DK143885B - PROCEDURE TO INCREASE AND IMPROVE THE FOOD VALUE OF FIBER PLANT MATERIALS USING ALKALI UNDER CONTROL OF WATER CONSUMPTION - Google Patents

Description

(19) DENMARK (W), \ Ra /

| P (12) PUBLICATION WRITING (11) 143885 B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

(21) Application No. 2425/75 (51) IntCI * A 23 K 1/12 (22) Filing Day 30 · May 1975 (24) Running Day 30 May 1975 (41) Aim. available 1. December 1975 (44) Posted Oct 26 1981 (86) International application no.

(86) International Filing Day (85) Continuation Day - (62) Application No. - (30) Priority 31 · May 1974, 7407230, SE * (71) Applicant FREDRIK WEHTJE, S-530 63 Haellekis, SE.

(72) Inventor Same.

(74) Clerk of the Office of Industrial Excellence v. Svend Schønning.

(54) Method of increasing and improving better fiber-containing plant material = feed value of alkali with water consumption reduction.

The invention relates to a method of the kind specified in the preamble of claim 1 for increasing and improving the feed value of fibrous plant material.

Q

3 Every year, many millions of feed units go to waste D with the straw being burned or plowed. It may be too partial to return some straw to the soil by plowing, but in many cases it can have an adverse effect and sometimes cause major soil problems.

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In the past, straw was used to a much greater extent than now as animal feed, but the interest in using straw for animal feed, especially as feed for dairy cows, has gradually declined for a number of reasons, mainly due to the low protein content of the straw and the low digestibility of the cellulose.

However, by technical treatment, the fiber material can be made more accessible to the animals and the nutritional value of the straw significantly increased. In fact, it is possible to more than double the nutritional value of the straw currently used for animal feed.

Such a development of a process technique in order to utilize the feed value of straw and other fiber-rich plant materials in the cheapest and environmentally friendly way possible is therefore attractive.

The original method of improving the value of the straw is the common straw leaching in Norway that can be traced back to the Beckman method of 1921.

In this process, straw is soaked for 20-24 hours in a 1.5% sodium hydroxide solution, after which the straw is rinsed with fresh water several times. Water consumption is very large.

It amounts to 5000 - 10,000 liters per liter. 100 kg dry straw.

This method is very labor intensive in its original form, and a large part of the valuable nutrients found in the straw are lost, namely those which are soluble in water or in weak aqueous alkaline solution. This is no less than 20-30% of the straw's dry matter that comes with the rinsing water. This biologically highly active "waste" is a serious source of pollution.

Another known method, which was found on an experimental basis a few years ago, is based on the rapid reaction of the straw cellulose with alkali. In this process, the straw is sprinkled with a sodium hydroxide solution. The concentration thereof varies (3-15%) depending on the structure and moisture content of the material and the amount of liquid used in the spray. At low fluid volume and low concentration, the straw can be used directly as feed for a few hours after treatment. At higher amounts of alkali solution and stronger concentration, a portion of the excess NaOH is neutralized by sprinkling the straw with an acid. Depending on the acid used for the neutralization, substances that are important to the animals may be provided. In this process, the nutritional value of the material and also its flavor is increased, but the nutritional value of the material is still only exploited incompletely.

At the Research Institute for Commercial and Industrial Plants in Kolding, for some years, a project has been worked on an alkali treatment with so-called dry leaching.

In this Danish method, the straw is treated with sodium hydroxide (sodium hydroxide) under very high pressure, up to 500 atmospheres, and high temperature, approx. 100 ° C, reducing the reaction time to a minimum. The eco-friendly process - no spills - reduces the alkali consumption in comparison with the method used in Norway, and eliminates the requirement for ample water supply. It is easy to pack and transport the product unlike the conventionally leached or "opened" straw. It remains to be seen whether the product satisfies the requirements for taste and dietetic properties.

By using leached straw when feeding animals, it can be found that it has properties that substantially differentiate it from straw that is untreated. Leaching of the straw increases the dry matter content of marketable energy from 1.4 to 2.0 mega calories per day. kg and doubles the yield of net energy.

In addition to the fact that the straw's energy content can thus be better utilized by the animals, experience has also been observed in other benefits. It has been found that animals that have previously been fed a conventional grass fodder diet can increase their production when this feed is supplemented with leached straw. a physiologically more favorable relationship between coarse feed and concentrate can be maintained even for high-lactating animals. Supplementation with leached straw thus appears to allow the animals to increase their total energy intake, which in turn leads to a better utilization of their production capacity.

