DE214558C

DE214558C -

Info

Publication number: DE214558C
Application number: DE1908214558D
Authority: DE
Priority date: 1908-03-01
Filing date: 1908-03-01
Publication date: 1909-10-11

Description

PATENTAMT.PATENT OFFICE.

KAISERLICHESIMPERIAL

KLASSE 12 r. GRUPPECLASS 12 r. GROUP

Destillationsprodukten.Distillation products.

Bei der trockenen Destillation von Holz entweicht aus den Verkohlungsapparaten ein Dampf gasgemisch, bestehend aus Holzessigdämpfen, Teerdämpfen und unkondensierbaren Gasen. Nach dem Verfahren der Patentschrift 189303 gelingt es, die Teerdämpfe aus diesem Gemisch in tropfbar flüssiger Form vor der Kondensation der übrigen Produkte abzuscheiden Nach dem Verfahren der Patentschrift 60520, Kl. 12, werden die entteerten Holzessig dämpfe nach dem Austritt aus den Verkohlungsapparaten dadurch in Calciumacetatlösung und Holzgeistlösung zerlegt, daß man sie durch Vorlagen leitet, welche mit Kalkmilch gefüllt sind. Dieses Verfahren hat sich aber in der Praxis nicht eingeführt, weil· die Entteerung nicht vollständig gelingt, und weil die in der vorgelegten Kalkmilch zu überwindenden hohen Flüssigkeitsschichten einen ganz erheblichen Gegendruck auf den Verkohlungsapparat ausüben. Dieser Gegendruck kann nur mit Hilfe von stärk wirkenden Ventilatoren überwunden werden. Durch die Wirkung der Ventilatoren wird vor diesen Vorlagen ein dem zu überwindenden Gegendruck entsprechendes Vakuum geschaffen. Da nun die aus dem Verkohlungsapparat entweichenden Gase und Dämpfe ihrer Menge nach in der Zeiteinheit sehr verschieden sind, so kann es leicht vorkommen, daß auch innerhalb des Verkohlungsapparates Luftleere entsteht, falls die Gasdampfentwickelung eine geringe ist. In diesem Falle tritt Luft durch die bei Verkohlungsapparaten fast immer vorhandenen kleinen Undichtigkeiten ein, wodurch sekundäre Reaktionen eingeleitet werden, welche wiederum auf die Ausbeute und die Qualität der erhaltenen Produkte reduzierend wirken. Außerdem bedingt das vor den Kalkmilch vorlagen erhaltene relativ hohe Vakuum ein Schäumen der Kalkmilch, wodurch sehr leicht andere Betriebsstörungen jeder Art möglich sind. .During the dry distillation of wood, steam escapes from the charring apparatus gas mixture, consisting of wood vinegar vapors, tar vapors and non-condensable gases. According to the method of patent specification 189303 it is possible to remove the tar vapors from this mixture to be deposited in drip liquid form before the condensation of the remaining products Process of patent specification 60520, class 12, the de-tarred wood vinegar vapors after The exit from the charring apparatus is broken down into calcium acetate solution and wood spirit solution, that they are led through templates which are filled with milk of lime. This method but has not been implemented in practice because tar clearing is not completely successful, and because the high layers of liquid to be overcome in the milk of lime presented exert a considerable amount of counter-pressure on the charring apparatus. This back pressure can only be overcome with the help of powerful fans. By the effect of the fans, a vacuum corresponding to the counterpressure to be overcome is created in front of these templates. Because now the amount of gases and vapors escaping from the charring apparatus in the unit of time are very different, it can easily happen that also within the charring apparatus Air void arises if the gas vapor development is low. In this case air passes through the charring apparatus small leaks almost always present, causing secondary reactions which in turn affect the yield and quality of the obtained Products have a reducing effect. In addition, the obtained before the milk of lime templates relatively high vacuum a foaming of the milk of lime, which very easily causes other malfunctions of any kind are possible. .

