CA1304223C - Composite fuel - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A composite stabilized colloidal fuel is disclosed characterized in that carbonized material is subjected to continuous super colloidal milling to less than 30 microns, oil and water being added thereto, and also a process and equipment for manufacturing the same.

Description

~ 3~223 The present invention relates to a composite colloidal fuPl comprisin~
carbonized plant material, oils and water, (abbreviated as CCO~ herein) and to a process and equipment for manufacturing the same.
In the drawings Fig. 1 is a diagram showing the conventional processes for the manufacture of CCOM. Fi~. 2 is a diagram showing the process For manufacturing CCOM
according to the invention. Fi~s. 3(A) and 3(~) are respectively a side ~lew and a sectional side view of the super colloid mill used according to the invention. Fig. 4 ~onsists of diagrams o manufacturin~ equipment ussd ln the example of the invention.
In Fig. 3, D - 5 ................. Stator Masscolloider D - 6 ................. Rotor Masscolloider In Fig. 4 1 ..................... Hixing tank 2 ..................... First ~asscolloider 3 ..................... Storage bath 4 ..................... Finishing (second) Hasscolloi~er 5 ..................... Line mixer 6 ..................... Allocation storage bath 1 P4 ------------- Sludge pump Carbonized plant substances are inconvenient from the point of ViQW of handling such as transport on and storage compared with liquia fuels because of the loose solid form thereof. Research into a technique to convert these carbonlzed substances into liquid fuel has begun in many places.
The conventional processes for manufacturing composite colloidal fu91s comprising carbonized substances, oils and wa~er (hereinafter abbreviated as CCOM) are classified roughly, as shown in Fig. 1 of the drawlngs into the process of system A wherein CCON is manufactured after pulverizing carbonlzed plant material în a dry process and that of system B wherein CCOH is manufactured after pulverizin~ carbonized plant material in a wet process.
Both require a sta~e for pulverizin~ the carbonized plant substances and a separate stage for mi~ing with oils and reducing to colloldal form.
For this reason, much tims is required for the manufacture and, ln addition, the operatin~ co~ts of the whole process become expensive.

,, ~1 304~23 When using screen mills (hammer mills), roll mills, vibratory ball mills, mortars, etc. which are currently employed for coarse or fine p~ rlzat~on of carbonized plant material, two or three process sta~es are necessary Por the manufacture of CC0~. Horeover, the particle size of the carbonized plant material never becomes less than 100 microns in these cases.
As a result o~ various investigations in view of this sit~atlon, the present inventors have found that, thr~u~h an improvement in a super colloid m~ trade mar~: ~asscolloider), the carbonized plant material can be pulverized to particles less than 20 microns and, at the same t~me, oil and ~ater are ~ell mixed with the carbonized plant material ana the whole brought to colloidal form to produce CC0~.
For the improvement to the super colloid mill, attention was direoted to t~e fact that the clearance could be adjusted below O.Olmm by ma~ing two upper and lower ~rinders which onm the basis of the Masscolloider* composite, and vitriied grinders (w~etstones) were made composite through the polrmerlz~tion and impregnation of various polymers to provide an improved material. These vitrified grinders having been i~pre~nated with polymer (trade mark: Grindel~*
were fîtted to the Masscolloider* and tests were carried out o~er a long time. Consequently, it was confirmed that carbonized plant material could be pulverize~ to less that 20 ~icrons without ~ama~e. Therefore, oils were then added to the super colloid mi~l in equal æ~ounts and water ad~ed to the resulting sl~rry to less than 2~ of water and also very small amounts of dispersln~ and stabilizing ~gents. When the grinder was allowed to rotste at 19450 rpm u~er predeter~ined conditions and the clearance ~arrowed to a~ low as 0.01 mm, stable CC0~ was continuously pro~uced. AS a result o~ repeatsd experi~ents using this equipment for manufacturing CC0~ contlnuDusly, improvements were achieved and problems solved. Casbonizefl plant materlal was pulverized using three such ~aterials ~nd oils and predete ~ ned amounts of water were added to give CCOM continuou~ly ;n extremely stsble form thro~gh t~e action of dispersing and stab~lizin~ agents. Furthermore, gecondsry a~ære~ation was prevented by passin~ the m~terial ~hrough a line mixer, an~
CC~ havin~ stsbility over a long pefiod of time coul~ be manufactu~e~.
FrGm trial calculations of the operating costs for manufacture compared with that of conventional processeæ, it became clear that the cost wa~ abo~t ~00 yen/ton aceorains-to the process of the invention wh~c~ co~responde~ to ; PAT 6433-1 A grindstone-polymer composlte of thermoplastic or thermosetting polymer filling 30 $0% of the voids in the grindstone surface and wherein the volume fraction of poly~er is 0.09-0.21.
_ L_ ' one third to one fourth of that of conventional processes. The fact that CCOM
can be manufactursd continuously through a one-stage process as in the invention contributes greatly to improvement in productivity.
The process according to the invention for manufacturing CCOH in one process wherein the pulverization of carbonized plant material and the conversion to colloidal form (fluidization~ are carried out simultaneously and the equipment used therein ha~e been developed over many years. The invention relates to a process for manufact~ring colloidal fuel wherein oils, water and very small amounts of dispersing and stabilizing agents are adde~ to carbonized plant material ~CCOU) by one process and to equipment therefor.
CCON is a Bingham fluid (non-Newtonian property) having a yield value and the apparent viscosity thereof depen~s on the rate of defor~ation or shear force. It exhibits thixotropy, which is seen frequently among fluids of dispersed systems and it is time dependent. Therafore, a variety of factors can influence the manufacture of CCO~ having both fluidlty and stability.
These factors are (1) the physical properties of carbonized, plant material (2) type, addition amount and state of addition of dispersing and stabilizing a~ents, (3) the amount of water in CCOM, in other words, the composition ratio by weight of the components constitutin~ CCO~, (4) the equipment for the manufacture, (5) the process for manufacture, and so on.
(1) Carbonized plant materials are porous and can adsorb moisture, being difEerent from coal. Noreover, althou~h the basic physical properties of coal vary depending to the producing area, those of substances obtained by the carbonization of plants are not significantly influenced by the types of plants, the conditions of carbonization, or the like. ~he content of impurities, for example, ~ulfur, is low and organic matter is hardly present in the carbonized subst~nces. The content of pure carbon lies between 45% and 557..
This fact also means that carbonized plant material is not only very clean but also easy to pulverize. Uoreover, as to particle size and particle size distribution, when manufacturing CCON by using a ~asscolloider* equipped with Grindel*, the particle size distribution concentrates to 20 to 5 microns, dependin~ on the adjustment of the clearance. Such features have also been noted as good shape of the flame at the time of combust~on because of the uniformity of the particle size, and plugging o~ burner nozzles does not occur.

