460

30 Feasibility and Economics of Biobutanol from Lignocellulosic and Starchy Residues

Food processing waste

Croped biomass

Energy crops

Forest waste

Agricultural residues

0

50

100

150

200

250

350

300

400

Quanitity × 103 (Tons/year)

Figure 30.2

Worldwide availability of lignocellulosic feedstock.

lignin at various compositions. Lignocellulose and starchy waste generated from var-

ious industrial activities from food, paper and pulp, timber processing and forestry

waste creates a serious waste management problem. Surplus of biomass from these

sectors can be diverted for biobutanol production which will benefit the combination

of waste management and energy generation to fulfill the current energy demand.

30.3.1

Types and Sources of Waste Generation

Few of the commonly used lignocellulosic feedstock and its availability for biofuel

conversion are highlighted in Figure 30.2. China produces 830 million tons of ligno-

cellulosic biomass per year from bagasse, straw, rice husk, and wood residue. Accord-

ing to statistics in a year 9.8% global energy is derived from biomass, where 70% of

biomass is used for traditional purpose such as domestic heating and combustion

[16]. As per the report made by United Nations Environment Programme (UNEP

2015), worldwide generation of agricultural biomass amounts to 140 billion tons.

Among these 415.5 million tons of agro wastes are generated in India. The shares of

various lignocellulosic sources from agricultural and non-agricultural commodities

for the global biofuel production have strongly increased since 2019. The biomass

generated from the agricultural activities contributes major lignocellulosic resources

(342 million tons/year) for biofuel production followed by forest waste (hardwood

and soft wood) with a capacity of 325 tons per year [17]. From an economic per-

spective, forest waste is probably a good choice of feedstock for the production of

biobutanol (Figure 30.2).

The lignocellulosic waste generated from agro and forest wastes are proved to be

cheaper than other sources. One of the lignocellulosic feedstock generated from

agro waste are cocoa pod biomass. It is reported that the chocolate industry gen-

erates about 3.5 million tons/year of cocoa pods and is disposed off as waste [18].

The forest waste such as Kans grass, growing on the barren land and on the banks of

river as weeds are generally disposed off by incinerating. The waste biomass gener-

ated from industrial activities also can be diverted toward producing biofuel [19]. In

twenty-first century, biodiesel production from non-edible seeds has gained impor-

tance resulting in generation of large quantities of seed cake as a by-product from

biodiesel industries. The above mentioned lignocellulosic feedstocks are inexpensive