WO2021193111A1

WO2021193111A1 - Wood chip and use thereof

Info

Publication number: WO2021193111A1
Application number: PCT/JP2021/009823
Authority: WO
Inventors: 謙史郎宮内; 英治岩田; 林　和典; 直希根岸
Original assignee: 日本製紙株式会社
Priority date: 2020-03-27
Filing date: 2021-03-11
Publication date: 2021-09-30
Also published as: JPWO2021193111A1; JP7053962B2; CN115334873A

Abstract

The purpose of the present invention is to provide a wood chip useful for various applications such as pulp. Specifically, the present invention provides: a wood chip which is derived from a plant of the genus Eucalyptus, has a wood density of 635 kg/m3 or more, has a pulp yield of 48-60% determined when the kappa value is 18, and has a fiber length of 0.50-1.10 mm; pulp and paper produced using the same; and methods for producing these. The plant of the genus Eucalyptus is preferably a hybrid of Eucalyptus pellita and Eucalyptus brassiana or a hybrid of Eucalyptus urophylla and Eucalyptus grandis, and is also preferably 2 years old or older.

Description

Wood chips and their uses

The present invention relates to wood chips and their uses.

In order to prevent global warming and build a sustainable society, it is important to control greenhouse gas emissions _{, promote the absorption and fixation of CO 2} , and promote the use of biomass, which is a recyclable resource. To reduce greenhouse gas emissions, it is effective to switch to non-fossil fuels and promote energy conservation, and it is thought that biomass fuels will become more important in the future from the viewpoint of carbon neutrality. In addition, large-scale commercial tree planting is effective as a method for absorbing and fixing _{CO 2 and increasing the production of biomass resources.} When implementing commercial tree planting, it is essential to reduce costs, and for that purpose, increasing the production of biomass obtained per unit area becomes an issue. In addition, when processing biomass into pulp and paper, quality (yield, fiber length, etc.) is required to increase productivity. Wood chips obtained from commercial tree planting are transported by chip ship. The loading capacity of a chip ship is limited, and there is a demand for high-volume heavy chips capable of loading a larger amount of chips with the same volume (capable of reducing transportation costs). In addition, the high-volume heavy-duty chips improve operability even during pulp production in a factory and contribute to the improvement of productivity.

Patent Document 1 states that among the Eucalyptus plants (seedlings) cut down 8 to 9 years after planting, the one with the largest volume weight is 620 to 640 kg / m 3, and the volume weight of the cloned individuals ^{is 620 to 640 kg / m 3.} It is stated that the largest one is 580 kg / m ^3.

According to Patent Document 2, when mechanical pulp derived from the genus Eucalyptus having a volume weight of 450 kg / m ³ or more is used for the production of coated paper for printing, the bulky structure of the base paper can be maintained and low-density coated paper for printing is produced. It is stated that it can be done.

Non-Patent Document 1 describes Eucalyptus pellita and E. et al. In eucalyptus afforestation in tropical regions. It is described that interspecific hybrids between pellita and Eucalyptus brassiana show excellent growth potential.

Japanese Unexamined Patent Publication No. 2007-236328 JP-A-2010-106421

However, all of the prior arts focused on a single index such as tree growth and paper bulkiness, and did not focus on the combination of multiple indexes as wood chips.

An object of the present invention is to provide wood chips useful for various uses such as pulp.

