SE442307B - SETTING OUT OF BIOMASS, CONSISTING OF Peat AND WOOD MATERIALS, EXTRACTS ONE FOR THE MANUFACTURE OF A PAPER PASS PRODUCT SUITABLE FIBER MASS AND A FUEL PRODUCT - Google Patents

Description

s2u6sz1-4 Ze The invention is described in more detail in connection with the accompanying drawing, which very schematically illustrates the various treatment steps in the new way.

As mentioned in the introduction, an upper layer of biomass containing peat and coarse and fine wood material is excavated from a peat extraction (not shown). The wood material varies and can thus contain felled tree trunks, roots, shrubs, fine twigs, etc. The biomass usually also includes small amounts of completely unusable material such as stones.

The biomass may have to lie down and dry naturally or be partially dewatered mechanically, for example by pressing. If the biomass contains coarse wood, for example tree trunks, these can suitably be cut into smaller pieces to facilitate the transport of the biomass to the processing plant illustrated in the drawing, and tree trunks are suitably reduced to lengths of about H meters or less for the subsequent mechanical treatment in drums. of, for example, the type described in Swedish patent application 81 07559-0.

After the biomass, as indicated in the drawing 1, has obtained a dry matter content of at least 10%, it is transported to the reprocessing plant and fed to the rotating reindeer drum 2. The reindeer drum 2, which is cylindrical and driven by drive means not shown here, has holes on its mantle surface. and (or slits 2 '. The slits, which may be fixed or adjustable, have, for example, a length of 20-890 mm and a width of 3-60 mm. At the inlet A of the drum 2, the biomass has a dry matter content of at least 10%. the rotating drum 2 is supplied with pressurized water by means of one or more nozzles 3. The water, which is injected directly into the interior of the drum, has a high pressure in order to achieve a direct mechanical impact on the entangled biomass. to a viscous suspension with a dry content of 0.5 ~ 6% and preferably between 1 - H% In the tumbling movement of the biomass in the reindeer stock 2, the fine material, ie peat o ch fine wood material, gravel, etc. to pass through the 'slits of the boom 2' while the coarse wood material is discharged through the outlet 2 of the drum 2. The fine material consists primarily of peat fibers and colloñal peat particles and in the new part of wood material and the coarse wood material of large pieces of wood, stutbar etc. Due to the mechanical processing in the drum 2, an efficient debarking of the coarser wood material will be obtained. According to the invention, the coarser material is fed to a crust 22 of a kind known per se for decomposing the wood into small pieces or chips, which, as described below, forms the starting material for the production of lignocellulosic fibers for the production of mechanical pulp, so-called refiner pulp, or thermomechanical pulp or chemical mechanical pulp such as CTMP pulp. It is assumed in the following that refiner pulp is to be manufactured. The chips have a length of 10-90 mm and preferably 8-H0 mm and a thickness of 2-26 mm.

The fine material leaving the slits 2 'of the drum 2, which essentially contains peat fibers and colloidal peat particles, is fed to a sedimentation and fractionation unit 6, which here is shown to consist of a tank divided into two sections 7 and B, respectively, by means of a partition wall H, which forms a ski table. The material leaving through the slots 2 'or the holes in the mantle surface of the drum 2 is divided in the unit 6 so that gravel and other high density particles, for example gravel, are stored on the bottom of the compartment 7 while lighter material flows over the ski table H to the compartment or space 8. This lighter material consisting of thinner wood particles, peat fiber and colloidal peat particles is pumped via a line 9 to a vibrating screen 10 of conventional type, for example a Jönsson screen. In this sieve larger particles are separated, for example particles with a size exceeding 8 mm, since in the present case the sieve pouring diameter was 8 mm and the reject, i.e. particles with a size exceeding 8 mm are transferred via a line 11 to the coarse material from the drum 2, which decomposed as described below. The fines from the screen 10 are transferred to a tank 12 of the same type as the tank 6, i.e. a tank divided into two chambers. 8206331-4 =.

In the left chamber 12 'of the figure, the lightest material is collected from the screen 10 and pumped via a line 13 to a vortex cleaner. The reject 15 from this reindeer step was transferred to a pond 16 before final disposal.

