DD260712A5 - METHOD FOR PROCESSING CARBON CONTAINING WASTE - Google Patents

Abstract

1. A process for the production of hydrocarbons from carbonbearing wastes by the hydrogenating separation of the carbon-bearing wastes with hydrogen and/or hydrogen-bearing gases and/or compounds which give off hydrogen, characterised in that the hydrogenating separation operation is effected at 250 to 900 degrees C and 5 to 280 bars in a fluidised bed.

Description

Field of application of the invention

The present invention relates to a process for the treatment of carbon-containing wastes.

The invention is applied in municipal and industrial fields for the disposal of synthetic organic wastes.

Characteristic of the known state of the art

It is well known in the public and in the art that the world's waste is an increasing burden on the environment.

For decades, landfill waste, e.g. stored in abandoned gravel pits, mine pits and other places. For a long time, the chemical structure of the waste and its long-term impact on soil and groundwater were ignored. More recently, certain waste has been stored in so-called special landfills. Here it is endeavored to seal the landfill against groundwater and soil.

For some time now, experts have been working hard to recycle or process the waste, for once to protect the environment and to extract usable products from the waste.

Thus, in "The Oil and Gas Journal", Dec. 25, 1978, p. 80, a pilot plant is described in which plastics can be converted into gases and oils by pyrolysis.

In "Hydrocarbon Processing", April 1979, p. 183, a combustion plant is described in particular for special waste.

The biochemical degradation of plastics has also been investigated (see, for example, "European Chemical News", Sept. 10, 1979, p.

In "Chemical Engineering", August 13, 1979, p41, a process is described according to which hazardous wastes are poured into hardening materials, eg cement.

An overview of the most important processes is presented in "Chemical and Engineering News", Oct. 1, 1979, page 34. Here, in particular, the gasification of biomass, namely wood waste and the like to carbon monoxide and hydrogen is described.

On p.36, left column of this document, an experimental program for the implementation of crushed wood in water is suspended, described with hydrogen in the presence of Raney nickel, as a catalyst.

In "Europa Chemie", 25, 1979, p.417, a process is described, after plasticized unsorted plastic waste and pressed.

Fluidized bed incineration of wastes is described in "Chemische Industrie", XXXII, April 1980, p 248. The conversion of waste and biomass by heating with water and alkalis is described in "Chemistry International", 1980, p. 4,

P. 20.

In addition, numerous other publications have become known.

Most recently, incineration in state-of-the-art plants has been further developed and large-scale plants built using this process have been built. Although dedusting and flue gas scrubbing are integrated into such systems, pollutants also escape to the atmosphere in small amounts, even with careful cleaning, such as heavy metals, SO ₂ , NO _x and others. The pyrolysis is now also operated on an industrial scale (see, for example, "Vereinigte Wirtschaftsdienste GmbH", Oct. 4, 1985, p.9) .Pyrolysis, however, has the disadvantages of the predominant formation of gaseous products and a heavily polluted coke residue

 The problem of waste processing is therefore still unsatisfactory according to this prior art.

Object of the invention

The aim of the invention is to provide an improved process for the treatment of carbon-containing wastes.

Explanation of the essence of the invention

The invention has for its object to carry out the processing of carbon-containing waste by hydrogenation in such a way that no unwanted emissions.

A surprising, compared to the prior art much cheaper solution to this problem, especially with regard to the recovery of very high levels of valuable products, the present invention, characterized in that the carbon-containing waste in the fluidized bed with hydrogen and / or hydrogen-containing gases and / or hydrogen donating compounds are reacted.