The present invention provides:
[1] The volume weight is 635 kg / m ³ or more, and the volume weight is 635 kg / m 3 or more.
When the copper value is 18, the pulp yield is 48% or more and 60% or less.
The fiber length is 0.50 mm or more and 1.10 mm or less.
Wood chips derived from Eucalyptus plants.
[2] The wood chip according to [1], wherein the calorific value is 19.0 MJ / kg or more.
[3] The wood chip according to [1] or [2], wherein the plant of the genus Eucalyptus is a hybrid of Eucalyptus pellita and Eucalyptus brassiana, or a hybrid of Eucalyptus urophylla and Eucalyptus grandis.
[4] The wood chip according to any one of [1] to [3], wherein the Eucalyptus plant is 2 years or older.
[5] The wood chip according to any one of [1] to [4], which is used for fuel.
[6] A wood chip mixture containing the wood chip according to any one of [1] to [5] and another wood chip.
[7] Pulp produced from at least one of the wood chips according to any one of [1] to [5] and the mixture according to [6].
[8] The pulp according to [7], which is kraft pulp.
[9] Paper produced from a pulp raw material containing the pulp according to [7] or [8].
[10] A method for producing pulp, which comprises a step of producing the wood chip according to any one of [1] to [5] from a tree of a plant belonging to the genus Eucalyptus, and a step of pulping the wood chip.
[11] A step of producing the wood chip according to any one of [1] to [5] from a tree of a plant belonging to the genus Eucalyptus, and a step of mixing the wood chip with another wood chip to obtain a mixed material. as well as,
A method for producing pulp, which comprises a step of pulping a mixture.
[12] The production method according to [10] or [11], wherein the pulp is kraft pulp.
[13] A method for producing paper, which comprises a step of forming a sheet from a paper raw material containing pulp obtained by the method according to any one of [10] to [12].

By using the wood chip of the present invention as a pulp raw material, high-quality pulp can be produced with high profit. Since the wood chip of _{the present invention can be produced from wood having a large volume weight and a large amount of CO 2} fixed, the process of growing a tree as a material by mass-producing the wood chip of the present invention in a large-scale commercial tree planting. Can efficiently fix carbon dioxide in the air. Therefore, the wood chip of the present invention can contribute to the realization of a sustainable society as a mitigation measure against global environmental changes and a control measure against global warming. Further, the wood chip of the present invention has a high calorie combustion per unit volume because the volume weight, pulp yield and fiber length are within a predetermined range, and is excellent in utilization efficiency as energy and as a fuel. You can expect value.

[Wood chips]
The wood chip of the present invention has a predetermined volume weight, pulp yield, and fiber length.

(Volume weight)
Volume weight of wood chips, 635kg / m ³ or more, preferably 640 kg / m ^3, more preferably above 645kg / m ³ or more, more preferably 650 kg / m ³ or more. If the volume weight satisfies the above value, it can be produced from wood with a larger fixed amount of carbon dioxide, so the fixed amount of carbon dioxide can be increased as a result of mass production of such wood chips, and measures to mitigate global environmental changes. , Can contribute to the realization of a sustainable society as a measure to control global warming. The upper limit is usually 800 kg / m ³ or less, preferably 750 kg / m ³ or less, more preferably 730 kg / m ³ or less, still more preferably 720 kg / m ³ or less. Volume weight is the ratio of weight to volume. The volumetric weight is measured by putting wood chips into a graduated cylinder containing water, reading the increased scale, confirming the increase in volume, drying the chips, and measuring and calculating the weight of absolute dryness ( It can be performed by JAPAN TAPPI No. 3: 2000), and the measurement method of the latter embodiment is also the same.

(Pulp yield)
The pulp yield of wood chips is 48% or more, preferably 49% or more, and more preferably 52% or more. As a result, the amount of pulp produced from wood chips can be improved, and a large amount of paper can be made. The upper limit is 60% or less, preferably 59% or less, more preferably 58% or less, still more preferably 57% or less. The pulp yield is an estimated value of the pulp yield when the kappa value is 18 when kraft pulp is obtained. The kappa value of pulp is a value calculated according to the TAPPI test method T236hm-85. The measurement of pulp yield is obtained by mixing chemicals (alkali and sulfur compounds) with wood chips and calculating from the amount of pulp obtained by steaming under high pressure and high temperature conditions and the amount of chips tested. The same applies to the measurement method of the latter embodiment.

