CN1067655C

CN1067655C - Method for producing high performance active carbon from nut shell

Info

Publication number: CN1067655C
Application number: CN 97118398
Authority: CN
Inventors: 胡福昌
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-10-29
Filing date: 1997-10-29
Publication date: 2001-06-27
Anticipated expiration: 2017-10-29
Also published as: CN1215694A

Abstract

The present invention relates to a method for manufacturing high-performance unshaped granular active carbon by chemical activation, which uses fruit kernel hulls as raw material. Coarse fruit kernel hulls with granularity not larger than 30mm are processed at 25 to 130 DGE C by a phosphoric acid solution of a concentration of 50 to 85 wt%, the kernel hulls are carbonized at 160 to 250 DEG C after being wetted and expanded and are activated at 400 to 600 DEG C, phosphoric acid is recovered by a common method, and finished products are obtained after the kernel hulls are washed with water, dried, crushed and sieved. Maximal hole capacity reaches 1.6 ml/g, maximal surface area reaches 2500m<2>/g, and middle holes account for 40 to 60%.

Description

The method of producing high performance active carbon from nut shell

The invention relates to the fruit stone shell is the method that raw material is made unsetting granular carbon, is a kind of high pore volume, high surface area, the manufacture method of the unsetting granular carbon that mesopore prosperity and raw material consumption are very low.

Existing production fruit stone shell process of active carbon, normally earlier raw material is put in the charring furnace dry distillation charring under 300-700 ℃ of temperature, then with the broken screening of carbonized material, again in activation furnace under 800-1000 ℃ of temperature water flowing steam, burning gas or both mixed gass activate, be referred to as gas activation method (physics method).The shortcoming that this method is main, the one, product is less-developed based on micropore, mesopore, not too adapts to absorption of liquid phase macromole and solvent recuperation, the 2nd, raw material consumption is very high, activation charcoal per ton need consume tens tons on fruit stone shell, even up to two, 30 tons, serious waste of resources.Adopt pharmaceutical chemicals activatory methods (chemical method) such as zinc chloride, phosphoric acid, can high yield ground manufacturing hole volume big, the gac of mesopore prosperity, but this method always only to be used for the wood chip be that raw material is made powdered carbon.This method requires activating agent to be penetrated into fully among the cell tissue of raw material, because the fruit stone shell is hard closely knit, conventional method is difficult to achieve the goal.In view of this, Chinese patent application 93120298 has proposed elder generation the fruit stone shell has been crushed to the 20-40 order, is that the phosphoric acid solution of 20-50% floods down at temperature 60-100 ℃ then with concentration, and the method for flotation comes down to a raw material fruit stone shell wood chipization.This scheme weak point one is that broken fruit stone shell efficient is low, power consumption is big, and produces considerable fine powder and can not utilize; This scheme weak point two is because used phosphoric acid solution concentration is not high, even soak into raw material fully, material acid improves than also being difficult to, can not make the product of high pore volume, high surface area, mesopore prosperity, and because of the severe corrosive of intermediate concentration phosphoric acid solution, when industrializing implementation, all many troubles can appear on technology and the equipment.This scheme weak point three is to make the big activated carbon product of granularity, and the granularity of finished product must be less than the granularity of raw material, so the product maximum particle size of this scheme is less than 20 orders (0.9mm).

The purpose of this invention is to provide and make high pore volume, high surface area, mesopore prosperity, and a kind of high yield of the unsetting granular carbon of fruit stone shell that can in wide region, select of granularity, low-cost and maneuverable method.

The inventor finds through further investigation, the fruit stone shell mixes and stirs by a certain percentage with the high concentration phosphorus acid solution, handle at a certain temperature then, can make the raw material swollen, expanded, reach the purpose of activator uniformly penetrating, further improve temperature and finish plasticizing process and dehydration carbonization, thereby solved key issue of the present invention.Carbonized material activates under 400-600 ℃ of temperature again, has made to meet the high quality active carbon product that the object of the invention requires.

