【発明の詳細な説明】[Detailed description of the invention]
本発明は、良質な木酢液と高級活性炭を同時に
製造する方法に関するものである。
木酢液はこれまで木炭の焼成工程で出る煙を冷
却して採取する方法が採られている。木酢液の主
成分は水で酢酸約３％を含むが、その他各種有機
酸など多数の成分を含んでいる。
木酢液の利用は明治10年代に始まるが、第二次
大戦までは酢酸石灰の原料として使用する以外、
目ぼしい用途がなかつた。しかし、ここ数年来多
くの利用方法が開発され、種々様々な特異な用途
が生まれてきている。即ち、農薬的な使い方とし
て土壌殺菌剤としての利用は、合成農薬と異なり
農薬の残留公害の心配がないので注目されてきた
し、家畜飼料への添加により家畜の健康管理に効
果がある。また、畜舎散布による屎尿臭、醗酵臭
の脱臭効果、食品工業への利用ではその強力な抗
酸化性を利用して魚類の鮮度保持加工のための燻
液として利用され、医薬的利用方法としてその滲
透性を利用した皮膚病薬、肝臓解毒作用、尿酸の
毒性抑制作用の発見など様々な用途が開発されて
きており、合成薬剤の見直しの時代に入つて、木
酢液は天然薬用資源として今後の発展が期待され
る。
従来の木酢液製造法は炭がまの煙を冷却筒に導
びいて採取する方法がとられているが、この場合
炭化初期の排煙温度80℃以下の場合は大部分が水
分とメタノールを含み、後期の排煙温度200℃以
上の場合は青紫色の煙が混ざり、これは有害なポ
リフエノール類を多く含むので採取せず、その中
間の排煙温度80℃以上200℃以下の時のみ採取し
木酢液とした。この場合木酢液の生産量は木炭量
の３分の２程度しか得られない。
以上のようにこれまでの木酢液は単に炭焼きの
副産物としてのみ生産され、木酢液製造を目的と
することはなかつた。本発明は木酢液を積極的に
生産する方法で、従来炭焼法に比べて対木材木酢
液生産量は５〜10倍と効率が極めて良く、酢酸濃
度も高くその他の品質も良好な製法であり、しか
も同時に木炭よりもはるかに付加価値の高い高級
活性炭を生産することができる。
即ち本発明は、木質原料100重量部にリン酸100
〜250重量部を加え、徐々に加熱して400℃未満の
温度で乾溜し、その際発生する熱分解ガスを冷却
捕集し木酢液として回収すると同時に乾溜炭化物
を活性炭として用いることを特徴とする良質な木
酢液と高級活性炭を同時に製造する方法を提供す
るものである。
本発明において、リン酸添加量が100重量部に
達しないとリン酸の空気酸化防止の効果が低下
し、250重量部を超えても無駄で操作上も好まし
くない。また、乾溜は通常200℃程度より初まり、
良質の木酢液を得るためには400℃未満の温度に
とどめる。
本発明による木酢液の製法は、木材原料100重
量部に対し100〜250重量部という大量のリン酸を
添加して乾溜するものであり、木材原料を全く空
気にふれさせないでリン酸の脱水縮合性、難燃性
と温度とにより木材を分解し、最高の効率で木酢
液を製造するものであり、木炭の場合のように後
期炭化温度を500〜600℃にする必要がなく、従つ
て有毒なポリフエノール類の生成もない。また、
乾溜工程で空気酸化しないので炭酸ガスや一酸化
炭素の発生によるガス化ロスがなく、使用原料の
殆んど全量が木酢液と活性炭とに分けられる。リ
ン酸は乾溜後の炭化物（活性炭）から水により多
段抽出し再使用される。乾溜工程での温度が400
℃未満と低いことと乾溜ガスの２段冷却により木
酢液中にリン酸分は殆ど含まれず、万一微量含ま
れた場合でも、リン酸は各種食品添加物として使
用されるものであり有害性はない。例えば同じ脱
水縮合性と難燃性のある塩化亜鉛を触媒とした場
合、活性化のための温度が600℃と高くしなけれ
ばならないこと、塩酸の同時添加の必要性からこ
の場合の木酢液には、亜鉛及び塩素の混入が不可
避で木酢液として使用不能である。乾溜温度が
400℃未満と低いことのもう一つの利点は、リン
酸の脱水、縮合力ともあいまつて分解ガス中に木
タール等高分子の有害物質の発生がないことであ
る。更には乾溜の際、炉の材質に安価なガラスや
黒鉛などが利用できる利点がある。
ここで得られる木酢液の量は従来の炭焼法の場
合に比べてはるかに多く、炭焼法の木材100重量
部に対する木酢液生産量20重量部に対し、本発明
によれば100〜180重量部が得られるので５〜９倍
の生産が可能となる。
木酢液の酢酸濃度も炭焼き法の３％に対し、本
発明による方法では木酢液収量の少ない場合５％
の高濃度のものとなる。木酢液の品質も炭焼き木
酢液が褐色であるのに対し、淡黄色の透明なもの
が得られる。一方得られる活性炭は木材原料に含
まれる炭素分の理論歩留りに近く、乾燥木材原料
