    <SEC-DOCUMENT>0001437749-23-025690-index.html : 20230912
    <SEC-HEADER>0001437749-23-025690.hdr.sgml : 20230912
    <ACCEPTANCE-DATETIME>20230912160120
    ACCESSION NUMBER:		0001437749-23-025690
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		34
    CONFORMED PERIOD OF REPORT:	20230912
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20230912
    DATE AS OF CHANGE:		20230912

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			FUEL TECH, INC.
    		CENTRAL INDEX KEY:			0000846913
    		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
    		IRS NUMBER:				205657551
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-33059
    		FILM NUMBER:		231250061

    	BUSINESS ADDRESS:
    		STREET 1:		27601 BELLA VISTA PARKWAY
    		CITY:			WARRENVILLE
    		STATE:			IL
    		ZIP:			60555
    		BUSINESS PHONE:		6308454431

    	MAIL ADDRESS:
    		STREET 1:		27601 BELLA VISTA PARKWAY
    		CITY:			WARRENVILLE
    		STATE:			IL
    		ZIP:			60555

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	FUEL TECH N V
    		DATE OF NAME CHANGE:	19930510
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>ftek20230911_8k.htm
    <DESCRIPTION>FORM 8-K
    <TEXT>
    Document 1 - file: ftek20230911_8k.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>ex_568537.htm
    <DESCRIPTION>EXHIBIT 99.1
    <TEXT>
    Document 2 - file: ex_568537.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>3
    <FILENAME>ftek-20230912.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
    <TEXT>
    Document 3 - file: ftek-20230912.xsd

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    <DOCUMENT>
    <TYPE>EX-101.DEF
    <SEQUENCE>4
    <FILENAME>ftek-20230912_def.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION DEFINITION LINKBASE
    <TEXT>
    Document 4 - file: ftek-20230912_def.xml

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    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>5
    <FILENAME>ftek-20230912_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE
    <TEXT>
    Document 5 - file: ftek-20230912_lab.xml

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    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>6
    <FILENAME>ftek-20230912_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE
    <TEXT>
    Document 6 - file: ftek-20230912_pre.xml

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>fueltech1.jpg
    <TEXT>
    Document 7 - file: fueltech1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>fueltech2.jpg
    <TEXT>
    Document 8 - file: fueltech2.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>fueltech3.jpg
    <TEXT>
    Document 9 - file: fueltech3.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>fueltech4.jpg
    <TEXT>
    Document 10 - file: fueltech4.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>fueltech5.jpg
    <TEXT>
    Document 11 - file: fueltech5.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>fueltech6.jpg
    <TEXT>
    Document 12 - file: fueltech6.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>fueltech7.jpg
    <TEXT>
    Document 13 - file: fueltech7.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>fueltech8.jpg
    <TEXT>
    Document 14 - file: fueltech8.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>fueltech9.jpg
    <TEXT>
    Document 15 - file: fueltech9.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>fueltech10.jpg
    <TEXT>
    Document 16 - file: fueltech10.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>fueltech11.jpg
    <TEXT>
    Document 17 - file: fueltech11.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>fueltech12.jpg
    <TEXT>
    Document 18 - file: fueltech12.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>fueltech13.jpg
    <TEXT>
    Document 19 - file: fueltech13.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>fueltech14.jpg
    <TEXT>
    Document 20 - file: fueltech14.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>fueltech15.jpg
    <TEXT>
    Document 21 - file: fueltech15.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>fueltech16.jpg
    <TEXT>
    Document 22 - file: fueltech16.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>fueltech17.jpg
    <TEXT>
    Document 23 - file: fueltech17.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>fueltech18.jpg
    <TEXT>
    Document 24 - file: fueltech18.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>fueltech19.jpg
    <TEXT>
    Document 25 - file: fueltech19.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>fueltech20.jpg
    <TEXT>
    Document 26 - file: fueltech20.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>27
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 27 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>28
    <FILENAME>ftek20230911_8k_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 28 - file: ftek20230911_8k_htm.html

    Document 28 - RAW XML: ftek20230911_8k_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>29
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 29 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>30
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 30 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>31
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 31 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>32
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 32 - file: FilingSummary.html

    Document 32 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>34
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 34 - file: MetaLinks.json

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    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>35
    <FILENAME>0001437749-23-025690-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 35 - file: 0001437749-23-025690-xbrl.zip

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