This process makes it possible to process wastes from which larger inorganic constituents of glass, metals, stone materials and the like are largely processed without further sorting into valuable hydrocarbons, ie to C 1 -C ₄ -hydrocarbons, to hydrocarbons boiling in the gasoline range and to middle-grade hydrocarbons. , and heavy oils, which can be used as diesel oil and for heating purposes. It is furthermore of particular advantage that the starting materials need only be comminuted to a small extent, that the products are virtually olefin-free and that heteroelements are obtained as hydrogen compounds which can easily be worked up according to the prior art. Pre-sorted materials are also processable according to this method, in particular in such a way that z. For example, contained in household waste mixtures of carbonaceous waste of synthetic origin, such as plastics or plastic mixtures, rubber, tires, textile waste and the like. At least roughly separated from the vegetable portion or biomass fraction and then subjected to the hydrogenating treatment, possibly together with industrial waste , such as As paint and paint residues and organic chemicals, industrial waste, organic-synthetic shredder waste of the auto industry, cable waste, scrap tires, sewage sludge or waste oils u.dergl. In this case, other waste such as paper, food residue, agricultural and forestry waste, wood, plants and the like can be largely separated, but also remain to some extent in the synthetic portion.

Also, the synthetic individual components are very easy to process under the conditions of the invention to valuable liquid products. In particular, production-specific or waste-specific waste can also be used, at least temporarily, separately from other types of waste.

For example, in the cable industry large quantities of Käbelabfällen to fall in the auto industry large amounts of so-called shredder waste, in the paint industry incurred large amounts of paint and paint waste, in the carpet industry to large amounts of carpet waste, in the rubber and In the plastics industry, for example in the production and processing of plastics, foams, elastomers, insulating materials, large amounts of waste accumulate, in the chemical industry large quantities of synthetic-organic waste are produced in the production of chemicals, which can not be enumerated here in detail. However, pre-sorted synthetic organic waste can also be produced in technical waste collection plants.

The enumeration of said production-specific or waste-specific waste is not to be considered as limiting, since according to the present invention, all synthetic organic compounds can be hydrogenated into valuable products.

In most cases, these production-specific or waste-specific wastes are mixtures; shredder waste usually consists of plastic mixtures, cable waste of mixtures of various components, textile waste of mixtures.

The same applies to other waste. According to the invention, however, even or very uniform waste can be implemented very well. The use of the waste-producer or production-specific waste can take place at least temporarily, for example until a stock of such waste has been consumed.

In the meantime, non-waste producers or production-specific waste can be converted, ie mixtures of several types of waste or z. B. mixtures of synthetic-organic waste as incurred in waste separation plants. The process is also very well suited for the co-hydrogenation treatment of said waste mixtures with coal, coal constituents such as coal oil residues, coal oils, pyrolysis oils, petroleum, petroleum residues, other petroleum components, oil shale, oil shale constituents, oil sands, bitumen and the like Mixtures of these materials. It is common that in the case of simultaneous hydrogenating cleavage of these additives many catalysts are suitable.

According to the present invention, the carbon-containing wastes to be reacted with hydrogen and / or hydrogen-containing compounds are optionally reacted in the presence of biomass or other vegetable or cellulose-containing materials in a fluidized bed with these gases, said with the aid of said gases Fluidized bed is at least partially generated or maintained. The gases may additionally contain other components, such as N ₂ , CO, CO ₂ , CH ₄ or water vapor. In total

however, the gases contain about 25% by volume of hydrogen. As fluidized bed reactors, both the prior art reactors and advanced fluidized bed reactors can be used. The used, solid, carbon-containing waste can be crushed to different material size, or even be used without comminution. In addition, a solid carrier material can be used, both in the straight pass as well as at least partially recycled. Such materials may be, for example, inert materials such as sand, gravel, corundum, ceramics, clay, coke or the like, which materials may also serve as heat carriers. However, it may also be catalytically active solid materials such as Fe, Mo, Ni, Co, W and other hydrogenating metals and / or catalysts containing their compounds, which may consist of individual or at least two of these components and the metals and / or whose compounds can be applied to carriers, eg on alumina, silica, aluminosilicates, zeolites, the abovementioned solid adjunct materials and other carriers known to those skilled in the art or of carrier mixtures. However, they can also be used without a carrier. Certain zeolites as such are also suitable.

