CN1052703C - Coal-produced active carbon as fluidized bed carrier and its production method - Google Patents

Abstract

The present invention relates to coal-produced active carbon as a fluidized bed carrier and a preparation method thereof, and relates to active carbon products as synthetic catalyst carriers and preparation methods thereof. The active carbon comprises pulverized coal whose ash content is from 3.7 to 4.5% and a binding agent prepared from coal tar and coal pitch, and products are prepared by mixing formation, chemical treatment, hardening by roasting, carbonization and activation. In the mixing process, 100 portions of pulverized coal are added to 3 to 4 portions of zinc chloride-ammonium chloride composite solution. After carbonization, carbonized materials are immersed by a dissolved bismuth salt solution (BiOCl content is 0.012%) whose hydrochloric acid concentration is 6.5%. The products of the present invention have the advantages of high catalytic activity, good catalytic selectivity, little side reaction and long catalytic life.

Description

Coal-produced active carbon as fluidized bed carrier and manufacture method thereof

The invention belongs to the Chemicals field, particularly relate to a kind of manufacture method of making high application performance vinyl acetate between to for plastic ebullated bed synthetic catalyst carrier active carbon product and this product by coal.

At present, be used for ebullated bed vinyl acetate between to for plastic synthetic carrier active carbon mainly by hardwood raw material productions such as coconut husks.China's coconut husk shortage of resources is produced active carbon as fluidized bed carrier, and will not only cost an arm and a leg every year from external a large amount of import finished products and former charcoal, and needs a large amount of foreign exchanges of cost.China is not ideal enough with the product catalytic activity that coconut husk makes.Chinese patent has proposed a kind of manufacturing microballoon process of active carbon for No. 85102191, and it is to be raw material with the coal dust, makes through choosing grain, oven dry, charing, activation, and its main purpose is to replace the coconut husk charcoal aspect ebullated bed carrier charcoal.But the size range of this carrier is 0.3-0.7mm, make such bead particle, the technical requirements height, and it is big to implement difficulty, is difficult for to the suitability for industrialized production transition.

The objective of the invention is to overcome the weak point of above-mentioned active carbon as fluidized bed carrier making method, providing a kind of is raw material with abundant hard coal, employing is easy to the processing method of suitability for industrialized production, produces the vinyl acetate between to for plastic ebullated bed synthetic catalyst carrier active carbon of high use properties.

Weigh the boiling-bed catalyst performance and mainly see four aspects: 1. catalytic activity, it is determining same working condition to obtain the height of product production down, it is represented with " space time yield (STY) " usually; 2. catalytic selectivity, selectivity is good, and then side reaction is little, and impurity is few, the quality product height; 3. abrasive wear resistance, carrier active carbon is to use under the fluidization situation, requires material ceaselessly keeping the long time (4-5 month) in the frictional impact; 4. catalytic life, the factor of above-mentioned 2,3 liang of aspects has considerable influence to the length of catalytic life.Use method of the present invention to produce carrier active carbon, bigger improvement is arranged aspect catalytic performance.

