DE4329436C1 - Process for the preparation of synthesis gas from petroleum residues and used plastic or used plastic mixtures - Google Patents

Abstract

In the preparation of synthesis gas, the aim is to allow used plastics or used plastic mixtures to be admixed proportionately with the petroleum residues without significant predegradation and injected into the gasification reactor without causing any disturbances in the plant operation, and reacted. The used plastics or used plastic mixtures are melted in melting units after removal of impurities, brought into contact with partially compatible petroleum intermediates at temperatures below 300 DEG C and mixed with the main feed stream of petroleum intermediate by means of mixing devices. The entire feed stream is injected into the gasification reactor under increased shear forces, the proportion of used plastic being from 1 to 10% by weight. The used plastics or used plastic mixtures can be degassed during melting and mixed with additives. Recycling of used plastics in the preparation of synthesis gas from petroleum residues.

Description

The diverse and economically advantageous applications of Plastics have grown rapidly in manufacturing and the commitment, but with which recycling does not step could hold. There are several reasons for this.

The consumer goods made from recyclates are made from them New goods usually for quality and cost reasons inferior. Take the properties of such recyclate products but continues to decrease after each life cycle, so that on the one hand for Recycled only a limited market is available and for others will eventually go downcycling, analogous to the recycling of paper.

The so-called industrial waste that occurs during production batches, approach and bypass products, samples from continuous pro zeß- and analysis devices, etc.) or processing (incorrect char gates, sprues, etc.) have been used again for 20 years Material processed and used.

Waste plastics from industrial waste can usually be disposed of if single or similar, and depending on the contact Return the degree of minimization to material recycling. Waste plastics from household waste pose a problem Due to fluctuating composition, various types of pollution grade and different contamination and damage shares.  

Some of these plastics can be processed differently treatment processes (stopping process, floating-sink separation technology, Hydrocyclone, centrifuges etc.) separated according to their density and processed and used again in a manner typical of plastics. In usually this goes with a loss of properties in the Quality cascade and the use of such recyclates limited in quantity and property and only limited buildable.

The mixed old plastics, which due to their together setting and their degree of damage a material Withdrawing re-use, make it increasingly scarce Landfill opportunities pose a serious problem, so a substance Liche use of the damaged plastics must be done. It it is also known that plastics due to their structure (predominantly carbon and hydrogen) a high calorific value own and are considered petroleum-based finishing products, so that you can also use them energetically.

One way out of this problem is raw material recycling in which the waste plastics in refinery plants in niedermo lecular components are split back and used as a substitute act for petroleum products. Methods are e.g. B. pyrolysis or the hydrogenation.

It has also been suggested that the old plastics or old plastic mixtures as a substitute for fossil fuels (petroleum or coal) for the production of fuel gas, synthesis gas, reduction gas for the blast furnace process or of hydrogen alone or in Combination with petroleum intermediates or coal (DE 41 25 517, DE 41 25 518, DE 41 25 519, DE 41 25 520, DE 41 25 521, DE 41 25 522) to use.  

In the process of fixed bed pressure gasification, the old art substances or plastic mixtures analogous to the use of Lignite compacted into briquette-like shapes and up to 50% by mass added to the lignite briquettes.

Various methods have also been proposed to achieve this Process used plastics so that they can be used in refinery processes can be used and thus again in low-molecular cleavage products to be led back.

So in DE-OS 40 17 089 for the production of synthesis gas and analogously proposed in DE-OS 40 29 880 for fuel gas, the plastic waste by adding reactive gases such as sow material, air, possibly hydrogen and water vapor or water, which is given up as moistening of the feed material, with increasing to liquefy the temperature by degradation of the polymers, that they with conventional devices in combustion chambers or Reactors can be injected.

The disadvantage of these processes is that they are added from reactive gases to products that are not suitable for all ver are suitable for use or for considerable corrosion carry rates. So with the addition of oxygen or Air also contains oxygen-containing breakdown products, which some typesetting purposes are undesirable. When using water or water steam is generated in the presence of PVC or chlorine-containing additives substances an increased amount of aqueous hydrochloric acid, which is too high signs of corrosion. In the manufacture of Granules cause small "steam explosions" on the granulator head and you get at least partially foamed products.  