(Calorific value)
The calorific value of the wood chip is preferably 19.0 MJ / kg or more, more preferably 19.5 MJ / kg or more. As a result, a large amount of combustion energy can be obtained when the wood chips are used as they are for fuel use, or when they are processed into pellets and then used as fuel. The upper limit is not particularly limited, but is usually 30 MJ / kg or less. In the present specification, the calorific value means a higher calorific value. The calorific value can be measured in accordance with the Japanese Industrial Standards (JIS Z 7302-2 Waste solidified fuel-Part 2: Calorific value test method). Eucalyptus is also suitable for fuel chips because it grows quickly and yields a large amount of wood chips. In addition, after logging, it is possible to reforest from the stump by coppicing, so sustainable tree planting is possible.

(The amount of heat generated per volume)
The calorific value per volume of the wood chip ^{is preferably 12000 MJ / m 3} or more, more preferably 12500 MJ / m ³ or more, and further preferably 13000 MJ / m ³ or more. The upper limit is not particularly limited, but is usually 24000 MJ / m ³ or less. The higher the calorific value per volume, the larger the amount of heat that can be stored in a constant volume, and the higher the transportation and storage efficiency. The calorific value per volume can be calculated by the product of the calorific value and the volume weight.

(Fiber length)
The fiber length of the wood chip is 1.10 mm or less, preferably 1.05 mm or less, and more preferably 1.00 mm or less. As a result, the paper produced from pulp obtained from wood chips has a good texture, the ink inking property at the time of printing can be improved, and the occurrence of printing unevenness can be suppressed, so that printing with good printability is possible. It can be expected to be used as paper (eg, newspaper paper). In addition, since the occurrence of uneven coating can be suppressed, it can be expected to be used as coated paper. By growing Eucalyptus plants for a long period of time, ^{chips with a volume weight of 635 kg / m 3} or more can be obtained, but by growing them for a long period of time, the fiber length may be higher than 1.10 mm, which is suitable for printing. Tends to decrease. The lower limit is 0.50 mm or more, preferably 0.55 mm or more, more preferably 0.60 mm or more, still more preferably 0.65 mm or more. The fiber length can be measured as a length-weighted average fiber length using a fiber tester (manufactured by Lorentzen & Wettre) in accordance with JIS P 8226: 2011 “Pulp-Fiber length measurement method by optical automatic analysis method”.

(Tree)
Wood chips are derived from woody plants. The woody plant is usually a forest tree, and examples thereof include broad-leaved trees such as eucalyptus, acacia, white birch, and beech, and coniferous trees such as red pine, cedar, and hinoki, preferably broad-leaved trees, and more preferably plants of the genus Acacia. And Eucalyptus plants, more preferably Eucalyptus plants. Eucalyptus plants can efficiently obtain wood chips that produce pulp in high yields, which can improve the efficiency of pulp production and paper production. The Eucalyptus plant, for example, Eucalyptus pellita, Eucalyptus brassiana, Eucalyptus urophylla × Eucalyptus grandis, Eucalyptus pellita × Eucalyptus brassiana, Eucalyptus urophylla, Eucalyptus grandis, Eucalyptus maculata, Eucalyptus tereticornis, Eucalyptus camaldulensis, Eucalyptus rudis, Eucalyptus resinifera, Eucalyptus propinqua, Eucalyptus sideroxylon, Eucalyptus botryoides, Eucalyptus viminalis, Eucalyptus saligna, Eucalyptus ovata, Eucalyptus globulus, Eucalyptus nitens, Eucalyptus saligna, Eucalyptus cladocalyx, 2 or more species of hybrid selected from these. Of these, those suitable for the environment of the plantation (for example, in the case of planting in the tropics, tree species that are adaptable to the tropics) can be selected. perlita, E.I. brassiana, E.I. urophylla, a hybrid of Eucalyptus brassiana and Eucalyptus pelrita, E. coli. urophylla and E.I. A hybrid of grandis, a hybrid of two or more tree species selected from these, is preferred. perlita x E. brassiana, E.I. urophylla × E. grandis is more preferred. E. Pellita and E.I. Although none of the brassianas are always particularly good in volume weight and pulp yield, unexpectedly high yields of chips can be obtained from these hybrids. It is considered that the reason for this is that an individual having inherited the excellent characteristics of the parents by interspecific crossing or developing heterosis and having a trait superior to that of the parent strain was obtained.