Other suitable catalysts may be so-called. Disposable catalysts, such as hearth furnace coke, Winklervergasungsstäube, dusts and ashes incurred in the hydrogenating gasification of coal to methane (HVAC dusts) but also iron oxides and other iron compounds containing mixtures such as red mud, Bayermasse, · Lux mass, dusts from the iron industry and others, which materials may also be doped with hydrogenation-active metals and / or metal compounds, in particular with heavy metal salts, such as. For example, iron salts or salts of chromium, zinc, molybdenum, tungsten, manganese, nickel, cobalt, and also with alkali, alkaline earth, u.a. as well as with mixtures of these compounds.

The catalysts may be at least partially pretreated sulfidizing. It is understood that all of the mentioned support materials and catalysts can be used both individually and in mixtures.

In the fluidized bed both solid and liquid waste and optionally. Additionally biomass or other vegetable or cellulose-containing materials may be used, wherein the gas supply is adjusted accordingly. By way of example, as solid wastes, which can be used both individually and in a mixture, are mentioned:

Plastics, rubber, tires, textiles, paint and varnish residues, shredder waste, in particular from the automotive industry, cable wastes, paper, solid vegetable wastes, wood, plant and other cellulose-containing wastes, other solid organic-synthetic industrial wastes. Solid additives to these wastes may be: coal, such as brown or hard coal, peat, oil shale, bitumen, or mixtures thereof. However, other solid, carbon-containing wastes not mentioned here can be converted into valuable products under the conditions according to the invention. As liquid wastes may be mentioned as examples:

Waste oils, petroleum and coal refining oils, pyrolysis oils, crude oils, oil shale and oil sand oils, industrial organic liquid synthetic wastes, biosurfactants. However, other liquid feed products or waste products not mentioned here can also be converted into valuable products under the conditions according to the invention. The fluidized bed region may consist of liquid waste or molten solid waste, said additives such. Residual oils, coal, etc. may also be included, and solid, finely divided catalysts or inert solid materials, or both, are maintained in fluidized motion by the gas supplied within the liquid. In the case of non-meltable waste materials in the temperature range according to the invention, the fluidized bed process can also be carried out without the presence of liquid or in the presence of only slightly liquid product. The conditions of the hydrogenating reaction according to the invention can be varied within wide limits, depending on the starting materials. Thus, the temperature is from 300 to 900 ^° C., preferably from 350 to 800 ^° C., and more preferably from 400 to 600 ^° C. The pressure is from 1 to 320 bar, preferably from 5 to 280 bar and particularly preferably from 8 to 240 bar. The ratio of hydrogen to feedstock is determined in particular by the required amount of gas at a certain piece or grain size or amount of solid and / or liquid feedstock, which is necessary to maintain the fluidized bed. The gas velocity can be, for example, in the case of so-called stationary fluidized beds at 0.05 to 1.5 m / sec, preferably at 0.2 to 1 m / sec. However, even in the case of so-called fast-riser fluidized beds up to 30m / sec. to reach. It should be noted, however, that also by additions of other gases and by the addition of water vapor, the maintenance of the fluidized bed mitbestimmt wind as well as by the flow rate of inserted liquids. As hydrogen gas all hydrogen qualities can be used, even with admixtures such. As CO, CO2, H2S, methane, ethane, water vapor, among others

Highly suitable are hydrogen qualities, such as those produced in gasification reactions of carbonaceous materials with water vapor. Such materials may be residues from the processing of mineral oils or coal, wood, peat or residues from coal processing, for example hydrogenation. Also suitable are biomasses or the vegetable parts separated from domestic waste.

Of course, also very suitable are pure H ₂ -qualities such as electrolysis hydrogen. For example, according to the invention, for example, household waste can firstly be separated into vegetable and synthetic components, and then the vegetable component for hydrogen production can be fed to a gasification, while the synthetic component is subjected to the hydrogenating treatment. The vegetable portion may also be subjected to fermentation or other processing.

