DE561487C - Process for the production of organic fertilizers - Google Patents

Description

Process for the production of organic fertilizers It is known Pulp waste liquor by evaporation with quick lime or magnesia or mixtures both on fertilizers to process. It has also been suggested that more recent and fossil plant bodies in the presence of gases containing ammonia and oxygen pressure oxidation and carbohydrates such as wood sugar with ammonia to heat under pressure to high temperatures, for example 300 °.

It has now been found that fertilizers of high value are obtained if you sulphite pulp waste liquors after the addition of ammonia and optionally under Supply of oxidizing gases of pressure heating in such, consistently below Aoo ° lying temperatures subjects that no carbon deposits occur. It is particularly advantageous to use waste liquors containing ammonium sulfite for this purpose or ammonium bisulfite, which was previously used in pulp production because of the high price of ammonia received practically no attention; such 'wood pulping processes obtain through the present process, after which the nitrogenous waste liquors processed into a valuable nitrogen fertilizer is of great importance. When using ammonium bisulphite, the procedure is to remove the ammonia-containing waste liquor heated under pressure for a few hours in the presence of a little excess ammonia will. The heating is best done at 150 to 150 degrees or even lower temperatures, because at too high temperatures carbon deposits occur and the nitrogen more and more in a more difficult to assimilate form. The obtained by drying, Any ground residue is a well spreadable fertilizer, that compared to the residue obtained by evaporation of the untreated liquor is characterized by a higher nitrogen content ..

The nitrogen uptake can be increased even further if the Post-heating in the presence of oxidizing gases, e.g. B. of air or oxygen. For this purpose, the pressure heating can be carried out in a trickle system, in which of the trickling liquor the gas is directed towards. The ammonia can do this take the path of the lye or that of the air flowing in the opposite direction.

A further enrichment of the lye in nitrogenous organic Substance can can still be achieved in that the lye before the Pressure treatment sawdust, peat waste and similar substances are added. In this In this case, correspondingly larger amounts of ammonia are to be used. Instead of the cellulose cooking liquor to use immediately, you can first evaporate them in whole or in part.

The fertilizers obtained by the present process have proven themselves Tried and tested in field tests and are not as effective as the usual fertilizer salts according to: Example 1 One in the digestion of wood chips with 4% sulfuric acid Acid and 0.5% ammonia obtained, expediently by blowing off the excess Waste liquor freed from sulphurous acid is neutralized with ammonia and added a slight excess of ammonia heated to 15o 'in a pressure cooker for 2 hours. After evaporation and grinding, a spreadable fertilizer with about 100 / a is obtained Nitrogen.

EXAMPLES The waste liquor specified in Example i is after addition of some excess ammonia in the pressure cooker at an initial pressure of r8 at air heated to 150 ° for 2 hours. After cooling down, the pressure is still 14 at. By evaporating the liquid you get a good fertilizer with 12.6% Nitrogen.

Example 3.

A waste liquor obtained during a digestion of spruce chips with 7.5% sulfurous acid and 0.70 % ammonia, freed from sulfur dioxide by blowing off, is neutralized with ammonia, concentrated and in the presence of excess ammonia for 4 hours under a pressure of 15 at air heated to iSo ° with stirring. Evaporation gives a residue with a nitrogen content of 120%.

EXAMPLE 4 A waste liquor obtained from the digestion given in Beispie13 is, after the addition of a little excess phosphoric acid, heated until the evolution of sulfur dioxide ceases, neutralized and in the presence of a little excess ammonia under a pressure of 4 atmospheres for 4 hours at 15 ° to 170 ° heated. The residue obtained on evaporation contains 14% nitrogen, of which about 82% can be driven off as ammonia with potassium hydroxide solution. Example s Calcium bisulfite waste liquor is neutralized with ammonia and concentrated to a dry matter content of 20 to 30 % . This lye is treated with air in the presence of excess ammonia for 2 to 4 hours at 120 to 160 ° and, after drying and grinding, a spreadable fertilizer with a nitrogen content of 10.6% is obtained. By a known implementation of the calcium bisulfite waste with ammonium salts of acids that give sparingly soluble calcium salts, z. B. with ammonium sulfate, ammonium carbonate or diammonophosphate, you can still nitrogen-rich products such. B. obtained with a nitrogen content of 13.5%. The insoluble calcium salts can be separated off or left in the mass and the reaction with the ammonium salts can be carried out before or after the treatment with ammonia and air.

Example 6 A calcium bisulphite waste liquor which is used for the purpose of obtaining sulphite fuel a part of the dissolved carbohydrates has been withdrawn through fermentation, becomes 2 '/ 2, hours Heated for a long time at 12o to 14o ° with ammonia and air under pressure. By evaporation and grinding the residue gives a spreadable fertilizer with 13% nitrogen.

Instead of the calcium bisulfite pulp you can also use one with good success Use stillage from ammonium bisulfite waste liquor.

Example ? 100 parts of a obtained by evaporation of sulphite waste liquor dry residue are mixed with 15 parts of liquid or gaseous ammonia in closed vessel heated to 180 °. Products with a nitrogen content are obtained from 7 to 10 ° / a.

Example 8 100 parts of a dry residue of sulphite waste liquor are heated to 180 ° in a closed vessel with 60 parts of ammonium carbonate or ammonium carbamate. The fertilizer obtained in this way contains about 9 % nitrogen.

Claims (3)

PATENT CLAIMS: i. Method of making fertilizers from Sulphite pulp waste liquors, in particular from ammonia-containing pulp waste liquors, thereby characterized in that these starting materials after the addition of ammonia and optionally with the supply of oxidizing gases of a pressure heating with such, consistently below Temperatures below 200 ° ! en be that no carbonaceous Deposits occur, whereupon the mass obtained is converted into spreadable form. 2. The method according to claim i, characterized in that the liquor before the pressure heating Peat waste, sawdust and similar substances are mixed in. 3. The method according to claim i and 2, characterized in that the pulp waste liquor is initially partially or completely evaporated.