The plant from which the wood chips are derived is usually a planted tree grown from cloned seedlings and seedlings. The age of the tree is not particularly limited as long as it is the age at which wood chips can be obtained (usually 2 years or more), preferably 5 years or more. The upper limit is not particularly limited from the viewpoint of quality, but it is better to be short from the viewpoint of economy. In the case of Eucalyptus plants, it is usually 15 years or less, preferably 10 years or less, although it depends on the planted area.

The wood chips may be wood chips derived from a single plant, or may be a combination of two or more wood chips derived from plants of different ages.

[Wood chip manufacturing method]
Wood chips may be produced from a plant from which they are derived (for example, a plant of the genus Eucalyptus) according to a conventional method. For example, after cutting a plant, the bark can be removed from the wood parts (trunk and branches) and crushed to obtain chips.

[Size and use of wood chips]
The size of the wood chip may be determined according to the intended use and is not particularly limited. Wood chips are used, for example, for pulp (for example, for paper pulp), for fuel (for example, for white pellets, for black pellets), for wood board (for example, for oriented strand board (OSB)), and for particle board. For, medium density fiberboard (MDF)), for pavement, for agriculture (eg, for compost, for fungal beds), preferably for pulp.

[Wood chip mixture]
The wood chips may be used in combination of two or more, or may be used in combination with other wood chips other than the wood chips. Other wood chips include wood chips that differ in at least one of volumetric weight, pulp yield and fiber length. The blending ratio when combined with other wood chips can be appropriately determined according to the intended use. Examples of sizes and uses of the wood chip mixture are similar to those of wood chips. The method for producing the wood chip mixed material is not particularly limited as long as it includes a step of mixing the wood chips constituting the mixed material to obtain the mixed material. Mixing may be performed by a conventional method.

〔pulp〕
The wood chips and mixed materials can be used as raw materials for pulp. The conditions or method for producing pulp may include the above-mentioned step of pulping wood chips or mixed materials, and are not particularly limited. Examples of the pulping method include a chemical method for cooking (chemical pulp) such as a craft method, a sulfite method, a soda method, and a polysulfide method, and a mechanical method using equipment such as a refiner and a grinder (mechanical pulp). Examples thereof include, but are not limited to, pulping methods generally used in the paper industry, such as a method of pulping by mechanical force after pretreatment with chemicals (semi-chemical pulp). Further, processing such as bleaching and beating may be performed. The resulting pulp may be unbleached (before bleaching) pulp, bleached (after bleaching) pulp, beaten pulp, or unbleached pulp. Examples of the chemical pulp include sulfite pulp and kraft pulp, and kraft pulp is preferable.

〔paper〕
The production of paper from pulp may be carried out by a conventional method, and examples thereof include a production method including a step of forming a sheet from pulp. The sheet may be formed according to, for example, Japanese Industrial Standards (JIS) P 8122 "Pulp-Method for preparing handmade paper for testing" (1989 edition), and a method of forming pulp into a sheet shape with a paper machine can be mentioned. When forming the pulp into a sheet, additives generally used for papermaking may be added to the pulp. Examples of the additive include a paper strength enhancer, a bulking agent, a pigment, a yield improver, a filter water improver, an internal sizing agent (rosin-based sizing agent, a sulfate band, etc.), a pH adjuster, an antifoaming agent, and a pitch control. Examples include agents and slime control agents. The amount of the additive used is not particularly limited as long as it does not impair the effects of the present invention. When forming the sheet, a paper raw material other than pulp may be used, and examples thereof include other materials such as rayon fiber and film. The paper raw material may be obtained by preliminarily molding other materials into a shape such as a sheet, a film, a roll, etc. together with the pulp obtained from the above-mentioned Eucalyptus plant. The paper raw material may contain pulp made from other plants, but is preferably not contained.

