JP6173187B2 - Solid fuel reforming method and apparatus - Google Patents

Description

  The present invention relates to a solid fuel reforming method and apparatus. Specifically, the present invention relates to a technique for reforming and using a solid fuel containing moisture such as lignite as a solid fuel having higher utility value.

  Solid fuel refers to carbonaceous materials that are solid at room temperature and can be heated by combustion. Low-grade coals including lignite, lignite and subbituminous coal are known as such solid fuels. It has been. Peat is also known as a solid fuel similar to these low-grade coals. These solid fuels contain a large amount of moisture, have a low calorific value, and are difficult to handle because they may cause spontaneous ignition and combustion during storage and transportation after drying. For this reason, although the above-described solid fuel is required to be effectively used with the depletion of oil and coal and the conversion of nuclear energy, it cannot be said that the fuel is sufficiently utilized as a fuel.

  In particular, as a technique for dehydrating solid fuel, (1) mechanical dehydration methods such as pressing, centrifugation, and filtration are known, but as described above, there is a risk of spontaneous ignition, High cost is a problem. In order to eliminate such problems, (2) thermal drying methods (evaporation methods) such as fluidized bed / airflow drying and reforming in oil have been developed (for example, Patent Documents 1 and 2). However, these methods have problems such as low energy efficiency and difficulty in increasing the recovery rate of used oil due to the large amount of heat required to vaporize moisture. ) A thermal dehydration method (non-evaporation method) using saturated steam or hot water is also being studied (Patent Document 3), but there are serious problems in practical use such as the need for a high-temperature and high-pressure environment.

Japanese Patent Publication No. 07-047751 JP 07-233383 A JP 2001-139957 A

  Therefore, in order to effectively use solid fuel, further improvement in energy efficiency is required with a simple apparatus configuration, and further, supply of reformed fuel at low cost is required.

  Therefore, in view of the above circumstances, an object of the present invention is to provide a technology for supplying solid fuel containing moisture as energy having high utility value by reforming with high efficiency.

[Configuration 1]
The characteristic configuration of the solid fuel reforming method of the present invention for achieving the above object is as follows.
A method for reforming a solid fuel containing moisture,
While supplying exhaust heat from the heat equipment to the solid fuel containing moisture, supplying and contacting the dried vaporized gas that is vaporized liquefied natural gas, the dried solid fuel and the moisture-containing vaporized gas that has absorbed moisture As you get
The moisture-containing vaporized gas is heat-exchanged with liquefied natural gas to vaporize the liquefied natural gas and obtain a fuel gas and separated water dehumidified from the moisture-containing vaporized gas, and heat the obtained fuel gas. It is in the point which burns with an apparatus and obtains the said exhaust heat.

[Function 1]
For example, lignite, lignite, subbituminous coal, peat, biomass-based recycled solid fuel, and the like contain moisture and can be used as fuel by dehydrating and reforming.

  When dry vaporized gas that has just vaporized LNG is supplied to the solid fuel, the water vapor pressure in the solid fuel atmosphere can be kept extremely low. Therefore, the atmosphere of the solid fuel can be maintained in a state where the water vapor pressure is extremely low with the dry vaporized gas, and the vaporization of moisture can be promoted to efficiently dry. In addition, dry vaporized gas of liquefied natural gas is supplied to and contacted with solid fuel while supplying exhaust heat from the thermal equipment, and moisture is vaporized and removed to dry and simultaneously use the exhaust heat of the thermal equipment Thus, moisture-absorbed gas that has been absorbed is obtained, so that the efficiency of heat recovery from the thermal equipment can be increased.

  The obtained humidified gas is heated and humidified as the solid fuel is dried. The amount of heat of the moisture-containing gas can be used to vaporize LNG in the LNG vaporizer, and at the same time, the moisture-containing gas is cooled and the saturated vapor pressure is lowered. Will be. As a result, the moisture-containing gas can be dehumidified to produce separated water, and the moisture content can be reduced to a fuel gas that can be continuously combusted in the combustor. The fuel gas obtained here is supplied to the combustor.

  Therefore, when LNG is supplied to the thermal equipment, it contributes to drying the solid fuel, and the exhaust heat of the thermal equipment can be used effectively, so that the solid fuel can be reformed efficiently. become. In addition, as exhaust heat of the thermal equipment, unused exhaust heat of about 100 ° C. to 150 ° C., which is normally difficult to use, can be effectively used, and for example, it is necessary for drying and vaporizing LNG with unused exhaust heat of a gas engine or the like. Since the amount of heat can be sufficiently covered, by providing ancillary equipment (LNG vaporizer and drying device) for existing thermal equipment, it is possible to reform solid fuel with substantially no energy cost required for operation. .

