Abstarct: At the end of a performance triple pressure heat recovery steam ganarator with reheat in condition using biomass As an alternative fuel to fossil fuels have been analyzed As well as its design parameters using Genetic optimization algorithm With the aim of gaining maximum power and efficiency Cycles, is optimized. Given that HRSG boiler performance by the kind of fuel consumption and inlet gas temperatures to it, Therefore, by changing the fuel cycle, the amount of power Qabltghyyr cycle efficiency and exhaust emissions as it will also be changed. In this thesis biomass to gas conversion technology has been analyzed. Among the factors influencing the composition of gas produced from biomass such as type of reactor producing gas from biomass, gasification of biomass and biomass can be mentioned. In the present work effectiveness of all these factors on the performance of the HRSG design parameters Such as steam, pinch temperature changes, pressure changes, as well as production capacity, cycle efficiency and emissions have been analyzed. The analyzes carried out on cycle efficiency in the use of fixed bed reactors with streams rising and falling, bubbles and Circulating Fluidized bed, It was found that fuel cycle efficiency in the use of fixed bed reactor with ascending flow, over other reactor fuel. They also showed that the production of NOx gases from combustion of a fixed bed reactor with the reactor is falling relative to other fuels. Biomass gasification processes were identified by comparing gas produced from biomass by air because of low combustion temperature no justification for the To use it as fuel. Also used in the production of a steam-gas cycle maximum power over gas-producing agent is oxygen. It was found that the amount of NOx emissions from fuel combustion gasification of other factors is less air than fuel. Finally, the gas produced from biomass and natural gas comparisons some common ones is comprehensive.