You are referring to Frankfurt am Main Airport (FRA / EDDF).
The Flughafen Frankfurt airport is by far the busiest passenger traffic airport in Germany. They are the main hub of the Lufthansa airline and are located at 60547 Frankfurt, Germany.
The biggest airport near Frankfurt, Germany is Frankfurt International Airport, about 7 Miles/11 Km from the city center.
Frankfurt International Airport (FRA)
You could ride Ryanair from Kaunas International Airport(KUN) to Frankfurt-Hahn Airport(HHN). Then ride a bus to Frankfurt am Main International Airport (FRA) and go on a China Airlines plane to Taiwan Tauyuan International Airport(TPE).
Luxembourg-Findel International Airport is located just 6km outside Luxembourg city. Frankfurt-Hahn is about two hours from Luxembourg city.
You can travel from Frankfurt International airport to Büdingen by train with a change at Frankfurt/Main (Hauptbahnhof) and another at Geinhausen. Total journey time: about 1h20. Frequency: approximately hourly.
I guess you mean from Frankfurt Airport to Frankfurt-Hahn Airport. There is no train to Hahn Airport, but a bus line.
The nearest major airport is Frankfurt am Main Airport(FRA / EDDF). This airport has international and domestic flights from Frankfurt, Germany and is about 34 road miles / 55km driving distance from the center of Hünstetten.
There are flights leaving from Frankfurt International Airport every two or three minutes. It is Germany's largest airport and the third largest in Europe.
The nearest International commercial airport is Frankfurt am Main, which is 56 miles away.
The Frankfurt International airport ( by car half an hour, by train around 40 min)