Page 88 - Energy from Toxic Organic Waste for Heat and Power Generation

74 Energy from Toxic Organic Waste for Heat and Power Generation

the protein fractions must be free from unwanted contaminants that cause
off-properties. In addition, the biorefinery strategy must ensure the profit-
ability of the process. A recent publication indicated that up to 80% of the
costs of biorefining—downstream processing—of algae is due to the first
step of the separation train (extraction of purification of the main target
component). In this regard, several strategies can be implemented in order
to ensure cost reduction:
• Valorizing several—if not all—biomolecules with market potential.
• Targeting high-end market applications (pharmaceutical, cosmetics,
foods, feeds).
• Intensifying and integrating unit operations.
• Implementing recycling and reuse strategies to ensure low operational
costs.
The first step in most algae biorefinery applications involves the disinte-
gration (disruption) of the biomass in order to release components into the
liquid phase. Several investigations performed in our group identified bead
milling as a highly efficient disruption method. In recent years, ionic liquids
(IL) have been considered as novel “green” solvents with potential applica-
tion for the fractionation and purification of biomolecules. Consequently, it
is suggested that IL can be implemented as green solvents for the extraction
of proteins from algae. Furthermore, the extraction can be performed simul-
taneously with the disruption step—Dixtraction—as described in Fig. 6.3.

6.2.1.5 Animal Fats
Fish fat, chicken fat, tallow, and white grease or lard are used to produce
biodiesel. Biodiesel production from animal fat methyl ester has some advan-
tages like noncorrosive, high cetane number, and clean and renewable prop-
erties. Animal fats have a tendency to be low in the FFAs and water; however,
there is a restricted measure of these oils being accessible, which means these
could never have the capacity to meet the fuel needs of the world [12].

Recovery Product A
Feed
Dixtraction
Purification Product B
Byproduct
Fig. 6.3 Overview of integrated disruption-extraction steps (Dixtraction) with solvent
recycling.