DD223076A1 - CARBONIC ADSORB AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Abstract

The invention relates to a carbonaceous adsorbent and process for its preparation. The invention may be used to remove hydrocarbons from or from aqueous media in environmental technologies and in the treatment of industrial effluents. The inventive adsorbent is obtained by subtraction of lignite and is by a specific pore volume of at least 0.10 cm3 / g for pores having a diameter smaller than 15 nm, a specific pore volume of at least 0.02 cm3 / g for pores with a diameter less than 2 nm characterizes. The adsorbent is hydrophobic and has a density such that it has a density of 1 g / cm 3 before and after the hydrocarbon uptake.

Description

Title of the invention ,

Carbon-containing adsorbent and method for its. Production '

Field of application of the invention

The invention relates to a carbonaceous adsorbent for the removal of hydrocarbons from or from. aqueous media and a process for its preparation, the adsorbent according to the invention can in environmental technology 'and in the treatment of industrial wastewater or _o zu2? ·: 'Cleaning of surface washers used ». The process for the preparation of the adsorbent can be used in coal operations and in the working ¹ adsorbent manufacturing industry.,

Characteristic of the known technical solutions

For the preparation of carbonaceous adsorbents ^is:; a variety of carbonaceous feedstocks are used, such as anthracite, hard coal, coke, carbonized shells of natural products, peat, and the like. The methods of their activation that cause the formation of void structures can be categorized into two categories. "

In the "chemical activation" of carbonaceous or charred starting materials, these are mixed or impregnated with activating additives, such as 'zinc chloride, phosphoric acid, alkali carbonates, sulfates or bisulfates, and then pyrolyzed or carbonized.'

Δ. fr r ! -I " L V i i- ': -.->

The second category includes methods, "which are known as" gas activation ", in which the or to charring, char to temperatures up to 1273 K in the presence · carbon dioxide ·, oxygen, chlorine, water, hydrochloric _v or other gases heated becomes. .

Purely the "processes of the two categories usually require additional Yor and aftertreatments of the starting materials or of the carbon-containing adsorbents obtained, which considerably increase the technical complexity, such as, B ₀ acid treatment of the starting materials, mixing of thecomponents, Incorporation of the activating agents, washing processes for 'removal of the activating agent.'

Fach DD-WP 207 183 a method for the production of water and gas cleaning coal from lignite is known, after a combination of extraction and chemical activation is claimed.

 The ..IT-ac.hte.il-e of these "procedures consist.

- That: the activating agent from the carbonaceous adsorbents in aufwiger'Wise removed and recovered

, must be: (DD- ¹ IP .140 241 and 146 277),. Λ

- That, predominantly recognizable hydrophilic carbon-containing adsorbents arise which wetting and sinking in aqueous systems. (DD-WP 138 013) and therefore for the hydrocarbon removal of aqueous surfaces not in each

'-.-.-]? are all suitable, -. "

- That the activation of the starting materials depends on many parameters of the technical process, in order. to ensure a reproducible quality of the carbonaceous adsorbents (DD-WP 125 598). -. '.' '.

' Object of the invention; ·. · -; '. ·

The object of the invention is to convert hydrocarbons into suitable form by suitable adsorbents with high uptake and retention capacity so that they can be economically removed from or from aqueous media, as well as these adsorbents from carbonaceous starting materials that are available in sufficient quantity to produce in a simple economical way. ,

Explanation of the essence of the invention; ,

  The invention has for its object to achieve by using a carbonaceous adsorbent, the removal of hydrocarbons from or from aqueous media having said objective and to produce these adsorbents by creating a suitable cavity structure for a high .. recording and retention capacity. >. It has been found that a carbonaceous adsorbent is suitable for hydrocarbon removal from or from aqueous media, by subtraction processes. / * "% Brown coal is obtained and a specific pore volume of at least 0.10 cm / g for pores with a diameter

 'smaller than 15 nm, a specific pore volume of at least

• 5 ~ · ..,

0.02 cm / g for pores having a diameter less than 2 nanometers, is 'hydrophobic and has such a density' that the adsorbent before and after hydrocarbon uptake

'"'''''"""''".'. ~ \ "'r>"' - · ......... -. ,

has a density 5 = .1 g / cm.

According to the invention, these adsorbents are obtained by removing the soluble and volatile constituents of a brown coal with organic solvents or thermally at temperatures up to 773 K.