Professor D.N. Mowart at the University of Guelph, at the Nutrition Conferance for Feed Manufacturers in Toronto, Ontario, in April 1973 reported on trials of lined straw feeding in the feed. From the experiments (with sheep), it was found that the feed consumption of dry matter increased by 48%. The digestibility of the solids. "" Increased by 41% and the retention of nitrogen by 78%. The treated material proved to be very tasty.

The good dietary effect of the leached straw is not explained in more detail. It has been found that, upon leaching, a physical effect is obtained which causes the "stripped" cells in the straw to "swell" or swell and have a greater ability to retain fluid. This, in turn, makes the cells more accessible and the material becomes a better substrate for enzymes.

For good reason it can be assumed that the straw also acts as a pH regulator in the rumen, due to ion exchange properties of the "undressed" cellulose by virtue of the leaching, and since a certain amount of alkali remains in the final product of the leached straw. Addition of bicarbonate or bentonite pH regulators to counteract the adverse effects of vigorous grain feeding has been the subject of long-term studies, but no significant effects have been achieved. On the other hand, there are reasons to say that protein power feedstuffs both cover the animals' protein needs and at the same time have a production-stimulating effect by the fact that the ammonia released for these feeds acts as a buffer substance. If this effect can be otherwise induced, the protein standards should be able to be lowered. It should then be possible, in theory, to arrive at the paradoxical fact that a feed such as leached straw, containing only vanishing amounts of protein, can save on feed protein.

Thus, the alkali treatment of the straw has two important effects, namely to influence the structure of the fibers in such a way that the animals can better digest and utilize the nutrients in the straw, and partly by stimulating the appetite of the straw and the alkali content of the animals to consume more feed. and production increases. The latter effect has not been previously known.

The straw leaching process or straw harvesting process, in its original design, has several serious disadvantages as mentioned above. A serious disadvantage is the large water consumption when rinsing the leached straw. This disadvantage is all the more serious as accessible water recovery sites are often already fully utilized. Of course, in areas where access to water is limited, a straw leaching method with high water consumption cannot be considered at all. Another very serious disadvantage of this method is the large quantities of contaminated wastewater that must either be discharged at risk of environmental damage or must be collected and destroyed, which cannot be done without heavy costs. The waste water also contains large quantities of substances that are released from the straw and which are valuable from a nutritional point of view.

Swedish Patent No. 46,598 discloses a method for treating fibrous plant materials such as straw with alkali in aqueous solution to increase the feed value of the plant material with subsequent flushing of the excess alkali and water. According to claim 3 of this patent, it is stated that the first liquor is displaced with other, already used or fresh liquor portions for the purpose of utilizing the various liquors as repeatedly as possible in repeated use. After leaching is completed, wash with water to remove the alkali residues harmful to the animal body. This leads to significant disadvantages which consist in large water consumption, loss of substances valuable from a nutritional point of view and triggered by the straw, and a need to dispose of large quantities of contaminated washing liquid, which is usually discharged into existing watercourses and causes serious environmental damage or is subject to a severe environmental damage. costly destruction.

German Pat. completely to acidic reaction, whereby the first treatment is performed with weaker lye and the last with stronger lye. Also, in this case, the disadvantages of a large consumption of water for washing the treated straw and environmental problems or destructive problems are avoided due to the large quantities of contaminated rinsing liquid that inevitably appear and which must be placed somewhere, as well as losses. of valuable substances.

It is the object of the present invention to provide an improved leaching method by which water consumption is reduced substantially to the amount of water absorbed by the straw and eliminated the need for spillage of waste liquid and where the dissolved substances or suspended particles are retained to be utilized as feed or otherwise; and by which method the production of finished fiber material per unit of time is increased while keeping the consumption of alkali as low as possible.

This object is achieved by proceeding according to the invention as set forth in the characterizing part of claim 1.

The alkali treatment of fibrous plant material, which may be made up of various kinds of straw or other fiber-containing plant materials such as roofing or reed, bagasse, depleted corn cobs, forest products, special deciduous hardwood, cellulose-containing waste from the wood industry, etc., and the removal of the excess alkaline solution. thus, substances dissolved therein for the material are carried out in a closed system. This means, among other things, that the used alkali solution, which is drained from the treated material, is used again for the treatment of additional material after new alkali has been added as a replacement for consumed alkali. This way you save both water and alkali.

