WO2018020726A1

WO2018020726A1 - Method for pretreating biomass, and method for producing biomass fuel

Info

Publication number: WO2018020726A1
Application number: PCT/JP2017/009528
Authority: WO
Inventors: 鈴木　崇幸; 慶喜辰巳; 裕太田原; 靖▲訓▼ 田中; 裕司福田
Original assignee: 太平洋セメント株式会社; リマテックホールディングス株式会社; 株式会社関西再資源ネットワーク
Priority date: 2016-07-28
Filing date: 2017-03-09
Publication date: 2018-02-01
Also published as: JPWO2018020726A1

Abstract

[Problem] To remove an alkali metal from a biomass with high efficiency to promote the effective utilization of the biomass as a biomass fuel. [Solution] A biomass containing an alkali metal and a chlorine content, such as an oil palm empty fruit bunch, is squeezed, and is then washed with water while applying a physical impact on the biomass. By squeezing the biomass to disrupt plant cells in the biomass and then washing the biomass with water while applying a physical impact on the biomass, it becomes possible to remove the alkali metal from the softened biomass with high efficiency. Subsequently, the biomass that has been washed with water is drained and is then washed by water spraying. This washing by water spraying enables the reduction of the amount of the alkali metal remaining in the biomass to 0.2% by mass or less. The biomass in which the content of the alkali metal has been reduced to 0.2% by mass or less is dried, crushed and then shaped to produce a good-quality biomass fuel having a reduced alkali metal content.

Description

Biomass pretreatment method and biomass fuel production method

The present invention relates to a method for pretreatment when effectively using biomass containing an alkali metal as fuel, and a method for producing biomass fuel from biomass after pretreatment.

Considering the possibility of depleting fossil fuels such as oil in the future, attempts have recently been made to promote effective use of biomass as fuel. Biomass refers to biological organic resources that can be used as fuel, etc., excluding fossil fuels.

By the way, since biomass contains a large amount of alkali metal, when biomass is supplied as it is to a heating device, the alkali metal in the biomass causes a chemical reaction in the heating device to generate a low melting point material, and the generated low melting point material However, there is a risk of causing operating troubles in the heating device.

In addition, as an operation trouble of the heating device, for example, when biomass is supplied as a fuel to the fluidized bed type heating device, the alkali metal in the biomass reacts with the silica sand that is the fluidized medium to generate a low melting point material, which is a fluidized bed. Hindering the flow.

In order not to cause such troubles, the alkali metal content in the biomass used as fuel is desirably 0.2% by mass or less.

However, among biomass, those having plant cells are particularly hard, and even when such biomass is washed with water, the alkali metals in the biomass cannot be efficiently eluted into the washing water. It was difficult. Therefore, it is not easy to effectively use biomass as fuel.

This point is regarded as a problem especially in the palm oil industry. Oils and oils called palm oil can be obtained from the fruit pulp and seeds of oil palm. Today, palm oil is effectively used in various foods and detergents. On the other hand, a large amount of oil palm empty fruit bunches (hereinafter referred to as “empty fruit bunches”) is produced as a by-product of palm oil production. Since this empty fruit bunch contains a large amount of alkali metal and has plant cells, a large quantity of alkali metal remains in the empty fruit bunch even if the empty fruit bunch is washed with water. Therefore, empty fruit bunches are difficult to use effectively, and many of them are discarded and left in the palm oil production area, and environmental pollution has become serious.

Therefore, in Patent Document 1, by applying pressure treatment to biomass containing alkali metal, cells in the biomass are destroyed to soften the biomass, and the softened biomass is washed with water, so that the alkali metal contained in the biomass is It is described that it is efficiently eluted in washing water.

Japanese Unexamined Patent Publication No. 2010-270320

However, although the technique described in Patent Document 1 can remove alkali metals from biomass containing alkali metals, it is particularly difficult to reduce the alkali metal content of empty fruit bunches to 0.2% by mass or less. There was room for improvement.

