RU2554577C2 - Synthetic gas production method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to the production process of synthetic gas by hydrocarbon conversion, and namely to processes of oxidative conversion. The synthetic gas is produced at the combustion of a hydrocarbon stock with an oxidiser with the oxidiser excess coefficient less than 1 at a temperature less than 1400 K inside a cavity formed partially or completely by a three-dimensional matrix permeable for the mixture of the gas and oxidiser. Input of the hydrocarbon stock with the oxidiser is made through a permeable bottom of the cavity or through permeable walls and bottom of the cavity, while the output of combustion products is made through the upper cross-section of the cavity. Before input to the cavity the mixture of the gas and oxidiser or one gas of the mixture partially or completely is heated by heat produced by combustion products. The matrix is heated additionally by heat radiation reflected from the screen placed in the matrix cavity and permeable for the combustion products.

EFFECT: increased efficiency due to the increased output of the synthetic gas at the usage of hydrocarbon mixtures with the high content of non-combustible products having a low calorific value.

2 cl, 7 dwg, 1 tbl

Description

The invention relates to processes and devices for producing synthesis gas by the conversion of hydrocarbons, and in particular to processes of oxidative conversion.

A known method of producing synthesis gas, carried out in a flow-through two-chamber reactor in a turbulent mode by burning a mixture of hydrocarbon feedstocks and an oxidizing agent. In addition to this mixture, superheated water vapor is supplied to the flow reactor in an amount of 5-20 wt.% With respect to the weight of the supplied carbon in the form of hydrocarbon feed. The three-component mixture is ignited in the combustion chamber by a stream of hot gas from an external source, the pressure of which during ignition exceeds the pressure in the first chamber. The combustion products from the first reactor chamber through a nozzle with a critical pressure drop are sent to the second chamber and the combustion process is continued until the oxygen content in the combustion products is not more than 0.3 vol.% / RU 2320531, C01 B3 / 36, 2008 /.

The disadvantage of this method can be attributed to its low efficiency, which is associated with a high consumption of oxidizing agent and the inability to convert hydrocarbon mixtures with a high content of non-combustible components having a low calorific value.

Closest to the claimed one is a method of producing synthesis gas by burning a mixture of hydrocarbon feed with an oxidizing agent with an oxidizing agent excess ratio of less than 1 at a temperature of less than 1400 K inside one or more cavities formed completely or partially by a material permeable to a mixture of hydrocarbon feed with an oxidizing agent. Moreover, the mixture of hydrocarbons with the oxidizing agent is introduced through the permeable bottom of the cavity / cavities, or through the permeable walls of the cavity / cavities, or through the permeable walls and the bottom of the cavity / cavities, and the combustion products are removed through the upper section of the cavity / cavities / RU 2374173, C01 B3 / 34, 2009 /. This technical solution is selected as a prototype.

The prototype is also characterized by insufficient efficiency associated with a large loss of heat with exhaust gases and, as a consequence, the inability to convert hydrocarbon mixtures with a high content of non-combustible components having a low calorific value.

The authors solved the problem of creating a method for producing synthesis gas devoid of this drawback. The technical result of the invention is to increase efficiency by increasing the yield of synthesis gas and the related possibility of using hydrocarbon mixtures with a high content of non-combustible components having low calorific value for conversion.

To solve the problem, as well as to achieve the claimed technical result, a method for producing synthesis gas by burning a mixture of hydrocarbons with an oxidizing agent, with an excess coefficient of an oxidizing agent of less than 1, is carried out at a temperature of less than 1400 K inside a cavity that is fully or partially formed by a permeable matrix for a mixture of gas with an oxidizing agent. Moreover, the mixture of hydrocarbons with the oxidizing agent is introduced through the permeable bottom of the cavity, or through the permeable walls of the cavity, or through the permeable walls and the bottom of the cavity, and the output of the combustion products through the upper section of the cavity. A distinctive feature of the proposed method is that a mixture of hydrocarbon feedstock with an oxidizing agent or one of these gases in full or partially before being introduced into the cavity is heated due to the heat generated by the combustion products, and the matrix is additionally heated by thermal radiation reflected from the screen permeable to the combustion products placed in the cavity of the matrix.

Additionally, the combustion process is proposed to be carried out in several cavities.

Preheating a mixture of hydrocarbon feedstock with an oxidizing agent or one of these gases in full or partially before entering the cavity due to the heat released by the combustion products, with additional heating of the matrix by thermal radiation reflected from the screen permeable to the combustion products, placed in the matrix cavity, allows increase the yield of synthesis gas by expanding the combustion range of rich mixtures.

In FIG. 1 shows a diagram of a reactor for producing synthesis gas, FIG. 2 shows a diagram of an installation in which a combustion process is carried out in several cavities; FIG. 3 shows a setup diagram where the cavity is completely formed by a matrix; FIG. 4 is a diagram of an installation in which hydrocarbon feed is introduced through the permeable bottom of the cavity; FIG. 5 and 6 are plant diagrams in which the entire gas mixture is heated before being introduced into the cavity; FIG. 7 is a diagram of the installation, in which the mixture is partially heated before entering the cavity, where 1 is the outer shell of the reactor, 2 is the reactor vessel, 3 is the matrix, 4 is the screen permeable to the combustion products, 5 is the mixer, 6 is the discharge pipe, 7 is heat exchanger.

The method is as follows. In the mixer 5 serves hydrocarbon feed and air with an excess coefficient of oxidizing agent less than one. The resulting mixture, washing the outer shell of the reactor, cools it and enters the heat exchanger 7, where it is heated by the heat generated by the combustion products. After which the mixture enters the matrix, where the combustion process takes place. The localization of the flame front near the matrix surface leads to a strong heating of the inner surface of the matrix cavity. The combustion products, passing through the screen 4 permeable to them, are then sent to the exhaust pipe 6. The radiation that occurs on the heated surface of the matrix is reflected from the screen 4 back onto the matrix surface, raising its temperature and the temperature of the combustion products.

Table 1 presents data on the modes of implementation of the proposed method.

Experiments have shown that use of the invention allows for the possibility of conversion to synthesis gas with a low calorie content biogas CO ₂ and 50%. At the same time, the efficiency of organizing heat recovery to achieve stable operation of the reactor up to the value α = 0.35-0.39, i.e. the limiting value that determines the boundary of soot formation.

Claims (2)

1. A method of producing synthesis gas by burning a mixture of hydrocarbon feedstocks with an oxidizing agent with an oxidizer excess ratio of less than 1, carried out at a temperature of less than 1400 K inside a cavity that is fully or partially formed by a bulk matrix permeable to the gas mixture with the oxidizing agent, and introducing the mixture of hydrocarbon feedstock with the oxidizing agent is produced through the permeable bottom of the cavity, or through the permeable walls of the cavity, or through the permeable walls and the bottom of the cavity, and the output of the combustion products through the upper section of the cavity, characterized in that a mixture of hydrocarbon feedstocks with an oxidizing agent or one of these gases in full or partially before being introduced into the cavity is heated due to the heat generated by the combustion products, and the matrix is additionally heated by thermal radiation reflected from the screen permeable to the combustion products placed in the matrix cavity. 2. The method according to p. 1, characterized in that the combustion process is carried out in several cavities.

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