The sealed system according to the invention also implies that rinsing liquid used to reduce the lye content of the treated material is not discharged but used for the treatment (pre-leaching) of further untreated or pre-leached material treated with alkaline aqueous solution. .

The treatment of the straw or other plant material with alkaline solution is carried out stepwise in such a way that the material is pre-treated with one or more weak alkali solutions before the final treatment with a stronger alkali solution.

To pre-treat the material, an alkaline aqueous solution obtained from the "rinsing" of straw or other material treated with a stronger alkali solution is used.

Also, the rinsing of the straw or other starting material treated with the stronger alkali solution is carried out in steps such that the material is rinsed with one or more weak alkali solutions before the final rinsing with fresh water. In this process, no more fresh water is required to be introduced into the system than substantially the amount of water retained in the straw. For the initial rinse (s), the solutions previously used for the pretreatment of the straw are used.

According to the invention, water consumption is calculated for SOOSSO liters of water per liter. 100 kg dry straw. The leached straw contains approx. 80% water, which means that the animals' need for drinking water goes down. In the closed system, in addition to the water consumed, approx. 1200 liters of water per 100 kg of dry straw under treatment. This amount of liquid can be used. reduced.

Prior to any commencement of the last liquor treatment phase in the circuit, such a large amount of alkali, preferably sodium hydroxide, consumed during the preceding liquor treatment is added to the treatment liquor. Using the original method, the consumption was approx. 8 kg NaOH per 100 kg 8 143885 dry straw. By carrying out the present process without decanting, the alkali consumption decreases by about 20%. The concentration of the starch should not be less than 1.6% at the beginning of the process and may advantageously be somewhat higher, however, not higher than when using the process of the present invention in the leached and pre-rinsed straw a content of not more than 1%. , 5 g NaOH per ml. kg. leached straw. The leached straw preferably has an alkali content corresponding to 1.0-1.5 g NaOH per liter. kg of leached material with a water content of approx. 80%. If the leached straw is completely flushed, the taste goes down significantly and the consumption of animals decreases. If the NaOH content is slightly higher than 1.5 g / ml. It is possible to aerate it before feeding with it, as the amount of NaOH decreases partly as the process progresses, and partly as part of the NaOH goes into carbonate form by contacting carbon dioxide from the atmospheric air. The amount of NaOH remaining in the pre-rinsed straw is more important than a precise pH. This is usually between 8.5 and 9.0. Thus, it is not necessary to completely neutralize alkali-treated feed before it is used for animal feeding. The pH value of ruminants in ruminants is often lower in feeding with such feed than in feeding with untreated, due to the formation of more organic acid in the rumen, but depending on the amount of saliva.

In order to obtain a higher effect in the treatment, the material used must be dry or dried and in some cases finely distributed. The leaching effect on straw (85% dry matter) becomes uniform whether the straw is whole (pressed) or chopped. The capacity of the liquor container increases by 40-45% using chopped straw. There are approx. 45 kg dry whole straw and

ISLAND

ca. 75 kg minced straw per m.

As mentioned above, the cellulose in fibrous fibrous materials reacts rapidly with alkali. The leaching time depends on several factors such as alkali concentration, temperature, pressure, material consistency and humidity etc. In the original method the treatment with sodium hydroxide takes approx. 24 hours.

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In the treatment process of the present invention, the straw is "pre-coated" before being treated with "starch", which means that the time can be reduced to approx. 18 hours at a working temperature of 10-20 ° C and a minimum concentration of strong liquor of 1.6%. "Rinse" or "pre-vent" can be done continuously, ie one phase takes place immediately after the previous one is completed. At lower temperatures, the process takes a little longer and the leaching effect also becomes somewhat inferior. At higher temperatures the process goes faster and with an increase in temperature at 10 ° C the time is shortened to approx. The half.

Using the original method of alkali treatment of straw or other fibrous plant material, as mentioned above, the substances that have been released from the material or have been suspended in the solutions are rinsed with the rinsing water. By "leaching" into a closed system according to the present invention, enrichment is gradually achieved in the alkali solutions used stepwise during the process. As mentioned above, these are significant quantities, 25-30% of the straw's solids content. It has been found that these nutrient-rich substances largely remain in solution at a temperature not below 10 ° C if the pH does not fall below 9.0 and they accompany the straw at feeding as they are found in the straw absorbed by the straw. liquid. If the temperature drops and / or the pH falls below 9.0, some of the solutes precipitate as "sludge".

