The invention relates to a device for subjecting carbon contained materials to pyrolysis, which device comprises: a reactor with a housing and a reactor space present therein; a first feed for contained materials material or other organic material connecting to the heated up to 400° C. upper zone of this reactor space; a second feed for heated space, connected to the upper side of this reactor space; a first discharge for pyrolysis gas connecting to the upper zone of this reactor space at a distance from the first feed; and a second discharge connecting to the middle zone of this reactor space; and discharge for solid material, for instance carbon material, connecting to the underside of this reactor space. Such a reactor is known in many embodiments from, among others, U.S. Pat. No. 1,777,449, U.S. Pat. No. 3,507,929 and U.S. Pat. No. 4,210,491.
In pyrolysis process wherein a hydrocarbon containing mixture is heated to decomposition or cracking temperature, a certain portion of the combined or organic carbon present in the hydrocarbon is converted to its elemental state. The undesirable phenomenon is that fine particles accumulate on solid surface of the reactor, and cause blockage thereof after a period of time. Problem of the carbon deposits formation during the pyrolysis process is less serious for the process temperature of 1000° C. and higher.
Pyrolysis processes of hydrocarbons and hydrocarbon-hydrogen mixtures at temperatures between 1450-2000° C. are described for example in U.S. Pat. No. 3,156,733 or U.S. Pat. No. 3,156,734. However, as the temperature level of operation during pyrolysis increases, the number of construction materials which can be used is drastically reduced.
At temperature level of 1400 to 1500° C., even the refractory oxides begin to suffer under attack by hydrogen, carbon or hydrocarbons during the pyrolysis process. In the range of 1500 to 2000° C. and higher, there are no readily available materials which can be economically used, have the good mechanical properties required, resist the attack of hydrogen, carbon and hydrocarbons, and also have oxidation resistance over long periods of operating time.
High temperature reactions and processes typically require more complex, costly, and specialized equipment to tolerate the intense heat and physical stress conditions, and leads to lowering the upper limits of temperature for many of the processes and facilities.
In addition to physical temperature limitations for reactor materials, many prior art reactor materials that are inert at lower temperatures may become susceptible to chemistry alterations at high temperature, leading to premature equipment degradation.
Further complicating the material stability and reliability issue has been exposure to large, cyclic temperature swings encountered during many pyrolysis processes. Changes in temperature and feedstock flow can impose severe physical strength and toughness demands upon the materials at high temperature. Material life expectancy at high temperature can be severely limited. Reactor component functions and shapes have been limited for high severity services.
Due to high temperatures involved in cyclic pyrolysis reactors, generally only ceramic components have the potential to meet the materials characteristics needed in such aggressive applications. Ceramics components generally can be categorized in three material categories: engineering grade, insulation grade, and refractory grade.
The term “engineering grade” has been applied to ceramic materials which typically have very low porosity, high density, relatively high thermal conductivity, and comprise a complete component or a lining. Examples include dense forms of aluminum oxide (Al2O3), silicon nitride (Si3N4), silicon carbide (SiC), silicon aluminum oxynitride (SIALON), zirconium oxide (ZrO2), transformation-toughened zirconia (TTZ), transformation-toughened alumina (TTA), and aluminum nitride (AlN).
Insulation grade ceramics are typified by relatively high porosity. Many may have fibrous crystalline grain structures and are more porous than engineering grade ceramics, have lower density, and have lower thermal conductivity than engineering grade ceramics.
Many refractory grade ceramics typically have porosity, strength, and toughness properties intermediate to such properties in engineering grade and insulation grade.
The reviewed arts are demonstrated that the coating has only modest adherence and frequently suffers from partial or fatal barrier spallation or thermal shock cracking after relatively short periods of exposure to high temperature. This causes quality control and adherence problems. Moreover, the method of application required to produce the graded layer is tedious.
Coatings utilizing NiCrAlY and other complex aluminized coatings have been proposed (see, for example, U.S. Pat. Nos. 3,869,779 and 3,676,085). Further, U.S. Pat. No. 3,410,716 (Hiltz) discloses that zirconium dioxide can form a component of an oxide composition that bonds well to tungsten substrates. The Hiltz patent also discloses that magnesium oxide and yttrium oxide in small amounts may be utilized for stabilization purposes.