The subtraction (extraction) of the soluble and volatile components from the. Lignite can be treated with organic solvents, eg. aromatic and aliphatic hydrocarbons, chlorinated hydrocarbons, unpressurized or under pressure * '

It was further found that a 1 hermobehandiung. the brown coal to 773 K under exclusion of oxygen leads to carbon-containing adsorbents having the same property of the obtained by extraction with organic solvents. "By the inventive method vrf: rd obtained in a simple procedure without the addition of activating components, a cavity structure, the allows the 'use of the adsorbents according to the invention in the field of water and wastewater treatment.

Generally customary extraction apparatuses are for the preparation of the adsorbents according to the invention applicable, erdstromverfahren or DC, in Geg _s be-operated in geschlos.-Senen System ", '' The thermal treatment or the coupled ^procedure! Extraction / thermal treatment is carried out in common heatable apparatuses, eg in rotary kilns, multi-stage ovens, fixed bed reactors, tubular reactors, retorts.

The adsorbent according to the invention is hydrophobic and forms with hydrocarbons a buoyant mass whose consistency / uptake from or from aqueous media, even with a salt content, in a known manner facilitates hydrocarbons which are removed from or from aqueous media with the inventive sorbents are, z. B "Carburetor fuels, diesel fuels, motor oils, petroleum. It has moreover been found that, for the removal of hydrocarbons according to the invention, a particle size of the adsorbent of less than 1 mm is particularly suitable; The choice of particle size of the adsorbent according to the invention depends on the properties of the hydrocarbons. <. /

The application of the adsorbent to .Aqueous media contaminated by hydrocarbons, can be prepared by known methods, for. B. manual, mechanical, inflation or'aviotechnical. '. "''.'

embodiments

Example 1: "" ^Γ '

The testing of the adsorbents is carried out according to the "Directive on the suitability and use of substances as an oil binder" of the Ministry of Environmental Protection and Water Management of the GDR.

2 cm ^{J of} diesel fuel (DZ) were poured onto a water surface ·. After 5 minutes, this amount of hydrocarbons occupied a nearly circular area of 3.8 cm diameter. , '- ..

^v 'By applying 1 g of adsorbent according to the invention (particle size <0.8 mm, specific pore volume for pores <2 nm diameter 0.03 cnrVg, for pores <15 nm diameter' .0.12 cm / g). occurred within 5 minutes, a contraction of the DK film to 3.2 cm diameter. The viscous coal DK mixture formed can be compared to pure DK with sieve. l.Offein (mesh size 0.5 mm) scoop off bsw, lighter than pure DK suck off the surface. The buoyancy of the DK coal mixture persists longer than 24 hours. From the extracted DK coal mixture, the DK can be separated by distillation. On the water surface less than 1 % of the applied DK remain.

Example 2:. , '

The procedure according to Example 1, xlur instead of.Wasser. ; a 3% saline solution is used. The effectiveness of the adsorbent according to the invention is not impaired by the use of salt water.

Example 3:

On a water surface, 5 ml of machine oil IiN 232 are applied. The oil spreads to a spot 4.8 cm in diameter. By applying 1 g Inventive Adsorbent

""" - " -

(Grain size <LO, ^:; 3 mm, specific pore volume for pores'< 2 nm diameter 0.04 cnrvg, for pores <15 nm diameter 0.14 CDrVg). diameter of oil stain decreases: to 4,1 cm. The formed oil-coal mixture can draw _t by switching off or sucking from the water surface can be easily removed. Oil and coal can be largely separated by pressing or ^; burn together in suitable combustion plants. / '.-' .. '

Example 4:: "-2 ....

By applying 5 cm machine oil MV 232, an oil surface of approx. 4.8 cm is produced on a water surface. After · application, of 2.5 g erfindungsg'emäi3en adsorbent (particle size <C ... 0 '5 mm, specific pore volume for pores <2 nm throughput ¹ razor. 0.02 cm / g, for pore <15 ^ m diameter 0.12 cm ^ / g) reduces the, oil film to 3 »9 cm in diameter. Within TO minutes, a bitumen-like, buoyant

' ¹ . , ,

Product that can be mechanically removed from the water surface. ^{; i} The remaining water surface is nearly oil

Example 5: '·' ".: - '

5.cm "of diesel fuel (DK) are applied to a water surface and the water surface is mechanically charged, resulting in a large number of small droplets and films on the water surface, by application of 2 g, according to the invention Adsorbent (particle size / ^ 0.3 mm, specific pore volume for pores C 2 nm diameter 0.02 cnrVg, for pores

<15.nm diameter 0.10 cm / g) produce a few large DK coal aggregates, which are easily removable by suction bzwo skimming from the water surface. ,

Example .6: ·; ^: '·'.,.

