Environmental Engineering Reference
In-Depth Information
Corn germ
CO
2
DGHP
Corn
grain
Pre-treatment
Fermentation
Distillation
Bioethanol
Bran
Corn
stover
Pre-treatment
Fermentation
Distillation
Bioethanol
Whole crop
Residue
CO
2
Biogas
Figure 1.10
POET-DSM advanced biofuels biorefinery, US: an example of a whole-crop
biorefinery.
including ethanol and bioplastics, as it is currently done in phase II biorefineries.
In parallel, the straw may undergo various conversion processes as described in
the previous section.
POET (formerly known as Broin Companies), one of the largest producers
of ethanol in the world, has built a commercial whole-crop biorefinery in Iowa
which started operations in 2014. Through the Liberty project (jointly funded by
POET, DSM Advanced Biofuels and the US Department of Energy), a corn grain-
to-ethanol plant was converted into a commercial-scale whole-crop biorefinery
designed to utilise advanced corn fractionation and lignocellulosic conversion
technology to produce ethanol from corn cobs, leaves, husk and some stalk (see
Figure 1.10). The facility also produces a number of valuable products including
corn germ and a protein-rich dried distillers grains (Dakota Gold® HP or DGHP),
which can be used as animal feed.
1.5.2.3.3 Green Biorefinery
Green biorefinery is another form of phase III biorefinery which has been exten-
sively studied in the EU (especially Germany, Austria and Denmark) over the last
10-20 years [42, 43]. It takes green biomass (such as green grass, lucerne, clover,
immature cereals, etc.) and converts it into useful products including energy,
chemicals, materials and feed through the use of different technologies including
fermentation (see Figure 1.11). Rich in water, green biomass is typically separated
into a fibre-rich press cake and a nutrient-rich green juice. The green juice con-
tains a number of useful chemicals such as amino acids, organic acids and dyes.
The press cake can be used for fodder or to produce energy, insulation materials,
construction panels and biocomposites, etc.
