Utilization of waste nitrogen for biofuel production in China

The net energy balance (Output-Input) of BPWN is 570 GJ ha−1 year−1 (1 GJ = 109 J) in China, about 15-30 times that of current major biofuel production systems (e.g. corn, switchgrass, low-input high-diversity grassland). The feasibility analysis shows that, although the land resources for BPWN are not sufficient in one-fifth of China's provinces if considering all of the potential waste N supply, the total maximum land requirement is only 17.5% of China's total untilled land resource. Further research on the imbalance between land requirement and waste N supply on the regional and local scales will help to refine the estimate of biofuel production potential.