Chapter 3 Methodology
4.1 Environmental performance
4.1.1.2 Scenario 2
Inputs of material and energy are referred to the data from Omette et al. (2004).
Subsystem 1, have four subsystems in this system. Amount of material: water, pesticide and sugarcane; fuels and labor are examined based on local data. Subsystem 1 has outputs of energy loss, material outflow and sugarcane.
1. Material inflow (1) Rainfall
According to the Central Weather Bureau, the amount of averaged rain water in Taiwan per year is 2400 mm/year (Central Weather Bureau, http://www.cwb.gov.tw/) Total amount of rainfall input = (density of rain water) ×(rainfall/area/year) × area × time
= 103 kg/m3 × 2400 used because the soil condition and the land use.
Therefore, the total amount of pesticides used for the 465.75 ha of a sugarcane field is:
yr
②. Herbicides used for production of sugarcane were 3.0kg per hectare according to de Oliviera (2005). 0.80 GJ per hectare of energy is used. With the same
Amount of fertilizer used on 268.75 ha land in Taiwan was calculated. According to Taiwan Sugar Corporation (1999), fertilizer applied to per hectare of farm land was 684 kg/ha from 1989 to 1999. Within that amount Nitrogen was117 kg/ha, then 19.45 kg of P2O5 and 40 kg of K2O (Table. 4.1).
Table 4.1 Fertilizers used for sugarcane field kg/ha (data provided by Taiwan Sugar Corporation, Taiwan sugar Statistics 1999)
Year Fertilizer Contents per ha
N P2O3 K2O
According to Taiwan Sugar Corporation (1999) averaged planted area for sugarcane was 53,305 hectare (Table. 4.2). The estimation used in here is assumed that the sugarcane is planted for sugar production cane rather than for eating fresh. Then sugarcane production to the harvested area was 10,252 ha/year, yield of 63,502/ha and production of 651,041 ton has shown by Agricultural Statistics Yearbook 2006.
Table 4.2 Cane planted area (Ha). (Taiwan Sugar Corporation, 1999) Year Cane planted area (Ha)
1998-1999 40,709
According to National Agricultural Research Center for Kyusyu and Okinawa Region (2007), 1 kg of sugarcane grows about 4 to 5 m. When the sugarcane is planted about 30 cm of stem is planted. Then the assumption of sugarcane bud is carried by calculating 1 kg of 450 cm grown sugarcane from 30 cm sugarcane bud is:
1kg ×
Therefore it can be assumed the weight of sugarcane bud would be 0.07 kg. From this value the total amount of sugarcane bud can be calculated. According to Agricultural Statistics Yearbook (2006), the amount of produced grown sugarcane was 651,041 ton.
The amount of sugarcane will be:
area
Then the sugarcane bud per hectare is calculated:
ha
This is the amount of sugarcane bud required per hectare.
Calculating the total amount of sugarcane bud to produce 3.3 × 104 ton of sugarcane from 268.75 ha of land is:
2. Material Outflow (1) Energy Loss
Energy outflow at agricultural stage estimated in fuels considered to be energy loss.
This is calculated by: assumed to be 0.1 of soil type of sandy soil with 2% slope.
= 0.1 ×103 kg/m3 × 2400
CO2 emitted from diesel use in subsystem 1 is calculated. It was 1.31 × 105 kg diesel consumed. To calculate CO2 emission, emission factor of 0.284 kg per kg of diesel is adapted from Simapro 7.1.
1.31 × 105 kg diesel/year × 0.284 kg CO2/kg = 3.72 × 104 kg CO2/year (4.1.1.21)
It should be noted that soil loss would not be count in consideration of less amount of soil been lost at sugarcane production.
(4) Sugarcane
3.30 × 104 ton sugarcane is required to produce 108 L of E3.