~3~223 (2) As to dispersin~ and stabilizin~ a~ents, all of th~se on the market currently for CCOH can be used. Since CCOH contains water within a range of 10 to 20%, the selection of dispersin~ and stabilizlng agents is broad.
The addition rate is pre~erably less than 0.1~ in te~ms of pure matter baqed on the total weight of CCOM and the method of add~tion i5 preferably to stir well with an homogenizer after addin~ the required ~mounts of aqueous solution of dispersing and stabilizing a~ents to the oil beforQhand.
CCo~ comprises four components, that is, carbonized plant substances, oil, water and very small amounts of dispersin~ and stabilizin~ agents, and both the quantity of heat and the vlscosity vary with the ratio of components by weight thereof.
Water adsorbed is present in small voids in the porous carbonized plant material, oil fills up the large pores and the dispersing agent lies at the interface of the carbonized substance with the oil. One of the feat~tres of CCO~ is that 10 to 20% by weight of water is present. This makes the manufacture through one process possible.
The ratio of carbonized plant material: oil is preferably within a range of 50:50 to 35:~5, and 10 to 20% of water becomes necessary based on the weight of the carbonized material and oil.
t3) As to the equipment for the manufacture, it is a special feature that the millin~ part of the Masscolloider* mill is made of a composite with polymer, and that the ~ixed slurry comprising carbonized plant substances has been pulverized coarsely, oil, water and very small amounts of dispersing and stabilizin~ agent being fed continuously into the lnlet. When the slurry passes through the millin~ part adjusted to a predetermined clearance, the coarsely pulverized carbonized substance is subjectad to fine pulverizatlon, while portions of the oil and water enter the carboni~ed substance and take on a homogeneous colloidal form under the influence of the dSsperslng and stabilizing a~ent, with CCO~ flowin~ from the outlet. When a high viscos1ty slurry is ~sed, heatin~ to 80C is possible since the outside of the super colloidal mill is ~ept warm by a heating jacket.
For the manufacture, the clearance of the ~rinders of the super colloid mill is adjusted to a predetermined settin~ to control the particle size and the production rate.
Bssed on the aforementioned facts, the stabilization mechanism at the time . - 4 of the manufacture of CCOM using the manufacturing process and equipment of the invention is inferred as follows: the porous carbonized substance has a large surface area and the exposed surface is almost covered with polar -OH
groups. Any water molecules adhere to the -OH groups preferentially. When high molecular substances and surfactants with hydrophilic groups intrude into such a system, the surface tension is lowered and water covers the surface of the carbonized substance. At this time, the adsorbed state of an ionic surfactant is considered as follows: the functional groups oP the carbonized substance adsorb the hydrophilic groups and the hydrophobic groups are compelled to orient towards the water molecules. But this is unstable thermodynamically, so that bimolecular adsorption is realized. Mor~over, the hydrophobic groups adhere to the surface of the carbonized material.
On the other hand, at the watertoil interface, the surfactants are oriented with the hydrophilic groups thereof in the water phase an~ the hydrophobic groups thereof in the oil phase because of the existence of ionic surfactants and water on the surface of the carbonized material, that surface carries electric charges. As described, when approaching each other, the particles of carbonized substance become stable thermodynamically through reduction of the interfaces with water and oil. And, when a balance is realized between the ~lectrostatic repulsive for~e and the van der Wasls force, the particles of ca~bonixed substance bacome stablQ.
When manufacturin~ CCON by the use of the manufacturing proce3~ an~
equipment of the inYention, it became possiblè to produce CCO~ which was stable over a lon~ period of time with inexpensive operatlng costs.
In Fig. 2 of the drawings an outllne of the process for manufacturing CCO~
of the invention is shown. In the following the diagram ~8 expla~n~d.
A carbonized material from bark (moisture content: about 7% or so) with a particle size of less than 5 mesh (less than 3,962 ~m~, ejected from an impact pulverizer wherein the pulverization is effected by impact and shear action and the particle size is regulated on a screen by means of centrifugal force and air flow, was stored in R tan~.
On the other hand, 510 Xg of grade A heavy oil were transferred from an oil tank into a mixin~ tanX, and 4.43 k8 of dispersing and stabllizing agent and 126 kg of water introduced through respective pipes into the mixing tanX.
In the mixing tank, the mixture was stirred at about 1000 to 1500 rpm to P~T 6433-l i~ - 5 -, ~ .