Therefore, the present invention provides a biomass pretreatment method capable of efficiently removing alkali metals from an empty fruit bunch, and a biomass fuel production method using biomass obtained by the pretreatment method. The purpose is to do.

In order to achieve the above object, the present invention provides a pretreatment method for biomass, which is a squeezing step of squeezing biomass containing alkali metal, a rinsing step of rinsing while giving physical impact to the squeezed biomass, and rinsing And a sprinkling cleaning step of sprinkling and cleaning the subsequent biomass after draining.

In the biomass pretreatment method of the present invention, first, in the pressing step, the biomass is squeezed to destroy plant cells in the biomass, and the moisture in the biomass is removed to 60% by mass or less. By this squeezing process, the alkali metal in the biomass is removed from the biomass together with the squeezed compressed water, and further, the plant cells of the biomass are destroyed, so that the alkali metal is efficiently removed from the biomass in the next washing step. It becomes possible to do.

In the biomass pretreatment method of the present invention, in the next water washing step, the biomass is physically impacted, and further washed with water while destroying plant cells in the biomass. Thereby, the alkali metal in the biomass which has not been squeezed out in the squeezing step can be eluted in the washing water.

The physical impact in this water washing step may be continuous pressurization, but the time required for the water washing step can be minimized by applying momentary impact continuously.

Next, in the biomass pretreatment method of the present invention, in the watering washing step, the biomass after the water washing step is drained and then washed with water. The alkali metal adhering to the biomass can be removed by watering and washing after draining.

In addition, since the washing water sprayed into the biomass in the watering washing process has a small amount of dissolved alkali metal, it can be used for the washing water in the washing process. Thereby, while reducing the amount of water required for implementation of this invention, the drainage process of the wash water after use can be abbreviate | omitted.

In the biomass pretreatment method, the biomass may include a chlorine content. Thereby, chlorine content can be efficiently removed simultaneously with the alkali metal, and both the alkali metal content and the chlorine content of the biomass can be efficiently reduced.

Moreover, in this invention, you may provide the re-pressing process which squeezes biomass again after the said watering washing | cleaning process. By this re-pressing step, the alkali metal dissolved in the washing water in the washing step or the washing water in the sprinkling washing step included in the plant cells of the biomass destroyed in the pressing step or the washing step Chlorine can be removed, and the removal rate of alkali metals and chlorine from biomass can be improved.

Furthermore, in the present invention, after the re-pressing step, the biomass may be sprayed again, and a final pressing step may be provided in which the biomass after the sprinkling cleaning is compressed again for the third time. Thereby, while fully removing the alkali metal and chlorine which are adhering to biomass, the trace amount alkali metal and chlorine which remain | survived inside biomass, such as in the destroyed plant cell, can also be removed.

Further, the present invention is a biomass fuel production method, characterized in that the biomass obtained by the biomass pretreatment method is dried, crushed and molded into a fuel. Thereby, biomass from which alkali metal and chlorine content have been sufficiently removed can be suitably used as fuel.

As described above, according to the present invention, it is possible to efficiently remove alkali metals from biomass and promote effective use of biomass as fuel.

It is a flowchart for demonstrating the pre-processing method of biomass and the biomass fuel manufacturing method which concern on this invention. It is a whole block diagram which shows an example of the apparatus which implements the biomass pre-processing method and biomass fuel manufacturing method which concern on this invention.

Next, an embodiment for carrying out the present invention will be described in detail. In addition, in the following description, the case where the empty fruit bunch of oil palm is pre-processed and made into fuel is demonstrated as an example as biomass containing an alkali metal.

As shown in FIG. 1, the biomass pretreatment method of the present invention comprises at least an empty fruit bunch squeezing step, a squeezed empty fruit bunch water washing step, and a water-washed empty fruit bunch watering washing step.

The empty fruit bunch to which the present invention is applied is a fruit which has been defruited from an oil palm fruit bunch and contains a large amount of potassium among alkali metals, and its content is 1.5 to 3.0% by mass. The empty fruit bunches contain 65 to 90% by mass of water.

