XML 42 R28.htm IDEA: XBRL DOCUMENT v3.25.4
Note 2 - Revenue Recognition (Tables)
12 Months Ended
Dec. 31, 2025
Notes Tables  
Disaggregation of Revenue [Table Text Block]
  

Twelve Months Ended December 31,

 
  

2025

  

2024

 

Air Pollution Control

        

Technology solutions

 $5,420  $7,897 

Spare parts

  1,739   1,616 

Ancillary revenue

  1,749   1,729 

Total Air Pollution Control technology

  8,908   11,242 

FUEL CHEM

        

FUEL CHEM technology solutions

  17,769   13,891 

Total Revenues

 $26,677  $25,133 
Revenue from External Customers by Geographic Areas [Table Text Block]
  

Twelve Months Ended December 31,

 
  

2025

  

2024

 

United States

 $21,022  $17,802 

Foreign Revenues

        

Americas

  707   924 

Europe

  2,239   2,146 

South Africa

  318   2,570 

Pacific Rim and other

  2,391   1,691 

Total Foreign Revenues

  5,655   7,331 

Total Revenues

 $26,677  $25,133 
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]
  

Twelve Months Ended December 31,

 
  

2025

  

2024

 

Products transferred at a point in time

 $21,257  $17,236 

Products and services transferred over time

  5,420   7,897 

Total Revenues

 $26,677  $25,133 
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
  

As of

 
  

December 31, 2025

  

December 31, 2024

 

Trade receivables

 $4,494  $5,375 

Unbilled receivables

  887   2,075 

Receivable for employee retention credit

     1,677 

Other short-term receivables

  82   347 

Allowance for credit losses

  (108)  (106)

Total accounts receivable

 $5,355  $9,368