Sulfur Removal in Bio Briquette Combustion Using Seashellinto the flue gas, the sulfur removal efficiencies were only 40 60% [17] Moreover, when the adsorbents were physically mixed with the coal, the desulfurization efficiencies were usually lower than 40% [17,18] In recent years, a bio briquette produced from a mixture of coal and biomass under high compression pressure has been developed ...