Environmental Engineering Reference
In-Depth Information
that industry: compounds such as lactic acid, succinic acid and fatty acids, glycerol
and sugars, as well as ethanol and butanol are all needed to feed the industry, using
green chemistry methods to convert them into replacements for the very large num-
ber of organic chemicals in current use. This includes developing synthetic path-
ways starting from oxygenated, hydrophilic molecules, but we must avoid wasteful
and costly separations from dilute aqueous fermentation broths. A wider range of
chemistry in water including more water-tolerant catalysts is needed, as are other
important synthetic strategies such as the reduction in the number of process steps
through telescoped reactions. The future green chemistry toolkit needs to be
flexible and versatile as well as clean, safe and efficient [27, 28].
1.5
The Biorefinery Concept
1.5.1
Definition
A biorefinery is a facility or a network of facilities that converts biomass including
waste (Chapter 2) into a variety of chemicals (Chapters 4 and 5), biomaterials
(Chapter 6) and energy (Chapter 7), maximising the value of the biomass and mini-
mising waste. This integrated approach is gaining increased commercial and aca-
demic attention in many parts of the world [29, 30]. As illustrated in Figure 1.4,
advanced biorefineries are analogous in many ways to today's petrorefineries [31].
Similarly to oil-based refineries, where many energy and chemical products
are produced from crude oil, biorefineries produce many different industrial
products from biomass. These include low-value high-volume products such
as transportation fuels (e.g. biodiesel, bioethanol), commodity chemicals and
materials and high-value low-volume products or specialty chemicals such as
cosmetics or nutraceuticals [32]. Energy is the driver for developments in this
Fossil resources
Products
Petro-refinery
Crude oil
Natural gas
Energy (fuel, etc)
Chemicals (speciality &
commodity)
Materials (plastic, etc)
Biomass
Products
Bio-refinery
Tr ees, Crops
Energy (fuel, etc)
Chemicals (speciality &
commodity)
Materials (plastic, etc)
Food & feed
Grass, Clover
Waste
etc
Figure 1.4
Comparison of petrorefinery v. biorefinery.