~L3q~42;~3 homogenize these three components and fed to the slurry bath via P. The stirrer in the slurry bath rotated at a speed of 200 to 500 rpm and, when 316 kg of the aforementioned bark charcoal were added gradually to this slurry bath, the mixture became a homogeneous slurry after several minutes. The homogenized slurry was fed to respective hoppers D-l of the first super colloid mill D and then of the finishing super colloid mill D
~Masscolloider*2~KZA 10-10 with built-in Grindel*~ by using a line homo~enizer mixer. The explanation hereinafter is made according to Fi8. 3 Of the drawings.
The clearance of Uasscolloider D in the first super colloid mill was adjusted beforehand to 0.06 mm, and D-2 was closed ~nd D-3 locked in the off position. Then, D-4 was turned and, taking the point at which D-6 contacts D-S and D-4 does not move as O-point, the clearance bein~ inspected again.
When D (device) was switched on, D-6 rotated at 1450 rpm and the slurry converted to CCOM was ejected continuously from the outlet. This was introduced again to Masscolloider* D of the finishing super colloid mill.
By allowing the slurry to pass continuously through D , the clearance thereof havin~ been adjusted to 0.03 mm, CCOM was ejected from the outlet of D and accumulated in a storage bath. It then entered a storage tank from the storage bath via a line mixer.
The particle size of the carbonized material in CCOM obtained was as follows:

~i~ht (~ _ 0 0 0 8.521.8 8.7 llqS 8.4 ~.8 _. . _ _ _ _ Particl~ size S~m) 60 50 40 30 20 10 8 . O 6 . O 5 . O 4 . O
_ _ _ _ _ , _ Weight (~)10. 3 10.1 9.1 2 . 8 _ _ 100 _ Particle size ~m) 3.0 2.0 1.0 0.8 0.6 0.5 _ _ .