If excessive amounts or hard coherent lumps occur, there is a risk that these substances will not accompany the straw, but settle in the leaching vessels or in pipelines and disrupt the process. To avoid this or if you want to use these valuable, material-triggered substances for yourself, one or more of the enriched solutions included in the process can be passed a separate treatment container while lowering the pH value by addition of chemicals.

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For this purpose, acids which are useful in feeding such as propionic acid, formic acid, acetic acid, citric acid or lactic acid may advantageously be used. Phosphoric acid may also come into play, as the phosphates formed during the precipitation can be used for animal feed and meet the animal's need for phosphorus, or used as fertilizers. A mixture of various acids may be appropriate, thereby obtaining suitable nutrients and other substances adapted to the production device.

When lowering the pH, the precipitated substances settle together with the particles suspended in the alkali solutions as "sludge" on the bottom of the treatment vessel. A decanter can be used as a treatment vessel. To facilitate the handling of the "sludge," one may affect its consistency by selecting an appropriate acid or a mixture of acid. The "sludge" is separated from the solution, to which is then added the required amount of alkali so that it can be reused in the closed system to treat additional material.

As mentioned above, the nutrient-rich "sludge" obtained can be used for feed use alone, or it can be added again to the leached product. It can also be used as a fertilizer, and there is also the possibility of extracting the chemical product thereof.

According to the invention, it is particularly convenient to proceed as claimed in claim 2, in that the four such circulating treatment solutions in the closed system denote an optimal use of the principles of the invention. When proceeding according to the invention as claimed in claim 3, minimal water consumption is obtained by the process.

The process according to the invention will now be elucidated in more detail by an exemplary embodiment showing the application of the method to the treatment of straw with an aqueous solution of sodium hydroxide.

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Example This example assumes that the working temperature does not fall below 10 ° C. 4 alkaline solutions circulate in this closed system, namely:

The starch cloth supplemented with sodium hydroxide after each treatment. After each leaching completed and before supplementation with sodium, the solution is called black liquor.

Rinse liquid I, used alternately for a first flushing of the pre-leached straw and for a third pre-treatment of the straw to be discharged.

Rinse liquid II, used alternately for another flushing or over-spraying of the leached straw and for a different pre-treatment of the straw to be discharged.

Rinse liquid III, used alternately for a third sprinkling or flushing of the leached straw, and for a first pretreatment of the untreated straw to be eliminated.

Supply of water. The loss of black liquor is covered by over-pumping to the black liquor part of the rinse liquid I. Substitution of the corresponding amount of liquid and the loss of liquid of the rinse liquid I are covered by over-pumping of a corresponding amount of the rinse liquid II.

Similarly, the volume reduction of flushing liquid II is covered by over-pumping of flushing liquid m. Flushing fluid Ill's volume reduction, which is 3-3 l / 2 times the weight of the dry straw, is covered with fresh water after it has been used for the last flushing. or sprinkling of the pre-leached straw. This amount of liquid thus constitutes the total water consumption.

It is also possible to work with a smaller or larger number of rinsing liquids and / or in connection with the precipitation to provide a final product which contains no more free NaOH than it is suitable as animal feed.

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Work program

The figures, denoted by A, B, C, D, E, Z 1 and Z 2, represent the various processing containers used to carry out the process.

I — 11 — I - i— O O

Outline anxiety in tooth:

Container A

Filled with pre-rubbed straw and black rye (ie used strong rye). Container B

Filled with pre-leached straw and rinsing fluid I.

Container C

Filled with pre-leached straw and rinsing liquid II.

Container D

Filled with pre-leached straw and rinsing liquid III.

Container E

Container emptied of pre-rinsed, leached straw ready for use as feed and refilled with untreated dry straw.

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Decanter container z 1

Contains "sludge" from the latest decanting taken out of the container.

Decanter container Z 2 Empty.

Z 1 and Z 2 are used alternately.

Working moments Moment 1

Rinse wash III is pumped from D and sprayed over the dry, untreated straw in E.

Moment 2

Rinse wash II is pumped from C and sprayed over the pre-leached straw in D.

Moment 3

Rinse wash I is pumped from B and sprayed over the pre-leached straw in C.

Moment 4

The black liquor in A is pumped to B.

Moment 5

Rinse wash I is pumped from C and sprayed over the pre-leached straw in A. From there, first from the bottom layer in A is pumped so much liquid to B that B is filled and the rest is pumped back to C.

