TW201321674A - Combined biocoal and power generation system - Google Patents

Abstract

The invention discloses a combined biocoal and power generation system including a subsystem for generating biocoal and a subsystem for generating power. The power generation subsystem is connected to the biocoal generation subsystem, and supplies flue gas with different temperature thereto for generation of biocoal by exchanging heat with the biomass in the biocoal generation subsystem.

Description

Carbon electricity symbiosis system

The present invention relates to a process integration technology, and more particularly to an integrated system called a "carbon symbiosis system" that effectively manages the load of a coal-fired power plant to improve overall efficiency and utilizes low production of existing equipment in a coal-fired power plant. Cost, high quality biocoal.

For today's large-scale coal-fired power plants, the flue gas generated by coal-fired boilers has a large amount of heat energy, and if it can be recycled, it can achieve the effect of energy saving and carbon reduction. However, the process of a coal-fired power plant itself has no steam demand other than power generation, and since the steam cannot be effectively stored and sold, the heat energy of the flue gas of the coal-fired boiler is used in addition to the steam power generation. Effective recycling and sales are a major issue facing the industry in the current world of energy saving and carbon reduction.

In addition, the biomass of one of the renewable energy sources can reduce the excessive dependence of humans on fossil fuels and reduce carbon dioxide emissions. However, due to the variety of biomass, and most of them have shortcomings such as low calorific value and poor abrasiveness, they are subject to extensive utilization. limit. For example, at present, a pulverized coal boiler with a high combustion efficiency needs to be ground into a powder of more than 70% through a 200 mesh screen. Therefore, a roasting technique is utilized to convert biomass into high-quality, relatively easy-to-grind and other biomass coals that are close to coal in order to be utilized in large quantities. The calcination is an endothermic reaction that must be provided with appropriate heat. However, the conventional raw coal production technology mainly uses a roasting system composed of an independent fuel heating furnace, a cooling system and a smoke exhausting treatment system, which is complicated in procedure and high in cost and not profitable. For example, some conventional roasting systems utilize indirect heating methods, which are inefficient in heat efficiency and increase energy consumption; some conventional roasting systems use cooling water for cooling, and there is a waste of water resources, and the cooling water after heat exchange is still There are issues with subsequent processing issues and heat recovery. Therefore, the current use of raw coal roasting systems seems to run counter to the world trend of energy saving and carbon reduction. In addition, some of the conventional simple roasting systems have doubts about poor quality of raw coal and pollution of the environment.

In summary, the industry urgently needs a more effective energy management technology to produce low-energy, high-quality raw coal, improve the utilization of biomass in energy and power generation, and implement the goal of energy conservation and carbon reduction.

In view of the above problems and needs, this case is a carbon-electricity symbiosis system that uses raw materials such as low-oxygen (oxygen concentration less than 6 vol%) flue gas at different temperatures to directly heat the biomass and produce raw coal.

In one embodiment, the carbon-electricity symbiosis system comprises: a primary coal generation subsystem and a coal-fired power generation subsystem. The coal-fired power generation subsystem is connected to the biomass coal generation subsystem, and provides flue gas having different temperatures to the biomass coal generation subsystem to directly exchange heat with the biomass input into the biomass coal generation subsystem. Prepared into raw coal.

In another embodiment, the carbon-electricity symbiosis system includes a biomass coal generation subsystem and a coal-fired power generation subsystem. The raw coal generation subsystem includes: a drying unit for drying the input biomass, a calcining unit for roasting the dried biomass, and a cooling unit for cooling the calcined biomass to obtain the raw coal. Cooling unit. The coal-fired power generation subsystem is connected to the raw coal generation subsystem, and provides flue gas having three different temperatures to the drying unit, the baking unit and the cooling unit, respectively, for drying, roasting and cooling purposes of the biomass.

