The FFG project "BioFlame - Numerical optimization of biogas combustion in marine engines" intends to supply the basic information needed in the development of an optimized large gas-fuelled lean engine. CFD simulations of reactive flows require some chemical kinetic reaction mechanism. In order to keep calculation times as short as possible, a reduced mechanism seems highly desirable. On the other hand, such a mechanism must simulate combustion as accurately as possible. This work investigates various recently published chemical kinetic reaction mechanisms and calculates the ignition delay time and laminar flame speed for relevant conditions. This master thesis discusses published reaction mechanisms for the combustion of lean methane/propane mixtures and examines their performance under engine-relevant conditions. In an assessment a number of suitable candidates for further reduction emerge. 25 reaction mechanisms were evaluated with a view to the species covered, which included NOX formation under lean conditions, their design for high pressures of more than 100bar and their covering of a temperature range of 700K to 1000K before ignition. The mechanisms yielding the most promising results were NUIG NGM3, POLIMI C<4, SAN DIEGO+NOX and USC-II. For this selection, a systematic parameter variation was used in calculating ignition delay times and laminar flame speeds. The model calculating ignition delay times was a zero-dimensional isochoric adiabatic homogeneous batch reactor. The pressure was varied from 70bar to 140bar in 10bar increments. The temperature was varied between 700K and 1000K in 25K increments. Twelve binary methane-propane mixtures ranging from pure methane to pure propane were assumed as fuel gases. The dependence of ignition delay time on pressure, fuel composition and temperature was examined. Both increasing pressure and increasing the amount of propane in the mixture have been found to reduce ignition delay times. The four mechanisms have shown significantly different dependence on varying temperature, especially between 800K and 900K, as soon as the fuel contains propane. A high amount of propane in the mixture has resulted in a pronounced negative temperature coefficient with some mechanisms. This results in considerable differences in the calculated ignition delay times at medium and low temperatures. The laminar flame speed was calculated using a one-dimensional freely propagating flame as a model. The basic conditions were pressures of 70bar and 100bar, temperatures of 700K, 850K and 1000K, and four fuel gases: methane and three methane/ethane/propane mixtures. On the whole, the results provided by the mechanisms show only little difference to each other. Laminar flame speed rises with temperature.