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Step 6 When the black liquor in B is supplemented with flushing liquid I as stated in step 5, a large amount of sodium hydroxide is added to the black liquor to achieve the predetermined concentration (strong liquor).

The starch cloth in B is circulated (stirred) with appropriate time intervals.

The leaching moment in B is now in the final phase.

Moment 7

Rinse fluid II is pumped from D and sprayed over the pre-leached straw in A. From there, first from the bottom layer in A, so much liquid is pumped to C that C is filled and the rest is pumped to D.

Moment 8

Rinse wash III is pumped from E and sprayed over the finished straw in A. From there, from the bottom layer in A, so much liquid is pumped to D that D is filled and the rest is pumped to E.

Step 9 As large an amount of fresh water as can be fitted with flushing fluid III in E, is sprayed over the finished straw in A (final rinse) and then pumped to flushing flask III in E, which is thus filled.

Moment 10

After step 9 the leaching of straw in A is completed and the straw is ready for use as feed.

A is completely emptied; leached straw and refilled with dry straw.

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Then the leaching proceeds according to the same work program as described, but so that A is replaced by B, B with C, C with D, D with E and E with A etc.

If the pH value of any of the alkali solutions during the course of the work program - this can be almost flushing no. III and II - is approaching 9.0, noting that the working temperature is assumed to be above 10 ° C, this solution is pumped to decanting vessel Z 1 or Z 2 at the same time that the pH is lowered by the addition of an acid or acid mixture by means of a servicing pump or dosing pump.

When the resulting precipitate and some particles that have been suspended in the solution are separated, the solution is pumped back into the system while the pH is adjusted by the addition of sodium hydroxide by means of a batch or dosing apparatus and the process proceeds according to to the schematic work program in front. Hereby, by decanting the last rinsing liquid, it is possible to provide a final product, if any. desired pH value,

The precipitate and the separated suspended particles, collectively referred to as the "sludge", are removed from the decanting vessel Z 1 or Z 2, possibly. by means of a auger, and used in the desired manner.

If there is no risk of precipitation, if the alkaline solution pH is above 9.0 'and / or the temperature is significantly above 10 ° C) and there is no desire to win the "sludge" separately, then the work program is carried out without any of the alkali solutions being pumped through Z 1 or Z 2.

Instead of a discontinuous method according to the exemplary embodiment, the process can also be performed continuously in exactly the same treatment sequence.

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This continuous process can be carried out in a conveyor or other device, optionally. in a series of conveyors or apparatus where pumping systems allow circulation of the various alkali solutions and rinsing water over the material during transport. The material can be cut to different lengths before the treatment if deemed necessary.

If the substances present in the alkali solution released from the material are desired to be separated from the material, a continuous precipitation is carried out according to the same principle as in the embodiment.

In this specification and in the appended claims, it has not been possible to clearly distinguish between rinsing and treatment or between rinsing and treatment fluids, since most "rinsing liquids" contain more or less alkali, which is why in most cases the rinsing also occurs. treatment.

Claims (2)

143885 17 A method of increasing and improving the feed value of fibrous plant material by alkali, limiting water consumption, by which process the plant material is treated stepwise, wherein the first treatment with alkali is carried out with the lowest alkali content of the solution and the last treatment with the highest alkali content. the solution and the alkali used are utilized as far as possible by repeated use of the solutions, characterized by working in a closed system where the treatment fluids are moved incrementally within the system, whereby the alkali solution used in the last treatment step, after replacing the consumed alkali, is used for final treatment. of pretreated plant material and the other alkali-containing treatment fluids are alternately used for pre-treatment of plant material to be treated and for rinsing of the finished plant material so that at least one pretreatment of the plant material is carried out with a weak alkali solution. ng obtained from the rinsing of plant material finished with stronger alkali solution, and at least one rinsing is carried out with a weak alkali solution used for the pre-treatment of plant material, where fresh water is used only for the last rinsing of the finished plant material and where desired substances emitted from the plant material from a treatment liquid in a container and separate the precipitated substances from the solution with particles suspended in the solution which are carried by the precipitate. Process according to claim 1, characterized in that the closed system comprises four circulating treatment solutions, namely an aqueous alkali solution, black liquor, which is used for the final treatment of pretreated plant material and supplemented with alkali after each treatment, a liquid No. I used for a third pre-treatment of plant material to be treated and then to a first rinse of the finished plant material, a liquid No. II used for a second pre-treatment of plant material to be treated and then to a second rinse of the finished plant material, and a liquid No. III used for a first pre-treatment