US-12618032-B2 - Method for producing organic substance and device for producing organic substance

Abstract

A method for producing an organic substance includes a step of passing a synthesis gas G 1 discharged from a gasifier 11 through a gas cooling tower 21 to cool the synthesis gas G 1 with water sprayed in the gas cooling tower 21 , a step of passing the synthesis gas G 1 cooled in the gas cooling tower 21 through a filtration-type dust collector 22 and a step of bringing a synthesis gas G 2 that has passed through at least the gas cooling tower 21 and the filtration-type dust collector 22 into contact with a microbial catalyst to generate an organic substance.

Inventors

• Kokoro HAMACHI
• Satoshi Shimizu

Assignees

• SEKISUI CHEMICAL CO., LTD.

Dates

Publication Date

20260505

Application Date

20210121

Priority Date

20200123

Claims (9)

1. 1 . A method for producing an organic substance comprising: a step of passing a synthesis gas discharged from a gasifier through a gas cooling tower to cool the synthesis gas with water sprayed in the gas cooling tower; a step of passing the synthesis gas cooled in the gas cooling tower through a filtration-type dust collector, and a step of bringing the synthesis gas that has passed through at least the gas cooling tower and the filtration-type dust collector into contact with a microbial catalyst to generate an organic substance, wherein the synthesis gas contains: 0.1 vol % or more and 80 vol % or less of carbon monoxide, 0.1 vol % or more and 80 vol % or less of hydrogen, and 0.01 vol % or more and 5 vol % or less of oxygen, and wherein oxygen is removed from the synthesis gas by a deoxidation device and carbon dioxide is removed from the synthesis gas by at least one selected from the group consisting of a pressure swing adsorption type separator, a temperature swing adsorption type separator, and a pressure/temperature swing adsorption type separator.
2. 2 . The method for producing an organic substance according to claim 1 , wherein a temperature of the synthesis gas discharged from the gasifier is 900° C. or higher.
3. 3 . The method for producing an organic substance according to claim 1 , wherein the synthesis gas is cooled to a temperature of 100° C. or higher and 200° C. or lower in the gas cooling tower.
4. 4 . The method for producing an organic substance according to claim 1 , wherein the synthesis gas discharged from the filtration-type dust collector is further passed through a water scrubber, and the synthesis gas that has passed through at least the gas cooling tower, the filtration-type dust collector and the water scrubber is brought into contact with a microbial catalyst to generate an organic substance.
5. 5 . The method for producing an organic substance according to claim 4 , wherein the synthesis gas is cooled to 40° C. or lower in the water scrubber.
6. 6 . The method for producing an organic substance according to claim 4 , wherein the water sprayed in the gas cooling tower is vaporized and mixed into the synthesis gas, and at least a part of water mixed into the synthesis gas is condensed and removed in the water scrubber.
7. 7 . The method for producing an organic substance according to claim 1 , wherein the organic substance is generated in a reactor filled with at least the microbial catalyst and water, water is separated from an organic substance-containing liquid containing the organic substance obtained in the reactor, and the separated water is supplied to the gas cooling tower.
8. 8 . The method for producing an organic substance according to claim 1 , wherein the gasifier gasifies waste to generate a synthesis gas.
9. 9 . The method for producing an organic substance according to claim 1 , wherein the organic substance contains ethanol, a filtration-type dust collector through which the synthesis gas cooled in the gas cooling tower is passed.

Description

TECHNICAL FIELD The present invention relates to a method for producing organic substance in which an organic substance is produced using a synthesis gas as a raw material and a device for producing an organic substance in which an organic substance is produced using a synthesis gas as a raw material. BACKGROUND ART Techniques that thermally decompose a variety of wastes such as industrial waste and general waste to generate a gas in a gasification furnace and then reform the generated gas to obtain a synthesis gas in a reforming furnace are broadly known. The obtained synthesis gas is combusted as it is and used for power generation or the like or is used for power generation or the like after heat is recovered with a boiler or the like as necessary. In addition, recently, attempts have been underway to use a synthesis gas as a chemical synthesis raw material, and, for example, attempts have been underway to convert a synthesis gas to an organic substance such as ethanol using a microbial catalyst (for example, refer to PTLs 1 to 3). Synthesis gases obtained in the gasification furnace and the reforming furnace contain a large amount of an impurity such as a tar component, and it is difficult to use the synthesis gases as they are for power generation and chemical synthesis, and thus it is ordinary to purify the gases. It is known that synthesis gas is cooled as appropriate during the purification of the gas. For example, PTL 4 discloses a method for purifying a gas in which a synthesis gas is guided to an indirect heat exchanger such as a boiler heat transfer pipe, cooled to approximately 300° C. to 600° C. by recovering heat, then, guided to a spray tower to remove approximately 50% of tar mist while the synthesis gas is cooled to a temperature of 100° C. or lower by water spray spraying and then guided to a wet-type electric dust collecting device to remove 90% or more of the remaining tar mist. In addition, PTL 5 shows a method in which a harmful component such as tar or char is removed from an obtained synthesis gas with a bag filter. Ordinarily, it is not possible to pass high-temperature gas through a bag filter, and thus, in the present method, a gas cooler for cooling the synthesis gas is installed in the pre-stage of the bag filter, and the synthesis gas is cooled to approximately 200° C. before passing through the bag filter. CITATION LIST Patent Literature PTL1: International Publication No. WO 2015/037710PTL2; JP 2019-167424 APTL3: JP 2019-088240 APTL4: JP 2009-298825 APTL5: JP 2007-237135 A SUMMARY OF INVENTION Technical Problem Incidentally, in a case where a synthesis gas is used as, for example, an organic synthesis raw material, it is necessary to strictly control the temperature in some cases. For example, in a case where a synthesis gas is converted to an organic substance such as ethanol using a microbial catalyst, it is necessary to cool the synthesis gas to a temperature of 40° C. or lower to prevent the death of the microbial catalyst. However, in the case of using a synthesis gas for power generation or the like, strict temperature control is not required. In addition, it is ordinary that nitrogen or an air is often blown to cool a synthesis gas; however, in the case of using a microbial catalyst, nitrogen or an air mixed into the synthesis gas decreases the conversion efficiency of an organic substance. Therefore, even when the conventional methods for purifying a synthesis gas described in PTLs 4 and 5 are applied to the case of using a microbial catalyst as they are, it is difficult to synthesize organic substances at a high conversion efficiency. Therefore, an objective of the present invention is to provide a method for producing an organic substance and a device for producing an organic substance that are capable of synthesizing an organic substance at a high conversion efficiency even in the case of converting a synthesis gas to an organic substance using, for example, a microbial catalyst. Solution to Problem As a result of intensive studies, the present inventors found that the above-described objective can be achieved by cooling a synthesis gas with water sprayed in a gas cooling tower and purifying the cooled synthesis gas using a filtration-type dust collector and completed the present invention below. That is, the present invention provides [1] to [20] below. [1] A method for producing an organic substance includinga step of passing a synthesis gas discharged from a gasifier through a gas cooling tower to cool the synthesis gas with water sprayed in the gas cooling tower,a step of passing the synthesis gas cooled in the gas cooling tower through a filtration-type dust collector, anda step of bringing the synthesis gas that has passed through at least the gas cooling tower and the filtration-type dust collector into contact with a microbial catalyst to generate an organic substance.[2] The method for producing an organic substance according to [1], in which a temperatur