[Configuration 2]
In addition, the characteristic configuration of the reformer for the solid fuel containing moisture is as follows:
In addition to providing a drying device for solid fuel containing moisture, an LNG vaporizer for vaporizing liquefied natural gas to obtain dry vaporized gas is provided, and the fuel gas obtained by the LNG vaporizer is burned to be used for heat and discharged. A thermal device that generates heat,
The LNG vaporizer is provided with a heat exchange section for vaporizing the supplied liquefied natural gas, and a dry vaporized gas passage for supplying the obtained dry vaporized gas to the drying device is provided.
The drying apparatus includes a drying chamber, a solid fuel supply unit that supplies solid fuel containing moisture to the drying chamber, and a dry vaporized gas supply unit that supplies the dry vaporized gas. A waste heat supply unit that heats the drying chamber by exhaust heat, and the drying chamber discharges the moisture-containing gas generated when the dry vaporized gas contacts the solid fuel and absorbs moisture. A gasification gas path, a solid fuel discharge path for discharging the dried solid fuel,
The LNG vaporizer is provided with a fuel gas passage that cools the moisture-containing vaporized gas by exchanging heat with the liquefied natural gas supplied in the heat exchange unit, and discharges it as dehumidified fuel gas. A drainage channel for draining moisture condensed from the vaporized gas is provided.
The thermal device is provided with a combustion section that burns the fuel gas to make the heat available.

[Operation effect 2]
When the above configuration is adopted as a solid fuel reforming apparatus capable of realizing the above-described solid fuel reforming method, the LNG vaporizer, in the LNG vaporizer, includes a liquefied natural gas vaporized in the heat exchange section and moisture, and an LNG And the dried vaporized gas and the dehumidified fuel gas can be obtained, and the fuel gas obtained here can be burned by a thermal device to obtain exhaust heat. Further, the dry vaporized gas generated from LNG is supplied to the drying device via the dry vaporized gas path. Further, when the dehumidified fuel gas is obtained, the moisture-containing vaporized gas is cooled and the saturated vapor pressure is lowered, so that it is dehumidified. Moisture generated by dehumidification is discharged from the drainage channel, and the moisture-containing vaporized gas has a low moisture content and becomes a fuel gas that can continue to be burned in the combustor. The fuel gas obtained here is supplied to the combustor.

  In the drying apparatus, since the solid fuel containing moisture and the dry vaporized gas are introduced into the drying chamber, the water vapor pressure in the atmosphere of the solid fuel is kept extremely low, and thus drying can be promoted. At the same time, since the moisture-containing vaporized gas is obtained from the dry vaporized gas using the exhaust heat of the thermal equipment supplied from the exhaust heat supply unit, the saturation vapor pressure can be increased and the drying efficiency can be further increased. The heat recovery efficiency from can be increased. The obtained humidified gas is heated and humidified as the solid fuel is dried. The amount of heat that the moisture vaporization gas has can be used to vaporize LNG in the LNG vaporizer. The dried solid fuel can be taken out from the solid fuel discharge section and used as a fuel for a combustion furnace or the like.

  In the thermal equipment, the fuel gas is burned in the combustion section so that the heat can be used, so that it is possible to generate unused exhaust heat while effectively using the obtained fuel gas. This unused waste heat has a sufficient amount of heat to vaporize, heat, and dehumidify the normally supplied LNG. Therefore, it is possible to continuously use the supplied LNG after drying the solid fuel containing moisture. It will be possible.

  Therefore, when LNG is supplied to the thermal equipment, it contributes to drying the solid fuel, and the exhaust heat of the thermal equipment can be used effectively, so that the solid fuel can be reformed efficiently. become. Therefore, by providing an LNG vaporizer and a drying device for existing thermal equipment, it is possible to reform the solid fuel using unused exhaust heat. Quality can be done.

[Configuration 3]
Moreover, a water-containing low grade coal can be used as the solid fuel containing water.

[Operation effect 3]
For example, lignite, lignite, subbituminous coal, peat, biomass-based recycled solid fuel, etc. contain moisture and can be used as a reform target because it can be used as a fuel by dehydrating and reforming. Suitable as a solid fuel.

