WO2019097326A1

WO2019097326A1 - Gasification of carbonaceous matter biomass mixture and coal using a cyclone-type forced flow furnace

Info

Publication number: WO2019097326A1
Application number: PCT/IB2018/058068
Authority: WO
Inventors: Ivan Ernesto BARRAGAN GUTIERREZ; Yaneth Pineda Triana; Enrique Vera Lopez; Alfonso LOPEZ DIAZ
Original assignee: Universidad Pedagogica Y Tecnologica De Colombia Uptc
Priority date: 2017-11-17
Filing date: 2018-10-18
Publication date: 2019-05-23
Also published as: CO2017011719A1

Abstract

The present invention discloses a system for gasifying carbonaceous matter biomass mixture and coal comprising: a feed hopper (2), a device (3) for feeding the mixture, a gasification chamber (7, 8) connected to the feed hopper (2) by way of a device for feeding the mixture (3), a primary air fan (6), a mixture feed duct (5), a retort (4), a refractory material (12) from the ash tray, a lower, fixed-bed gasification chamber (7), an upper, fluidised-bed gasification chamber (8), one or more radial injection nozzles (9) arranged on the lid (10) of the upper gasification chamber, a refractory cyclone with wings (16), one or more lateral ports (14) with handles (15) and an outflow duct (11) for the syngas. The invention also discloses a method for gasifying carbonaceous matter in the system.

Description

GASIFICATION OF CARBONACEOUS MATERIAL BIOMASS AND MINERAL CARBON MIXTURE THROUGH A CYCLONIC FORCED FORCED FLOW OVEN

TECHNOLOGICAL SECTOR

The present invention provides a system and a gasification process of carbonaceous material mixture of biomass and mineral coal in a cyclonic forced-flow combustion chamber. The present invention pertains to the technical field of the production of gases containing carbon monoxide and hydrogen, as synthesis gas or city gas, from solid carbonaceous materials by partial oxidation processes using oxygen or steam.

STATE OF THE ART

Gasification is a thermochemical process that transforms solid fuels into gaseous fuels producing synthesis gas, using temperatures above 900 ° C in atmospheres with low oxygen percentage, below that required for complete combustion. The gasification process is favored with the increase of pressure and using fuels of small particle sizes.

In the state of the art processes and systems have been disclosed for the gasification of materials derived from biomass and carbonaceous materials. Below are some patent documents that deal with the subject:

The patent application in national phase file No. 08051684 relates to a process and system for gasifying biomass or other carbonaceous starting materials in an indirectly heated gasifier and supplies a method for the removal of condensable organic materials (tars) from a gas product. More specifically, this tar removal stage uses the circulating heat carrier to crack the organics and produce additional product gas. As a benefit of the previous process, and because the heat carrier circulates through alternating zones of steam and oxidation in the process, deactivation of cracking reactions is eliminated.

The patent application in national phase file No. 08113967 refers to a method for the production of hydrocarbons or oxygenated hydrocarbons. In the preferred version of the invention, liquid alæans can be produced directly from biomass-derived compounds, including polysaccharides, monosaccharides, polyols through an integrated process that involves catalytic conversion into gas mixtures (synthesis gas). The conversion of the reactive feed tank to the synthesis gas is carried out using a catalyst comprising Pt-Re on a carbon support.

The patent application in national phase file No. 13030376 deals with a system for the gasification of biomass materials, comprising a gasification unit for the conversion of biomass materials into a gas, wherein the gasification unit is configured for allow the biomass materials and other materials that are contained within the gasification unit to move in a specific flow pattern at a specific rate; and a feeding mechanism for introducing biomass materials into the gasification unit wherein the feeding mechanism is configured to accelerate the biomass materials at the specified rate in the gasification unit. Another aspect is directed to a system for the gasification of biomass products; the system includes a gasification unit for the conversion of the biomass materials into a gas and a feeding mechanism for the introduction of the biomass materials into the gasification unit. The gasification unit includes a plurality of injection ports that are distributed vertically along one or multiple circumferential locations, ie, diametrically opposed for bilateral injection, for example, and each of the plurality of injection ports has a corresponding injection angle. The injection ports tangentially inject a gasification and / or biomass medium towards the gasification unit at prescribed angles, and the injection angles can be oriented in horizontal, ascending and / or descending directions. Patent application CN106010655 describes a biomass gasifier. The biomass gasifier comprises a gasifier body, a feed tube disposed on the body of the gasifier, a top seal discharge module and a bottom seal discharge module distributed in the feed tube; each sealing discharge module comprises a hinge sealing plate, a pivoting hinge shaft and an oscillating rod connected to the pivoting hinge shaft. A piston cylinder is connected to the end of each oscillating rod. The upper side of the gasifier is connected to a combustion burner. The combustion burner is connected to an oxygenation pipe and an oxygenation fan by the structure of the gasifier, according to the characteristics of the biomass fuel.

