Page 78 - Energy from Toxic Organic Waste for Heat and Power Generation

64 Energy from Toxic Organic Waste for Heat and Power Generation

Organic polymers
Fats, proteins, poly-saccharides

Hydrolysis Fermentative NH , S 2–
+
micro-organisms 4
4% 76% 20%
Alcohols,
+
C carboxylic acids
3
Acetogenesis
24% 52%
Acetogens
H , CO 2 Acetate
2
Homoacetogenesis
Hydrogenophilic 72% Acetophilic
Methanogenesis methanogens 28% methanogens
CH 4 , CO 2
Fig. 5.2 Process flow of biomethanation.

reactor types (fully mixed, plug-flow, biofilm, UASB, etc.) and process con-
ditions (retention times, loading rates, temperatures, etc.) in order to maxi-
mize the energy output from the waste and also to decrease retention time
and enhance process stability. Biomethanation has strong potential for the
production of energy from organic residues and wastes. It will help to re-
duce the use of fossil fuels and thus reduce CO 2 emission [53]. The process
flow of biomethanation [54] is depicted in Fig. 5.2.
In this section, the economic importance of leather industry, the stages
involved in leather processing, and the chemicals involved are presented.
Later, the waste produced from leather processing along with the classi-
fication of the toxic substances is explained. Finally, the two appropriate
methods through which the toxic waste from the leather industry may be
utilized to generate heat and energy generation are stated.

REFERENCES

[1] Dixit S, Yadav A, Dwivedi PD, Das M. Toxic hazards of leather industry and technologies
to combat threat: a review. J Clean Prod 2015;87:39–49.
[2] International Trade Centre, http://www.intracen.org/itc/sectors/leather/.
[3] Kolomazník K, Adámek M, Andel I, Uhlirova M. Leather waste—potential
threat to human health, and a new technology of its treatment. J Hazard Mater
2008;160(2):514–20.
[4] Hüffer S, Taeger T. Sustainable leather manufacturing: a topic with growing importance.
J Am Leather Chem Assoc 2004;99(10):424–8.