accordingly the above equation even at ordinary temperature carry out if one can absorb the gas mixture of nitrosyl chloride and hydrogen Radiation. The reaction then proceeds smoothly and with good yields in the above sense. Just by exposing the mixture, rays become more ordinary long wavelength, the inertia at ordinary temperature is eliminated.

The resulting hydrochloric acid is removed from the nitric oxide by washing with water separated and the nitrogen oxide converted into nitrogen dioxide by oxygen and for the production of nitric acid or nitrates ends.

In a compilation of older works, the biggest so far will be achieved effect of a photochemical decomposition of nitrosyl chloride with strong Light sources indicated by io 0/0.

After these poor yields it was not foreseeable that with the reaction of N O Cl with H2 can achieve such favorable yields under exposure to light let that this reaction appears suitable for industrial utilization.

It was also known that a mixture of H2 and Cl, under the Exposure to light, i.e. as a photochemical reaction, combined with one another, but this reaction is explosive (hence the name as chlorine detonating gas) and. is therefore technically not viable. So it was to be feared that the reaction of N O Cl with H2 is not in the moderate orbits that a technical one Allow recovery would proceed.

According to the literature, mixtures of N O Cl and H2 are approximate of a burning body explosive. Experimentally, however, it has been found that .thies.e Reaction to the exclusion of the conditions by which the reaction according to the invention is to be accelerated is extremely sluggish.

The risk of explosion is reduced by the use of a relatively low temperature and the choice of such catalysts excluded, whereby platinum metals, nickel etc. expressly because of excessive reactivity and other reactions (formation of N and NH, C1) must be switched off should. Embodiments i. A mixture of equal parts by volume of N O Cl. And Hydrogen is passed through an empty reaction vessel in a moderate stream of about 21 per hour, which is heated to 35o °, passed. In the withdrawing gas there are 90/0 of the passed Nitrosyl chloride as N O and H Cl.

2. In the same apparatus, under the same conditions as in example i, the Gasg.em2sch is passed over 20g of granular manganese dioxide, which is obtained from KMn04 by decomposition with concentrated H2504. The NO Cl is converted to 96 0/0 to NO and H Cl.

3. Using the same conditions as in Example i, using Zog A1203 as a catalyst, produced from precipitated Al. (OH) "a conversion of NO Cl was found to be 97%.

4. Using? -O g of active charcoal (Bayer) in the reaction vessel was under the same conditions of speed and mixing ratio a 99% conversion was found at 2oo °.

5. If the above gas mixture of N O Cl and hydrogen is supplied Room temperature through a glass vessel on which one receives the rays of an ordinary A light bulb of about 60 watts can act directly, so are in the escaping gas mixture 45% of the N O Cl split into NO and HCl while using the same mixture without exposure undergoes no change.

Claims (1)

PATENT CLAIM: Process for the production of nitrogen oxide and hydrogen chloride from nitrosylchloride in a mixture with hydrogen or containing these components Mixtures, optionally in the presence of catalysts, characterized in that that the in and for itself slow boiling reaction either by heating up to 400 ° or by catalysts such as A12 O3, Mm 02, Mn C12, Cri O3, Si 02 or active charcoal, or by natural rays that can be absorbed by the gas mixture or artificial light sources or activated by a combination of these measures.