Specifically granularity being no more than 30 millimeters gas dry fruit nucleocapsid (water ratio should less than 20%) and concentration 50-85% (W/W) phosphoric acid solution adds in the treatment facility by solid-to-liquid ratio 1: 0.6-1.5 (W/V) successively, at temperature 25-130 ℃, 110-130 ℃ of following stir process preferably, acid solution is infiltrated in the cell tissue of fruit stone shell gradually, Mierocrystalline cellulose, hemicellulose and xylogen are dissolved and are degraded, and the continuous swollen of particle, expanded, free acid solution are blotted.Treat that particle surface moist feeling and viscosity become not obvious, when being loose shape between each particle, temperature is increased to 160-250 ℃ and handles 1-3hr, because polyphosphoric acid intensive dehydration and katalysis, material the plasticizing reaction takes place and then by charing earlier.This carbonization process, the pore structure of remarkably influenced product and absorption property will be made the gac of mesopore prosperity, and this stage is very necessary.Should grasp according to raw material condition.Good conditions is temperature 180-220 ℃, time 1-2hr, and regularly stir material and make carbonized material be good loose condition (of surface) with anti-stick.Activation temperature is controlled at 400-600 ℃ (best 450-500 ℃), and soak time is grasped flexibly according to raw material and material quantity, generally expects to keep this temperature 0.5-2hr, (best 40-60 minute) after temperature reaches specified temperature.Usually the activation temperature height helps improving the intensity and the density of product, but too high temperature is unfavorable to the mesopore development; The too short long intensity and the absorption property that all can reduce product of soak time, soak time also has certain influence to the yield of product.

Activated material is pressed well-established law and is reclaimed phosphoric acid, washing, drying, fragmentation and screening, the finished product that can obtain meeting the requirements.

Be applicable to the Type of equipment of above-mentioned manufacture method, can adopt existing setting non-type equipment with suiting measures to local conditions, but preferably specialized designs stirring formula is soaked material equipment, stir formula charring furnace and moving-bed activation furnace.

The activation medicine is the difficult point place of the gac of chemical method production always to the strong corrosion of equipment and materials; the present invention is because the operation respectively of three stages of employing; having avoided preferably should anticorrosive resistant to elevated temperatures again contradiction; on the other hand; the corrodibility of high-concentration phosphoric acid is less; polycondensation becomes polyphosphoric acid in charcoal reactivation process; tetra-sodium; its corrodibility is littler; and has excellent corrosion resisting performance at equipment surface formation layer protecting film behind the material plasticizing; thereby make the selection of charcoal activation equipment material become more or less freely, can correspondingly reduce facility investment or increase the service life.

The present invention has following distinguishing feature:

The firstth, good product performance, high pore volume (maximum reach 1.6ml/g), high surface area (the maximum 2500m that reaches ²/ g) mesopore prosperity (40-60% that is about full pore volume), therefore very suitable liquid phase macromole absorption and gas phase organic solvent reclaim, and for example will improve 50-100% to the decoloration performance of industrial citric acid feed liquid than the unsetting granulated carbon of fine physics method activation shell in liquid phase.Is 1.5-2 times of above-mentioned physics charcoal in gas phase as the loading capacity to fuel gasoline steam, and has the performance of good low temperature desorption.Be fit to use in the gasoline car fuel evaporation control device.

The secondth, raw material consumption is low, and activation charcoal per ton needs nucleocapsid 2-3 ton approximately, the 10-30% of material consumption when only producing for the physics method.

The 3rd is that most of fruit stone shell need can directly not use through fragmentation, as wild jujube nucleocapsid, almond shell, tallow seed shell, nut-shell, China tree seed shell etc., Exocarpium cocois (Cocos nucifera L), Nux Canarii albi are also as long as coarse crushing to granularity is not more than 30mm and just can uses, thereby simplified production process, significantly save energy and raw material consumption.

The 4th is that the granularity of product can be selected in wide region and regulate and control, and is particularly conducive to and makes oarse-grained gac (maximum particle diameter 20mm).

The 5th is operation and the equipment of having save separate raw materials and phosphoric acid solution, and has simplified operation.

The 6th is owing to adopt high-concentration phosphoric acid and the operation respectively of three stages, has reduced the difficulty that equipment and materials is selected.