In the squeezing process of empty fruit bunches, the empty fruit bunches are pressurized at the same time as the empty fruit bunches are destroyed, so the alkali metal contained in the empty fruit bunches is squeezed out together with moisture. In this pressing step, the empty fruit bunch is squeezed until the water content becomes 60% by mass or less. In this pressing step, the alkali metal content of the empty fruit bunches is reduced to 1.0 to 1.5% by mass.

The water washing step is a step of washing the empty fruit bunches while physically damaging the empty fruit bunches and destroying the plant cells of the empty fruit bunches. The amount of washing water used in this washing step is preferably 2 with respect to 1 part by mass of empty fruit bunches to be washed from the viewpoint of efficiently removing alkali metals and the amount of washing water used. To 13 parts by mass (3 to 20 parts by mass with respect to 1 part by mass of empty fruit buns on a dry mass basis (hereinafter referred to as “dry base”)), more preferably 3 to 5 parts by mass (in terms of dry base). 5 to 8 parts by mass).

The washing water used in the washing step is preferably one having a high temperature from the viewpoint of efficiently removing alkali metals from the empty fruit bunch, and the washing water temperature is preferably 20 ° C. or more, more preferably 40 ° C. or more. It is. Although there is no upper limit to the temperature of the washing water from the viewpoint of alkali metal removal, from the viewpoint of fuel cost and the like, if it exceeds 80 ° C., the cost increases, which is not preferable.

Through this washing step, the alkali metal content of the empty fruit bunches is reduced to 0.3 to 0.8% by mass.

The water sprinkling washing step is provided for removing the alkali metal adhering to the empty fruit bunch by draining the water after washing off the washing water adhering to the empty fruit bunch. The washing water used in this sprinkling washing process uses water that does not contain alkali metals or chlorine.

Water draining in the sprinkling washing process may be performed by removing the attached moisture to the extent that it is possible to visually confirm that no large water droplets remain on the biomass by, for example, applying vibration to the biomass placed on the sieve.

In sprinkling washing after draining, 2 to 12 parts by weight (3 to 20 parts by weight on a dry base) of washing water is sprinkled on 1 part by weight of empty fruit bunch. By passing through this sprinkling washing step, the alkali metal content of the empty fruit bunches is reduced to 0.2% by mass or less.

Furthermore, the biomass fuel production method of the present invention is directed to the empty fruit bunch obtained by the biomass pretreatment method described above, and includes a drying step, a crushing step, and a molding step as shown in FIG.

The drying process was obtained by drying the empty fruit bunches obtained by the above pretreatment method, improving the working efficiency of the subsequent crushing process and molding process, and homogenizing the quality of the obtained biomass fuel. It is a process for suppressing the quality change by the moisture of biomass fuel. In this drying step, the water content of the empty fruit bunches is set to 20% by mass or less.

The crushing process is a process for crushing the empty fruit bunch after the drying treatment to improve the work efficiency of the subsequent molding process. The empty fruit bunch after the drying step has a long fiber length of 40 to 80 mm, and is crushed to preferably 20 mm or less, more preferably 10 mm or less. In the molding process described later, when the biomass fuel after the drying process can be molded, the crushing process may be omitted.

A shaping | molding process is a process which uses the empty fruit bun supplied from the crushing process as a molded object. By this step, a biomass fuel having a bulk density of 0.50 kg / L or more, a compressive strength of 1.5 N / mm ² or more, and a calorie of 3800 kcal / kg or more can be obtained. In this molding step, the molded body is heated by heat from the press device and the moisture is evaporated, so that the moisture content of the obtained biomass fuel is 5 to 15% by mass. Moreover, at this shaping | molding process, the palm fats and oils byproduced at the said pressing process can be mixed with biomass, and can be utilized as a shaping | molding adjuvant and auxiliary fuel.

Hereinafter, the present invention will be described in more detail with reference to the drawings. However, the scope of the present invention is not limited by the embodiments described below.