Main raw material of the present invention is selected hard coal, and ash requires between 3.7-4.5%.The solvable composition of hydrochloric acid should account for 30-50% in the ash, and copper-lead content is less than 10mg/kg, and phosphorus content is less than 35mg/kg.Other raw material has industrial chemicals such as coal tar, coal-tar pitch and hydrochloric acid.Cleaned coal is worn into powder, and fineness is 75 μ m, with coal tar and coal-tar pitch by 10: the weight ratio of 6-10 is mixed with tackiness agent, be heated to 120 ℃ standby to drive away moisture content and lower-boiling impurity.Add 3-4 part zinc chloride-ammonium chloride composite solution in 100 parts of weight coal dusts, the chlorination zinc concentration is 20%, and the concentration of ammonium chloride is 10-14%.Add 60-68 part tackiness agent again, the amount of tackiness agent medium pitch matter should reach 4.5-5 part (method of calculation of asphalt content: the slightly fluctuation in the different places of production of coal tar medium pitch content, generally in the 54-62% scope, this index is informed by supply factory; Used coal-tar pitch is that mid-temperature pitch matter content is by 95%; The coal-tar middle oil content that can calculate tackiness agent medium pitch matter with the bituminous ratio of known binders, add-on according to tackiness agent can be calculated bitum amount), add 10-15 part hot water again, water temperature is 50-80 ℃, regulate the soft or hard that stirs material, be squeezed into the fine and close material of sheet or strip.Sheet material should be broken into and add antiseized coal dust behind the following particulate state fritter of 8-20mm to send into converter roasting hard, makes material slowly be warming up to 240-360 ℃ through 100-120 minute.Lower boiling fraction in the tar is driven away, and closed bituminous matter oxidation hardening, bonding possibility takes place between test portion to eliminate.Then material is carried out charing and handle, temperature is 500-650 ℃ eventually, and material carries out pickling after the charing, make iron-holder be lower than 0.2% after, wash with water to pH value between 5-7, water is drained.Hydrochloric acid with 4.5% soaked material 15 minutes, emit recovery, be that 6.5% the BiOCl that contains is 0.012% bismuth salts solution submergence material again with solvent concentration of hydrochloric acid, keep and emit solution (regulate concentration after repeatedly use) after 15-20 minute, with a small amount of 4.5% hydrochloric acid flushing reclaim particle surface bismuth salt (when concentration of hydrochloric acid reduce to 4.9-5.1% when following BiOCl in the solution precipitate separate out).Water repetitive scrubbing charing material is deposited in the charcoal material BiOCl, reaches the 6-7 discharging to pH value.Can activate after the oven dry, activation temperature 880-940 ℃, oxygen level is less than 1% in the stove, wash with the hydrochloric acid of 2-4% the activation back, and then water washes to PH and reaches 6-7, and activated material is broken before pickling or after the pickling, and the particle that sieves out between 0.3-0.7mm is finished product.

The present invention has following advantage:

1. in the spice process, admix an amount of ZnCl ₂-NH ₄The Cl composite solution, cause foaming in the material accelerating heat-up rate (with initial test time compare) Shi Buhui, this is to form the fine channel that flue gas is overflowed to the conversion of charcoal and when bituminous matter begins to decompose because it can quicken pitch on the one hand in the material grain, under this passage can be consolidated, and help improving the catalytic activity of product in bituminous matter decomposition course thereafter.

2. add water after adopting solvent bismuth salt hydrochloric acid soln submergence carbonized material, BiOCl is deposited in the charcoal, BiOCl at high temperature resolves into Bi ₂O ₃Under activation temperature, exist, but away from boiling point, the affinity interaction between polar molecule has attached to the effect bismuth oxide molecule that moves on the impurity there with liquid state, thereby can suppress the caused side reaction of impurity effectively, can obtain to be satisfied with and to help catalytic effect.Because pyroprocessing has been driven away the deleterious chlorion of Dichlorodiphenyl Acetate ethene synthesis system.

3. higher bituminous matter add-on and corresponding post-treating method make product have the long-term friction process that the intensity higher than general granular carbon makes it to adapt to ebullated bed.

4. above-mentioned three measures makes product of the present invention have high catalytic activity, and catalytic selectivity is good, and side reaction is little, and impurity is few, and quality product is qualified, and intensity is higher, premium propertiess such as long catalytic life.

Embodiments of the invention are as follows:

Embodiment one: with the selected hard coal of Ningxia Tai Xi is raw material, and ash oontent is worn into 75 μ m fineness coal dusts with it between 3.7-4.5%.With coal tar (asphalt content own is 58%), be made into tackiness agent by 10: 8 weight ratio with coal-tar pitch.ZnCl ₂-NH ₄The Cl composite solution is formulated as: ZnCl in this solution ₂With NH ₄The concentration of Cl is respectively 20% and 10%.Per 100 parts of weight coal dusts add 66 parts of heat adhesives, 4 parts of composite solutions and 50-80 ℃ of hot water of 10-16 part.Be squeezed into the fine and close material of sheet behind the mixing, sheet material is broken into fritter below 20 millimeters, add that to send into converter behind the antiseized coal dust roasting hard, top temperature 360-400 ℃, residence time 100-120 minute, then carry out pickling, washing, when emitting water flow velocity when slow, pH value reaches 6-7, stop washing water is drained, close the dewatering outlet, add the 4.5% hydrochloric acid submergence bed of material, keep bleeding off in 15 minutes water (waiting until the back uses), add the hydrochloric acid soln of bismuth subcarbonate.The method of joining of this solution is that 1.2 parts of bismuth subcarbonate are dissolved in 10,000 part 6.5% the hydrochloric acid (bismuth subcarbonate is transformed into BiOCl).The time that the charcoal bed of material is soaked is selected between 15 to 20 minutes according to the size of carbon granule degree.Soak the back and regain this solution, the hydrochloric acid with a small amount of 4.5% (be about charcoal heavy 6%) washes carbon-coating, washes charcoal material (being aided with heating) repeatedly with clear water then, when charcoal layer pH value emitted water during for 5-7.To expect that the oven dry back adds activation furnace, 880 ℃-940 ℃ of activation temperatures, this activation furnace has the function of discharging flue gas when replenishing charing.Activation is washed the back carrier charcoal that gets product of drying after sift out the 0.3-0.7mm particle after the fragmentation with 2-4% hydrochloric acid and clear water.This product is listed in the table below with the performance index and the synthetic test effect that contrast sample after trying out:

