The researchers studied how different types of biomass affect the burning of briquettes. They used cypress, bamboo, rice husk, and paper to make briquettes of various sizes. They found that the time briquettes burn with flames depends on their surface area and density, which is related to the amount of holocellulose in the biomass. The time they burn as char is related to the surface area and fixed carbon content, which is linked to the ash content in the biomass. This means that the type of biomass used affects how long the briquettes burn with flames and as char.