CN1091073C - Preparation of active carbon adsorbing and storing methane - Google Patents

Abstract

The present invention relates to a preparation method of activated carbon adsorbing and storing methane. In the method, petroleum coke or pitch coke used as raw material and a KOH activating agent are used for preparing pulverulent activated carbon with large specific surface area; the pulverulent activated carbon is mixed with adhesive by the ratio of 1:0.30 to 0.60; the mixture is formed by extrusion under the conditions of 20 to 130 DEG C and 50 to 320MPa pressure, the mixture is carbonized at 700 to 1000 DEG C, and is activated at 700 to 1000 DEG C by using water vapor or carbon dioxide, and thus, formed activated carbon with large specific surface area is prepared. The formed activated carbon prepared by the method has a methane volume adsorbing amount of 140 to 170 V/V at 26 DEG C and 3.5MPa and 190 to 240 V/V at 5.5MPa. The formed activated carbon has the advantages of simple preparation method, large methane volume adsorbing amount, etc. The present invention provides favorable prospects for large-scale application in the future.

Description

The preparation method of active carbon of absorbing and storing methane

The invention belongs to a kind of preparation method of active carbon, being specifically related to a kind of is the method for the active carbon with high specific surface area of feedstock production absorbing and storing methane with refinery coke or pitch coke.

Sweet natural gas is subjected to the generally attention of automobile industry just day by day as a kind of aboundresources, the oligosaprobic automobile fuel that substitutes.Yet compare with gasoline, the energy density of Sweet natural gas (combustion heat of every volume fuel) is lower, and in order to address this problem, people have worked out compressed natural gas (CNG) technology, and have been applied to automobile industry.But (＞the safety 20MPa) brought and economic problems have limited it and have used widely and develop because high pressure.By contrast, absorbed natural gas technology (ANG) can (3-4MPa) charge into Sweet natural gas in the lightweight container that sorbent material is housed under relatively low pressure, utilizes adsorption technology to come natural gas-storing, thereby is expected to be applied in the development of automobile industry.Selecting the suitable sorbent material with high methane loading capacity and adsorption desorption speed is the step that absorbed natural gas technological direction practical large-scale is used most critical.In general sorbent material, gac is to loading capacity maximum (the Parkyns ND of methane, Quinn D F.Porosity in Carbons, ed.Patrick J W.Edward Arnold, London, 1995.PP.302), yet commercial at present ordinary granular gac is because the too low (1200m of specific surface area²About/g), pore distribution is too wide, and the amount of absorbing and storing methane only is equivalent to 1/2nd (Quinn D F, Macdonald J A.Carbon, 1992,30 (7): 1097 of 20MPa lower compression storing methane amount under normal temperature, 3.4MPa.Under normal temperature 3-4MPa, the absorption of methane mainly is to occur in micropore, and along with the increase of gac specific surface area, the adsorptive capacity of methane also is the trend of increase.The active carbon with high specific surface area that makes with the KOH activation method mostly is Powdered greatly, packing density is smaller, though the quality adsorption to methane is bigger under normal temperature 3.5MPa, the volume adsorption that is scaled under the standard state is about 122V/V, less relatively, can not satisfy requirement of actual application.

The object of the present invention is to provide the high preparation method of active carbon of a kind of methane volume loading capacity.

Preparation method of the present invention comprises the steps:

(1) refinery coke or pitch coke are milled to 180-40 μ m, mix with the KOH solution impregnation dry back, wherein refinery coke or pitch coke and KOH weight ratio are 1: 1-6 under nitrogen protection, activates 0.5-2.0hr down at 700-1000 ℃ and makes the powdered active carbon with high specific surface area then;

(2) powdered carbon that aforesaid method is made and binding agent (weight ratio) are by 1: mixed (0.30-0.60) is even, and compression moulding under 20-130 ℃, 50-320MPa pressure obtains block charcoal;

(3) block absorbent charcoal temperature rise rate with 0.5-5.0 ℃/min under protection of nitrogen gas is risen to 700-1000 ℃ of charing processing 0.5-2 hour;

(4) with the block charcoal after the charing, under 700-1000 ℃, activate 0.5-2.0 hour with activator, can make the active carbon with high specific surface area of moulding.

Described binding agent is pitch, coal tar, resin.

Described activator is water vapour, carbonic acid gas.

The present invention has following advantage:

1. the pressed active carbon BET specific surface area of the present invention's preparation is 1916-2700m²/ g.

2. utilize the method moulding of adding binding agent, improved the packing density of gac, thereby improved the volume adsorption of gac for methane, the volume adsorption to methane under 3.5MPa can reach 170V/V, and the methane volume adsorption under the 5.5MPa can reach 240V/V.

Embodiments of the invention are as follows:

Comparative Examples

Get 40 gram refinery cokes, mix with the KOH solution impregnation that contains 160 gram KOH, activate 1.5hr down at 800 ℃, make the powdery active carbon with high specific surface area, this powdered carbon quality adsorption for methane under 26 ℃, 3.5MPa is 0.35g/g, and the volume adsorption that is scaled under the standard state is 122V/V; 5.5MPa the volume adsorption to methane is 158V/V down.