に対し約50％の活性炭が得られる。
活性炭の製造方法として木粉などにリン酸を加
えて加熱する方法は、薬品賦活法として遠化亜鉛
賦活法と共に知られている。しかし従来法は賦活
（加燃）時に発生する排煙はガスの水洗処理法又
はアフターバーナーによる燃焼法両方を組合せる
処理法等が採られてきた。その理由は従来法では
発生ガスが木酢液であることに気付いていない
か、気付いていたとしても排ガスから木酢液を回
収することが不可能と考えられていたものであ
る。即ちこれまでのリン酸法による活性炭の製造
は活性化の温度を部分的に500〜600℃に上げざる
を得ない炉の構造のため排ガス中にかなり多くの
リン酸ガスの混入がさけられず、生成する木酢液
にリン酸が混入した。更には炉の形式が殆んど内
燃法であり、加燃用燃焼ガスがこれに加わるので
排ガス中のHC、SOx、NOx、ばいじん等の有害
物質が回収木酢液に混入することが避けられず、
木酢液として使用に耐えないものである。
そこで発生する排煙の洗浄に際しては活性炭１
トンの製造に対し排煙量２〜3.5トン及びそのた
めの水洗水が同量以上必要なため４〜７トンの排
水が生じ、その処理を行わなければならない。そ
の排水の水質もPH３、COD物質が2500〜
3000ppmあり、活性汚泥法、凝集沈澱法、活性炭
法、濃縮法等の組合わせによる高度な排水処理を
行わなければならない。そこに加熱用排ガスが加
われば水処理量は更に増加する。アフターバーナ
ーで燃焼させるにしても排煙ガス２〜3.5トンを
600〜700℃に昇温分解させなければならず、更に
は排ガス中のリン酸ガスを別途処理しなければな
らない。このいずれの方法を採用するにしても排
ガス処理に多額の費用がかかり活性炭の製造コス
トに大きなウエイトを占めることとなる。
本発明によれば排ガス処理の必要がないばかり
か多量で良質の木酢液が製造できると同時に活性
炭が製造され、まさに一石二鳥である。
更にはここで副生する活性炭は低温乾溜である
ため吸着に関与する細孔径が大きな製品となつて
いる。即ち一般ガス賦活法による活性炭の細孔径
は10〜30Å、塩化亜鉛法で20〜40Åであるのに対
し、本発明により副生する活性炭の細孔径は10〜
160Åと極めて大きく分布巾が広い。低温乾溜の
もう一つの利点は炭素表面に表面官能基として
種々の酸性官能基を多く残しており、これがイオ
ン交換的収着作用として働き、一般市販活性炭に
は見られない特徴となつている。細孔径が大き
く、分布巾が広いことは、単に吸着量が多いとか
広い範囲の吸着ができるとかの特性があるばかり
でなく、被吸着物質の脱離も容易である。従来法
による活性炭はその再生に際しては600〜700℃に
加熱する方法が採られている。本発明により副生
する活性炭は脱離し易いので熱アルカリ溶液等に
よる薬液洗浄のみで再生可能で、高温焼成の必要
はない。このことは従来の焼再生による再生ロス
が１回再生毎に数％であるのに反し薬液再生での
ロスは0.1％以下である。細孔径の大きいことの
もう一つの利点は吸着速度が早いことである。液
相吸着では溶液の高い場合が多いが、この場合特
に差が出る。例えば砂糖液Brix60゜温度70℃の場
合で一般活性炭の３〜６倍の吸着速度を示す。即
ち吸着設備の小型化が可能となる。
本発明により副生する活性炭はこのように数多
くの特徴を持つた高級特殊活性炭である。
炭焼法と本発明による製法で得られる木酢液と
木炭又は活性炭の収量及び品質を比較すると次表
のとおりである。（表において部及び％は重量に
よる。）
The present invention relates to a method for simultaneously producing high-quality wood vinegar and high-grade activated carbon. Up until now, wood vinegar has been collected by cooling the smoke produced during the charcoal firing process. The main component of wood vinegar is water, which contains about 3% acetic acid, but it also contains many other components, including various organic acids. The use of wood vinegar began in the 1880s, but until World War II, it was used as a raw material for lime acetate.
