Co-Production of Hydrogen, Synthetic Amylose, and Ethanol from Nonfood Biomass will Address the Food, Biofuels and Environmental Trilemma

Hydrogen is arguably the best future transportation fuel due to its high conversion efficiency and nearly zero pollutants generated. However, its high-density storage and costly infrastructure prevent its wide application. At the same time, growing population and food consumption per capita mean that the global demand for food could double another 40 years.

Here we present our unique solution to address the food, biofuels and environmental trilemma. First, we can convert all biomass sugars including glucose and xylose to high-yield hydrogen (i.e., 12 H2 per glucose and 10 H2 per xylose) by using cell-free non-natural synthetic enzymatic pathways for the first time [1,2]. In addition, we increased enzymatic hydrogen rate by nearly 800 fold to 0.3 g H2/L/h, fast enough to run in stationary hydrogen generations.  Second, we converted cellulose to starch, along with ethanol, by simultaneous enzymatic biotransformation and microbial fermentation [3]. Third, we propose to use synthetic amylose as a high-energy density hydrogen carrier with a hydrogen storage density of 14% for future sugar hydrogen fuel cell vehicles.

In a word, human beings could have enough biomass resource for meeting the three goals at the same time: feeding 9 billion people, providing renewable materials, and producing transportation biofuels if we can increase biomass utilization and conversion efficiency greatly [4].  

References

1. Martín et al. Angew. Chem. 2013, 52:4587-4590.

2. Ye et al. ChemSusChem 2009, 2:149-152.

3. You et al. PNAS 2013, 110:7182-7187.

4. Zhang. Energy Sci. Eng. 2013, 1:27-41.