In another embodiment, the carbon-electricity symbiosis system includes a coal-fired power generation subsystem and a primary coal generation subsystem. The coal-fired power generation subsystem includes a fuel boiler that provides a first flue gas, a second flue gas, and a third flue gas, wherein the temperature of the first flue gas is between 130 ° C and 160 ° C. The temperature of the second flue gas is between 350 ° C and 500 ° C, and the temperature of the third flue gas is between 60 ° C and 100 ° C. The raw coal generation sub-system is connected to the coal-fired power generation subsystem, and includes a drying unit, a roasting unit, and a cooling unit. Wherein, the drying unit receives the first flue gas to directly dry the input biomass; the roasting unit receives the second flue gas to directly roast the dried biomass, and the second flue gas flows out of the roasting unit and returns The fuel boiler; the cooling unit receives the third flue gas to directly cool the calcined biomass to obtain the raw coal.

First of all, this patent application (hereinafter referred to as "the case") has about biomass energy, and the source of raw materials for developing biomass is diverse, such as livestock excrement, crop waste (such as rice straw, corn stalk, bagasse), Wood or bamboo, municipal waste, organic sludge, biogas, energy crops, algae, etc. can all be used as sources of biomass energy. Coupled with the rapid growth of plants and the planned cultivation of energy crops, the source of biomass energy will not be scarce. The biomass energy in renewable energy is defined as “the energy generated by the direct use or treatment of agricultural and forestry plants, biogas and domestic organic waste”.

In addition, the focus of this case is to effectively integrate the thermal energy and exhaust gas treatment system of the boiler power generation system, to carry out the drying, burning and cooling procedures of the biomass, to prepare a large amount of high-quality and easy-grinding raw coal and then return it to the power generation boiler. For fuel. Examples of innovations and benefits of the examples in this case are as follows:

For example, the load can be maneuvered: the embodiment of the present invention provides a new high-carbon production with low carbon footprint and a carbon-electricity symbiosis system for preparing raw coal. The thermal power plant can maneuver power generation and carbon production, and is a new energy management system. system.

For example, thermal efficiency can be improved: the thermal efficiency of a coal-fired power generation boiler is much higher than that required for a general biomass energy generation system, and all of the thermal energy of the biomass coal sub-system can be recycled back to the secondary boiler system. Therefore, the embodiment of the present invention can save the cost of the device of the independent fuel heating furnace and achieve the goal of energy saving.

For example, water resources can be saved: the general biomass energy-burning system requires a cooling water system for cooling the raw coal, and the embodiment of the present invention uses the colder flue gas at the end of the thermal power plant for cooling.

For example, practical and high economic efficiency: general thermal power plants have no steam demand, and steam can not be stored for sale, so the benefits of steam and electricity symbiosis cannot be obtained. Only the products of the present example are storable raw coal and coal. The power plant itself can also be used. This carbon-electricity symbiosis system is more practical and economical.

In summary, the embodiment of the present invention provides a low-carbon, environmentally-friendly and flexible procedure for preparing low-quality raw coal, which makes the use of raw coal (renewable energy) for carbon reduction an achievable goal.

Hereinafter, a comparative example and a preferred embodiment of the present invention will be described in order with reference to the accompanying drawings.

1 is a schematic view showing a coal-fired power plant of a comparative example. As shown in FIG. 1, the conventional coal-fired power plant mainly includes a power generation boiler 10, a steam turbine 15, an economizer 20, a denitration device 30, an air heater 40, a dust removal device 50, a heat exchanger 60, and sulfur removal. Process unit such as device 70. The process units described above are connected to one another by different lines, as will be further described below.

The power generation boiler 10 mainly mixes and burns the preheated air input via the line ST10 and the fuel input via the line ST2 to generate high temperature flue gas, heats the preheated liquid water input from the economizer 20 via the line ST11a, and generates steam via the line ST3. The steam turbine 15 is input to perform a power generation process, and then the condensed water generated by the power generation process is discharged from the steam turbine 15 via the line ST4, and is collected from the supplementary water sent via the line ST7, and then enters the economizer 20 through the line ST11 to receive the preheating. In addition, the flue gas generated by the power generation boiler 10 is discharged from the line ST5 and input to the economizer 20 to preheat the liquid water entering the economizer 20. Here, the air that is input to the air heater 40 via the line ST1 is preheated by the flue gas from the denitration device 30 and passing through the line ST8, and then the preheated air enters the power generation boiler 10 via the line ST10 to improve the combustion efficiency. Among them, the power generation boiler 10 can treat coal, oil or natural gas. In the case of coal, the power generation boiler 10 can treat pulverized coal, and more than 70% of the powder of the pulverized coal can pass through a 200 mesh screen.

