Grain drying is necessary when selling the grain to the main grain buying companies Hankkija and Raisio. In Finland the moisture content requirement for grain is 13%. This is the lowest moisture content requirement in Europe. Drying is very important for grain farms, so today almost all grain farms have their own dryers. This Bachelor's thesis was made for a grain producing farm with a field area of 110 hectars. The farm has a grain dryer that uses light fuel oil for heat production. In this thesis a study was made to find out if it would be feasible to invest on a biofurnace for the grain dryer on this farm. The aim was to study the economy and technique of using a biofurnace instead of a regular oil burner to produce heat for the drying process. Technical information, experiences of using biofurnace and information about costs were collected through different means, including a query for two finnish producers of biofurnace, Arskametalli and Antti-teollisuus. The study revealed, that an investment for a biofurnace for a grain dryer is not economically viable at the moment, because the yield of grain is low and light fuel oil is relatively inexpensive, at about 80 cents per liter. Investment and operating costs for biofurnace proved to be higher than were originally assumed. It seems, that investing on larger (400 kW or larger) biofurnace is economically feasible only for large farms with more than 200 hectares of fields.