FIG. 2 shows an example of an apparatus for continuously performing a biomass pretreatment method and a biomass fuel production method according to the present invention. This biomass fuel conversion apparatus 1 includes a hopper 2 that receives empty fruit bunches e1, A squeezing machine 3 that squeezes the empty fruit bun e1 discharged from the hopper 2, a water washing apparatus 4 that performs water washing while giving a physical impact to the empty fruit bun e2 discharged from the squeezing machine 3, and a rinsing water W1 , A vibrating sieve 6 for separating the mixture M of empty fruit buns e3 and waste water washing water W2 discharged from the washing apparatus 4 into empty fruit bunches e3 and waste water washing water W2, and a vibrating sieve 6 The waste water washing water W2 that has passed through the squeezed water and the oil / water separator 7 that separates the squeezed water SW1 discharged from the squeezing machine 3 into the water W3 and the oil / fat O1, and the vibration sieve 6 are installed continuously. Vibrating sieve 8 to which upper empty fruit bun e3 is supplied, and vibrating sieve A washing water addition device 9 for adding washing water W4 for sprinkling washing the empty fruit buns e3 on the sieve, a waste washing water tank 10 for storing the waste washing water W5 that has passed through the vibrating sieve 8, and a waste washing water tank 10 A liquid pump 11 for sending the waste washing water W5 stored in the washing water adding device 5 to the washing water adding device 5, a squeezing machine 12 for squeezing the empty fruit bun e4 discharged from the vibrating sieve 8, and a squeezing machine 12 A dryer 13 for drying the empty fruit bun e5, a crusher 14 for crushing the empty fruit bun e6 discharged from the dryer 13, and a molding machine 15 for molding the empty fruit bun e7 discharged from the crusher 14. The waste water W3 discharged from the oil / water separator 7, the waste washing water W5 discharged from the vibrating screen 8, and the compressed water SW2 discharged from the press 12 are subjected to waste water treatment to obtain an appropriate waste water W6. Oil separated by the treatment device 16 and the oil / water separator 7 Comprising oil feed pump 17 for sending the partial O1 to molding machine 15.

The empty bunches e1 are received by the hopper 2 and the empty bunches e1 are appropriately supplied from the hopper 2 to the pressing machine 3. The empty fruit bun e1 has an alkali metal content of 1.5 to 3.0% by mass and a chlorine content of 0.3 to 0.8% by mass.

The pressing machine 3 is equipped to pressurize and simultaneously press the alkali cell contained in the plant cell of the empty fruit bun e1 together with moisture, destroying the plant cell of the empty fruit bun e1. The press machine 3 is not particularly limited as long as it can squeeze the moisture content of the empty fruit bun e2 after squeezing to 60% by mass or less, and is a hydraulic press machine (vertical type, horizontal type), uniaxial press. General-purpose devices such as a machine (screw type) and a twin screw press (extruder) can be used. Especially, it is preferable to use the biaxial pressing machine (extruder) in which required time is short and a continuous process is possible.

Furthermore, by the destruction of the plant cells in the empty fruit bun e1 by the pressing machine 3, in the water washing process in the water washing device 4, the washing water enters the broken plant cells and remains without being removed. Can be dissolved in washing water and removed.

Here, since most of the alkali metal contained in the empty fruit bun e2 after squeezing by the press 3 is dissolved in the water in the empty fruit bun e2, the alkali metal content of the empty fruit bun e2 is: Since it is proportional to the residual moisture content of the empty fruit bunches e2, the residual moisture content can be used as an index of the alkali metal content. Furthermore, the residual moisture content of the empty fruit bunches e2 also serves as an index of the degree of destruction of the plant cells in the empty fruit bunches e1 by the press 3, and the smaller the residual moisture content, the more the destroyed plant cells.

