DD269156A1 - METHOD FOR THE PLASMAPYROLYSIS OF HIGH VISICIAN, TEERARTIC, HYDROCARBON PRODUCTS - Google Patents

Abstract

The invention relates to a process for the plasma pyrolysis of highly viscous, tarry, hydrocarbon-containing products with the aim of a rational use of the carbon or hydrogen substance contained in these substances for the production of unsaturated C2-hydrocarbons and carbon monoxide in the hydrogen plasma jet. From a thermostated Vorratsbehaelter be pressed by piston pressure Teeroel solid residues from the coal pressure gasification in the Zumischebene a plasma reactor and injected there over one or more nozzle-like constrictions in a turbulent hydrogen plasma laterally and perpendicular to the flow direction of the plasma. Due to a suitable choice of the injection conditions, there is a rupture of the injected substance flow through the plasma, the formation of Troepfchen, their swirling, heating and their thermal degradation with subsequent chemical reaction, in particular to acetylene, ethylene and methane-containing pyrolysis gas.

Description

Field of application of the invention

The field of application of the invention relates to the plasma pyrolysis of liquid or liquefiable hydrocarbons and hydrocarbon-containing substrates, in particular of tar oil FeststotVrückständen from the coal-pressure gasification, preferably unsaturated hydrocarbons, especially acetylene and ethylene, in the hydrogen plasma jet.

Characteristic of the known state of the art

In recent decades, a number of processes for plasma-chemical material conversion have been developed and also technically implemented internationally, which increasingly use viscous, bituminous, but also solid carbon carriers as starting material. These inventions have the goal of addressing plasma-chemical material transformations of high yield and with the lowest possible expenditure of energy. It shows ways, as with brown coal ode; their extracts are to be carried out as Eiiisatzstoffe plasmachemic material conversions. DD-144533 discloses a process in which solid, liquid or low-oxygen brown coal constituents in solid or liquid form are fed into a thermal arc, spark arc or stripping plasma with hydrogen as carrier gas and heated. The formed fission products are quenched and, in particular, acetylene, ethylene and methane are formed as gases. PS-DD-159081 discloses methods and apparatus for converting liquid or liquefiable carbon carriers to, preferably, acetylene and ethylene. De bei the reacted starting hydrocarbons are atomized and mixed as a cloud of droplets with a turbulent plasma hydrogen jet. In the patent US-3697612 and in DE-OS 2731042 Method and apparatus are described which use as starting materials ^r lai coal. Also, with the implementation of coal, which is supplied in admixture with hydrogen or methane as the carrier of an electric arc discharge, the patents US-4378232; U.S. 4,358,629 and GB-1089092. In a more recent method, pulverized coal mixed with an oil or gaseous hydrocarbon is introduced into an arc chamber (US-4010090).

The viscosity of a liquid carbon suspension can be further reduced even by the addition of CO ₂ -GaS in the form he prefers bubbles prior to introduction into a plasme reactor (US-456-196). The production of acetylene and synthesis gas by means of a hydrogen plasma, brown coal as Ausgangsmat. ial is described in the publication DD-114395. Fine-grained lignite with a particle diameter <1 mm is without or with the aid of a suitable carrier gas through a plasma torch shore directly into a plasma reactor and reacted below the sublimation temperature of the carbon.

The previous methods are limited to the pyrolysis of solids (such as coal) or to the implementation of liquids (oils, coal ingredients) or mixtures of both components. In most cases, the electric arc is preferred over the plasma jet for technical and historical reasons. Certain advantages also provides the feed of the starting hydrocarbons in a vacuum reactor. In the plasma-chemical conversion of the coal grinding to particle sizes of a few hundredths of a millimeter and drying require increased effort. For pyrolysis of the finely ground solids, suspensions with liquids are sometimes prepared and, in addition, auxiliary gases are used for introduction into the plasma. The present invention shows a way how highly viscous or solid at normal temperature hydrocarbons, some of which still have a high ash content, can be made accessible to a plasma pyrolysis.

The aim of the invention is the production of unsaturated CJ hydrocarbons and carbon monoxide on the basis of highly viscous, teeraitigen or at normal temperaUir solid hydrocarbons, especially of tar oil-Foststoff residues from the coal-pressure gasification, bher also of hydrocarbons of other origin (eg from petroleum processing ) with similar physical and chemical properties, by pyrolysis in hydrogen plasma.

Explanation of the nature of the invention

The invention has the object of providing a process for the complex material use of carbon-hydrogen-substance to evolve from tar oil ^C eststoff residues from the coal gasification under pressure, but also hydrocarbons of different origin with similar material properties. In this case, a costly drying of the starting hydrocarbons and their grinding is to be bypassed to small particle sizes and a ma ¹ · ma material use of the introduced with the carbon carrier in the process carbon and hydrogen substance can be achieved. According to the invention the object is achieved in that from a thermostatic reservoir by piston pressure highly viscous tarry hydrocarbonaceous starting products via connecting lines of at most 1 m in length at elevated pressure (<1Oat) and while maintaining the preheating temperature (preferably 80 to 130 ^c C) in the admixing plane of a plasma reactor pressed and injected there over a odor several nozzle-like constrictions in a turbulent hydrogen plasma laterally and perpendicular to the flow direction 'o's plasma.

