Biomass is plant origin organic waste that is used for energy production, generally as a fuel. Co-firing is a combustion technology where two or more fuels are burned at the same time. It is a source of interest for many, due to provided greenhouse gas reduction and controlled use of fossil fuels. This paper takes a closer look on biomass co-firing equipment in Riga Technical university (RTU). It offers a literature review on co-firing technologies, characteristics and implementation experiences. Paper includes description of the laboratory equipment, possible experiment plan and the design of three factor experiment for an example of CO2 emissions. Calculations for determining necessary fuel proportions are made.