Berkeley Lab researchers provide new insights into the role of bioproducts in improving the economics of biorefineries

Type of post: RESEARCH NEWS.

Coproduction of high-value bioproducts at biorefineries is a key factor in making biofuels more cost-competitive. Through synthetic biology, it is possible to produce valuable chemical compounds as biomass crops grow. Researchers at the Berkeley Lab have provided new insights into how bioproduct accumulation in planta affects biofuel selling prices.

News (Berkeley Lab): “Making Biofuels Cheaper by Putting Plants to Work”, 6/4/2020.

Article: “Accumulation of high-value bioproducts in planta can improve the economics of advanced biofuels”, PNAS April 14, 2020 117 (15) 8639-8648; first published March 27, 2020.

Figure 1. Sorghum is a common bioenergy crop and was used in the study of the Berkeley Lab (Credit: Marilyn Sargent, Berkeley Lab)

Cellulosic biofuels have so far not reached cost parity with conventional petroleum fuels. As highlighted in the news from the Berkeley Lab, one strategy to address this challenge is “to make plants do some of the work themselves”. Engineering bioenergy crops to generate value-added bioproducts in planta can reduce costs in conversion steps. These bioproducts can be extracted from the plant and the remaining plant material can be converted into fuel.

Until now, there has been no systematic analysis devoted to quantifying the impact of such engineered bioenergy crops on biorefinery economics. Researchers at the Lawrence Berkeley National Laboratory (Berkeley Lab) and the Joint BioEnergy Institute (JBEI) have provided new insights into how bioproduct accumulation in planta affects biofuel selling prices.

The researchers first gathered information on a group of well-studied bioproducts that plants can already effectively produce. They then designed and simulated what it would take to extract these bioproducts from plant material in the context of an ethanol biorefinery. In this context, valuable bioproducts would be extracted from the plant, while the remaining plant material would be converted into ethanol.

This helped them answer two important questions: what amount of bioproduct the plant needs to produce in order to make the process of extracting it worthwhile, and what amount needs to be made in order to reach the target ethanol selling price of 2.50 $ per gallon. Their results show that this strategy for reducing the cost of biofuels is feasible. However, because the market for each high-value product is limited in size, the researchers suggest that crops need to be engineered to produce a broad range of products to make sure the industry is diversified and the market is not flooded for any one product.