Harvested area was in average of 50,267 ha from 1989 to 1999 (Taiwan Sugar Corporation, 1997) (Table. 4.3). Cane harvested amount was in average of 4,272,417.3 tons from 1989 to 1999 (Taiwan Sugar Corporation, 1997) (Table. 4.4). Therefore 4.28
× 109 kg of sugarcane was produced per year in Taiwan. After the harvest of sugarcane, there is also 80.6 ton/hectare of sugarcane yield recorded (Taiwan Sugar Corporation, 1997).
Table 4.3 Harvested area of sugarcane (ha). (Taiwan Sugar Corporation, 1999)
Year Harvested area of sugarcane (Ha)
1998-1999 36,339
Table 4.4 Sugarcane harvested amount from 1989 to 1990. (Taiwan Sugar Corporation, 1999)
Year Cane harvested amount (ton)
1998-1999 3,071,259
4.1.2 Transportation 4.1.2.1 Scenario 1 and 2
3.30 × 104 ton of sugarcane was carried from sugarcane farm to ethanol factory. The travel distance of sugarcane from farm to the factory was assumed to be 30 km in both Scenario 1 and 2.
1. Material inflow (1) Sugarcane
3.30 × 104 ton of sugarcane will be transported to the sugar refinery factory.
(2) Fuels
The distance between every farm and the factory are different. It was assumed that the traveling distance from the farm to the sugar refinery factory is 30 km. Assume that the truck with the capacity of 5 ton was occupied with 80%, thus 4 ton of sugarcane was carried by a truck. According to the data reported by Japan Institute of Logistics Systems (2006), the amount of diesel required is 0.0686 L/ton·km.
Therefore the amount of diesel used to carry 4 ton of sugarcane is:
3.30 × 104 ton sugarcane ×
km ton
L
0686 .
0 diesel × 30 km = 6.79 × 104 L diesel
(4.1.2.1)
2. Material outflow (1) Energy Loss
The diesel consumption in this subsystem was 6.79 × 104 L. The energy content of diesel is 38.2 MJ/L (Ministry of the Environment, 2003). These energy was either used
to power the truck or exhausted as waste heat. The amount of energy loss from transportation of sugarcane is calculated as following:
L Diesel
MJ 2 .
38 ×6.79 × 104 L diesel = 2.59 × 106 MJ (4.1.2.2)
4.1.3 Industrial production of ethanol 4.1.3.1 Scenario 1
Process of producing ethanol was examined with inputs of materials: water, lime, diesel and electricity. Ethanol production plants have outputs of energy loss and material outflow of bagasse and molasses which are the byproduct of sugar production and necessary to produce ethanol. At the stage of bioethanol production, basically there are two steps of fermentation and hydrolization as shown in Figure 4.1. In the case of sugarcane, ferment molasses which is a byproduct of sugar production then dilute this fermented molasses to be a finally produce hybrid ethanol (Kadam, 2002).
Figure 4.1 The process of ethanol production (Su, 2006) 1. Material inflow
(1) Water
Water was required to wash excess soils and leaves of sugarcane for production ethanol. According to Ometto et al (2004), the amount of water required to produce 1 ton of ethanol was 1.29 ×105 kg/ton ethanol.
1.29 ×105 kg/ton ethanol × 3.0 × 106 L × 0.789 L kg ×
kg ton
1000 = 3.05 ×108 kg water Cane Juice Fermentation Distillation Dehydration Ethanol
(2) Lime
An amount of lime used as clarifying materials at sugar production is calculated by Ometto et al (2004). It was 11.68 kg/t alcohol of lime used.
3 × 109 mL ethanol × 0.789 g/mL = 2.37 ×109 g = 2367 ton (4.1.3.2) 11.68 kg/t × 2367 ton = 2.76 ×104 kg lime used (4.1.3.3)
(3) Sugarcane
The amount of sugarcane as input in this section was 3.30 × 107 kg.