In the state of the art, conventional gasification systems are bulky ovens that require a large grill area and an equally large gassing chamber. In addition, the combustion of coal and biomass in solid form generates pollution due to incomplete combustion, volatile carbonic matter, VOCs, unburned and particulate material by ash; Energy efficiency is reduced by the difficulties in controlling the stoichiometry of the fuel and comburent mixtures. The production costs of furnaces that use coal and biomass in solid form are increased by the value of equipment maintenance and low productivity. The health of the workers deteriorates when handling coal and biomass due to the contact with the fuel and the high temperatures to which they are exposed in traditional ovens. Therefore, there is a need to solve the problems previously presented.

BRIEF DESCRIPTION OF THE INVENTION

The present invention solves the technical problems raised above by providing a system and a gasification process that combines the system conventional fixed-bed and co-current flow with the counter-current fluidized bed system.

In one embodiment of the invention there is provided a gasification system of a carbonaceous material mixture of biomass and mineral coal comprising: a feed hopper (2), a feed device (3) of solid fuel (biomass - coal), a gasification chamber (7, 8) connected to the feed hopper (2) by means of a feeding device (3) of the solid fuel; a primary air fan (6) located in the lower part of the feed hopper (2); a solid fuel feed duct (5); a retort (4) located inside a lower gasification chamber of fixed bed (7); a refractory (12) of the ashtray, which covers the retort (4); a lower fixed bed gasification chamber (7); an upper fluidized bed gasification chamber (8), located on the lower fixed bed gasification chamber (7), forming a single gasification chamber; radial injection nozzles (9) arranged in the lid (10) of the upper gasification chamber (8); a finned refractory cyclone (16), located inside the upper fluidized bed gasification chamber (8); side gates (14) with handles (15), located in the lower part of the lower fixed gasification chamber (7); and an outlet duct (11) of the synthesis gas.

In another embodiment of the invention a gasification process of carbonaceous material (mixture of biomass and mineral coal) is provided, which comprises the following steps:

(a) loading into a hopper (2) with the carbonaceous material (mixture of biomass and mineral coal);

(b) feeding said carbonaceous material into a lower fixed bed gasification chamber (7);

(c) feeding compressed air by means of an air fan (6) to a retort (4) located inside the lower gasification chamber of fixed bed (7); (d) performing a first gassing effect in the lower fixed bed gasification chamber (7);

(e) performing a second gassing effect in an upper fluidized bed gasification chamber (8);

(f) remove the ash generated in the two effects of gasification. wherein the lower fixed bed gasification chamber (7) and the upper fluidized bed gasification chamber (8) form a single gasification chamber.

Brief description of figures

The figures that accompany the description illustrate, by way of example, embodiments of the present invention, do not seek to be limiting thereof:

Figure 1 presents the isometric view of the gasification system.

Figure 2 presents the front view of the gasification system.

Figure 3 presents the top view of the gasification system.

Figure 4 shows a vertical section of the combustion chamber.

Figure 5 shows in detail the finned refractory ring of the refractory gasification cyclone (16).

Figure 6 shows the temperature profile (° C) of two runs using the gasification system.