The economizer 20 mainly uses the flue gas input through the line ST5 to heat the liquid water input via the line ST11, and then returns it to the power generation boiler 10 to manufacture steam for use in a power generation process, so that the liquid water can be continuously recycled. In addition, the flue gas after use of the economizer is input to the denitration device 30 via the line ST6 for denitration. The temperature of the flue gas entering the economizer 20 is between 450 and 500 ° C, and the temperature of the flue gas leaving the economizer 20 is between 350 ° C and 400 ° C.

The denitration device 30 mainly performs denitration treatment on flue gas input at 350 to 400 ° C, and then the flue gas after denitration is input to the air heater 40 through a line ST8.

The air heater 40 mainly uses the flue gas from the denitration device 30 to preheat the air that is input to the air heater 40 via the line ST1. The air heated by the air heater 40 is input to the power generation boiler 10 through the line ST10. The temperature of the flue gas leaving the air heater 40 of the pipeline is about 130 ° C to 160 ° C and is input to the dedusting device 50 via the line ST9.

The dust removing device 50 mainly performs a dust removing process on the flue gas from the air heater 40 so as to comply with environmental regulations when subsequently discharging. The flue gas leaving the dust removing device 50 is input to the heat exchanger 60 via the line ST12.

The heat exchanger 60 mainly performs a heat exchange process on the flue gas from the dust removing device 50, and inputs the flue gas into the sulfur removing device 70 through the pipeline ST13 to perform a sulfur removal process, and the flue gas temperature after desulfurization is about 50 ° C and is via the pipeline. The ST 14 is again returned to the heat exchanger 60 for heat exchange, and finally the flue gas is sent to the chimney via the line ST15 at a temperature between 80 and 100 ° C and discharged into the atmosphere.

2 is a schematic view showing a carbon-electricity symbiosis system according to an embodiment of the present invention. 2 and FIG. 1 are the same components, please refer to the related content of FIG. 1 and will not be described in principle.

First of all, the so-called "carbon-electricity symbiosis system" in this embodiment is a system in which the process of the coal-fired power plant of Fig. 1 is integrated with the current biomass coal roasting system, and the coal is effectively utilized and managed. The thermal energy of the power plant produces high quality raw coal with high efficiency. Further, in this embodiment, the flue gas and the thermal energy of the coal-fired boiler of the coal-fired power plant are utilized to prepare the raw material or the high-moisture low-calorie lignite into a high-calorie, easy-grinding and stable and preserveable raw coal. Furthermore, it is the procedure of drying, roasting and cooling the biomass or lignite by using flue gas of different temperatures in different stages (units) of the coal-fired power plant process to prepare high-heat, easy-grinding raw coal. . When the demand for electricity is high, when the demand for raw coal is low, the heat energy of the flue gas is recovered to generate steam power. When the demand for electricity is low, when the demand for raw coal is high, the heat energy of the flue gas is transmitted to the embodiment. The raw coal production subsystem (shown in Fig. 2, mainly composed of a drying unit 80, a calcining unit 90, and a cooling unit 100) produces raw coal. The carbon-electricity symbiosis system of the present embodiment is also applicable to a fuel-fired power generation system, a gas-fired power generation system, or the like. Hereinafter, the carbon electric symbiosis system of the present embodiment will be described in detail with reference to FIG. 2 as follows.