The residual moisture content of the empty fruit bunches e2 is preferably 60% by mass or less, more preferably 55% by mass or less, and particularly preferably 50% by mass or less from the viewpoints of both alkali metal content and plant cell destruction. If the residual moisture content of the empty fruit bun e2 is 60% by mass or less, at least the water washing step by the water washing device 4 and the water spray washing step by the vibration sieve 6, the vibration sieve 8, and the washing water addition device 9 are performed as subsequent steps. By passing, an empty fruit bunch with an alkali metal content of 0.2% by mass or less can be obtained. The empty fruit bun e2 having a residual water content of 60% by mass has an alkali metal content of 1.0% to 1.5% by mass and a chlorine content of 0.2 to 0.6% by mass.

The compressed water SW1 by the pressing machine 3 is sent to the oil / water separator 7 that separates the compressed water SW1 into the water W3 and the fat and oil content O1. The oil / water separator 7 can use an oil / water separator as an oil / water separator, but it is more preferable to use a centrifugal deoiler by high-speed centrifugation in order to clean the water W3 discharged out of the system after the waste water treatment. .

The water washing apparatus 4 is provided to wash the empty fruit bun e2 while applying physical shock to the empty fruit bun e2 and destroying the plant cells in the empty fruit bun e2. The water washing device 4 includes a rotating device (not shown) that is configured in a cylindrical shape and rotates in the axial direction, and an impact medium (not shown) that applies a physical impact to the empty fruit bunch e2 in the rotating device. As the impact medium, for example, a rod-shaped member or a spherical member can be used. Moreover, a physical impact may be given to the empty fruit bun e2 from the inner surface of the rotating device by stirring only the empty fruit bun e2 in the rotating device without providing such an impact medium. . Further, a shaft provided with a paddle may be provided inside the cylindrical device, and the paddle may crush the empty fruit bunches e2 by rotating the shaft. In addition, a desalting separator, a wet trommel, a paddle mixer, etc. can be used for the water washing apparatus 4.

The desalt separator is a drum-like container having a lifter on the inner surface that rotates about an axis extending in the horizontal direction or an axis slightly inclined from the horizontal direction, and is movably accommodated in the container. It is a device that has both the functions of a drum washer and a rod mill, and has the function of both the weight of the iron bar and the destruction of plant cells in the empty fruit bunch by the impact of the iron bar that falls after being lifted by the lifter. The empty fruit bunches can be efficiently crushed by the stirring effect of the rotation of the container.

Since the washing water W1 used in the washing step is used for dissolving and removing the alkali metal contained in the empty fruit bunch e2, water containing no alkali metal is most preferable. However, since the alkali metal concentration in the water contained in the empty fruit bun e2 is high, the alkali metal content of the washing water W1 may be 0.15% by mass or less. Therefore, from the viewpoint of suppressing the wastewater treatment amount in the wastewater treatment device 16, the waste washing water W5 in the next watering washing process can be used as the washing water W1. In addition, alkali metal content of waste washing water W5 is 0.02 mass% or less.

In the washing step, the amount of washing water W1 used is preferably 2 to 13 parts by weight (3 to 20 parts by weight on a dry base) with respect to 1 part by weight of the empty fruit bunches (e2) supplied to the washing apparatus 4. More preferably, it is 3 to 5 parts by mass (5 to 8 parts by mass on a dry basis). The rinsing water addition device 5 that supplies the rinsing water W1 to the rinsing device 4 includes at least a container portion and a faucet for storing the rinsing water W1.

In the case of a rod-shaped member, the use amount of the impact medium in the water washing apparatus 4 is substantially the same as the length of the sample chamber of the water washing apparatus 4 with respect to the volume Am ³ of the sample chamber of the water washing apparatus 4, It is preferable to use 4 to 10 rod-shaped members having a diameter of 0.015A to 0.04Am ³ , more preferably 5 to 8. In the case of a spherical member, a member having a diameter of 25 mm or more is preferably used at a filling rate of 7 to 15%.