Examples of the paper machine include a long net type paper machine, a round net type paper machine, a gap former, a hybrid former, a multi-layer paper machine, and a known paper machine that combines the paper making methods of two or more paper machines selected from these. Can be mentioned. The press line pressure in the paper machine and the calendar line pressure in the case of performing the calendar processing in the subsequent stage may be set within a range that does not affect the operability and the performance of the obtained plasticized cellulose.

Paper can be used for various purposes, but it is used as printing paper because it has a good texture, can improve ink inking property during printing, and can suppress the occurrence of printing unevenness, and therefore has good printability. can. In addition, since the occurrence of uneven coating can be suppressed, it can be used as coated paper.

Example 1
Approximately 200,000 seedlings (seedlings) of Eucalyptus plants, including tree species and hybrid species that can be adapted to tropical and subtropical regions, were prepared and planting tests were conducted in Brazilian plantations. Seedlings (age of seedlings at the time of planting: 100 days after sowing) are rooted in a greenhouse with a watering facility for about 100 days after sowing (about 3 weeks, high humidity (about 100%), shading). After passing through an acclimatization room (shading degree and humidity gradually decreased) and an outdoor field, the plants were planted in the plantation during the rainy season (end of December to June) (planting density: 1666 trees / ha). After childcare for about 4 years, they were selected by volume and tree shape and narrowed down to about 200 individuals. After that, the selected individuals were felled, and cloned seedlings were propagated from sprout branches by cuttings. The cloned seedlings were transplanted to a sand cultivation shelf, branches were extended as mother trees, and the branches were cut to proliferate the cloned seedlings. Then, a second planting test was carried out using cloned seedlings (30 plants per line). After childcare for 4 years, the volume, tree shape, and uniformity of clones were confirmed, and 40 clones were narrowed down. Then, using the mother tree of the sand cultivation shelf, large-scale cuttings were propagated, and the third large-scale planting test was carried out with cloned seedlings (500 trees per line). After childcare for 4 years, the volume, tree shape, homogeneity, and disease suitability as clones in a large area were evaluated, and 10 clones were narrowed down. Then, a pulping aptitude test based on TAPPI JAPAN was conducted and several clones were selected. This process was repeated for 5 years, and selection was carried out from a total of 1 million individuals. The volumetric weight, pulp yield and fiber length of the selected cloned wood chips were measured under the following conditions (Table 2).

(Volume weight) J TAPPI NO. Measured according to 3: 2000 "Wood Chip-Volume Weight Test Method".

(Pulp yield)
A cooking test was carried out using a rotary multi-digester under the conditions shown in Table 1, and the pulp yield was measured.

(Fiber length)
It was measured as a length-weighted average fiber length using a fiber tester (manufactured by Lorentzen & Wettre) in accordance with JIS P 8226: 2011 "Pulp-Fiber length measurement method by optical automatic analysis method".

For example, although the measurement conditions may be slightly different from those in the examples of the present application, the prior art describes the following regarding the measured values of wood of a plant belonging to the genus Eucalyptus. Miranda et al. (2012) “Incorporation of bark and tops in eucalyptus globalus wood pumping” Bioresurces 3 (7): 4350-4361, E. et al., 18 years old. It is described that the volume weight of globulus was 594 ± 43 kg / m ³ or less, the pulp yield was 55.8% or less, and the fiber length was 0.98 ± 0.09 mm or more. In addition, Duarte Neiva et al. (2015) “Chemical composition and kraft pumping potential of 12 eucalypt specials” Industrial Groups and products 66, 6 years old E. et al. It was described that the volume weight of grandis was 503 kg / m ³ , the pulp yield was 45.6%, and the fiber length was 0.759 mm. (2001) "The effects of remedial fertilizer treatments on growth and pulp properties of Eucalyptus grandis stands established on infertile soils of the Zululand coastal plain" The Southern African Forestry Journal, the 192,1,9-18, 8-year-old of E .. It is described that the volume weight of grandis was 448 kg / m ³ or more, the pulp yield was 52.3% or less, and the fiber length was 0.720 mm or more. In addition, according to the investigation by the present inventor, E. cerevisiae, which is 4 years old, was found. The volume weight of brassiana was 580 kg / m ³ , the pulp yield was 48.0%, and the fiber length was 0.80 mm. On the other hand, all of the clones A to E had high volume weight and pulp yield, and had short fiber lengths (Table 2).