As shown in FIG. 2, the carbon-electricity symbiosis system of the present embodiment includes a coal-fired power generation subsystem and a biomass coal generation subsystem. The coal-fired power generation subsystem includes the various units of the coal-fired power plant of FIG. 1, that is, the power generation boiler 10, the steam turbine 15, the economizer 20, the denitration device 30, the air heater 40, the dust removal device 50, and the heat exchange. The processor 60 and the process unit such as the sulfur removal device 70. In addition, the raw coal generation subsystem includes a drying unit 80, a calcining unit 90, and a cooling unit 100. In this embodiment, the power generation boiler 10 is used to treat pulverized coal, and more than 70% of the powder of the pulverized coal can pass through a 200 mesh screen.

For the power generation boiler 10 of Fig. 2, the input gas is more than the preheated air input through the line ST10, and more flue gas recovered from the calcining unit 90 by the line ST19. Further, the input fuel may optionally include the raw coal input from the cooling unit 100 via the line ST22a in addition to the pulverized coal input via the line ST2. In this embodiment, the power generation boiler 10 generates high-temperature flue gas, which is discharged from the line ST5 and can be partially supplied to the economizer 20 via the line ST5a, and the other portion is input to the calcining unit 90 via the line ST5b to roast the biomass. Note that the flue gas input to the calcining unit 90 via the line ST5b can handle a wider variety and a large amount of biomass because the temperature is about 400 ° C to 500 ° C. Of course, in other embodiments, the flue gas obtained from the economizer 20 having a temperature between 350 ° C and 400 ° C (that is, via the line ST6b) may be utilized to roast the biomass, which will be described later.

For the economizer 20 of Fig. 2, the flue gas output via the line ST6 may be partially supplied to the denitration device 30 via the line ST6a, and the other portion is input to the calcining unit 90 via the line ST6b to roast the biomass. Specifically, it is necessary to take the flue gas from the line ST5b or the line ST6b to roast the raw material in the calcining unit 90, depending on the power generation load, the kind of the biomass, and the amount of the desired treatment. And set.

For the denitration device 30 and the air heater 40 of FIG. 2, please refer to FIG. Here, only the flue gas use of the drying unit 80 that is output from the air heater 40 to the raw coal production subsystem will be described. As shown in FIG. 2, the flue gas output from the air heater 40 through the line ST9 may be partially input to the dedusting device 50 via the pipeline ST9a for subsequent processing (please refer to FIG. 1 for details), and the other portion is input to the drying unit 80 via the line ST9b. The raw material input via the line ST16 is dried. The flue gas leaving the drying unit 80 is input to the dedusting device 50 via the line ST17, and exits the dedusting device 50 via the line ST12, and is input to the heat exchanger 60, and then enters the desulfurization device 70 for subsequent desulfurization treatment (please refer to FIG. 1 for details). The flue gas leaving the heat exchanger 60 at a temperature between 60 ° C and 100 ° C enters the cooling unit 100 via the pipeline ST15 and the line ST15a for cooling the raw coal produced by the calcination (that is, via the pipeline ST20) Then, it leaves the cooling unit 100 via the line ST21, and finally enters the chimney via the line ST23 to be discharged. In another embodiment, the flue gas output through the line ST15 can also be discharged directly into the chimney through the line ST15b and the line ST23.

For the calcining unit 90 of Fig. 2, the raw material from the line ST5b or the line ST6b is mainly used for baking the raw material which is dried by the drying unit 80 and input through the line ST18. Please note that the flue gas leaving the calcining unit 90 is rich in biomass volatiles and can be returned to the inlet end of the power generation boiler 10 via line ST19 to recover thermal energy. Further, after the green matter calcined by the calcining unit 90 becomes the raw coal, the cooling unit 100 is input to the cooling unit 100 via the line ST20 to perform cooling. The cooled raw coal leaves the cooling unit 100 via the line ST22, and can be selectively sent to the power generation boiler 10 via the line ST22a, the line ST2a, or sent to the warehouse for storage via the line ST22b.

Although the present case is illustrated by a number of preferred embodiments, those skilled in the art can make various forms of changes without departing from the spirit and scope of the present invention. The above implementations are for illustrative purposes only and are not intended to limit the scope of the present invention. All kinds of modifications or changes that are not in violation of the spirit of the case are the scope of patent application in this case.