It had no obvious use. However, over the past few years, many usage methods have been developed, and a variety of unique uses have been created. That is, its use as a soil fungicide has attracted attention because, unlike synthetic pesticides, there is no concern about residual pollution, and its addition to livestock feed is effective in managing the health of livestock. In addition, it has a deodorizing effect on urine odor and fermentation odor when sprayed on livestock sheds, and in the food industry, it is used as a liquid smoke to preserve the freshness of fish due to its strong antioxidant properties, and as a medicinal use. A variety of uses have been developed, such as skin disease drugs that utilize permeability, liver detoxification effects, and the discovery of uric acid toxicity suppression effects.As we enter an era of rethinking synthetic drugs, pyroligneous vinegar is expected to be used as a natural medicinal resource in the future. Development is expected. The conventional method for producing pyroligneous vinegar is to collect smoke from a charcoal pot by guiding it into a cooling cylinder, but in this case, if the flue gas temperature is below 80°C in the early stages of carbonization, most of the water and methanol are removed. If the flue gas temperature in the latter stage is over 200℃, blue-purple smoke will be mixed in. This contains a lot of harmful polyphenols, so it is not collected, and only when the flue gas temperature is between 80℃ or higher and 200℃ or lower. It was collected and made into wood vinegar solution. In this case, the amount of wood vinegar produced is only about two-thirds of the amount of charcoal. As mentioned above, pyroligneous acid was produced only as a by-product of charcoal burning, and was never intended for the production of pyroligneous vinegar. The present invention is a method for actively producing pyroligneous vinegar, which is extremely efficient, producing 5 to 10 times more wood vinegar than the conventional charcoal burning method, and has a high acetic acid concentration and other good qualities. At the same time, it is possible to produce high-grade activated carbon, which has much higher added value than charcoal. That is, in the present invention, 100 parts by weight of phosphoric acid is added to 100 parts by weight of wood raw material.
~250 parts by weight is added, gradually heated and dry distilled at a temperature below 400°C, and the pyrolysis gas generated at this time is collected by cooling and recovered as pyroligneous vinegar, and at the same time, the dry distilled char is used as activated carbon. The present invention provides a method for simultaneously producing high-quality wood vinegar and high-grade activated carbon. In the present invention, if the amount of phosphoric acid added does not reach 100 parts by weight, the effect of phosphoric acid in preventing air oxidation will be reduced, and if it exceeds 250 parts by weight, it is wasteful and undesirable in terms of operation. In addition, dry distillation usually begins at around 200℃,
To obtain high-quality wood vinegar solution, keep the temperature below 400℃. The method for producing pyroligneous vinegar according to the present invention involves adding a large amount of phosphoric acid (100 to 250 parts by weight) to 100 parts by weight of wood raw material and dry distilling it, which involves dehydration and condensation of phosphoric acid without exposing the wood raw material to air at all. This method decomposes wood based on its properties, flame retardancy, and temperature to produce pyroligneous vinegar with the highest efficiency. It does not require a late carbonization temperature of 500 to 600 degrees Celsius, as is the case with charcoal, and is therefore non-toxic. There is no generation of polyphenols. Also,
Since air oxidation is not performed during the dry distillation process, there is no gasification loss due to the generation of carbon dioxide gas or carbon monoxide, and almost all of the raw materials used can be divided into wood vinegar solution and activated carbon. Phosphoric acid is extracted from the charcoal (activated carbon) after dry distillation in multiple stages with water and reused. The temperature in the dry distillation process is 400℃.