The reviewed arts are void of teaching how to prepare or select a material having a range of properties that are suitable for use in constructing a furnace for performing substantially continuous, cyclical, high temperature pyrolysis chemistry. The studied art is believed to be similarly deficient at revealing materials suitable for complex, irregular, or functionally-shaped reactor components. The art needs a materials that can endure prolonged exposure to high severity temperatures, substantial temperature swing cycles, cyclic flows of reaction materials, and concurrently provide the needed structural integrity, crystalline stability, and chemical inertness in the presence of high temperature chemical reactions that is required for large scale, high productivity applications. Lack of materials availability and selection criteria for identifying the materials for use in the reactive and most severe temperature regions of a reactor system is one of the most critical remaining issues in design and large-scale commercial operation of such reactors and processes.
In addition the pyrolysis process is difficult to control sufficiently to ensure feedstock distribution, aeration and to avoid bridging the reactor. WO 2007/081296 A1 indicates that there are generally three types of gasification process, namely updraft (in which heated air is fed upwards through the pyrolysis zone and the fuel is allowed to descend through the pyrolysis zone), downdraft (or co-flow) in which heated air and fuel enter the reaction zone from the top of the reactor and descend together through the pyrolysis zone, or fluidised bed, in which the fuel is suspended on (typically) steam, and allowed to be processed by contact with heated air. According to the prior art, there is provided a downdraft gasification process in which shredded municipal waste is allowed to descend through a pyrolysis reactor and the waste is pyrolysed in the reactor to form a condensable fraction and a combustible gas, wherein the waste is contacted in the pyrolysis reactor in a downdraft with air which has been preheated successively by heat exchange with the pyrolysis reactor and by heat exchange with exhaust gas from the pyrolysis reactor. The process according to the prior art permits the use of a reactor, which will take loose shredded feedstock with higher moisture content; this has a major impact on cost and efficiency.
A recurring problem in methods and apparatus for the pyrolysis processes is the generation of ash that tends to fuse into irregular-sized chunks, known as slag, the formation of which tends to block gas passageways and so reduce the efficiency of the pyrolysis of the solid waste materials. Another common problem which reduces pyrolysis efficiency is the buildup of condensates of tar and resin, resulting in blinding and otherwise restricting filters, grates, and gas passageways. Still another problem in the art is the production of an off gas from such solid waste pyrolysis that contains insufficient concentrations of combustible gases to comprise a useful fuel product. These and other problems are addressed and resolved by the pyrolysis reactors of the present invention, which are summarized and described in detail below.
Reactor and methods for pyrolysis of carbonaceous material are provided herein. In accordance with the present embodiment, a method for thermal processing of carbonaceous material is provided. The method comprises the steps of contacting a carbonaceous feedstock with heated inorganic heat carrier particles at reaction conditions effective for the carbonaceous feedstock to be pyrolyzed and to form a product stream comprising process gas, pyrolysis oil, and solids. The solids comprise char and cooled inorganic heat carrier particles.
The solids are separated from the product stream. An oxygen-containing gas and the solids are combined at combustion conditions effective to convert the char into ash and heat the feedstock material.
In accordance with the present embodiment, an apparatus for producing heat for rapid thermal processing of carbonaceous material is provided. The apparatus comprises a reactor that is configured to contact a carbonaceous feedstock with heated plural surfaces at reaction conditions effective for the carbonaceous feedstock to be pyrolyzed and to form a product stream comprising the process, pyrolysis oil, and solids. The solids comprise char and cooled inorganic particles. The exhaust stream comprises flue gas, entrained inorganic particles, and ash.
In the thermal coating system of the present invention the inner metal bond coating layer, which contacts the surface of the pyrolysis reactor, consists essentially of enamel frit, sand mixed with 50% solution of sodium tetra-Borat (Na2B4O7), clay, titanium dioxide, and colloidal silicon dioxide (SiO2).
The metal bond coating layer is, in turn, coated with an outer layer containing fluoroplastic F4D and oxiethylated alkylphenols (polyethylene-ethylene-alkyl phenyl ethers) (RC6H4O(CH2CH2O)nH or Neonol AF 9-12 oxyethylated nonylphenol (C9H19C6H4O(C2H4O)12H).