DESCRIPTION OF THE INVENTION

The present invention provides a novel system and a gasification process that combines the conventional fixed-bed system and co-current flow with the fluidized bed system in counter-current generated by a vortex from a high-temperature refractory cyclone where the Synthetic gas is produced by separating simultaneously from the ash. The gasification system is composed, in general, of two feeding systems, a gasification system of upward flow, a descending fluidized gasification system, a cyclonic separation system, a gas recirculation system, and an ash extraction system.

The numbers that reference the elements of the gasification system in the following description correspond to those presented in figures 1 to 5.

In one embodiment of the invention a gasification system is provided, which is composed of a feed hopper (2), with cover (1), connected to a gasification chamber (7, 8) by means of a feeding device (3). ) of solid fuel (biomass - mineral coal); in the lower part of said hopper (2) there is located a primary air fan (6) of variable speed that together with a solid fuel feed duct (5) allow to graduate the production of synthesis gas to the demand of the process and adjust the various mixtures of co-gasification biomass - mineral coal. The solid fuel is fed by the feeding device (3) to a retort (4) located inside a lower gasification chamber of fixed bed (7); the retort is made of cast iron and has a series of perforations (13) to distribute the primary air that is driven by the primary air fan (6). The gasification operation is initially carried in the lower gasification chamber of fixed bed (7), first gasification effect, where the solid fuel rises through a refractory (12) of the ashtray, which covers the retort (4) forming a plane external inclined, towards the surface of the ashtray and then the synthesis gas produced enters an upper fluidized bed gasification chamber (8); said chambers form a single combustion chamber. Solid fuel with a granulometry of less than 1 mm, is injected through radial injection nozzles (9) arranged in the lid (10) of the upper gasification chamber (8), which has a refractory cyclone inside ( 16) conformed by refractory rings where radial fins are housed that orient with an angle of attack the carbonaceous material to form a descending vortex that reaches temperatures higher than 900 ° C, generating the second effect of gasification in countercurrent with the synthesis gas produced in the lower fixed bed chamber (7). The formed ash descends to side gates (14) with handles (15) and is removed together with the ash generated in the lower chamber that advances on the refractory (12) falling by gravity in the inclined plane that forms the refractory (12) of the ashtray. The synthesis gas separated from the ash by the cyclonic effect is removed by an outlet duct (11), located on the axis or vertical central part of the upper fluidized bed gasification chamber (8).

(a) loading into a hopper (2) a carbonaceous material (mixture of biomass and mineral coal) with volumetric proportions ranging from 10% -90% to 90% -10%, where the granulometry of the carbonaceous material is between 10% and 90% -10%, mm to 100 mm particle size;

(b) feeding said carbonaceous material in a lower gasification chamber of fixed bed (7), this is done through a feeding device (3) of solid fuel (carbonaceous material) graduated by a variable speed motor that goes from 10 rpm until 1600 r.p.m. with a speed reducer system for high torque,

(c) feeding compressed air by means of a fan (6), which has a variable speed system, to a retort (4) located inside the lower gasification chamber of a fixed bed (7);

(d) perform a first gasification effect in the lower gasification chamber of fixed bed (7), this occurs when the solid fuel ignites in the lower part of the retort (4) reaching a temperature above 900 ° C and a fuel column is formed that emerges on a refractory (12) obtaining the gasification in the lower gasification chamber of fixed bed (7), the stoichiometric ratio is adjusted below 80% of the required air regulating the speed of the supply device (3) of solid fuel and the primary air fan (6);

(e) performing a second gassing effect in an upper fluidized bed gasification chamber (8); Simultaneously with the operation of the lower fixed bed gasification chamber (7), the upper fluidized bed gasification chamber (8) is put into operation, in which the solid fuel with a granulometry of less than 1 mm is injected through radial nozzles (9) arranged in the lid (10) of the upper fluidized bed gasification chamber (8). The pulverized fuel enters the upper chamber (8), which inside has a refractory cyclone (16) formed by refractory rings where the radial fins are located, which angle the carbonaceous material to form a descending vortex of the fuel that reaches temperatures above 900 ° C, obtaining gasification in countercurrent on contact with the synthesis gas produced in the lower fixed bed chamber (7). The vortex generated in the refractory cyclone (16) impels the particles to more than 5 m / s, generating a separation effect between the gas and the ashes generated in the two gasification chambers, upper (8) and lower (7);

(f) remove the ash generated in the two effects of gasification; the ash advances on the refractory (12) falling on the external inclined plane of this and descends by gravity to the side gates (14) where it is removed.