(4) Diesel
The amount of diesel used from Ethanol production plant to the Port and Santos Port in Brazil then from Brazil to Kaohsiung Port in Taiwan is calculated.
It is assumed that the distance from ethanol plant to the Santos Port is about 30 km.
Assume that the farm uses a truck that amount of sugarcane can carry 5 ton. According to the Japan Institute of Logistics Systems (2006), the amount of diesel required is 0.0686 L/ton·km.
Therefore the amount of fuel used to carry 4 ton of sugarcane is:
3.30 × 104 ton sugarcane ×
km ton
L
0686 .
0 × 30 km = 6.79 × 104 L (4.1.3.4)
Daishou (2004) has calculated the distance from Santos Port to the Yokohama Port in Japan. The distance from Santos Port in Brazil to Yokohama Port in Japan is 12,000 miles (21911.6 km) transporting by 100,000t transoceanic tanker. It was assumed that the distance from Yokohama Port to he Kaohsiung Port is 2600 km. In total, the ethanol will be shipped for 24511.6 km.
The amount of ethanol carried from Brazil to Taiwan was 2.36 × 103 ton Traveling distance is 24511.6 km therefore:
24511.6 km ×9.7149 ton/km = 2.38 × 105 ton (4.1.3.5)
Therefore 2.38 × 105 ton of diesel was required to transport ethanol from Brazil to Taiwan.
2. Material Outflow (1) Wastewater
In this section, the amount of biological oxygen demand (BOD) will be analyzed.
Vinasse will be produced as a residual substance left after sugarcane alcohol distillation stage and treatment of this vinasse is a most nuisance material to dispose (Polack et al., 1981; Cortez and Brossard Perez 1997). Vinasse has a light brownish color and contents high BOD5 and acid material. It produces up to 15 times larger of quantities than the alcohol.
Patzek and Pimentel (2005) calculated the amount of BOD as:
BOD =
According to Patzek and Pimentel (2005), a minimum BOD concentration of 20,000 mg will be contained per liter of water and 14 liter of water is required per ethanol.
Therefore approximately 0.28 kg of BOD will be emitted to produce one liter of ethanol.
In this study 3000 kL of ethanol is assumed to be produced. Therefore:
Ethanol
(2) Mass ethanol
The amount of ethanol produced is assumed 3 × 106 L.
(3) Diesel
The amount of diesel consumed by transporting bioethanol from ethanol factory to Santos Port in Brazil was 3.91 × 103 L. Therefore the energy loss from 3.91 × 103 L of diesel is 6.79 × 104 L ×
Diesel MJ 2 .
38 = 2.59 × 106 MJ (4.1.3.8)
3. Energy outflow
The amount of energy used to import 1 L of ethanol from Brazil was 0.8 MJ (Daishou, 2004). Taiwan needs 3 × 106 L of ethanol from Brazil therefore:
3 × 106 L ×0.8 MJ/L = 2.4 × 106 MJ (4.1.3.9)
4.1.3.2 Scenario 2
In the subsystem of industrial ethanol production, process of producing alcohol as a by product from sugar is examined with material inflows: sugarcane, water, lime, diesel then outflow of materials and energy. At the stage of bioethanol production, basically there are two steps of fermentation and hydrolization. In the case of sugarcane, ferment molasses which is a byproduct of sugar production then dilute this fermented molasses to be a finally produce hybrid ethanol (Kadam, 2002). In Taiwan, ethanol production from molasses had conducted in sugar milling plant.
1. Material inflow (1) Water
According to Stillwater Associates (2003) in Chang (2006), small alcohol factory can produce 37.86 kL of ethanol and require 1892.5 kL of water. The amount of ethanol
produced was 3 × 106 L. Therefore the amount of water required for producing ethanol
(2) Ethanol from cane juice
① Lime
An amount of lime used as clarifying materials at sugar production is calculated in this section.
The lime used from 1990 to 1998 at Taiwan Sugar Corporation (1999) was shown as Table 4.5.
