Figure 1
Compositional characterization of biomass-based feedstocks. The acid-insoluble lignin content of various feedstocks (A), acid-soluble lignin (B) and acid-insoluble glucose (C) expressed as percentage content per unit dry weight (DW). Each feedstock was examined for calorific value (D) and compared with values for low-grade and high-grade coal. Pairwise comparison of lignin (E) or cellulose (F) with calorific values and corresponding R2 values for the slope of the trend line. Feedstocks examined included high-lignin drupe endocarp tissue (from peach, olive, walnut and coconut), perennial grasses such as switchgrass (Panicum virgatum), woody biomass feedstocks such as Poplar (Populus deltoides and Populus trichocarpa) and leafy crops such as tobacco (Nicotiana benthamiana) and Brassica (Arabidopsis thaliana).