[Configuration 4]
Moreover, lignite with a moisture content of 20% or more can be used as the moisture-containing low-grade coal.

[Operation effect 4]
Among the above-mentioned moisture-containing low-grade coals, lignite is useful because it is easy to handle and can be easily converted into a solid fuel having a sufficient amount of heat by high-grade coal. In addition, lignite has a large reserve in the world and its economic effect is very large when it is easy to reform and promote its use.

  Therefore, the solid fuel can be efficiently reformed and the utility value can be increased.

Flow chart of solid fuel reformer

  The solid fuel reforming method and solid fuel reforming apparatus of the present invention will be described below. In addition, although suitable examples are described below, these examples are described in order to more specifically illustrate the present invention, and various modifications can be made without departing from the spirit of the present invention. The present invention is not limited to the following description.

[Reformer for solid fuel]
The solid fuel reforming apparatus according to the present invention is provided with a drying apparatus 1 for solid fuel d containing water, and an LNG vaporizer 2 for vaporizing LNG to obtain a dry vaporized gas a, which is obtained by the LNG vaporizer 2. The fuel gas c is burned and used for heat, and a heat device 3 for generating exhaust heat is provided.

[LNG vaporizer]
The LNG vaporizer 2 is provided with a heat exchange unit 21 for vaporizing LNG supplied from the LNG supply path L1, and the natural gas (NG) obtained by vaporization is dried as a dry vaporized gas a through the dry vaporized gas path L2. Supply to device 1. Further, the moisture-containing vaporized gas b obtained by the drying apparatus 1 is introduced from the moisture-containing vaporized gas passage L3, and the heat exchange unit 21 is configured to be able to exchange heat with the supplied LNG. A fuel gas passage L4 for supplying the moisture-containing vaporized gas b cooled by the heat exchange unit 21 as the dehumidified fuel gas c is provided, and a drainage passage L5 for discharging moisture condensed from the cooled moisture-containing vaporized gas b is provided. It is provided.

[Drying equipment]
The drying device 1 is a drum type dryer having a drum-shaped drying chamber 11 that is rotatable around an axis and a stirring device 12 for stirring solid fuel. The solid fuel d is provided on one side in the axial direction of the drying chamber 11. Is supplied from the solid fuel supply path L6. A jacket-like exhaust heat supply unit 14 that heats the drying chamber by introducing high-temperature exhaust gas e from the heat device 3 that flows through the exhaust gas passage L7 is provided on the outer periphery of the drying chamber 11. Further, on the other side in the axial direction of the drying chamber 11, the solid fuel d supplied to the drying chamber 11 is dried while being stirred and mixed, and is taken out from the solid fuel discharge path L <b> 8 as the dried reformed fuel f. 17 is provided. Further, a dry vaporized gas supply unit 15 for introducing the dry vaporized gas a from the dry vaporized gas passage L2 is provided on the other side in the axial direction of the drying chamber 11, and the dry vaporized gas a introduced into the drying chamber is stirred and mixed. A moisture-containing vaporized gas discharge unit 16 is provided which is brought into contact with the solid fuel d while being heated by exhaust heat to vaporize moisture contained in the solid fuel d and discharges from the L3 as the contained moisture-containing vapor b.

[Thermal equipment]
The thermal equipment 3 uses a gas engine cogeneration facility provided with a combustion section 31 that burns the fuel gas c to obtain power, and the exhaust gas e after heat recovery in the heat utilization equipment 32 is exhausted through the exhaust gas passage L7. Supplied to the supply unit 14.

[Operation example]
With the above configuration, for example, when the exhaust gas e at 117 ° C. is discharged from the thermal equipment 3 at 171.107 kg / h, the drying device 1 uses 10 ° C. when reforming 1000 kg / h of lignite with a moisture content of 60 mass%. (3575 kg / h) of dry vaporized gas a was discharged as a moisture vaporized gas b (4130 kg / h) at 60 ° C., and high quality modified lignite (444 kg / h) with a moisture of 10% by mass at 60 ° C. was modified. It can be obtained with high efficiency as a quality solid fuel. The exhaust gas e from the thermal equipment 3 is cooled to 100 ° C. and discharged.
Here, when LNG is supplied to the LNG vaporizer 2 at −160 ° C., and LNG at a humidity of 13.7 mol% and 60 ° C. is supplied at 3575 kg / h as the moisture-containing gas b, the moisture-containing air is supplied to the heat exchanger 21. Heat exchanged with gasified gas b (4130 kg / h), dry vaporized gas a (3575 kg / h) at 10 ° C., fuel gas c (3575 kg / h) with 1 mol% humidity at 1 ° C., and water (534 kg / h) ) Is obtained.
When the fuel gas c obtained as a result is supplied to the thermal equipment 3, an operation in which the exhaust gas e of 117 ° C. is discharged at a rate of 171.107 kg / h together with a predetermined output becomes possible.