In the additional patents DE-OS 40 38 897 and DE-OS 41 29 885 suggested that the liquefied plastics become granules or sprayed into powder and used as raw materials alone or together with the raw materials from Synthesis gas and / or other usable gases or as fuel substance or used as a reducing agent.

It has also been suggested to add these granules or powders closing in liquids, preferably oils with similar Mix in density between 0.9 and 1 g / cm³ or in water mash up.

However, practical tests have shown that it is unacceptable There is a high degree of segregation and settling, the disturbances and result in business interruptions.

DE-OS 40 29 880 describes a process for gasifying art substances for the production of fuel gases have been described in which Appropriate plastics by treatment at elevated temperature Neten devices are liquefied so far that they burn rooms or reactor rooms can be injected. In the case, that with certain plastics, gasification after the extruder is still not sufficient, the still liquid plastics according to the additional patent DE-OS 40 38 897 not in a combustion chamber or injected reactor, but in an upstream Ver gassing chamber which is heated and in which the gasification takes place.

However, it has been shown that ancient art treated in this way mixtures of substances due to their strongly fluctuating molecular weight weight distribution when adding to petroleum intermediates only insufficiently solved and mixed and it during the Delivery and injection into the reactors too irregular keiten is coming.  

In DD-PS 2 00 891 a process for the extraction of coal described hydrogen from polyolefins, in which the polyols can be finely dissolved in liquid hydrocarbon mixtures, the pumpable solution obtained similar to mineral oil is then obtained thermal treatment at temperatures above 100 ° C is thrown and the resulting mixture of either one subjected to normal recycling in the mineral oil industry or without further treatment of an energetic use, preferably as heating oil.

The invention has the disadvantage that, on the one hand, only a small amount of poly olefin fractions can be mixed, otherwise the viscosity is too fast increases, and secondly, an unacceptably high coke formation both in thermal cracking and in the intermediate formwork Teten hydrogenation of the components boiling up to 180 ° C occurs.

The task was to develop a process for the production of Synthesis gas from petroleum residues and old plastics or old plastic mixtures where the old plastics or Waste plastic mixtures without significant advance degradation were mixed proportionately and without disturbances in the plant urged to be injected into the gasification reactor and around can be placed.

The object was achieved by a method for producing Synthesis gas from petroleum residues and old plastics or old plastic mixtures by adding the waste plastics or waste plastic mixtures after removal of metallic, inorganic / orga niche and mineral impurities in melting units be melted with a partially compatible oil between product is brought into contact at temperatures below 300 ° C, these components are mixed via mixing devices and with one Proportion of waste plastic or mixture of waste plastics from 1 to 10% by mass,  preferably 3 to 5 mass%, who supplied the gasification reactor the, the total mixture of one when being injected into the reactor 5 to 10% compared to the use of the pure petroleum intermediate subject to higher shear.

When using extruders, both single screw and also twin screw extruders, preferably co-rotating twin screw extruders are used.

The extruder can be with or without, preferably with a vent tion facility, operated.

The melting of the old plastics or the old plastic mixtures at temperatures below 300 ° C is particularly advantageous because one at these temperatures and the short dwell times no noticeable decomposition of most polymers occurs. Except at these temperatures, the coke formation is still neglected sigbarly low. On the other hand, the problem product poly vinyl chloride, which despite presorting up to 1 to 2 Mass% can occur in the waste plastic mixture, a sufficient rapid dehydrochlorination so that the hydrochloric acid that forms can be effectively removed. It is also possible after the on melt the old plastics or old plastic mixtures, these in a known manner directly or after a calming stretch filter to fine powdery ingredients or unmelted portions to discard.

It is also possible to add additives to the extruder, for example Alkali and / or alkaline earth compounds (e.g. chalk, hydrated lime or soda) added by the still existing halogens the, or other additives such as commercially available coke rer.  