The synthesis gas separated from the ash by the cyclonic effect is removed by an exit duct (11). The synthesis gas exits through the duct (11) at a temperature higher than 500 ° C.

The feeding device (3) can be a worm or any other mechanism that allows the proper transport of particulate material. In another embodiment of the invention, it is possible to inject, through the nozzles (9), saturated and superheated steam, up to 30% by volume of the fuel fed into the upper gasification chamber (8) to increase the% H ₂ generated and regulate the temperature of the cameras before overheating. The steam is generated by coils located in the inner wall of the upper gasification chamber (8) in the form of a jacket, taking advantage of the residual heat that is transferred through the walls of the combustion chamber. Both the pulverized fuel and the saturated or superheated steam require injecting it through the nozzles (9) through a forced flow that is achieved with pressures higher than 150 psi.

The gasification capacity of the lower fixed-bed chamber (7) can range from 10 kg / h to 1,000 kg / h for small ovens, and from 1,000 kg / h to 10,000 kg / h for medium-sized ovens.

Synthesis gas obtained is obtained by mixing biomass fuel - coal, fuels that can also be substituted by carbonaceous material from agricultural, livestock, industrial, commercial and residential residues, wastewater treatment plants (WWTP), and landfills, among others.

The typical composition of the synthesis gas obtained is:

- C0 ₂ = 0% to 10%;

- CO = 0% to 20%;

- CH ₄ = 0% to 10%;

- H ₂ = 0% to 20%; Y

- other gases = 40% - 80%.

- Example of the use of forced flow cyclone gasifier replacing pulverized coal burners in a tunnel kiln for brick cooking Two runs were carried out, according to the procedure proposed, where the efficiency of the invention is demonstrated. In the following table the temperature profile (° C) is presented and in figure 6 the graph of said runs is presented.

Table 1. Temperature Profiles

Tables 2 and 3 show the stoichiometric balances and energy of the presented runs: Table 2. Stoichiometric and Energy Balances

Table 3. Gasification system calculations

As advantages of the invention are:

- Due to the system of simultaneous gasification of double fixed chamber in co-current and fluidized in counter-current, it manages to combine mixtures of fossil fuel and biomass reducing the emission of greenhouse gases, and maintaining a competitive cost relation per thermal unit. - Versatility to adapt to various types of fuel in origin, shape and size. This system makes it possible to feed the gasifier flexibly from the availability of materials, achieving a design adjusted to the offer of carbonaceous material.

- The gasification system integrated to the high temperature refractory cyclone allows, at the same time, to gasify and separate the ashes achieving the pre-cleaning of the synthesis gas in the same chamber, without requiring an independent gas cleaning train, increasing the index of gasification and therefore the energy efficiency of the system, for this reason more gas can be obtained from the same raw material, than in a conventional gasifier.

- This double effect system guarantees higher gasification rates in a smaller space and with a higher concentration of temperature and low energy losses for a high efficiency of the process.

- Compact size compared to traditional systems, up to 70% reduction in volume of gasification chambers. Savings in materials and space.

- The calorific value of the fuel remains stable. The manipulation of gas is facilitated in uses such as brick kilns, billet furnaces and systems where it can be carried through pipes. The synthesis gas generated can replace natural gas in similar applications at lower cost.

- The forced flow of solid fuel that enters the gasification chamber, which admits up to 30% of steam (saturated and / or overheated), reduces the gasification time, therefore, the retention time of particles in the interior of the system, generating greater gas productivity. The high and stable temperatures allow a greater proportion of steam injection, increasing the production of the et and CH ₄ , achieving a gas with higher calorific value. The above descriptions of specific elements and embodiments of the present invention have been presented for purposes of illustration and description. These are not intended to be exhaustive or to limit the invention to the precise forms described. Modifications and variations are possible in light of the previous teachings. The embodiments were described in order to better explain the principles of the invention and their practical application, to enable other experts in the art to better utilize the invention and vary the embodiments with modifications that are suitable for the particular use contemplated.

