DK147291B - CONTINUOUS PROCEDURE AND PLANT FOR MANUFACTURING FEEDS FROM A ROOM MATERIAL - Google Patents

Description

147291

The invention relates to a method of preparing feed from a beet material.

In the production of sugar from beet, the beets coming from the field are first subjected to a wash to remove 5 impurities from the beets' surfaces and then be converted into sugar beets.

In a process described in Patent Application No. 5580/78, the washed beets are peeled before being converted to sugar beets, thereby obtaining a greater sugar yield than the traditional washing method mentioned above. The sugar beets are then extracted with water to form a sugar juice which is then worked up, usually into crystalline sugar. The extraction can be carried out, for example, in an extraction apparatus consisting of an inclined trough with two or more rotatable transport augers which guide from the lower feed end of the trough towards the upper outlet end countercurrent with water introduced at the upper end and which is enriched with sugar at the lower end in the form of sugar juice.

The pulp extracts called pulp, which is the residue remaining after the majority of soluble sugars and salts have been removed by extraction, are usually subjected to a pressing, increasing the dry matter content of the material to between 11 and 21%, depending of the type of press used.

For chemical additives, e.g. addition of Al 2 SO 2, the solids content can be increased by a further 1-2%.

The pressed pulp can be used for livestock feed, either without further treatment or after silage.

Due to the relatively high water content of the pressed pulp, it is not convenient to transport it over larger distances, and in this case drying of the pulp is usually carried out. The resulting product is commercially available under the designation "Pulpets".

The dried product may optionally be added to molasses and a product of the latter type is commercially available under the designation "Composer". Both of these products are suitable as livestock feed.

35 Both the pressing of the pulp and the drying of the pressed pulp are highly energy intensive, and with the ever increasing energy prices there is an ever growing need to produce, from beets, a relatively water-poor feed by a less energy intensive method than the above-mentioned methods.

2 14729 1

This is achieved by the process according to the invention, which is characterized in that the raw material is heated to a temperature of 104-165 ° C and at a pressure of 0-7 ato, an acid hydrolysis, which separates the thus treated product into a liquid fraction. then neutralized and evaporated, and a solid fraction.

The invention is based on the recognition that beet materials, such as beet pulp and beet peel, are made up of a number of polymers such as pectin and pentosans which can be hydrolyzed with acid under pressure and elevated temperature to form a liquid product which is readily evaporated to form of a molasses-like product with a high solids content, e.g. of approx. 60%. Thus, it has been found that the method according to the invention requires approx. 20% less energy to produce a hydrolysis product having approximately the same feed value as for dried extracted cuts than in the known process for producing such cuts.

It has also been found that, after being liberated from hydrolyzable constituents, the solid fraction can easily be pressed to obtain a dry matter content of more than 30%, i.e. substantially above the 20 to 22%, which can be maximally obtained by the known method of chemical addition.

However, it should be noted that the solid fraction without compression can also be used to produce glucose by hydrolysis, since the cellulosic content of the starting material after the removal of the hydrolysable substances has been substantially increased.

During the hydrolysis step, the starting material is heated to a temperature of 100-165 ° C, preferably approx. 130 ° C, and the heating is particularly convenient by direct steam supply.

According to the invention, the pressure during the hydrolysis step is between 30 and 7 ato and especially between 2 and 4 ato.

The acid used is preferably a highly inorganic acid such as sulfuric acid, phosphoric acid and hydrochloric acid. It is preferred to impregnate the starting material with acid before heating under pressure.

The invention also relates to a plant for carrying out the method described above. This plant is characterized in that it comprises a mixer for mixing beet material or finely divided green crop with acid, a hydrolysis container connected to the mixer, in which a cone is placed at the place where the mixture of beet material or finely divided green crop and acid is pressurized. No. 3,147,291 is introduced into the vessel, heating means and a valve for extracting treated material, a filter for dividing the product formed by the hydrolysis into a liquid fraction and a solid fraction, and vessels for neutralizing and evaporating the liquid fraction.

The plant according to the invention may further comprise one of a voltage container disposed between the hydrolysis vessel and the filter.

Preferably, the mixer consists of a vessel in which are mounted two parallel rotatable shafts provided with propeller-like blades, which are designed so that a mixing of the starting material and acid can be made and a feeding of the mixture can be initiated.