In dem Dampfgasstrom sind neben den zu gewinnenden Produkten (Essigsäure und Holzgeist) noch Phenole und mit Wasserdämpfen flüchtige leichte öle, sogenannte Holzöle, vorhanden. Die Phenole werden von dem freien Ätzkalk als Calciumphenolat gebunden. Die Lösung . des essigsauren Kalkes in Verbindung mit der Lösung des Calciumphenolats und dem freien Ätzkalk hat nun in hohem Maße die Eigen-. schaft, die oben erwähnten Holzöle emulsionsartig zu binden, so daß sie mit Wasserdämpfen nicht mehr flüchtig sind. Aus diesem Grunde verbleiben die Phenole und Leichtöle in der Calciumacetatlösung und verunreinigen so den aus dieser Lösung durch Eindampfen erhältlichen essigsauren Kalk.In addition to the products to be extracted (acetic acid and wood spirit) Phenols and light oils, so-called wood oils, which are volatile with water vapors, are still present. The phenols are bound by the free quick lime as calcium phenolate. The solution . of lime acetic acid in connection with the solution of calcium phenolate and the free Quick lime now has its own to a large extent. shaft, the above-mentioned wood oils emulsion-like to bind so that they are no longer volatile with water vapors. For this reason the phenols and light oils remain in the calcium acetate solution and thus contaminate the lime acetic acid obtainable from this solution by evaporation.

Es wurde nun gefunden, daß sich alle diese Übelstände vermeiden lassen, wenn man die Absorption der Holzessigdämpfe nicht durch Kalkmilch, sondern · durch Kalkstein (Calciumcarbonat) bewirkt, der zweckmäßig in faustgroßen Stücken in Türmen aufgespeichert wird, durch welche die Holzessigdämpfe geleitet werden. Durch die Anwendung von stückigern kohlensauren Kalk als Neutralisations-It has now been found that all of these evils can be avoided if the The wood vinegar vapors are not absorbed by milk of lime, but by limestone (calcium carbonate) which is expediently stored in fist-sized pieces in towers, through which the wood vinegar fumes are passed. By using lumpy carbonate of lime as a neutralization

Claims

Medium for the wood vinegar vapors instead of milk of lime in a high layer does not work only the resistance which the neutralizing agent exerts on the charring apparatus, almost completely eliminate, rather it is also avoided that the phenols and the wood oils are bound to lime and so mix with the acetic acid lime, because phenols are not able to

ίο carbonate of lime to decompose, and likewise they lack the property to bind the wood oils in an emulsion-like manner.

The execution of the patented process is explained on the basis of the accompanying drawing, which is only of schematic value. '.

That emerged from some charring apparatus

• Softening vapors of wood vinegar, wood spirit, phenols, light oils and tar as well as the non-condensable gases pass through an apparatus (e.g. according to patent 189303) in which the tar constituents are removed from the steam gas stream. From here it enters through the tube α and tube c or d in towers (scrubbers) A or B made of copper or any other material of sufficient height, which carry a sieve in their lower part. on which fist-size. Pieces of carbonate of lime are spread out in a sufficiently high layer. In the concurrence of the acetic acid-containing gases with the limestone only the acetic acid is bound to the lime, while all the other components to escape (also volatile with steam phenols and HoIzöle) from the upper portion of the neutralization storms A or B to a part connected to this cooler m. The solution of the acetic acid lime flows out of the lower part of the tower A or B through siphon pipes g and arrives from here in wooden tubs h, which as. Florentine bottles work to separate the last residues of mechanically carried oils due to the different specific gravity of calcium acetate solution and oils.

The wetting of the limestone pieces required for good binding of the acetic acid can either by a reflux condenser connected to the limestone tower or by cooling the jacket with liquids or gases or, finally, by means of an internal irrigation Water, wood vinegar, wood spirit, calcium acetate solution, etc., or it can colder gases are also introduced into the interior of this saturation apparatus.

The gases and vapors escaping from the tower, which mainly consist of water vapors, wood spirit vapors, phenol vapors, wood oil vapors and non-condensable gases, go through the already mentioned cooler m, in which the mixture of water, wood oils, wood spirit and phenols is precipitated and flows out through siphon 0 . The non-condensable gases escape through the gas separator η and the pipe p and can be used to heat the charring apparatus ζμΓ. The condensate is then broken down into wood spirit by rectification with the addition of milk of lime, which is obtained as a distillate, while the phenols, wood oils and other by-products, bound to lime, are obtained as worthless bubble residue.

By using the carbonate of lime in lump form as an absorbent for the De-tarred, steam and gaseous distillation products of the wood succeed in a single operation, the 'wood distillation products in concentrated solutions of Calcium acetate and wood spirit decompose.

PateNT-AνSPRUcn:

Process for obtaining concentrated calcium acetate solution and wood spirit from those resulting from the dry distillation of wood, in a known manner from Tar-freed gaseous and vaporous distillation products, characterized in that that the absorption of wood acetic acid vapors by lumpy calcium carbonate (limestone) in scrubber-like Apparatus causes.

1 sheet of drawings.