~ oreover, the quantity of heat was 7990 Rcal~kg which was a little higher than the calculated value of 7810 Kcal/k~. The viscosity was 4,650 cp. The weight ratio of carbonized material to grade A heavy oil in the CCOM obtained was 45:55 and the content of water was about 15% based on total weight of dispersion, and the total volume was about 900~, p~T 6433-1 - 6 -,.~

9 3~ 3 the theoretical volume bsing g24~ . The apparent bu~k spec~fic ~ravity was 0.06.
The volume fraction of CCOU obtained was found to bP: Vc (carboni~ed substance) = 0.1g, Vo (oil) = 0.65, Vmo (water) = 0.16. A combustion test with a spray burner showed excellent combustion.
In Fig. 4 of the drawings manufacturing equipment for CCOM with a capaclty of 400 kg/hr is shown. A concrPte example will be illustrated below in detail. Carbonized material from a carbonization ~urnace whlch burned dead wood from a forest was pulverized coarsely with a simple device and screened to less than 5 mesh with a Supermicron* pulverizer (at this time, moisture content was about 7~ or 50), transported through a pipe and fed to mixing tank 1.
On the other hand, to 1.85kg of Ribolac* 400 (purity: 37.4~, made by Lion Oil and Fat Co.) and 0.95kg of CMC, both being used as dispersing and stabiliæing agents, were added 155kg of water and 466X~ of grade A heavy oil.
The mixture of oil and water having been ad~usted by weight the composition was t~ansported from a mixing tank through a pipe continuously to tank 1.
The ratlo of the carboni~ed material to the mixture of oil, water and dispersin~ and stabilizing agents was adjusted as follows and the mixture was stirred in tanX 1 until a homogeneous slurry was obtained: lcar~onized material 45%; oil 55%; water 15%; dispersing and stabilizing agent 0.3%].
The slurry mixed with the stirrer in tank 1 was fe~ to a super colloid mill 2 according to the invention via pump Pl. Super collold mill 2 was a Masscolloider* MKZB 15-50 with built-in Grindel* grinders. The slurry was milled with a ~rinder speed of 1,450 rpm and the clearance of the ~rinders of O.8 mm, and then collected in storage bath 3 (600~).
Then, after bein8 transported vi~ pumps P2 and P3, the slurry was introduced to super colloid mill 4 ~same as 2), wherein the grinders rotated at 1,450 rpm and a clearance of 0.02 mm, to enter Homonic* line mill 5 via pump P4. In this line mixer, by opening the clearance dial to maximum and by ad~usting t~e speed of rotation to less than 1000 rpm, secondary ag~regation was prevented, and, in this state, the ~lurry entered storage bath 6 ~lo00Q).
Special features of the invention are that the slurry passes through 2, 4 and 6, and the process for the manufacture includ~s steps 1 through 6.

- 7 ~
* Trade Mark ~L3~2~3 The test results of the quality of slurry in the storage bath 6 were as follows:
Carbonized material 38.0 Grade A heavy oil 46.5%
Moisture 15 . 5~o Viscosity 5900 ~p Specific ~ravity 1.09 Heat value 7620 Kcal/k~
Production rate 400 kg~hr 19 Volume fraction Yc = 0.22 Vo = ~.61 VMo = 0.17 A determination of the particle size distribution of the carbonized material gave following results.

