AD ALTA
JOURNAL OF INTERDISCIPLINARY RESEARCH
Figure 6. Layout of biomass supply sites (1-7), in first area
Source: created by the authors
Figure 7. Layout of biomass supply sites (1-5), in second area
Source: created by the authors
Distances between biomass mines are different based on the
quantity of available biomass resources.
The highest quantity of
biomass is extracted from areas that are located further from the
power plants in the cities. In operational terms, if demand for
biomass has increased significantly, it can be satisfied by
bringing supplies from the nearby areas. In other cases,
sustainable circulation of biomass supply is being developed,
taking into account established demand and fuel resources in the
area. Table 2 indicates the distances between biomass supply
sites and central consumption point in city A or B. Each supply
site is assigned a separate number. Supply sites are located at a
sufficiently optimal distance, which allows to sustain balance in
the supply chain processes.
Table 2 Distances between supply sites to power plants
Supply site
ID (First
area)
Distance
from supply
site to power
plant, km.
Supply site
ID (Second
area)
Distance
from supply
site to power
plant, km.
1
26
1
34
2
12
2
25
3
4
3
9
4
22
4
19
5
23
5
23
6
24
7
20
Source: created by the authors
To assess the supply chain functionality and costs, formulas
determining these components were selected and adapted to the
simulated case. Primary supply chain costs are related to
biomass processing and transportation. In each case they vary
because of the different distances between biomass supply sites.
Characteristics of processed fuels are also different. Whereas
Just-in-Time (JIT) system is used storage need is not being
considered.
In this simulated situation thermal energy is produced using four
biomass power plants in city A and two in city B. The demand
for biomass varies based on the changing weather. During the
warm season biomass is used to provide hot water and during the
cold season it is also used in thermal energy production. Data in
Table 3 shows how required biomass quantities are distributed
based on seasons. There are three periods - warm, intermittent
and cold. The intermittent period is exceptional because at that
time biomass power plants operate in a capacity that is just
slightly higher than average. The intermittent period partially
covers spring and autumn seasons.
Table 3 Distribution of biomass quantities based on seasons.
Month names and group ID
Biomass
demand in
city A, toe
Biomass
demand in
city B, toe
November - December -
January - February (1)
8058
820
March - April - October (2)
5760
570
May - June - July - August -
September (3)
4800
460
Source: created by the authors
The selected formulas help to assess biomass supply quantities
and the efficiency of logistics system. They are related to
biomass processing and transportation cost analysis. The
logistics system is based on the biomass supply chain. Despite
the fact that only two hypothetical areas were used for this
research, this research instrument can be applied in more
extensive research of other similar areas. Indicator values can
change significantly depending on the distances between the
biomass supply sites and power plants, fuel price and conversion
ratio. It is generally accepted that efficient transportation
distance is between 50 and 100 km. If distances are longer, the
logistics system needs to be rearranged to include other means
for transportation such as trains and water transport. In this
research diesel powered trucks were used for transportation.
Transportation costs play a vital role in the logistics system.
Optimal transportation plan enables competitive activities. If
biomass supply transportation distance is greater than 100 km
there is a risk to lose competitive advantage against subjects that
are using fossil fuels. For this reason when developing a supply
chain scheme it is important to estimate the transportation costs
from each biomass supply site. Alongside the estimation of
transportation distance it is important to include the
transportation costs per kilometer. In this case it is estimated
based on fuel consumption. The following formula is used to
estimate the transportation costs.
TC=∑(TD*2)*TP
TC – Transportation Costs (EUR); TD – Transportation Distance
(km); TP – Transportation Price (EUR/km).
To assess the efficiency of the supply chain it is important to
evaluate the extent of preparations required at each biomass
supply site. Production of biomass depends on the distance to the
biomass supply site, its potential and season. When developing
the supply chain system It is important to include the extent to
which different biomass supply sites will be exploited. The
exploitation extent is defined based on the quantity of unrefined
wood and its availability in particular site. Subsequently biomass
supply demand is calculated based on the time of year.
This
indicator can be calculated using the formula below.
BPC=FPR*DBP*RPC
BPC – Biomass Processing Coefficient; FPR – Feedstock
Production Ratio; DBP – Daily Biomass Production (TOE/Day);
RPC – Relative Production Capacity (depending on the season).
FPR is a percentage of biomass feedstock production per site
compared to overall production in the area. APB is daily
feedstock production capacity within the supply site. Relative
production capacity is calculated based on the biomass demand
during particular time of year. In winter, when the demand for
biomass is highest, the relative production capacity is 1 and this
coefficient is lower in warm seasons.
(2)
(1)
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