Embodiment 1

Make the high specific area gac of powdery by the method in the Comparative Examples; Get this kind powdery carbon 3 grams, add 1.9 gram mid-temperature pitches, at 80 ℃; compression moulding under the 160MPa pressure, then under nitrogen protection in 800 ℃ of charings 1 hour, again in 800 ℃ of following steam activations 1.5 hours; make high-specific surface area active form charcoal, its BET specific surface area is 2308m²/ g.This kind type charcoal is at 26 ℃, and the volume adsorption for methane under the 3.5MPa is 170V/V; 5.5MPa the volume adsorption for methane is 240V/V down.

Embodiment 2

Make the high-specific surface area powdered carbon by the method in the Comparative Examples; Get this kind powdery carbon 3 grams; mix with 1.8 gram mid-temperature pitches; compression moulding under 80 ℃, 160MPa pressure; then under protection of inert gas in 800 ℃ of charings 1.0 hours; again 800 ℃ of carbon dioxide activation 1.0 hours; make high-specific surface area active form charcoal, its BET specific surface area is 2053m²/ g.This kind type charcoal adsorptive capacity for methane under 26 ℃, 3.5MPa is 160V/V; 5.5MPa the volume adsorption for methane is 218V/V down.

Embodiment 3

Make the high-specific surface area powdered carbon by the method in the Comparative Examples; Get this kind powdered carbon 2 gram, mix, compression moulding under 25 ℃, 100MPa pressure with 3 gram coal tar; then under nitrogen protection in 800 ℃ of charings 1.0 hours; at 900 ℃ of following steam activation 0.5hr, make high-specific surface area type charcoal again, its BET specific surface area is 2700m²/ g.This kind type charcoal adsorptive capacity for methane under 26 ℃, 3.5MPa is 146V/V; 5.5MPa the adsorptive capacity for methane is 202V/V down.

Embodiment 4

Make the high-specific surface area powdered carbon by the method in the Comparative Examples; Get this kind powdery carbon 3 gram, mix, depress compression moulding down at 120 ℃, 50MPa with 1.3 gram resol.In 800 ℃ of charings 1.0 hours, and then in 800 ℃ of following steam activations 1.0 hours, obtain high-specific surface area type charcoal under nitrogen protection, its BET specific surface area is 2200m²/ g.This kind type charcoal volume adsorption to methane under 26 ℃, 3.5MPa is 148V/V; 5.5MPa the volume adsorption to methane is 191V/V down.

Embodiment 5

Make the high-specific surface area powdered carbon by the method in the Comparative Examples; Get this kind powdery carbon 3 grams, mix with 1.9 gram mid-temperature pitches, at 83 ℃, compression moulding under the 320MPa pressure.In 800 ℃ of charings 1.0 hours, and then in 800 ℃ of following steam activations 1.0 hours, obtain high-specific surface area type charcoal under nitrogen protection, its BET specific surface area is 2016m²/ g.This kind type charcoal volume adsorption to methane under 26 ℃, 3.5MPa is 154V/V; 5.5MP the volume adsorption with methane is 215V/V down.

Embodiment 6

Get 30 gram pitch cokes, mix, activate 1.5 hours down, make the powdery active carbon with high specific surface area in 800 ℃ with the KOH solution impregnation that contains 120 gram KOH; Get this kind powdery carbon 4 gram, add mid-temperature pitch 2.67 grams, compression moulding under 86 ℃, 160MPa pressure, then under protection of inert gas in 800 ℃ of charings 1 hour, in 800 ℃ of steam activations 1.0 hours, make the type charcoal again, its BET specific surface area is 1916m²/ g.This kind type charcoal volume adsorption to methane under 26 ℃, 3.5MPa is 142V/V; 5.5MPa the volume adsorption to methane is 196V/V down.

Claims (1)

Translated fromChinese

1.一种吸附储存甲烷的活性炭的制备方法，其特征在于包括如下步骤：1. a preparation method of gac for absorbing and storing methane, characterized in that it may further comprise the steps:(1)将石油焦或沥青焦磨碎至180-40μm，干燥后与KOH溶液浸渍混合，其中石油焦或沥青焦与KOH重量比为1∶1-6，然后于氮气保护下，在700-1000℃下活化0.5-2.0hr制得粉状的高比表面积活性炭；(1) Grind petroleum coke or pitch coke to 180-40 μm, dry and impregnate and mix with KOH solution, wherein the weight ratio of petroleum coke or pitch coke to KOH is 1:1-6, and then under nitrogen protection, at 700- Activation at 1000°C for 0.5-2.0hr to produce powdery activated carbon with high specific surface area;(2)将上述方法制得的粉状活性炭与沥青或煤焦油重量比按1∶0.30-0.60的比例混合均匀，在20-130℃、50-320MPa压力下压制成型，得到块状炭；(2) Mix the powdery activated carbon prepared by the above method with pitch or coal tar in a weight ratio of 1: 0.30-0.60, press and form at 20-130°C and 50-320MPa pressure to obtain block carbon;(3)将块状炭在氮气的保护下以0.5-5.0℃/min的升温速率升至700-1000℃炭化处理0.5-2小时；(3) Under the protection of nitrogen, the block carbon is raised to 700-1000° C. for 0.5-2 hours at a heating rate of 0.5-5.0° C./min;(4)将炭化后的块状炭，在700-1000℃下，用活化剂进行活化0.5-2.0小时，可制得成型的高比表面积活性炭。(4) Activate the carbonized lump carbon with an activator at 700-1000°C for 0.5-2.0 hours to obtain a shaped activated carbon with a high specific surface area.