The empty fruit bunch e3 washed with water is supplied to the vibrating sieve 6 as a mixture M with the waste water washing water W2. The mixture M is separated into empty fruit buns e3 (on the sieve) and waste water washing water W2 (under the sieve) by draining in the vibrating sieve 6. Next, the empty fruit bun e3 on the sieve is supplied to the vibrating sieve 8 connected from the vibrating sieve 6.

In the vibrating sieve 8, the washing water W4 supplied from the washing water addition device 9 is sprinkled into the empty fruit bun e3. The washing water W4 used in this watering washing step has an alkali metal content of 0.015% by mass or less, and the amount of watering of the washing water W4 is 1 mass part of empty fruit bunch (e3). The amount is preferably 2 to 12 parts by mass (3 to 20 parts by mass on a dry base), and more preferably 3 to 5 parts by mass (5 to 8 parts by mass on a dry base). In addition, the alkali metal content of the empty fruit bun e4 supplied from the sprinkling washing process by the vibrating sieve 6, the vibrating sieve 8, and the washing water addition device 9 is 0.2 mass% or less, and the chlorine content is 0.1 mass. % Or less.

The mesh size of the vibrating sieve 6 and the vibrating sieve 8 is preferably 4 mm or less and more preferably 2.8 mm or less in order to recover the empty fruit bunches e3 or empty fruit bunches e4. Further, the vibrating sieve 6 and the vibrating sieve 8 connected to each other can be used to remove the empty fruit bunch e3, and if the empty fruit batter e3 can be sprinkled and washed to obtain the empty fruit batter e4, the vibration of one machine can be obtained. The empty fruit bunches e3 may be drained on the upstream side using a sieve, and the empty fruit bunches e3 may be washed with water on the downstream side.

Waste water washing water W2 separated by the vibrating sieve 6 is sent to the oil / water separator 7 and separated into the water W3 and the oil / fat content O1 together with the compressed water SW1 from the pressing machine 3.

After the waste washing water W5 separated by the vibrating sieve 8 is collected in the waste washing water tank 10, a part thereof is supplied to the washing water addition device 5 by the liquid pump 11, and the remaining part is supplied to the waste water treatment device 16. . The liquid pump 11 is not particularly limited as long as it is a liquid pump, and a general-purpose device such as a spiral pump or a piston pump can be used.

According to the biomass pretreatment method according to the present invention, at least an empty fruit bunch with an alkali metal content of 0.2% by mass or less can be obtained from the watering washing step. FIG. 12 shows an embodiment including a re-pressing step according to FIG.

The pressing machine 12 is provided to pressurize the empty fruit bun e4 and squeeze out the washing water contained in the empty fruit bun e4. The press 12 is not particularly limited as long as it can squeeze the moisture content of the empty fruit bun e5 after pressing to 70% by mass or less, and is the same hydraulic press as the press 3 (vertical type, horizontal type), uniaxial General-purpose devices such as a press (screw type) and a biaxial press (extruder) can be used.

The alkali fruit content of empty fruit bun e5 whose water content became 70% by mass or less by this press 12 is 0.1% by mass or less, and the chlorine content is 0.05% by mass or less.

The compressed water SW2 discharged from the press machine 12 is supplied to the waste water treatment device 16.

The water W3, waste washing water W5, and compressed water SW2 supplied to the waste water treatment device 16 are discharged out of the system as waste water W6 after appropriate waste water treatment. Thereby, waste water treatment can be performed collectively in one place in the waste water treatment device 16. Here, the water W3, the waste washing water W5 and the compressed water SW2 have high BOD (biological oxygen demand), COD (chemical oxygen demand), and SS (suspension material), so the waste water treatment device 16 It is preferable to use a sedimentation tank or an activated sludge tank (aeration tank).

Next, a biomass fuel production method including a drying process, a crushing process, and a molding process will be described.

The empty fruit bun e5 supplied from the pressing machine 12 is dried by the dryer 13 so that the water content is preferably 20% by mass or less, more preferably 17% by mass or less. As long as the dryer 13 can dry the empty fruit bun e5 to a moisture content of 20% by mass or less, the type of the dryer is not particularly limited, but a rotary dryer capable of continuous operation is optimal. Further, if the environment such as temperature and humidity is prepared, it is possible to dry the empty fruit bun e5 to a moisture content of 20% by mass or less even by sun drying.