.5 cm of petroleum are applied to the surface of a 3% by mass saline solution. The resulting oil film can be "spread by sprinkling 1.5 g of the present invention Adsorbs (particle size

'-. .. '- 7 -

/ 0.1 mm, specific pore volume for pores C 2 nm diameter, diameter 0.05 cm-Vg, for pores <15 nm diameter 0.17 cnr / g) to a bituminous, buoyant mass solidify, the mechanically light 'is removable.

Example 7:

By pouring 5 cm ^ of MV 232 machine oil, an oil film of approx. 5 cm in diameter is produced on a water surface. After applying 1.5 g of adsorbent according to the invention, which by heating in nitrogen flow for 2 hours at 623 K ge ^; (pore size <C .0.3 mm, specific pore volume w: for pores <2 mn diameter 0.06 cnr / g, for pores ^ 15 nm diameter 0.16 cm / g), the oil film decreases to \ 4j1 cm diameter. The resulting oil-adsorbent mixture can be removed by skimming or suction from the water surface. ..,

Example 8:

, A crushed lignite is continuously in countercurrent _; with toluene at temperatures below the boiling point

, extracted The lignite treated in this way is characterized by an s-pezi. ·. '··. ..- '. 3 · "

pore volume of 0.15 cm ^ / g for pores with a diameter less than 15 nm and a specific pore volume of 0.05 cm / g for pores with a diameter smaller than 2 nm \. The adsorbent thus obtained aggregates;

: hydrogen layers, -z. 3. Carburetor fuel, diesel fuel, petroleum, on water surfaces »Die.Schwimmfähigkeit der

Hydrocarbon adsorbent mass remains for at least 24 hours. "

Example 3:

A comminuted lignite is heated in an autoclave at a Purer-liquid ratio of 1: 4 with toluene for one hour at 453 K, separated from the extraction medium after cooling and dried in a stream of nitrogen.

The 'obtained' adsorbent according to the invention has a specific pore volume of 0.20 omr / ß for pores with a. Diameter less than 15 nm and a specific pore volume of

3 ''

0.09 cnr / g for pores with a diameter less than 2 nm.

The adsorbent thus obtained and its mixtures with hydrocarbons, for example diesel fuel and crude oil, are floatable on water surfaces for at least 24 hours. .

Example 10:.

A milled. Brown coal is heated in an inert gas atmosphere for 5 hours in a rotary kiln at 623 K. »The resulting adsorbent has a specific pore volume of .18 cm / g for pores with a diameter smaller, 15 am and a sp.ezi

    '3

fish.es _; Pore volume of 0.07 cm / g for pores with a diameter of less than 2 mn to _o ·. · ... The erfiadungsgemäße adsorbent is in the position, hydrocarbon-'stoff layers .z _o 2 32 to aggregate 3 "of gasoline, machine oil> MV ... on water surfaces and in this.

'Way their distance. facilitate. _o : · ·. -.

Example 11:. , , '. "A lignite treated according to Example 1 'is heated at 773 K for 3 hours with exclusion of oxygenΊ. Adsorbent is by a specific pore volume of 0.19 'cm / g for pores having a diameter smaller than 15 nm and a.'* i

specific pore volume of 0.07 cm / g for pores smaller than 2 nm characterized. The adsorbent according to the invention thus produced aggregates hydrocarbon layers, eg, of carburetor fuels, diesel fuels, on water surfaces. "The buoyancy of the resulting adsorbent-hydrocarbon mass remains at least 24 'hours."

Claims (5)

F r c g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g g 1. Carbon-containing adsorbents for hydrocarbon removal from or from aqueous media, characterized by a brown coal treated by means of subtraction, which has a specific pore volume of at least. 0.10 cm / g for pores with a diameter smaller than 15 has a specific pore volume of at least 0.02 cnrVg for pores smaller than 2 nm, hydrophobic is some having a density such that the adsorbent before and after the hydrocarbon uptake has a density , 1 g / crn ^ has « 2. Procedure. for the preparation of the carbonaceous adsorbents for hydrocarbon removal, characterized that the soluble and volatile constituents of a brown coal are removed by treatment with organic solvents and / or thermally at temperatures up to 773 K. 3 · Procedure according to point 2, ' characterized in that the removal of the soluble and volatile constituents is carried out with solvents, preferably aromatic and aliphatic hydrocarbons, chlorinated hydrocarbons. 4 · method according to item 2 to 3, characterized in -that the removal of the soluble and volatile constituents, parts of brown coal with solvents' pressure or under pressure " 5. Procedure according to item 2, - ^l characterized by that the thermal treatment up to 773 K under extensive Oxygen exclusion takes place »