Due to its low temperature (less than 30°F) and the two-stage cooling using dry distillation gas, there is almost no phosphoric acid in the wood vinegar solution, and even if it does contain a trace amount, phosphoric acid is used as a food additive and is harmful. There isn't. For example, if zinc chloride, which has the same dehydration condensation properties and flame retardancy, is used as a catalyst, the activation temperature must be as high as 600°C, and the simultaneous addition of hydrochloric acid is necessary, so the wood vinegar solution in this case is cannot be used as wood vinegar because it inevitably contains zinc and chlorine. Dry distillation temperature
Another advantage of the low temperature of less than 400°C is that, together with the dehydration and condensation power of phosphoric acid, there is no generation of harmful substances such as polymeric substances such as wood tar in the cracked gas. Another advantage is that during dry distillation, inexpensive materials such as glass and graphite can be used for the furnace. The amount of pyroligneous acid obtained here is much larger than in the case of the conventional charcoal burning method, and the amount of wood vinegar produced by the charcoal burning method is 20 parts by weight per 100 parts of wood, whereas according to the present invention, the amount of wood vinegar produced is 100 to 180 parts by weight. can be obtained, making it possible to increase production by 5 to 9 times. The acetic acid concentration in wood vinegar is 3% in the charcoal burning method, but in the method of the present invention, it is 5% when the yield of wood vinegar is low.
It has a high concentration of Regarding the quality of wood vinegar, unlike charcoal-grilled wood vinegar which is brown in color, it is transparent and light yellow. On the other hand, the activated carbon obtained is close to the theoretical yield of carbon contained in wood raw materials, and the activated carbon yield is about 50% of the dry wood raw material. As a method for producing activated carbon, a method of adding phosphoric acid to wood flour and heating the mixture is known as a chemical activation method along with a distant zinc activation method. However, in conventional methods, exhaust gas generated during activation (burning) has been treated by a combination of a gas washing method or a combustion method using an afterburner. The reason for this is that in conventional methods, people are not aware that the generated gas is pyroligneous acid, or even if they were aware, it was considered impossible to recover pyroligneous acid from the exhaust gas. In other words, in the conventional production of activated carbon using the phosphoric acid method, the activation temperature had to be partially raised to 500 to 600°C due to the furnace structure, which meant that a considerable amount of phosphoric acid gas was unavoidable in the exhaust gas. , phosphoric acid was mixed into the wood vinegar produced. Furthermore, most of the furnaces are internal combustion type, and combustion gas for combustion is added to this, so it is inevitable that harmful substances such as HC, SOx, NOx, and dust in the exhaust gas will mix with the recovered wood vinegar solution. ,
It cannot be used as wood vinegar. When cleaning the flue gas generated there, activated carbon 1
For each ton of production, 2 to 3.5 tons of smoke emissions and the same amount of washing water are required, resulting in 4 to 7 tons of wastewater, which must be treated. The water quality of the wastewater is PH3 and COD substances are 2500~
It has a concentration of 3000 ppm, and requires advanced wastewater treatment using a combination of activated sludge method, coagulation sedimentation method, activated carbon method, concentration method, etc. If heating exhaust gas is added to this, the amount of water to be treated will further increase. Even if it is burned with an afterburner, it will produce 2 to 3.5 tons of flue gas.
The temperature must be raised to 600-700°C for decomposition, and furthermore, the phosphoric acid gas in the exhaust gas must be treated separately. Regardless of which method is adopted, a large amount of cost is required for exhaust gas treatment, which accounts for a large portion of the production cost of activated carbon. According to the present invention, not only is there no need for exhaust gas treatment, but also a large amount of high-quality pyroligneous vinegar can be produced, and at the same time activated carbon can be produced, thus killing two birds with one stone. Furthermore, since the activated carbon produced as a by-product here is dry distilled at a low temperature, the product has large pores that are involved in adsorption. That is, the pore diameter of activated carbon produced by the general gas activation method is 10 to 30 Å and 20 to 40 Å by the zinc chloride method, whereas the pore diameter of the activated carbon produced by the present invention is 10 to 30 Å.