Project		The Chifeng produces coconut husk carrier charcoal	Product of the present invention
				Main performance index	Acetic acid adsorptive capacity mg/g zinc acetate adsorptive capacity g/100ml filling proportion g/ml abrasive wear resistance %	554.9 8.6 0.44 69.9	469.8 6.3 0.44 67.4
Synthetic effect	Space time yield (STY) T/m 3Day crotonaldehyde % acetaldehyde % poisoning of catalyst coefficient (KP) powder abrasion loss liter/day	1.14 0.91 1.16 0.005-0.01 15.2	1.33 0.48 1.27 0.003 15.2

From the table data as can be seen, the adsorptive value of product of the present invention is starkly lower than the coconut husk charcoal, the synthesis catalytic effect all obviously is better than the former.Embodiment 2 also herewith.

Embodiment two:

The raw material coal dust is with example 1, and to be 57% coal tar and medium temperature coal pitch be made into tackiness agent, ZnCl in the composite solution by 10: 9 weight ratio to asphalt content ₂And NH ₄The concentration of Cl is respectively 20% and 14%, and per 100 parts of coal dusts add 61 parts of tackiness agents, 3 parts of medicaments, 50-80 ℃ of hot water of 10-15 part, be pressed into fine and close sheet after mixing thoroughly, be broken into the 0.5-8mm particle, add converter, firmly roasting and charing is once finished, the charcoal material stopped in stove 80-100 minute, and fugitive constituent is controlled at 7-10.5%, top temperature 580-650 ℃, then carry out pickling and soak operations such as secreting activation, method is with example 1.Be listed in the table below with the performance index and the synthetic test effect of contrast sample:

Project		The Chifeng produces coconut husk carrier charcoal	Product of the present invention
				Main performance index	Acetic acid adsorptive capacity mg/g zinc acetate adsorptive capacity g/100ml filling proportion g/ml abrasive wear resistance %	551 7.3 0.41 /	471 5.8 0.44 67.2
Synthetic effect	Space time yield (STY) T/m 3The average crotonaldehyde amount of per day day output T % acetaldehyde % work-ing life (my god) powder disperses liter/day	0.97 41.8 0.15 1.26 90-110 206	1.14 47.5 0.14 1.25 130-135 162

Claims (2)

1. the manufacture method of coal-produced active carbon as fluidized bed carrier, the main raw material of gac is: the tackiness agent that coal dust, coal tar and the coal-tar pitch of ash content between 3.7-4.5% is made into, make ebullated bed vinyl acetate between to for plastic carrier active carbon through mix moulding, chemical treatment, roasting hard, charing, activation, it is characterized in that:

A. with coal tar and coal-tar pitch by 10: the weight ratio of 6-10 is made into tackiness agent;

B. mix and stir in the process, 100 parts of coal dusts add 3-4 part zinc chloride-ammonium chloride composite solution, and the concentration of zinc chloride in solution is 20%, and the concentration of ammonium chloride is 10-14%;

C. the material that is added with composite solution adds 60-68 part tackiness agent and 10-15 part hot water, and water temperature is 50-80 ℃, and mixture is squeezed into sheet or the fine and close material of strip;

D. molding materials being added antiseized coal dust, to send into converter roasting hard, rose to 240-360 ℃ through 100-120 minute, carries out charing then.

2. coal-produced active carbon as fluidized bed carrier according to claim 1 is characterized in that: the space time yield of reflection catalytic activity is 1.14T/m ³Day, the average crotonaldehyde amount of reflection catalytic selectivity is 0.14%, and it is 162 liters/day that the powder of reflection wear resistance disperses, and be 130-135 days work-ing life.