Due to a suitable choice of the injection conditions and the turbulence of the plasma flow, there is a tearing of eirnespritzten substance flow, the formation of droplets, their vortexing, heating and their thermal degradation rr.it subsequent chemical reaction, in particular to acetylene, ethylene, carbon monoxide and methane-containing pyrtlyseyis , which is quenched in a conventional manner at the reactor outlet and led away. The particular advantages of the invention are, firstly, that a new class of highly viscous, tarry, ko'ik iwasserstoffhaltigen products such. As tar oil-solid residues from the coal-pressure gasification, which were previously fed eggs landfill, is opened up for the plasma chemical acetylene synthesis, on the other hand are by the type of storage, preheating and feeding, d. H. Choice of injection conditions into the plasma by correlation of the parameters of feedstocks originally plasma, the disadvantages of previously known methods, e.g. Drying and grinding as well as incomplete conversion of the starting materials avoided.

embodiments

Example 1:

Plasma pyrolysis of visbreakor residues

Visbreaker, a residue from the petroleum scission and at room temperatures a homogeneous syrupy mass of the composition 85Ma .-% carbon, 10Ma .-% hydrogen and 5% sand or slag is in a reservoir, the bottom of which is designed as a movable piston on 13O ⁰ C heated and passed from this by means of piston pressure in the admixing plane of the plasma reactor. To avoid coking in the supply lines, it is advisable to keep constant and control the preheating temperature from the storage cylinder to the mixing level. The feed into the plasma takes place at pressures up to max. 10 at three evenly distributed over the reactor circumference nozzle-like constrictions of I mm diameter perpendicular to the plasma flow. The pyrolysis gas produced by din plasma pyrolysis of visbreaker residues and leaving the reactor after quenching has the following composition:

- 82.9VoI .-% C ₂ H ₂ - 11.4 vol.% CH ₄ - 2.5VoI .-% C ₂ H ₄ - 1.1 vol. -% CO - 0.6VoI .-%

Other - 1.5Vol .-%

Example 2:

Plasma pyrolysis of tar oil-solid mixtures

The tar oil-solid mixtures of coal pressure gasification used for the plasma pyrolysis form at room temperature a highly viscous, heterogeneous mass of tar and water. The elemental analysis yields 66.2 mass% of carbon monoxide and 6.8 mass% of hydrogen, which corresponds to a molar ratio C: H = 5.5: 6.8.

The hydrocarbonaceous starting product (Staubdickteerj is heated in a storage container whose bottom is designed as a movable piston, heated to 90 ° C and from this while maintaining the preheating by means of piston pressure over a maximum of 1 m long line in the intermediate plane of the plasma reactor The plasma is carried out under elevated pressure (<10at) via a nozzle-like constriction of 2 mm diameter at the side of the reactor wall, perpendicular to the plasma flow The pyrolysis gas produced by the pyrolysis of dust-thicketore in the hydrogen plasma and leaving the reactor after quenching has the following composition:

H ₂ - 69.5% by volume C ₂ H ₂ - 14.0% by volume CH ₄ - 5.0Vol .-% C ₂ H ₄ - 2.0 Vol .-% CO - 8.5% by volume other -τ 1.5Vol .-%

Claims (2)

1. A process for the plasma pyrolysis of highly viscous, teorartiger, hydrocarbon oil Itiger products, in particular of tar oil solid residues from the coal-pressure gasification nr \ hydrogen plasma at temperatures of 2000 to 3500K to form preferably acetylene and Äthylhaltigem pyrolysis gas and carbon monoxide, characterized characterized in that the tarry hydrocarbon-containing starting materials in a reservoir whose bottom is designed as a movable piston, preferably heated to 80 to 13O ⁰ C and at this with a pressure to max. 10at via connecting lines of at most 1 m in length while maintaining the temperature in the admixing plane of the plasma reactor and there fed via one or more nozzle-like constrictions perpendicular to the flow direction of the turbulent plasma jet to the plasma so nd that it tearing the injected substance stream through the plasma, to the formation of droplets, their turbulence, heating and their thermal degradation with subsequent chemical reaction comes. 2. The method according to claim 1, characterized in that, starting from the per unit time in the plasma jet maximum convertible amount of nozzle diameter and injection pressure are chosen so that the entire stream of substance is torn into droplets, with optimum pyrolysis at average droplet diameter of 100 to 300 μηι with Residence times in the reaction zone of at most 4 × 10 ^-3 s are given.