Solvent treatment with hydrogen-transferring solvents can also be preceded by the hydrogenating treatment, followed by separation into dissolved and insoluble matter, and the insolubilization being fed to the fluidized-bed hydrogenation reactor (s).

Also in this process variant, the feedstock in admixture with coal and / or coal components and / or petroleum residues and / or petroleum u.a. be hydrogenated.

Suitable solvents are, for. As tetralin, anthracene oil, isopropanol, cresol-containing oils, decalin, naphthalene, tetrahydrofuran, dioxane, but also, for example, petroleum-derived or derived from the plant itself hydrocarbons and oils and oxygen-containing hydrocarbons and oils. Finally, water or steam can be added.

According to the said process, waste mixtures can also be hydrogenated in such a way that mixtures of vegetable and synthetic waste, optionally with the addition of biomass in different stages are reacted under conditions in which on the one hand substantially the hydrolytic and / or hydrogenating reaction

vegetable or paper and biomass portion and on the other hand, the hydrogenating reaction of the synthetic organic waste takes place.

Thus, in the first stage, for example, a hydrogenating treatment, if appropriate. In the presence of hydrogenation catalysts and a pressure of 1 bar to 150 bar, preferably 25-60 bar, preferably in the presence of water and other protic solvents such as alcohols is used.

Subsequently, the oils obtained predominantly from the vegetable fraction can be separated off by solvent extraction, after which the fraction which has not been hydrogenated can be hydrogenated in the second stage under the conditions already described in the fluidized bed.

The stepwise processing can also take place in such a way that vegetable fractions or paper fractions or biomass in the first step are cleaved hydrolytically, for example in the presence of alkalis or acids, this reaction optionally taking place in the presence of CO and preferably in the presence of water and / or other protic solvents such as alcohols and in the second stage of the synthetic or predominantly synthetic fraction in the fluidized bed is hydrogenated.

Alternatively, the waste and / or biomass may be previously separated into a vegetable portion and a synthetic portion and separately processed under the conditions described.

Also in these cases can be worked both with and without catalysts. If necessary, it can be dried before the 2nd stage.

According to the invention, it is also possible to use the waste and / or the biomass to be hydrogenated in the presence of hydrogen or gases containing it and / or in the presence of hydrogen-transferring compounds, in particular hydrogen donor solvents but also in the presence of inert gases, ie thermally in mixing devices. in particular in extruders and mixing / kneading devices pretreatment.

Numerous other mixing devices such as, for example, kneading disk screw presses, co-kneaders, hollow screw heat exchangers, screw kneaders, kneading extruders, stirring apparatus, continuous mixers, reaction mixers, kneaders, grinding devices or mills such as bead, hammer or vibrating mills are also suitable for the pretreatment according to the invention ,

The method according to the invention makes it possible to process even little or not pre-separated waste mixtures. However, it is desirable for instrumental reasons, before inorganic materials such as stones, metals, glass and the like. Separate, at least coarse materials. It can also be a pre-separation in, for example, predominantly vegetable or cellulose-containing and predominantly synthetic materials, wherein the vegetable part can be processed separately such as in a fermentation.

The previous disadvantages of the prior art are overcome in particular by the fact that, despite the use of completely non-uniform waste mixtures valuable hydrocarbon oils can be obtained in high yields and present in the waste hetero elements such as oxygen, sulfur, nitrogen, halogens are converted into hydrogen compounds, the can be treated according to the prior art in a known manner.

This applies in particular to chlorine-, bromine- or fluorine-containing wastes. The hitherto uncontrolled problems of waste disposal, in particular the toxic and halogenated waste are therefore solved according to the invention without risk.

Examples which may be mentioned are polychlorinated biphenyls, PVC, fluoropolymers or halogen-containing solvents. According to the invention with the waste materials and petroleum, petroleum components and succession products, coal, coal components and subsequent products, asphalts, bitumen, oils from pyrolysis z. From coking or waste pyrolysis, oil sand products, oil shale products, heavy residual oils and the like are added and processed together. Also oils and residues, which originate from the plant itself, can be used according to the invention.