10. . . Power generation boiler

15. . . Steam turbine

20. . . Economizer

30. . . Denitration equipment

40. . . Air heater

50. . . Dust removal equipment

60. . . Heat exchanger

70. . . Sulfur removal equipment

80. . . Drying unit

90. . . Roasting unit

100. . . Cooling unit

ST1, ST2, ST3, ST4, ST5, ST6, ST7, ST8, ST9, ST10, ST11, ST12, ST13, ST14, ST15, ST16, ST17, ST18, ST19, ST20, ST21, ST22, ST23, ST2a, ST5a, ST5b, ST6a, ST6b, ST9a, ST9b, ST11a, ST15a, ST15b, ST22a, ST22b. . . Pipeline

1 is a schematic view showing a coal-fired power plant of a comparative example.

2 is a schematic view showing a carbon-electricity symbiosis system according to an embodiment of the present invention.

10. . . Power generation boiler

15. . . Steam turbine

20. . . Economizer

30. . . Denitration equipment

40. . . Air heater

50. . . Dust removal equipment

60. . . Heat exchanger

70. . . Sulfur removal equipment

80. . . Drying unit

90. . . Roasting unit

100. . . Cooling unit

ST1, ST2, ST3, ST4, ST5, ST6, ST7, ST8, ST9, ST10, ST11, ST12, ST13, ST14, ST15, ST16, ST17, ST18, ST19, ST20, ST21, ST22, ST23, ST2a, ST5a, ST5b, ST6a, ST6b, ST9a, ST9b, ST11a, ST15a, ST15b, ST22a, ST22b. . . Pipeline

Claims (10)

A carbon-electricity symbiosis system comprising: a primary coal generation subsystem; and a coal-fired power generation subsystem, connecting the biomass coal generation subsystem, and providing smoke having different temperatures to the biomass coal generation subsystem The raw biomass is prepared by directly performing heat exchange with the raw material input into the secondary system of the raw coal. For example, in the carbon-electricity symbiosis system of claim 1, wherein the raw coal can be input into the coal-fired power generation subsystem. A carbon electricity symbiosis system comprising: a primary coal generation sub-system comprising: a drying unit for drying the input biomass; a calcining unit for roasting the dried biomass; and a cooling unit for Cooling the calcined biomass to obtain the raw coal; and a coal-fired power generation subsystem, connecting the raw coal to produce a secondary system, and providing flue gas having three different temperatures to the drying unit, the roasting unit, and the The cooling unit serves as drying, baking and cooling of the biomass, respectively. The carbon-electricity symbiosis system of claim 3, wherein the temperature of the flue gas input to the drying unit is between 130 ° C and 160 ° C. The carbon-electricity symbiosis system of claim 3, wherein the temperature of the flue gas input to the roasting unit is between 350 ° C and 500 ° C. The carbon-electricity symbiosis system of claim 3, wherein the temperature of the flue gas input to the cooling unit is between 60 ° C and 100 ° C. A carbon-electricity symbiosis system comprising: a coal-fired power generation subsystem, comprising: a fuel boiler, providing a first flue gas, a second flue gas, and a third flue gas, wherein the temperature of the first flue gas is introduced Between 130 ° C and 160 ° C, the temperature of the second flue gas is between 350 ° C and 500 ° C, the temperature of the third flue gas is between 60 ° C and 100 ° C; and a primary coal generation subsystem Connecting the coal-fired power generation subsystem, comprising: a drying unit, receiving the first flue gas to directly dry the input biomass; and a calcining unit receiving the second flue gas to directly roast the dried biomass; The second flue gas flows out of the calcining unit and returns to the fuel boiler; and a cooling unit receives the third flue gas to directly cool the calcined biomass to obtain the raw coal. For example, the carbon-electricity symbiosis system of claim 7 wherein the fuel boiler can treat coal, oil or natural gas. For example, in the carbon-electricity symbiosis system of claim 7, wherein the raw coal can be input into the coal-fired power generation subsystem. For example, in the carbon-electricity symbiosis system of claim 7, wherein the fuel boiler can process pulverized coal, and more than 70% of the powder of the pulverized coal can pass through a 200 mesh screen.