The empty fruit bunches e6 having a long fiber length of 40 to 80 mm dried by the dryer 13 are supplied to the crusher 14 to become empty fruit bunches e7 having a long fiber length of 20 mm or less. For the crusher 14, general equipment such as a uniaxial or biaxial crusher can be used. Note that this crushing step may be omitted if molding is possible even in the empty fruit bunch e6.

The empty fruit bun e7 crushed by the crusher 14 becomes pellets (biomass fuel) having a bulk density of 0.50 kg / L or more by the molding machine 15. The pellets obtained in this molding step have a crushing strength of 1.5 N / mm ² or more and a heat quantity of 3800 kcal / kg or more. The bulk density is the test method specified in JIS Z 7302-9 “Waste Solidified Fuel – Part 9: Bulk Density Test Method”, and the crushing strength is JIS Z 8841 “Granulated Product—Strength Test Method”. The amount of heat in the test method specified in 1 is a measured value obtained by a test based on the test method specified in JIS Z 7302-2 “Waste Solidified Fuel—Part 2: Calorific Value Test Method”.

In the molding of pellets, the oil and fat content O1 obtained by the oil / water separator 7 may be used as a molding aid in consideration of the alkali metal content of the oil and fat content O1. Since the fat and oil component O1 has a calorie, it also has an effect of increasing the calorie of the pellet (biomass fuel). The sludge-like fat and oil component O1 is sent to the molding machine 15 by the oil feed pump 17.

The size of the pellet can be appropriately determined in consideration of transportation efficiency and handling properties. The molded body can be used as a solid fuel in a CFB (circulating fluidized bed) boiler device or the like for power generation, or can be used as a coal substitute fuel in a cement baking device or the like.

Next, a test example of a pretreatment method using the pretreatment apparatus 1 will be described with reference to Table 1. The potassium content shown in Table 1 is the result of measuring the solution obtained by completely dissolving the sample with an acid by ICP emission spectroscopic analysis, and the chlorine content is JISＪZ 7302-6 “Disposal This is a test result obtained in conformity with the test method of “Solid Solid Fuel—Part 6: Total Chlorine Test Method”. In Table 1, the values without parentheses in the potassium or chlorine removal rate column indicate the total removal rate (% by mass) up to each step, and the values in parentheses indicate the removal rate (% by mass) from the previous step. Yes.

Table 1 shows potassium content and chlorine for each empty fruit bunch after untreated (e1), pressing step (e2), washing step (e3), sprinkling washing step (e4) and re-pressing step (e5). The content is shown. Here, the sprinkling washing step (e4) and the re-pressing step (e5) correspond to examples of the present invention.

The pressing step in Table 1 relates to empty fruit bunches (e2) that have been compressed to 56% by mass of water that was 70% by mass in the untreated (e1), and 44% of potassium and chlorine by this step 33% of this is removed. However, the potassium content in the empty fruit bunches (e2) is not reduced to the extent that it can be used as fuel.

The water washing process of Table 1 has an empty fruit bunch (e2) after the above-mentioned pressing process, the weight ratio of empty fruit bunch / wash water is 1/7, and is 0.02 times the sample chamber of the washing apparatus 4 as an impact medium. This relates to empty fruit bunches (e3) obtained by stirring for 10 minutes using six rod-shaped members having a volume, and 66% of potassium from empty fruit bunches (e2) by this step. And 60% of chlorine is removed, and the total removal rate from untreated (e1) reaches 81% for potassium and 73% for chlorine. However, the potassium content in the empty fruit bunches (e3) has not yet been reduced to the extent that it can be used as fuel.