According to the invention, metal-containing wastes can be worked up in a particularly advantageous manner, since the metals are obtained in the form of ashes after the hydrogenation and can then be fed to a metal work-up. The reaction zone can consist of one or more reactors connected in series or in parallel. The resulting liquid hydrocarbons can be further processed according to the prior art, such as by further hydrogenating cleavage stages or refining stages and distillative separation. The non-condensed gases are freed by gas scrubbing of H ₂ S, NH ₃ , HCl, if appropriate also CO and CO ₂ . The hydrogen in the resulting gas can be recycled as hydrogenation gas to the (the) hydrogenation reactor (s). A processing of the lower hydrocarbons contained in the gaseous products, for example by steam reforming is also possible, with additional hydrogen being recovered.

The liquid products can be fed to a refining stage which is simply hydrogenating. In this case, even small amounts of heteroatom-containing compounds can be worked up completely hydrogenating, so that then the products are virtually sulfur, nitrogen and halogen-free. Higher-boiling fractions can be fed to at least one cracking plant, in particular a hydrocracking plant. If necessary, certain components can also be recycled from the processing back into the waste hydrogenation or before the waste hydrogenation. The process of the invention may also be combined with other waste hydrogenation processes, such as a sump phase dehydrogenation.

embodiment

The invention is explained in more detail below with reference to some examples.

Example 1:

A waste mixture of the green ton, consisting of films, hard plastics, textile and paper shares, which had been obtained after prior separation of the recyclable components, such as metals, glass and paper, was at 470 ⁰ C and 60 bar in the fluidized bed (quartz sand) reacted with hydrogen. The products obtained were a gas phase (9% by weight), 75% liquid products in the boiling range up to 39O ⁰ C and 16% residue (inert materials, carbon black and high boilers).

The gas phase contained 2% CO and CO _{2 in} addition to cid hydrocarbons.

Similar results were obtained with hearth furnace coke as support material instead of quartz sand.

Example 2:

Example 1 was repeated, wherein the feedstock calcium oxide was added. In the context of the analytical accuracy unchanged product composition, a HCl-free gas phase was obtained. The released from the PVC components HCI was thus almost completely bound.

Example 3:

A mixture of synthetic waste, which consisted of daily samples of several waste separation plants was reacted without further purification at 480 ° C and 100 bar in the fluidized bed (cobalt / molybdenum catalyst on Al ₂ O ₃ ) with hydrogen. The hydrogenation was virtually quantitative, but in comparison to Example 1, a higher gas content was obtained, which is due to the higher proportion of paper and biomass. A product was obtained which consisted of 17% of a gas phase, 70% of liquid product in the boiling range to 39O ⁰ C and 13% of residue (carbon black, inert materials).

Example 4:

"Light material" from shredding plants, which mainly contained plastics, rubber and cushioning materials, was reacted by hydrogenation in a quartz sand fluidized bed, the reaction being carried out at 460 ° C. and 30 bar.

A product was obtained which contained 64% of hydrocarbons in the boiling range up to 390 ^° C. The gas phase, which was 12% of the total product, contained 3.5% CO / CO ₂ . The residue consisted essentially of inert materials, such as metals, fillers, etc., and carbon black.

Example 5:

A plastic-containing waste mixture consisting of 30% cable sheathing, 40% lightweight shredder equipment and 30% scrap tires was converted to molybdenum oxide-doped alumina. After hydrogenation at 490 ⁰ C and 120bar 80Gew .-% liquid products were obtained to 390 ⁰ C boiling point, which contained only small amounts of olefinic hydrocarbons. The gas phase, which was 6% by weight, contained essentially saturated C 1 -C 4 hydrocarbons.