_ _ ___ _ _ Weight (%) 0 0 0 0 9.7 23.8 7.5 9.5 7.5 8.4 .. _ _ _ __ I Particle size ~m) 60 50 40 30 20 10 8.0 6.0 5.0 4.0 Weight (%) 9.2 10.3 8.2 2.8 3.1 _ 100 ZO _ _ _ _ _ _ Particle size (~m) 3.0 2.0 1.0 0 8 Oo6 O.5 _ _ It is desirable that the raw materials to be used according to the inv~ntion lie within the ollowin~ regulation ranges.
1. Carbonized plant material Plants or solid matters therefrom such as wood substances, a~ricultural wastes, for exampIe, rice straw, peanut shells, etc., nuts, cottQn plant, further paper in industrial wastes, etc. are used. Th~
conditions for the carboniæation are not specifically limited. They may be such that the organic matters ~an vaporize at hi~h temperature and the fixed carbon is present in amounts more than 4070.
2. O~ls Kerosene, ~ and C grades of heavy oil, waste oil and other oils for fuel can all be used as raw materials.
PAT 6433~1 .-r -- 8 --~ * T~àde Mark ~.3~L223 3. Dispersing and stabilizing a~ent~
All of the commercial dispersing and stabilizing agents for COM and CCON usin~ surfactants as main raw materials can be used. However, Ribolan*
400 (liquid), Ribolan* 1400 (powdery), Teikapol* (liquid~, etc. are preferable because of low price.
The stability can be increased by adding CMC (carboxymethycellulose), sodium polyacrylate or the like at a rate of 20 to 3010 based on the wei~ht of the above surfactants. The rate of addition of dispersing agent is limited to 1% at most in terms of dry matter based on the totlil weight of CCOM.
4. Water Ordinary tap water may be used. Alchols in as much as 10% basea on the amount of water may be added. The content of water and alcohol has an uppe~ limit of about 20% based on the weight of CCOM.
5. Composition of CCO~
Although carbonized plant material and oil are the fundsmental components, fine powders from plants, petroleum coke, etc. can be added wlthin a range of about 3 to about 5% based on the weight of carbonized material and oil for the purpose of altaring the combustion characteristlcs such as centralization of flame, heat loss, exhaust gas and quantity of heat.
The pulverization of carbonized material by 8 dry process sntails health problems for workers, problems regarding disaster prevention, and the like and furthermore, it is difficult to obtain carbonized material o~ flne particle size considering that the operatin~ costs (consumption power) are hi8h. For these reasons, the use of a wet process generally prevails.
According to the invention, equipment hitherto considered lmpossible for pulverizing the material to less than 20 microns has been adapted to achieve this and besides a technique to make a composite with oil has been developed.
The significant means for these achievements is that the grinders for the super colloidal milling are composites with polymar.
According to the invention, it has been further found that the pulverization of carbonized material and the conversion to colloidal form csn be performed simultaneously as opposed to two to three stages ln the conventional manu~acturing process for colloidal fuel. Further, it has been confirmed that seconda~y aggregation does not occur, that the nozzles are not choked at the time of combustion, that the in~ection openin~ of the nozzles ~3~23 can be reduced, that the elongation and the spreading of the flame are excellent and that the combustion efficiency is high.
Calculations of the costs involved in the pulverization of carbonized plant material by the use of the Supermicron* pulverizer employed most frequently for the pulverization by the dry process from power consumption as an example, amounts to ~,5~2 yen/ton in the case of raw material with a moisture content of the carboni7ed material of 8.5'~ and 2,828 yen/ton when carboni~ed material in anhydrous state is used. According to the invention, the costs calculated from power consumptlon amount to 400 yen/ton inclu~ing both pulverization and conversion to the colloidal state. In the case of the Supermicron* pulverizer, the power consumption necessary for the mixing in of the oil and water and the conversion to the colloidal state costs a further 350 yen/ton. Therefore, calculations from power consumption for these show that the operating costs may be reduced to about one eighth in accordance with the invention. In addition, there is the benefit that the particla size is very fine being less than 20 microns, and furthel, remarkable effects such as reduction in labor costs and area of mill installation etc. can be expected economically as a result of the one stage procass.
Although the natural plant bodies decay over several years if left alone, it becomes possible to store them for thousands of years if carbonlzed.
Currently, the environment and the scale of life and industry have become different from those of the old days and instrumental systems are used on the assumption of the use of electricity, gas and liquid fuel. Tharefore, the use of firewood and charcoal as the fuels leaving them as they are can not really be considered.
CC0~ wherein the apparent bulk specific gravity is hi~h and fluidity (colloidal state) convenient from the point oP view of handlln~ such as transportation, storage, etc. has very large social benefit~ as a new fuel.
Leaving the a8e when single fuels, for example, patrol~um, coal or flrawoo~
are used, supplies of composite fuels havin~ a quantity of heat requlred for the purpose of use is tied in directly with saving of resources and energy conservation, so that it becomes a promislng fuel in a country where the fossil resources are poor.
Moreover, since the carbonized plant material i5 clean~ with the colloidal fuel made of a composite with oil, Sox per wei~ht i~ reduced and the function of water in CCO~ acts on the decrease in Wox. These facts may be advanta~eous for antipollution measures with the use of the fuel for boilers in the industrial area and those used in power stations.

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Claims (2)

1. A composite fuel in the form of a stabilized colloidal fuel which comprises pulverized carbonized plant substance, oil, water and dispersing and stabilizing agent, characterized in that the ratio by weight of carbonized substances to oil is within the range of 35:65-49:51, in that the water is included in an amount of 15-20% by weight, in that dispersing and stabilizing agent is included in a very small amount, and in that the colloidal fuel is manufactured by using a super colloid mill and in that the particle size of said pulverized plant substances is less than 30 µm.

2. A process for manufacturing a composite fuel which comprises coarsely pulverized carbonized plant substance, oil, water, and dispersion and stabilizing agent characterized by supplying the carbonized substances, the oil, the water and the dispersion and stabilizing agent to a super colloid mill in the following predetermined ratio by weight:
carbonized substances and oil within a range from 35:65 to 49:51, water in an amount of 15-20% by weight, and dispersion and stabilization agents in very small amounts, and then milling said mixture in a super colloid mill using grinders made of composite of grindstone with polymer until the particle size is less than 30 µm, thereby producing said composite fuel continuously in oneprocess.