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                                                                     Exhibit 5.0



May 2, 2000



Board of Directors
Fuel-Tech N.V.
Castorweg 22-24
Curacao Netherlands Antilles

Dear Sirs:


This opinion is rendered in connection with the registration on Form S-8 ("the
Registration Statement") of 1,600,000 shares of Common Stock (the "Shares") of
Fuel-Tech N.V. (the "Company") pursuant or subject to the 1993 Incentive Plan of
the Company as amended through June 5, 1998. In rendering this opinion I have
reviewed the Articles of Incorporation of the Company, as amended, and such
other documents as I deemed relevant in the circumstances.

In my opinion such of the Shares as are to be issued under stock option
agreements extant as of the date hereof have been duly authorized, and, when
approved by resolution of the Board of Directors of the Company and covered by
future stock option agreements, the remainder of the Shares shall have been duly
authorized. Further, in my opinion, when payment of the exercise price is made
to and certificates therefor are issued by the Transfer Agent and Registrar of
the Company, the Shares evidenced by such certificates shall be validly issued
and non-assessable.

I consent to the reference to this opinion in the Registration Statement and to
its inclusion as an exhibit to the Registration Statement.


Very truly yours,


/s/ C.W. Grinnell
-------------------------------
Charles W. Grinnell
Vice President, General Counsel
   & Corporate Secretary

