Page 26 - Refining Biomass Residues for Sustainable Energy and Bioproducts

Solid waste biorefineries 5

1.2 Solid wastes

SW: The useless and unwanted products in the solid state derived from the activi-
ties of and discarded by society. It is produced either as by-product of production
processes or arises from the domestic or commercial sector when objects or materi-
als are discarded after use. SWs can be classified into seven different classes are
showed in Fig. 1.1 (Muldowney et al., 2013). SW management reduces or elimi-
nates the adverse impact on the environment and human health. A number of pro-
cesses are involved in effectively managing waste for a municipality. These include
monitoring, collection, transport, processing, recycling, and disposal. The quantum
of waste generated varies mainly due to different lifestyles, which is directly pro-
portional to socioeconomic status of the urban population.

1.2.1 Agricultural and forestry residues

Nowadays agricultural wastes are increasing exceptionally, and huge amounts of
agricultural wastes are available in each day. The production of biobased products
such as biofuels and biogases from agricultural waste is the current research trend
everywhere. Particular methodologies, for example, thermochemical, maturation,
gasification, liquefaction, refining, ignition, and pyrolysis, could be inspected to
make bioinvigorates from various agricultural wastes. Production of biofuels and
other chemicals from the agricultural and forestry wastes was done through fermen-
tation by using microorganisms, especially genetically modified bacteria, which are
the recent trend in the research field of waste conversion process. Bacteria can con-
vert the toxic compounds either by being present in the waste material or by pro-
ducing as by-products when the wastes undergo conversion process. For example
the accumulation of the sulfur gas from the industrial wastes and gas fields is to be
converted into either valuable products or utilized by the bacteria for their function
as explained in Fig. 1.2 (Swain, 2017).

Figure 1.1 Classification of solid wastes.