From our research, we've found at least 23 fixed bed updraft gasifiers currently operating throughout the world:
Lurgi (12 units operating in the U.S., South Africa, China).
Bioneer (9 units in Finland and Sweden).
Babcock & Wilcox Volund (1 unit in Denmark).
Nexterra (1 operating unit in British Columbia, several under
    construction in U.S. and Canada).
Lurgi Gasifiers: Lurgi dry-ash gasifiers (12 units) have over 24 years of continuous commercial operation producing more than 54 billion standard cubic feet of synthetic natural gas annually at the Great Plains Gasification facility in Beulah, North Dakota. Multiple Lurgi gasifiers have been operating in South Africa (Sasol) producing syngas from South African bituminous coal which is converted into liquid fuels for transportation utilization throughout South Africa since the mid 60’s.
Bioneer Gasifiers: Nine gasifiers are in commercial operation using wood/peat ranging from 4 to 5 MW/th (8 units in Finland and one in Sweden).
Babcock & Wilcox Volund Gasifier: This gasification unit in Denmark has had continuous operation of updraft wood gasifier @ a 8,000 hour annual availability since 1996 in cogeneration mode.
Nexterra Gasifiers: Commercial gasification unit in British Columbia (Tolko Industries) for process heat (38 MMBtu per hour) used in veneer drying. Other gasifier projects under development are at the University of South Carolina, and Domar Industries (Lime Kiln). All gasification projects use wood waste as the fuel source.
In addition to the above currently operating units, there were numerous fixed bed updraft gasifiers (Wellman-Galusha design) which operated for decades within the eastern U.S. As recent as 1978 - 1981 Wellman-Galusha gasifiers were operating commercially in Hazleton, York and Reading, PA on locally mined anthracite coal.
In 1977-78 a 10-bart diameter Wellman-Galusha gasifier was installed at the Glen-Gery brick plant in York, PA to allow the brick kiln to be operated continuously when natural gas was not available. This updraft fixed-bed gasifier operated commercially until the mid 1980’s when natural gas availability was no longer an issue. Glen-Gery Brick Company operated as many as 7 Wellman-Galusha gasifiers to continuously produce fuel-gas from anthracite coal at their brick plants throughout eastern Pennsylvania firing continuous kilns from the mid 1950’s to the late 1960’s. Inexpensive natural gas displaced coal gas as the fuel for kin firing of bricks at the Glen Gary operations in the mid 1960‘s.
From the mid 1960’s to the late 1970’s National Lime and Stone in Cary, Ohio operated two 10-bart diameter Wellman-Galusha gasifiers continuously generating coal-gas from Ohio Bituminous coal for vertical lime kiln firing.
The Energy Crisis of 1975-78 brought back industrial coal gasification as a fuel security solution for industries in eastern Pennsylvania. Caterpillar Tractor Company in York, PA installed a Two-Stage Fixed bed updraft gasifier to generate coal gas for metal treating when natural gas was curtailed in the mid 1970’s.
A 10-bart diameter Wellman-Galusha gasifier was installed at the Howmet Aluminum Company in Lancaster, PA generating coal gas (providing tri-fuel capability for Howmet Aluminum). This 10-bart diameter gasifier generated coal gas which successfully melted aluminum for alloying in 1980.