The growing U.S. bioeconomy: Drivers, development and constraints.

Bioeconomy refers to economic activities using renewable biological resources to produce energy and domestic consumables. The U.S. bioeconomy emerged in the early 2000s as a result of the societal pursuit of energy independence and security, greenhouse gas emission mitigation and sustainable development. Founded on biotechnologies and stimulated by federal policies, the U.S. bioeconomy has been growing rapidly over the past decade. Intensive research and development endeavors have been carried out to explore advanced technologies for efficient biomass production, conversion, and valorization, through which numerous biotechnological innovations have been achieved to realize the commercial, cost-effective production of diverse transportation biofuels and high-value domestic bioproducts from various biomass feedstocks. The bioenergy products currently commercialized in the U.S. include bioethanol, biodiesel, biogas, bioheat and biopower; the commercialized bioproducts extend to biopolymers, biochemicals, biopharmaceuticals and bioadhesives. In 2017, more than 65.4 billion liters of biofuels and 2500 certified bioproducts were produced, creating 4 million job opportunities and sharing 2.5% of the U.S. economy. Commercial production of cellulosic ethanol, renewable diesel, green jet fuel and other advanced biofuels remains at the demonstration stage and needs further improvement in cost-competitiveness. Envisioning a Billion-Ton-Bioeconomy by 2030, the U.S. federal government has been implementing strategic activities to realize the goal. High costs of delivered biomass feedstock, immature biomass refinery technologies, lack of cost-comparative bioproducts, and low fossil fuel prices have been identified as the major constraints to a strong U.S. bioeconomy. To improve the bioeconomic viability, further biotechnological advances and integrated biorefinery processes are warranted.