Below further specify with example:

Example 1

(gas is done, water ratio about 13% without the commodity wild jujube nucleocapsid 300g of fragmentation, the about 4-8mm of particle diameter), place porcelain dish, the phosphoric acid solution 300ml that adds 85% concentration, mix thoroughly, leave standstill 17hr under the room temperature, send into then in the temperature automatically controlled electric furnace, handle 2hr down for 110 ℃, every 0.5hr turns material once, then at 220 ℃ of charing 1.5hr, again 480 ℃ of activation 40 minutes, taking-up is put cold, reclaims the phosphoric acid after washing and aligns pH6-7,120 ℃ of dryings, obtain the activation charcoal 116g of similar raw material profile, obtain the unsetting granular carbon 80g of 8-16 order through fragmentation.This product bulk density 0.29g/ml, intensity 65%, iodine sorption value 1001mg/g, methylenum coeruleum decolorizing ability 13ml, B caramel decolorizing ability＞100%, tetracol phenixin adsorption rate 140%, #90 gasoline vapor adsorption rate (52 ± 2 ℃) 52%, desorption residual rate (30 ± 2 ℃) 12%.

Example 2

(gas is done, water ratio about 13% without the commodity almond shell 300g of fragmentation, particle diameter 4-25mm), place porcelain dish, the phosphoric acid solution 300ml that adds 85% concentration, mix thoroughly, leave standstill 18hr under the room temperature, send into then in the temperature automatically controlled electric furnace, handle 3hr for 120 ℃, every 0.5hr turns material once, and then at 220 ℃ of charing 1.5hr, 480 ℃ activate 40 minutes, taking-up is put cold, reclaim the phosphoric acid after washing, and levelling PH6-7,120 ℃ of oven dry, obtain the activation charcoal 102g of similar raw material profile, get the unsetting granular carbon 70g of 8-16 order through fragmentation.This product bulk density 0.32g/ml, intensity 72%, iodine sorption value 950mg/g, methylene blue decolorizing ability 12ml, B caramel decolorizing ability＞100%, tetracol phenixin adsorption rate 120%, acetic acid absorption (24-48 order) 720mg/g, #90 gasoline vapor adsorption rate (52 ± 2 ℃) 49%, desorption residual rate (30 ± 2 ℃) 13%.

Example 3

Tallow seed shell 300g (water ratio about 11%, particle diameter 2-7mm), place porcelain dish, add and reclaim strong phosphoric acid (concentration about 85%) 300ml, mix thoroughly, send in the temperature automatically controlled electric furnace, handle 3hr for 110 ℃, every 0.5hr turns material once, then at 200 ℃ of charing 2hr, 480 ℃ activate 40 minutes, and taking-up is put cold, reclaim the phosphoric acid after washing and also align PH6-7,120 ℃ of oven dry, obtain the activation charcoal 140g of similar raw material profile, get the unsetting granular carbon 108g of 24-48 order, this product bulk density 0.36g/ml after the fragmentation, intensity 90%, iodine sorption value 980mg/g, methylenum coeruleum decolorizing ability 12.5ml, tetracol phenixin adsorption rate 115%, acetic acid absorption (24-48 order) 660mg/g, #90 gasoline vapor adsorption rate (52 ± 2 ℃) 48%, desorption residual rate 14%.

Example 4

Nut-shell 120g (gas do, the about 5-15mm of moisture about 14% particle diameter) places porcelain dish, adds the phosphoric acid solution 100ml of 85% concentration, mix thoroughly, send in the temperature automatically controlled electric furnace, handle 3hr for 120 ℃, every 0.5hr turns material once, 500 ℃ activate 40 minutes, taking-up is put cold, reclaims the phosphoric acid after washing and aligns PH6-7,120 ℃ of oven dry, get the activation charcoal 48g of similar raw material profile, get the unsetting granular carbon 32g of 8-16 order after the fragmentation.This product bulk density 0.28g/ml, iodine sorption value 900mg/g, methylenum coeruleum decolorizing ability 11ml, #90 gasoline vapor adsorption rate (25 ± 2 ℃) 40%, desorption residual rate (25 ± 2 ℃) 11.5%.

Claims

1, the method for unsetting granular carbon is made in the activation of fruit stone shell medicine, raw material floods with chemical solution, charing at a certain temperature and activation then, it is characterized in that: the coarse grain raw material floods to turn simultaneously to the abundant swollen of feed particles under 110-130 ℃ of temperature with the phosphoric acid solution of 85% concentration and absorbs phosphoric acid solution fully, material is loose condition (of surface), then 160-250 ℃ of charing, again 400-600 ℃ of activation.

2, according to the method for claim 1, it is characterized in that: the granularity of raw material is 1-30mm.

3, according to the method for claim 1, it is characterized in that: charing and soak time are that whole materials reach the time that keeps this temperature after the specified temperature, charing 1-3 hour, activate 0.5-2 hour.