The alkali and / or alkaline earth compounds become more advantageous premixed in part of the petroleum intermediate and in dosed this form in the extruder. In the presence of ali phatic polymer with halogen components have 200 to 1200 ppm alkali and / or alkaline earth compounds have been shown to be effective and in the presence of aromatic polymers with halo proportions 800 to 3000 ppm.

The addition of part of the Partially compatible petroleum intermediate already at the end of the ex truders, as this improves homogenization. It is possible to use both the main product for the Gasification vacuum visbreaker residue or preferably as a product add vacuum residue with lower viscosity. The relationship nis plastic mixture to petroleum intermediate at the end of Extruder is advantageously 1: 9 to 10: 0.

As an alternative to the extruder, a melting unit can also be used standing from a heatable container with integrated melt pump, used for the old plastic or for the old plastic mixture become. This reflow unit can also be used with a discharge unit and with metering devices for additives, which can also be added if necessary as described above, be equipped.

A stirred reactor with a turbo stirrer with stirring is preferred speeds of preferably 1000 to 1500 revolutions each Minute. In this case, the petroleum intermediate submitted and the waste plastic or the waste plastic mixture set. A ratio of waste plastic or mixture of waste plastics to Petroleum intermediate from 1: 9 to 1: 1 has proven to be special proven advantageous.  

In both cases the premixing of old plastic or old plastic mixture has in the union between main and sidestream homogenization via a static mixer proven. The main stream consists of the partially compatible Petroleum intermediate and the side stream from the melted Waste plastics or mixtures of waste plastics, possibly additives and if necessary, a portion of the partially compatible petroleum intermediate.

Has been particularly advantageous according to the inventive Ver drive proven when the mixture of old plastic or old art mixture of substances and petroleum intermediate at the entrance to the Verga solution reactor is subjected to increased shear. Show best results when using a print atomizing burner a pressure difference between the mixture from waste plastic or waste plastic mixture and petroleum intermediate pro product before and after the burner from 7.0 to 10.0 MPa, preferably 5.0 to 8.5 MPa, and so when using an annular gap burner probably between the mixture of old plastic or old plastic mixture and the petroleum intermediate, as well as the gasification oxygen and water vapor, a pressure difference before and after the burner from 0.3 to 0.7 MPa, preferably 0.3 to 0.5 MPa, is set.

From model studies in the technical center, it was possible to estimate that under these conditions the average particle size of the Droplet is between 10 and 15 µ.

It is also possible to use the feed mixture for the gasification reactor additional quantities of waste plastics or mixtures of waste plastics add, but then in degraded form.

As waste plastics or waste plastic mixtures in the sense of the Erfin can be used in the ge  advertising-related products, such as B. Agriculture films, transport packaging, canisters, hollow bodies, bottles etc. use, or the resulting in household waste, preferably the floating fraction (products with a density <1 g / cm³). It is but also possible to manufacture products (faulty batches, incoming and by-products in the event of a change of type, samples from process and Analyzers etc.) or processing (faulty batches, spray cast sprues etc.).

It was surprising that the Altkunststoffe / Altkunststoffge mix according to the procedure described without problems let the gasification process.

The invention is illustrated by the following examples explained in more detail.

Embodiments example 1

The plant produces synthesis gas from petroleum residues, which are listed in An presence of oxygen and water vapor to carbon monoxide (42 Vol-%) and hydrogen (40 vol-%) can be gasified at 1600 ° C, he testifies.

The petroleum residues are compared with one at 260 ° C Gasification reactor existing pressure drop of 8.0 MPa the pressure atomizing burner supplied.

The hourly mass flow consists of 20 t vacuum visbreaker back stand and 1.8 t of old plastic polypropylene.  

The old plastic is ent in a twin screw extruder Melting device melted at 280 ° C without the addition of additives and the petroleum residue using a static mixer added.

The mixture of petroleum residue and polypropylene is replaced by a Piston pump brought to such a pressure that for the Required increased pressure difference before and after shear Atomizing pressure burner is 8.5 MPa.

