The generation of biofuels, biochemicals and biomaterials from renewable biomasses are getting a great thrust as potential substitutes and supplements to the petroleum based counterparts. The biofuels like bioethanol, biobutanol and biodiesel derived from plant and forest resources are getting accelerated momentum across the world. All the components associated with the alternative fuels should be sustainable for a well-balanced bioeconomy. The downstream coproducts and byproducts from these emerging alternative fuel industries need value-added uses. In lingo-cellulosic biomass conversion into ethanol, the substantial quantity of low or negative value leftovers such as lignin, carbon dioxide and residues are finding great attention in their value-added uses. In ligno-cellulosic ethanol industries; ethanol and lignin are produced at 1:1 on a quantum basis in general. Similarly in corn ethanol dry-milling process, one bushel of corn produces 1/3rd as ethanol, 1/3rd as carbon dioxide and rest 1/3rd as Distillers' Dried Grains as Solubles (DDGS). Soy meal (SM), canola meal (CM), jatropha meal (JM) and crude glycerol are coproducts and byproducts of the biodiesel industry. This presentation will highlight the research results, current status, opportunities, and challenges on engineering uses of the downstream products as plastic resins, biodegradable plastics, bioadhesives, biorubber and biocomposites.