The heavier material consisting of wood fibers in the tank 12 can suitably be fed via a line to lignocellulosic fiber fibers 22-314- The material purified by the vortex cleaner, i.e. the acceptance is fed via a line 17 to a screen 18 for separating peat fibers from the colloidal peat material . the fibers are fed via a line 37 to a collection tank 19. The colloidal peat material is transferred by means of a line 38 to a sedimentation device 20 and removed therefrom to be dried or pressed in a wet state for, for example, briquettes, ie to form a high-quality fuel.

The peat fibers from the vortex cleaner 1n and the screen 18 were fed, as mentioned via the line 37, to a collecting tank 19, where a mixture of peat fiber and lignocellulosic fiber is produced. The lignocellulosic fiber, which suitably has a concentration of H-30%, is fed to the tank 19 via the line 21 and originates from the coarse wood material from the drum 2 and from the reject separated from the screen 10. The coarse wood material from the drum 2 is fed after a sorting out of any stone, which is done manually or with devices known per se to the said crusher 22, whereby the coarse pieces of wood are reduced to smaller pieces or chips. These smaller pieces are transferred to a tank 23 from which the pieces are pumped over via line 2u to a so-called scrap trap 25, in which gravel, stones and sand are separated.

These undesirable particles are passed via a drain 26 to a collection container or the like. The acceptance from the scrap trap, ie in principle pure wood particles, is pumped through the line 27 from the scrap trap 25 to a tank 29, which is built in the same way as the tank 6, ie with two chambers. The inflowing material first reaches the left chamber 29 ', whereby ev. residual gravel is separated and wood chips or small pieces of wood flow over to a right-hand chamber 29 "in the figure and from this via the line 30 to a conventional ____ ... ïíí-wí-aq-w fi- 8206331-4 screw drain 25 with cylindrical sieve plate 32 As mentioned, peat streaks are also supplied via the line 11 from the screen 10. After dewatering in the screw dewaterer 31, a thickened material with a dry content of 2G-AO 2 is obtained. This thickened fibrous material is fed by means of a screw conveyor 33 to a disc refiner 3fi of known construction, for example a disc refiner of the CELLWOOD brand, from which a strong mechanical mass was obtained.Typical properties have been compiled in Table 1 below and a comparison has been made with corresponding values for the strongest mechanical mass today. , namely so-called thermo-mechanical pulp.

TABLE 1 Thermom. Mass according to mass opg.

Tensile index Nm / g 38 28 Explosion index kPa m2 / g 1.9 1.6 Tear index mN m2 / g 6.8 5.1 It appears from the table above that a pulp, suitable for the production of a pulp product, has been obtained. The values according to the table have in the case of the pulp according to the invention been taken from a pulp according to the processing illustrated in the drawing and thus for example the wood material before the defibration in the refiner 3H has not been heated with steam or subjected to any other costly treatment, as in the thermo-mechanical mass used as the object of comparison. Equally important is that the energy consumption during refining is significantly below the amounts that conventionally apply. The difference in energy consumption can be estimated at 600-1800 kWh / ton depending on the degree of humification of the processed biomass, but regardless of the degree of humification, it is obvious that a significant energy saving is made. -çt fi li fl w M of: s's ”k. 8206331-4 .- The pulp obtained from the disc refiner 3H consisting of lignocellulosic fiber and peat fiber is fed via line 21 to a collection and mixing tank l9. The proportion of fiber from the disc refiner 3U was calculated to be about 10%, which means that the proportion of fiber extracted from room fl 2 became Cia 90 ä. The fiber mixture in the tank 19 was pumped via the line to a paper machine 36. On this paper machine 36 a carton-like product with a sheet weight was produced. of 230 g / m2. This product was cut into sheets measuring 80 x 60 cm and the sheets were bundled in bales of 180 kg / pc.

A small portion of the peat fiber lignocellulose fiber pulp was collected in rolls.

When evaluating the properties of the manufactured products, it appeared that the density was extremely low and amounted to, for example, 2M7 kg / m3 of a hard pressed material. Continued experiments showed that a mixture of conventional pulp resulted in a surprisingly rigid product in the production of corrugated board. The extremely surprising effect is that the pulp produced by the invention becomes significantly cheaper than conventional pulp produced only by wood and that completely new surprising properties, for example the low density, are obtained.

