Composition and Material. Biomass Briquetting Cakes are crafted from a meticulous blend of organic materials designed to maximize both efficiency and sustainability. The materials used include: Pralli Straw: A valuable byproduct of agricultural processes, pralli briquette (French: [bʁikɛt]; also spelled briquet) is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, peat, or paper) used for fuel and kindling to start a fir straw provides high combustion efficiency