It is extremely large at 160 Å and has a wide distribution. Another advantage of low-temperature dry distillation is that a large number of various acidic functional groups remain on the carbon surface as surface functional groups, which act as ion exchange sorption functions, a feature not found in general commercially available activated carbon. Having a large pore size and a wide distribution width not only means that the amount of adsorption is large and that adsorption can be performed over a wide range, but also that the adsorbed substance can be easily desorbed. Activated carbon produced by conventional methods is regenerated by heating it to 600 to 700°C. Since the activated carbon produced by the present invention is easily desorbed, it can be regenerated simply by cleaning with a chemical solution such as a hot alkaline solution, and there is no need for high-temperature firing. This means that while the regeneration loss due to conventional baking regeneration is several percent per regeneration, the loss during chemical regeneration is less than 0.1%. Another advantage of large pore size is a fast adsorption rate. In liquid phase adsorption, the solution is often high, but in this case there is a particular difference. For example, when the sugar solution Brix is 60° and the temperature is 70°C, the adsorption rate is 3 to 6 times that of general activated carbon. That is, it is possible to downsize the adsorption equipment. The activated carbon produced as a by-product according to the present invention is a high-grade special activated carbon having many characteristics as described above. The following table shows a comparison of the yield and quality of wood vinegar and charcoal or activated carbon obtained by the charcoal burning method and the production method according to the present invention. (In the table, parts and percentages are by weight.)
【表】
次に実施例によつて本発明を更に具体的に説明
する。以下の実施例において割合を出す部、％は
重量による。
実施例 １
杉材おが屑100部を乾燥機で60℃24時間乾燥し
た後、リン酸（工業用75％）を純リン酸分として
220部加えて良く混ぜ合す。混合物をマツフル炉
中で徐々に加熱し２時間30分で350℃まで昇温、
更に30分かけて390℃まで加熱し乾溜を完了した。
その間の熱分解ガスは30℃まで冷却し木酢液と
して回収した。炭化物はカラムに水を通してリン
酸を回収し、活性炭を得た。
原料および製品の割合は次のとおりである。
原料おが屑内地材杉（10〜100メツシユ） 100ｇ
−含有水分５％−
添加リン酸（75％）量 293ｇ
回収木酢液 182c.c.−酢酸濃度3.1％−
活性炭 47ｇ−ベンゼン吸着42％、見掛比重0.21
ｇ／c.c.−
実施例 ２
ヤシ殻（未炭化）100部を粉砕して粒度を10〜
20メツシユに揃えた後、リン酸（75％）を純リン
酸分として130部加え混合、リン酸分をよくしみ
込ませる目的で100時間ねかせる。その後マツフ
ル炉に入れ徐々に加熱し、３時間で380℃まで昇
温し更にその温度に３時間保持し乾溜を完了し
た。
原料及び製品の割合は次のとおりである。
原料ヤシ殻（10〜20メツシユ） 100ｇ−水分11
％−
添加リン酸（75％）量 173ｇ
回収木酢液 123c.c.−酢酸濃度5.0％−
活性炭 43ｇ−ベンゼン吸着42.3％、見掛比重
0.3ｇ／c.c.−[Table] Next, the present invention will be explained in more detail with reference to Examples. In the following examples, parts and percentages are by weight. Example 1 After drying 100 parts of cedar wood sawdust in a dryer at 60°C for 24 hours, phosphoric acid (industrial grade 75%) was added as pure phosphoric acid.
Add 220 parts and mix well. The mixture was gradually heated in a Matsufuru furnace and the temperature was raised to 350℃ in 2 hours and 30 minutes.
The mixture was further heated to 390°C over 30 minutes to complete dry distillation. During that time, the pyrolysis gas was cooled to 30℃ and recovered as pyroligneous vinegar. The charcoal was passed through a column with water to recover phosphoric acid, and activated carbon was obtained. The proportions of raw materials and products are as follows. Raw material Sawdust Inner material Cedar (10-100 pieces) 100g
- Moisture content 5% - Added phosphoric acid (75%) amount 293g Recovered wood vinegar 182c.c. - Acetic acid concentration 3.1% - Activated carbon 47g - Benzene adsorption 42%, apparent specific gravity 0.21
g/cc- Example 2 100 parts of coconut shell (uncarbonized) was crushed to a particle size of 10~
After preparing 20 meshes, add 130 parts of pure phosphoric acid (75%), mix, and leave to rest for 100 hours to allow the phosphoric acid to soak in. Thereafter, the mixture was placed in a Matsufuru furnace and heated gradually, raising the temperature to 380°C in 3 hours and maintaining that temperature for another 3 hours to complete dry distillation. The proportions of raw materials and products are as follows. Raw material coconut shell (10-20 mesh) 100g - moisture 11
% - Amount of added phosphoric acid (75%) 173g Recovered wood vinegar 123c.c. - Acetic acid concentration 5.0% - Activated carbon 43g - Benzene adsorption 42.3%, apparent specific gravity
0.3g/cc-