The sprinkling washing process of Table 1 corresponds to an embodiment of the present invention, and after emptying the empty fruit bunches (e3), the empty fruit bunches / washing water weight ratio is 1/7 after draining. The empty fruit bunch (e4) obtained in this way, 51% of potassium from the empty fruit bunch (e3) by this process. And 54% of chlorine is removed, and the total removal rate from untreated (e1) reaches 91% for potassium and 88% for chlorine. The amount of potassium in the empty fruit bunches (e4) is 0.17% by mass, which is lower than the standard value of 0.2% by mass, and can be used as biomass fuel.

The re-pressing process of Table 1 is one of the embodiments of the present invention described above, and the water content that was 76% by mass in the empty fruit bunches (e4) after the watering washing process is compressed to 70% by mass. The empty fruit bunches (e5), 47% of potassium from the empty fruit bunches (e4) by this process. And 55% of chlorine is removed, and the total removal rate from untreated (e1) reaches 95% for potassium and 94% for chlorine. The amount of potassium in the empty fruit bunches (e5) can be reduced to 0.09% by mass, which is half the reference value of 0.2% by mass.

As described above, according to the embodiment of the present invention, the amount of alkali in the empty fruit bunch of oil palm can be efficiently removed to 0.2% by mass or less. Moreover, in the said embodiment, chlorine can also be removed with the removal rate equivalent to an alkali.

Furthermore, according to the present invention, alkali metals can be removed from biomass other than oil palm empty fruit bunches as well as oil palm empty fruit bunches.

DESCRIPTION OF SYMBOLS 1 Biomass fuelizer 2 Hopper 3 Squeezer 4 Flushing device 5 Flushing water addition device 6 Vibrating sieve 7 Oil-water separator 8 Vibrating sieve 9 Washing water addition device 10 Waste washing water tank 11 Liquid pump 12 Squeezer 13 Dryer 14 Crusher 15 Molding machine 16 Waste water treatment device 17 Oil pump e1 to e7 Empty fruit bunch M Mixture SW1, SW2 Pressurized water O1 Oil and fat content W1 Wash water W2 Waste water wash water W3 Water W4 Wash water W5 Waste wash water W6 Waste water

Claims

It comprises a squeezing step for squeezing biomass containing alkali metal, a rinsing step for rinsing while giving physical impact to the squeezed biomass, and a watering rinsing step for watering and washing after draining the biomass after rinsing. To pre-process biomass.
2. The biomass pretreatment method according to claim 1, wherein in the pressing step, moisture in the biomass is removed to 60% by mass or less.
The biomass pretreatment method according to claim 1 or 2, wherein the physical impact applied to the biomass in the water washing step is an instantaneous impact applied continuously.
The amount of water used for rinsing biomass in the rinsing step is 3 parts by mass or more and 20 parts by mass or less with respect to 1 part by mass (dry mass) of the washed biomass. The biomass pretreatment method described.
The amount of water sprayed on the biomass in the sprinkling washing step is 3 parts by mass or more and 20 parts by mass or less with respect to 1 part by mass (dry mass) of the sprinkled biomass. The biomass pretreatment method described.
The method for pretreating biomass according to any one of claims 1 to 5, wherein the washing water used in the sprinkling washing step is used for the washing water in the washing step.
The biomass pretreatment method according to any one of claims 1 to 6, further comprising a re-squeezing step of squeezing the biomass after the watering washing.
The biomass pretreatment method according to claim 7, further comprising a final squeezing step in which the biomass after the re-pressing operation is sprinkled and washed.
A drying step of drying the biomass obtained by the biomass pretreatment method according to any one of claims 1 to 8 to a moisture content of 20% by mass or less, and the dried biomass into pellets having a bulk density of 0.50 kg / L or more A method for producing biomass fuel, comprising: a molding step.
The biomass fuel manufacturing method according to claim 9, further comprising a crushing step of crushing the biomass until a long fiber length is 20 mm or less between the drying step and the molding step.
The biomass fuel production method according to claim 9 or 10, wherein, in the molding step, the biomass-derived oil obtained by the biomass pretreatment method is used as a molding aid.