Claims

1. A gasification system of carbonaceous material mixture of biomass and mineral coal characterized because it comprises:

- a feed hopper (2);

- a screw fuel feeding device (3) of solid fuel (biomass - coal);

- a gasification chamber (7, 8) connected to the feed hopper (2) by means of a feeding device (3) of the solid fuel;

- a primary air fan (6) located in the lower part of the feed hopper (2);

- a solid fuel feed duct (5);

- a retort (4) made in cast iron located inside a lower gasification chamber of fixed bed (7) with a series of perforations (13);

- a refractory (12) of the ashtray, which covers the retort (4);

- a lower fixed bed gasification chamber (7);

- an upper fluidized bed gasification chamber (8), located on the lower fixed bed gasification chamber (7);

- radial injection nozzles (9) arranged in the lid (10) of the upper gasification chamber (8);

- a refractory cyclone with fins (16), located inside the upper fluidized bed gasification chamber (8);

- side gates (14) with handles (15), located in the lower part of the lower fixed gasification chamber (7); Y

- an exit pipe (1 1) of synthesis gas.

where the lower fixed bed gasification chamber (7) and the upper fluidized bed gasification chamber (8) are a single gasification chamber.

2. The gasification system of carbonaceous material mixture of biomass and mineral coal of claim 1 characterized in that the refractory (12) of the ashtray is an external inclined plane.

3. The gasification system of carbonaceous material mixture of biomass and mineral coal of claim 1, characterized in that the outlet duct (11) of the synthesis gas is located in the axis or vertical central part of the upper chamber of gasification of the bed fluidized (8).

4. A gasification process of carbonaceous material mixture of biomass and mineral coal, characterized in that it comprises the following stages:

(c) feeding compressed air by means of an air fan (6) to a retort (4) located inside the lower gasification chamber of fixed bed (7);

(d) performing a first gassing effect in the lower fixed bed gasification chamber (7);

(f) remove the ash generated in the two effects of gasification. where the lower fixed bed gasification chamber (7) and the upper fluidized bed gasification chamber (8) are a single gasification chamber.

5. The gasification process of carbonaceous material mixture of biomass and mineral coal of claim 4, characterized in that the carbonaceous material is loaded in volumetric proportions ranging from 10% -90% to 90% -10%, where the granulometry of This carbonaceous material is between 10 mm to 100 mm in particle size.

6. The gasification process of carbonaceous material mixture of biomass and mineral coal of claim 4, characterized in that it feeds the material carbonaceous in the lower gasification chamber of fixed bed (7) is made through a feeding device (3) of solid fuel (carbonaceous material) type auger.

7. The gasification process of carbonaceous material mixture of biomass and mineral coal of claim 4 characterized in that the first effect of gasification is made when the solid fuel (carbonaceous material) ignites in the lower part of the retort (4) of perforations (13) reaching a temperature higher than 900 ° C forming a fuel column that emerges on a refractory (12); the stoichiometric ratio is adjusted below 80% of the air required by regulating the speed of the solid fuel feed device (3) and the primary air fan (6).

8. The gasification process of carbonaceous material mixture of biomass and mineral coal of claim 4 characterized in that the second effect of gasification in the upper fluidized bed gasification chamber (8) is made by injecting solid fuel with a granulometry less than 1 mm through radial nozzles (9) arranged in the lid (10) of the upper fluidized bed gasification chamber (8); inside the upper chamber (8) there is a refractory cyclone (16) formed by refractory rings where radial fins are housed that orient the carbonaceous material with an angle of attack forming a descending vortex of the fuel and in countercurrent contact with the synthesis gas produced in the lower fixed-bed chamber (7) produces a synthesis gas, which is withdrawn through an exit duct (11).

9. The gasification process of carbonaceous material mixture of biomass and mineral coal of claim 4 characterized in that through the radial nozzles (9) arranged in the lid (10) of the upper fluidized bed gasification chamber (8) is it injects water vapor, saturated and superheated, up to 30% by volume of the fuel fed into the upper gasification chamber (8).