Page 315 - Biofuels for a More Sustainable Future

Key issue, challenges, and status quo of models for biofuel supply chain design 281

• Technology selection. Given a large number of technology options available
for biomass preprocessing and conversion, decisions need to made on
selecting suitable technologies for specific biomass (Yue et al., 2014).
Technology selections and following process design are often subject to
economic and technical constraints such as biomass properties, budget
limitations, and targeted products (e.g., upgrading to biofuels or high
value-added biochemicals) (Kim et al., 2011; Lea ˜o et al., 2011; Parker
et al., 2010; You and Wang, 2011; Zhang and Wright, 2014; Cambero
and Sowlati, 2016).
Table 10.2 presents literature identified that have considered strategic deci-
sions, and tactical and operational decisions (discussed in the next section).
Almost all previous BCS design studies considered strategic decisions and
different modeling approaches have been used. For example, Avami
(2013) determines biomass source utilization and allocation decisions using
linear programming (LP). Zhang and Wright (2014) selected different tech-
nology options and decided locations and capacities of biorefineries using
mixed integer nonlinear programming (MINLP).

3.2 Tactical and operational decisions
Tactical and operational decisions are the medium- and short-term decisions
which can be alternated annually, weekly, or even daily (Awudu and Zhang,
2012). They are made under the constrained structure of strategic decisions
that are typically made before investigating tactical and operational decisions
(De Meyer et al., 2014). Compared with strategic decisions, tactical and
operational decisions are typically made at a smaller scale(e.g., biorefinery
level or process level). Tactical and operational decisions may include the
following aspects:
• Production planning determines detailed design and operations of unit
processes included in BSC, such as supplying biomass and other raw
materials (Zhang and Hu, 2013), process design (Tong et al., 2013;
Kazemzadeh and Hu, 2013), and scheduling (Sharma et al., 2013;
Beamon, 1998).
• Inventory planning determines the quantity and timing of materials or goods
in stock (Cachon and Fisher, 2000; Stadtler, 2005; Min and Zhou, 2002)
which needs to be aligned with production capacity, fuel distribution, and
biomass supply (Tong et al., 2013; You and Wang, 2011; Azadeh et al.,
2014). The storage contains raw materials for manufacturing, intermediate
productions, and final product for distribution.