Example 2

The procedure was analogous to Example 1, with the following changes. The hourly mass flow exists when old plastics are added from 20 t of oil residue and 1 t of old plastic polypropylene as well 1 t old plastic polyethylene.

The waste plastic mixture is in a twin screw extruder with degassing device at 260 ° C with the addition of 1000 ppm Coke reducer as additive (Nalco 5272 from Deutsche Nalco- Chemie GmbH, Frankfurt a. Main) melted. At the end of Petroleum residue was fed in at 1 t per hour.

The old plastic mixture mixed with petroleum residue was over fed a static mixer to the piston pump at 260 ° C, which created such pressure so that those necessary for shear agile increased pressure difference before and after pressure atomization burner is 8.5 MPa.

Example 3

In a plant for the production of syngas from petroleum back  stalls that coals in the presence of oxygen and steam gasification of monoxide and hydrogen at 1600 ° C will be additional Lich used plastic.

The hourly mass flow consists of 20 t oil residue and 1.3 t old plastic polypropylene. The mass flow has one Temperature of 290 ° C.

The old plastic is melted at 280 ° C without the addition of additives zen and the petroleum residue (vacuum residue) in an agitator added. The speed of the turbo stirrer is 1100 revolutions per minute. Through the use of 3 melting devices and 3 agitators is the continuous addition to 19 t of oil back was secured every hour by a static mixer.

The mixture of petroleum residue and waste plastic is replaced by a Piston pump brought to such a pressure that for the Shear necessary increased pressure difference before and after printing atomizing burner is 8.5 MPa.

Example 4

The following changes were carried out analogously to Example 3: The hourly mass flow consists of 15 t oil residue, 0.3 t Waste plastic polypropylene and 0.3 t waste plastic mixture, that aliphatic and aromatic polymers with halogen components holds.

The polypropylene and the waste plastic mixture are combined in one Melted reactor at 270 ° C, previously in the stirrer vacuum residue has been submitted. The turbo used stirrer works at 1500 revolutions per minute. The mixture will chalk added as an additive. 1200 ppm of chalk are because of the  Presence of aliphatic polymers with halogen content and 2500 ppm Chalk with the presence of aromatic polymers Halogen content added.

The bypass from waste plastic polypropylene, waste plastic mixing, vacuum residue and additive is carried out with the help of a stati mixer is added to the main flow of vacuum viscous residue mixes.

This mass flow is transferred to such a piston pump Pressure brought that the increased pressure necessary for the shear difference before and after your pressure atomizing burner 8.8 MPa be wearing.

Example 5

The procedure was analogous to Example 1 with the following changes. The Oil residues are at 140 ° C with a compared to the Verga existing pressure drop of 0.41 MPa the annular gap burner fed. The pressure difference for the gasifying agent is 0.45 MPa.

The hourly mass flow consists of 20 t vacuum visbreaker back stand and 1.8 t of old plastic polypropylene. The old plastic will in a twin screw extruder with degassing device 280 ° C melted without the addition of additives and is the vacuum vis breaker residue using a static mixer given.

The mixture of waste plastic and petroleum residue is with a Screw pump brought to such a pressure that the Pressure difference before and after the annular gap burner is 0.45 MPa. The pressure difference for the gasifying agent is 0.48 MPa.  

Example 6

The procedure is analogous to Example 2 with the following changes. The old plastic mixture mixed with petroleum residue is about a static mixer with 19 t vacuum vacuum breaker per hour residue at 180 ° C fed to a screw pump, the generates such pressure that the necessary for the shear pressure difference before and after the annular gap burner 0.45 MPa is. The pressure difference for the gasifying agent is 0.48 MPa.

Example 7

The procedure is analogous to Example 3 with the following changes. The mixture of petroleum residue and old plastic is with a Screw pump brought to such pressure that the pressure difference required before and after the shear Annular gap burner is 0.45 MPa. The pressure difference for that Gasification agent is 0.48 MPa.