A pulp product in sheet form according to the invention has proved to be particularly suitable as a soil covering agent for growing vegetables, the soil being covered with lengths of a product prepared as described above. The low density of the product resulted in both good thermal insulation and good air supply, and it turned out that after the end of the growing season it could be plowed down and completely destroyed in the soil layer. Furthermore, the product has a superior ability to retain soil moisture relatively constantly.

In case a pulp product according to the invention is to be used for the production of, for example, cardboard, it may be suitable to mix in the produced pulp reinforcing fibers, for example fibers of plastic or the like It is of course also possible to reinforce a pulp according to the invention with, for example, conventional mechanical pulp, sulphate and sulphite pulp. It is also advisable to mix straw straw such as straw and bagasse. u 7 8206351-'4 The colloidal or particulate peat material. swn _ T * must be removed f- * a peat fiber-1ignocellulose fiber mass must have the excellent properties reported above and which to a not insignificant extent justify an economically favorable utilization of the biomass, which has hitherto been regarded as an environmentally harmful food waste tank; 23 by means of a screw press M0. In this case, in the screw press HO, the sedimented, colloidal material is mixed with coarse fiber suspension thickened in the screw drain 31 and this suspension is fed via the line 39 to the screw press. The mixture of the sediment from the tank 20 and the coarse fibrous material from the screw dewaterer 32 proved to be surprisingly easy to bring to high dryness. Thus, after the screwing process 40, a fuel material with a dry content of UU-H5 percent was obtained, which dry content is remarkably high in view of the high content of colloidal material, which in this case amounted to 50% dry weight.

After dewatering the fuel material, it was shredded in a coarse shredder H1 and fed in the form of flakes to a flake dryer H2. In the flake dryer H2, the material was dried to a dry content of 83% and then collected in a container H3. The resulting fuel product contained a surprisingly low ash content. Thus, the analysis showed an average value of only 0.7% ash content, which is to be compared with 2-7% of ordinary fuel peat, ie the peat taken up from a peat bog after the biomass treated according to the invention has been removed. The explanation for the low ash content should be that sand and gravel are removed in the sedimentation tanks 6, l2, l6, 23 and 29 and after: second cleaning in the traps ln and 25. It is of course also possible to dry the sediment of colloidal particles without adding coarse material from the screw water 32, in which case this coarse material is used only for the production of the pulp product.

The pulp produced can be used for double oblong ÜHHOP, sheet-shaped products, plates, discs, planting pots, cover materials for growing plants, etc. and the fuel product can be produced in the form of powders, flakes, briquettes, etc.

Claims (6)

8206331-4 s PATBNTSKRAV A method of extracting from a biomass (1), consisting of peat and wood material, a fibrous mass suitable for the manufacture of a pulp product with low density and high strength and a fuel product, wherein the biomass is added to water to obtain a liquid suspension, k characterized in that the peat in a first separating device (2) is mechanically separated from coarse wood material in the suspension, that the peat fibrous material in a second separating device (10) is separated from fine wood material contained in the peat, that the coarse wood material and the fine wood material are defibrated to obtain of wood fibers, that peat fibers contained in the peat fibrous material in a third separating device (18) are separated from colloidal peat material, that the peat fibers and wood fibers are mixed to provide a pulp mixture for making the pulp product and that the colloidal peat material is dewatered to form a fuel product. 2. A method according to claim 1, characterized in that a certain amount of the fibers of the wood material is added to the colloidal peat material and that the mixture thus obtained is dewatered and dried. 3. A method according to claim 1, characterized in that the biomass is added to water in such an amount that the dry content becomes 0.5-6%, preferably 1-R%. 4. A method according to any one of claims 1-3, characterized in that the coarser wood material is separated from the peat in a rotatable reindeer stream (2). 5. A method according to claim H, characterized in that the coarse wood material leaving the drum (2) is reduced to chip pieces with a length of 10-90 mm and preferably 8-H0 mm and a thickness of 2-20 mm . 9 8206331-4 6. A method according to the claim, characterized in that the chipped pieces obtained are defibrated into mechanical pulp.