(Calorific value)
Calorific value using the CA-4AJ measurement system (manufactured by Shimadzu Corporation) of the Fuel Research Institute type automatic bomb calorimeter in accordance with Japanese Industrial Standards (JIS Z 7302-2 Waste solidified fuel Part 2: Calorific value test method) Was measured.
(The amount of heat generated per volume)
It was calculated by the product of the calorific value and the calorific value.

Although the measurement conditions may be slightly different from those in this example, the prior art has the following description regarding the measured values of the volumetric weight and calorific value of the wood of the genus Eucalyptus. Pereira et al. "Quality of Wood and Charcoal from Eucalyptus Cloning for Ironmaster Use" International Journal of Forestry Research Volume 2012, Article ID 5230 It is described that the high calorific value of grandis was 19.05 MJ / kg and the calorific value per volume was 11049 MJ / m ^3. Senelwa and Sims "Fuel charactitics of short rotation biomass" Biomass and Bioenergy Volume 17, Issue 2, August 1999, Pages 127- The volume weight of nitens ^{is 417 kg / m 3} , the higher calorific value is 20.2 MJ / kg, and E.I. It is described that the volume weight of saligna was 470 kg / m ³ and the high calorific value was 19.8 MJ / kg. March and Meinkken "An evolution of South Africa fuelwood with regards to calorific value and enviromental impact" Biomass4 It is described that the volume weight of cladocalix ^{was 745 kg / m 3} , the higher calorific value was 18.87 MJ / kg, and the volume weight was 597. On the other hand, all of the clones A to E had a high volume weight and a high calorific value (Table 3).

Claims

The volume weight is 635 kg / m 3 or more,
When the copper value is 18, the pulp yield is 48% or more and 60% or less.
The fiber length is 0.50 mm or more and 1.10 mm or less.
Wood chips derived from Eucalyptus plants.
The wood chip according to claim 1, which has a calorific value of 19.0 MJ / kg or more.
The wood chip according to claim 1 or 2, wherein the Eucalyptus plant is a hybrid of Eucalyptus pellita and Eucalyptus brassiana, or a hybrid of Eucalyptus urophylla and Eucalyptus grandis.
The wood chip according to any one of claims 1 to 3, wherein the Eucalyptus plant is 2 years or older.
The wood chip according to any one of claims 1 to 4, which is for fuel.
A wood chip mixture containing the wood chips according to any one of claims 1 to 5 and other wood chips.
Pulp produced from at least one of the wood chips according to any one of claims 1 to 5 and the mixture according to claim 6.
The pulp according to claim 7, which is kraft pulp.
Paper produced from a pulp raw material containing the pulp according to claim 7 or 8.
A method for producing pulp, which comprises a step of producing the wood chip according to any one of claims 1 to 5 from a tree of a plant of the genus Eucalyptus, and a step of pulping the wood chip.
A step of producing the wood chip according to any one of claims 1 to 5 from a tree of a plant of the genus Eucalyptus, a step of mixing the wood chip with another wood chip to obtain a mixed material, and a step of obtaining a mixed material.
A method for producing pulp, which comprises a step of pulping a mixture.
The production method according to claim 10 or 11, wherein the pulp is kraft pulp.
A method for producing paper, which comprises a step of forming a sheet from a paper raw material containing pulp obtained by the method according to any one of claims 10 to 12.