The invention will then be described in more detail with reference to the drawing, which shows in the form of a principle sketch an installation for carrying out the method according to the invention.

In the drawing, 1 denotes a mixer comprising a vessel in which are mounted two horizontal rotatable shafts provided with blades which serve partly to mix beet pulp with acid such as sulfuric acid, phosphoric acid and hydrochloric acid and partly to advance the mixture through the vessel. By means of supply means 2 and 3, 20 beet pulp having a dry matter content of e.g. 12-16% respectively of hot, dilute sulfuric acid to one end of the vessel, and the impregnated material is introduced with a auger 4 into a hydrolysis vessel 5. The material is screwed into the container against a cone 6, the back pressure of which is set at a slight pressure. higher than the overpressure in the hydrolysis vessel. Hydrolysis 25 is carried out at an excess pressure of up to 7 ato and with a hydrolysis time of 10 min. when the pressure is high and with longer hydrolysis time at lower pressure. Heating of the pulp is carried out by blowing steam through steam supply pipe 7.

Through an appropriate valve 8, e.g. a large rotary ball valve with cavities known from the cellulose industry, the hydrolyzed pulp is fed to a relaxation vessel 9, where the mass is relaxed to atmospheric pressure, releasing steam discharged through a tube 10 and which may be utilized elsewhere.

From the relaxation vessel 9, the relaxed hydrolysed pulp is pumped through a conduit 11 to a filter 12 which e.g. may be a band filter where the non-hydrolyzed mass is separated from the hydrolyzed portion of the pulp. The liquid hydrolysis product is passed through a conduit 13 to a neutralization vessel 14 to which base is added, e.g. CaCOg, lime milk, NagCOg or an NHg solution through a conduit 15. After neutralization to pH ca. 6, the mixture is passed through a conduit 16 to a filter 17 where a solid filtration is effected and from which the neutralized hydrolysis product is pumped through a conduit 18 to a multi-stage evaporation plant 5 19 where the extract is evaporated to a dry matter content of approx. 60%. The liquid product thus obtained, which is withdrawn through a conduit 20, is suitable for livestock feed to replace molasses from beet sugar or cane sugar production.

Pressed beet pulp prepared as described above usually contains more than 30% organic undissolved solids and can be used in one of two following processes. First, the extracted pulp can be neutralized and dried just like untreated pulp but using less energy per day. kg of dried product due to the increased dry matter content. Second, the pressed pulp may be subjected to high temperature hydrolysis, i.e. between 200 and 250 ° C, whereby the pulp's cellulose will be converted to glucose under the action of the acid present in the pulp. The resulting glucose can be converted to ethanol by fermentation, which can be processed into ethanol by distillation.

The invention will now be described with reference to the following example:

EXAMPLE

Beet pulp with a content of organic dry matter of 15% and a temperature of 65 ° C is fed to a mixing container in an amount of 80 kg per liter. hour. At the same time, hourly 3.55 kg of sulfuric acid with a concentration of 25% (w / w) and a temperature of 90 ° C. After thorough mixing in the mixing vessel, the mixture is passed to a well insulated hydrolysis vessel, where the mixture with steam is heated to 30 131 ° C and kept heated at this temperature for 30 minutes. From the hydrolysis vessel, the mixture is continuously fed to a relaxation vessel where the material is unloaded, thereby causing a temperature drop to approx. 100 ° C. The hydrolyzed mass of approx. 92 kg per hour is passed to a belt filter where a liquid hydrolysis product is separated. From 92 kg, 17.6 kg of a solid fraction with an organic dry matter content of approx. 32%. The liquid hydrolysis product together with wash water from the washing of the pulp amounts to 90 kg, and the mixture contains 6.3 kg of organic matter in solution.

This liquid is neutralized, filtered and evaporated. The liquid product formed typically has the following data: Solids,% 57.6

Ash at 550 ° C,% 13.0 5 Ash at 1050 ° C,% 11.8

Reducing Sugars (Mtiller)% / 100RT 20.5

Uronic acids and pentoses determined by conversion to furfural 10% / 100RT approx. 50

Hexoses (enzymatically determined)% / 100RT approx. 2.5

Acetic acid (enzymatically determined)% / 100RT 0.8 Formic acid (enzymatically determined) I / 100RT 0.03.