In the anti-adhesive coating system of the present invention the inner metal bond coating layer, which contacts the surface of the exhaust system, consists essentially of perfluoropolyetheric acid “6MFK-180” (CF3O(CF2CF2O)nCF2COOH where n=34-35) mixed with 1,2-difluorotetracloroethane (C2Cl4F2) and 1,1,2-trifluorotrichlorethane (CF2ClCFCl2) at the 4:1 weight ratio.
The above and other objects and advantages and novel features of the present invention will become apparent from the following detailed description of the preferred embodiment of the invention illustrated in the accompanying drawings, wherein:
Specific details of several embodiments of the technology are described below with reference to
For the purpose of this description the pyrolysis reactor 1 should be understood to include an upper zone (
The reactor vessel 1 in the embodiment shown in
In the embodiment shown in
The presently preferred embodiment shown in
Referring to
Formation of the Composite Coating for Steel
One of the tasks of the present invention is creation of the silicate basis anti adhesive protective coating with the self-sedimentation of fluoride suspension deposition on the substrate surface. The problem is solved by the introducing two layers of coating comprised of: the first layer—enamel frit (B2O3—40.6-42.0; CoO—0.3-0.7; Na2O—6.0-6.5; CaO—6.0-6.5; Al2O3—16.0-16.8; TiO2—23.2-24.0; Li2O—0.3-0.7; SiO2—5.0-6.0 of mass %), sand, clay, titanium dioxide, mix of sodium tetra-Borat (Na2B4O7) and colloidal silicon dioxide (SiO2) at the weight ratio of 1:1; the second layer—fluoroplastic F4D and oxiethylated alkylphenols (polyethylene-ethylene-alkyl phenyl ethers) (RC6H4O(CH2CH2O)nH or Neonol AF 9-12 oxyethylated nonylphenol (C9H19C6H4O(C2H4O)12H);
In order to prepare the first layer of the protective coating the following ratio of components (Mas. %) have been used: The first silicate layer ESP-200 enamel Frit—56.75-70.67 Sand—14.13-22.70 Clay—4.24-5.68 titanium dioxide—0.07-0.28 50% mix of sodium tetr-borate ad colloidal silicone—0.28-0.34; Second fluoroplastic layer consist of: fluoroplastic F4D brand—37.40-42.20,
The F4MD brand—9.35-12.05, oxiethylated alkylphenols 3.61-6.54, distilled water—the rest.
This silicate layer (0.15-0.30 mm thick) was applied on the grounded surface with method of a regional pouring, then was dried up and heated at a temperature of 790°±10° C., at the heating increase ratio of 50° C. per hour. Then fluoroplastic suspension was applied and dried at the temperature of 350° C. for at least 3 hours. The silicate and fluoroplastic coating has high operational properties (anti-adhesion and wear resistance). As a result, of the pyrolysis, the treated product is decomposed into a solid phase (a mixture of carbon residue that contains coke and tar, and a gaseous phase (pyrolysis gas). A part of the pyrolysis gas developed in the pyrolysis reactor is sent to the waste drier and/or to the burners 8 of the reactor for use as an additional heat carrier.
Thus it has been shown that the invention provides a novel reactor for pyrolytic processing and more efficient utilization of carbon contained wastes as compared to conventional reactors of this type. The aforementioned reactor is simple in construction, provides efficiency in the pyrolysis reaction, sufficient compaction of the waste material for displacement of air from the material being treated, efficient mixing of the material being treated, and efficient loading, unloading of the material into and from the reactor along with efficient conveyance of the material through the reactor. The structure of the reactor is characterized by a low metal-to-power ratio and hence by low manufacturing cost.
Although the invention has been shown and described with reference to specific embodiments, it is understood that these embodiments should not be construed as limiting the areas of application of the invention and that any changes and modifications are possible provided that these changes and modifications do not depart from the scope of the attached patent claims. For example, the retort and the external casing that surrounds the retort may have shapes different from those shown in the drawings and can be made from different heat-resistant materials. The loading and unloading mechanisms of the pyrolysis reactor may have structures different from those shown in