Example 6:

Synthetic organic waste components including PVC from a daily sample of a waste separation plant were introduced together with residues of mineral oil processing in the fluidized bed reactor. The plastic content in use was 60% by weight. The fluidized bed consisted of aluminum silicate impregnated with iron compounds.

After reaction bei470 ° C and 200 were obtained in the boiling range ⁰ to 390 C with a high aromatic content and 11- wt .-% of high-boiling products and residues bar 84Gew .-% oil. The reaction gas (5 wt .-%) contained only traces of CO and CO ₂ and the PVC used corresponding amounts of HCl.

When repeating the experiment and addition of calcium oxide, no HCI was detected in the exhaust gas.

Example 7:

A mixture of PVC-containing plastic waste from a garbage sorting operation was added to the fluidized bed reactor along with chlorine-contaminated oils and organic chemical residues containing 1% by weight of chlorine. The plastic content was 60% by weight. On aluminum silicates containing nickel / molybdenum, this mixture was reacted at 48O ⁰ C and 50 bar with hydrogen.

In addition to the gas phase (9 wt .-%) and 6% higher-boiling products, an oil in the boiling range to 39O ⁰ C was obtained as the main fraction in 85% yield. The chlorine content of this fraction was 3800 ppm.

By hydrotreating of oil fractions at 50 bar and 280 ⁰ C in a fixed bed reactor, a product was obtained in which chlorine was no longer detectable.

Similar results were obtained with undoped hearth furnace coke as a catalyst.

Example 8:

A mixture of tire waste, paint residue and wood waste was reacted without support at 490 ⁰ C and 120 bar.

As a product 54Gew .-% to 390 ⁰ C, boiling oils, 25Gew .-% gases including small amounts of CO and CO ₂ and 21 wt .-% solids (metal residues, carbon black, pigment components) obtained.

Example 9:

A mixture of shredded waste cables, scrap tires, wood and coal particles was reacted in the presence of a FeSO ₄ doped furnace coke as a catalyst at 460 ° C and 150 bar. As a product was obtained 34Gew .-% to 39O ⁰ C boiling oils, 30wt .-% gases and 36Gew .-% solids (especially cable metal residues and soot).

Claims (10)

1. A process for the processing of carbon-containing waste, characterized in that reacting the carbon-containing waste with hydrogen and / or hydrogen-containing gases and / or hydrogen-releasing compounds in the fluidized bed. 2. A process for the processing of carbon-containing waste, characterized in that reacting mixtures of carbon-containing waste with hydrogen and / or hydrogen-containing gases and / or hydrogen-releasing compounds in the fluidized bed. 3. Process according to claims 1 and 2, characterized in that one works at a temperature of 250 to 900 ⁰ C, preferably at 350 to 800 ⁰ C and more preferably at 400 to 600 ⁰ C. 4. Process according to claims 1 to 3, characterized in that one operates at a pressure of 1 to 320 bar, preferably at 5 to 280 bar and more preferably at 8 to 240 bar. 5. Process according to claims 1 to 4, characterized in that one additionally uses biomass and / or other vegetable and / or cellulose-containing materials. 6. The method according to claims 1 to 5, characterized in that reacting in the presence of (one) additional solids (s) in the fluidized bed, which are inert and / or catalytically hydrogenation. 7. Process according to claims 1 to 6, characterized in that in the presence of so-called. Disposable catalysts works. 8. Process according to claims 1 to 7, characterized in that one works in the presence of catalysts containing hydrogenation metals, in particular Fe, Mo, W, Ni, Co. 9. Process according to claims 1 to 8, characterized in that the waste to be hydrogenated mixed with petroleum and / or petroleum ingredients, especially petroleum residues and / or coal and / or coal components and / or oil shale and / or oil shale components and / or oil sands extracts and / or bitumen and / or asphalt and Asphalthenen be implemented. 10. The method according to claims 1 to 9, characterized in that the hydrogen content in the feed gases in the fluidized bed s 25 vol .-%.