[Another Example]
(1)
As the solid fuel containing moisture, low-grade coal such as lignite, sub-bituminous coal, peat, or biomass-based recycled solid fuel can be used instead of lignite. Depending on the quality of these solid fuels, LNG The reforming efficiency can be balanced by changing the quantity ratio between the supply amount and the solid fuel.

(2)
Various specific configurations can be adopted as specific configurations of the LNG vaporizer, the drying device, and the thermal equipment. For example, a boiler or the like can be adopted as the thermal equipment. In addition, it is preferable to employ | adopt what can supply waste heat stably as a thermal apparatus like a gas engine cogeneration apparatus. Further, the configuration for supplying exhaust heat from the thermal device to the drying device may be a configuration for exchanging heat with the heat medium heated by the thermal device instead of circulating the exhaust gas of the thermal device.

  The solid fuel reforming method of the present invention can supply a solid fuel reformed as energy having high utility value by reforming a solid fuel containing moisture with high efficiency.

1: Drying device 11: Drying chamber 12: Stirring device 13: Solid fuel supply unit 14: Exhaust heat supply unit 15: Dry vaporization gas supply unit 16: Moisture vaporization gas discharge unit 17: Solid fuel discharge unit 2: LNG vaporizer 21: Heat exchange unit 3: Heating device 31: Combustion unit 32: Heat utilization device L1: LNG supply channel L2: Dry vaporization gas channel L3: Humidified vaporization gas channel L4: Fuel gas channel L5: Drainage channel L6: Solid fuel supply Path L7: exhaust gas path L8: solid fuel discharge path a: dry vaporized gas b: wet vaporized gas c: fuel gas d: solid fuel e: exhaust gas f: reformed fuel

Claims (4)

A method for reforming a solid fuel containing moisture,
While supplying exhaust heat from the heat equipment to the solid fuel containing moisture, supplying and contacting the dried vaporized gas that is vaporized liquefied natural gas, the dried solid fuel and the moisture-containing vaporized gas that has absorbed moisture As you get
The moisture-containing vaporized gas is heat-exchanged with liquefied natural gas to vaporize the liquefied natural gas and obtain a fuel gas and separated water dehumidified from the moisture-containing vaporized gas, and heat the obtained fuel gas. A method for reforming a solid fuel that is combusted in equipment to obtain the exhaust heat. A reformer for solid fuel containing moisture,
In addition to providing a drying device for solid fuel containing moisture, an LNG vaporizer for vaporizing liquefied natural gas to obtain dry vaporized gas is provided, and the fuel gas obtained by the LNG vaporizer is burned to be used for heat and discharged. A thermal device that generates heat,
The LNG vaporizer is provided with a heat exchange section for vaporizing the supplied liquefied natural gas, and a dry vaporized gas passage for supplying the obtained dry vaporized gas to the drying device is provided.
The drying apparatus includes a drying chamber, a solid fuel supply unit that supplies solid fuel containing moisture to the drying chamber, and a dry vaporized gas supply unit that supplies the dry vaporized gas. A waste heat supply unit that heats the drying chamber by exhaust heat, and the drying chamber discharges the moisture-containing gas generated when the dry vaporized gas contacts the solid fuel and absorbs moisture. A gasification gas path, a solid fuel discharge path for discharging the dried solid fuel,
The LNG vaporizer is provided with a fuel gas passage that cools the moisture-containing vaporized gas by exchanging heat with the liquefied natural gas supplied in the heat exchange unit, and discharges it as dehumidified fuel gas. A drainage channel for draining moisture condensed from the vaporized gas is provided.
A solid fuel reforming apparatus, wherein the thermal device is provided with a combustion section that burns the fuel gas to make the heat available.   The solid fuel reforming apparatus according to claim 2, wherein the moisture-containing solid fuel is moisture-containing low-grade coal.   The reformer for solid fuel according to claim 3, wherein the moisture-containing low-grade coal is lignite having a moisture content of 20% or more.

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