Example 8

The following changes are carried out analogously to Example 4. This mass flow is generated by a screw pump brought such pressure that necessary for the shear pressure difference before and after the annular gap burner 0.46 MPa is. The pressure difference for the gasifying agent is 0.49 MPa.

Claims (16)

1. Process for the production of synthesis gas from petroleum residues and waste plastics or waste plastic mixtures after the removal of metallic, inorganic / organic and mineral impurities, characterized in that the waste plastics or waste plastic mixtures are melted in melting units with a partially compatible petroleum intermediate at temperatures below 300 ° C are brought into contact, these components are mixed via mixer devices and are fed to the gasification reactor with a proportion of waste plastic or waste plastic mixture of 1 to 10% by weight, the total mixture being mixed by 5 to when injected into the reactor 10% is subjected to higher shear compared to the use of the pure petroleum intermediate. 2. The method according to claim 1, characterized in that the total mixture fed to the gasification reactor 3 to 5% by mass Contains waste plastic or waste plastic mixture. 3. The method according to claim 1, characterized in that as Melting unit an extruder, preferably a twin-screw extruder, with or without degassing device and with or without additive dosing for additives, and with dosing device device for petroleum intermediates at the end of the extruder is set. 4. The method according to claim 1, characterized in that as on melting unit a heatable container with integrated melt pump as well as with or without degassing, with or without additive dosing for additives, and with dosing device for petroleum intermediate products is used. 5. The method according to claim 4, characterized in that the heatable container, a stirred reactor, preferably with a Turbo stirrer is provided.   6. The method according to claim 5, characterized in that a Stirred reactor with a turbo stirrer with stirring speeds from 1000 to 1500 revolutions per minute. 7. The method according to claim 1 to 6, characterized in that the main application as a partially compatible petroleum intermediate product of heavy oil gasification vacuum visbreaker residue or as Product with lower viscosity vacuum residue used becomes. 8. The method according to claim 1 to 7, characterized in that the fission gases generated at temperatures <300 ° C preferably HCl, withdrawn via degassing devices and to be disposed of. 9. The method according to claim 1 to 8, characterized in that the bypass from melted old plastics or old plastic mixtures depending on the composition as additives, Alkali and / or alkaline earth compounds or coke reducer be added. 10. The method according to claim 9, characterized in that the Alkali and / or alkaline earth compounds in part of each homogenized and in this petroleum intermediate Form into the melted old plastics or old art mixtures of substances are mixed in. 11. The method according to claim 10, characterized in that the Used plastics or mixtures of used plastics in the case of the An Presence of aliphatic polymers with halogen content 200 to 1200 ppm and in the presence of aromatic Polymers with halogen content 800 to 3000 ppm alkali and / or Alkaline earth compounds are added.   12. The method according to claim 1 to 11, characterized in that the old plastics or old plastic mixtures with one Part of the partially compatible petroleum intermediate pre-mixed are either at the end of the extruder in a ratio of 1: 9 to 10: 0 or in the heated container / stirred reactor in the Ver Ratio 1: 9 to 1: 1, whereby in the heated container / Agitator the petroleum intermediate is submitted. 13. The method according to claim 1 to 12, characterized in that that the bypass from waste plastic or waste plastic mixed and optionally additive and optionally one Proportion of partially compatible petroleum intermediate with the Main stream from partially compatible crude oil intermediate over a static mixer is mixed and homogenized. 14. The method according to claim 1 to 13, characterized in that when using a pressure atomizing burner between Petroleum intermediate and waste plastic mixture before and after the burner a pressure difference of 7.0 to 10.0 MPa preferably 5.0 to 8.5 MPa. 15. The method according to claim 1 to 13, characterized in that when using an annular gap burner both between earth oil feed product, as well as the gasifying agents oxygen and water vapor before and after the burner a pressure difference from 0.3 to 0.7 MPa, preferably 0.3 to 0.5 MPa is posed. 16. The method according to claim 1 to 15, characterized in that the feed mixture for the gasification reactor further pre-dismantled old plastics or old plastic mixtures be set.