Table 4.5 Amount of lime used (kg). (Adapted from Taiwan Sugar Corporation, 1999) Year Amount of lime (kg) sugarcane. Therefore 0.56 kg lime used to produce 1 kg of sugarcane.
sugarcane
② Sugarcane
The amount of sugarcane required to produce ethanol was 3.30 × 107 kg.
③ Fuel Input
According to Taiwan Sugar Corporation (1999), the fuel consumption from sugar production was in average 75,574,868 L from 1989 to 1999 as shown in Table 4.6. In comparing to this fuel consumption, amount of sugar produced was in average 396,369 ton (Table 4.7). Average sugar production per hectare was also provided as Table 4.8.
The amount of sugarcane input to produce this amount of sugar was 4.2 × 109 kg.
Table 4.6 Fuel consumption amount from 1989 to 1999.
Year Amount of fuel oil used (L)
Table 4.7 Amount of sugar produced from 1989 to 1999. (Taiwan sugar cooperation, 1999) Year Amount of sugar produced (m.T)
Table 4.8 Average sugar production per hectare Year Average sugar production per hectare (ton/ha) 1998-1999 7.606
According to Taiwan Sugar Corporation (1999), the lime stone consumption from sugar production was in average 35,384,544 kg from 1989 to 1999 as shown in Table 4.9. The amount of sugarcane input to produce the amount of sugar was 4.2 × 109 kg. Therefore 6 × 104 kg of sugarcane is used to produce 1 kg of sugar.
Table 4.9 Average lime stone used in clarifying materials Year Average lime stones consumed in sugar
⑤ Coke
Coke was used as clarifying materials in ethanol production stage. According to Taiwan Sugar Corporation (1999), the coke consumption to sugar production was in average 4,629,502 kg from 1989 to 1999 as shown in Table 4.10. The amount of sugarcane input to produce the amount of sugar was 4.2 × 109 kg. Therefore 6 × 104 kg of sugarcane is used to produce 1 kg of sugar.
Table 4.10 Average coke consumed while sugar produced Year Average coke consumed in sugar production average 227, 962 as shown in Table 4.11.
3.3 ×107 kg sugarcane ×
Table 4.11. Average sulphur used in sugar production sugar factories. Amount of electricity used in sugar factories are shown as Table.4.12.
sugarcane
Table 4.12 An amount of electricity used (kWh). (Taiwan Sugar Corporation, 1999) Year Electricity used (kWh)
2. Material outflow (1) Energy Loss
There were fuel and electricity energy consumption observed in ethanol production.
Energy consumption of fuel and electricity were calculated.
①. Fuel
Energy loss from 5.89 × 106 L diesel consumption was calculated:
The energy of fuel
In this section, the amount of biological oxygen demand (BOD) will be analyzed.
Vinasse will be produced as a residual substance left after sugarcane alcohol distillation stage and treatment of this vinasse is a most nuisance material to dispose (Polack et al., 1981; Cortez and Brossard Perez 1997). Vinasse has a light brownish color and contents high BOD5 and acid material. It produces up to 15 times larger of quantities than the alcohol.
Patzek and Pimentel (2005) calculated the amount of BOD as:
BOD =
According to Patzek and Pimentel (2005), a minimum BOD concentration of 20,000 mg will be contained per liter of water and 14 liter of water is required per ethanol.
Therefore approximately 0.28 kg of BOD will be emitted to produce one liter of ethanol.
In this study 3000 kL of ethanol is assumed to be produced. Therefore:
Ethanol L
BOD kg 14 02 .
0
× 3000 × 103 L ethanol = 8.4 × 105 kg BOD (4.1.3.20)
(3) Mass ethanol
The amount of ethanol produced is assumed 3 × 106 L.
(4) CO2
The CO2 emission amount along with a production of sugar as well as ethanol was considered.
①. Lime
According to Ota et al (2008), the amount used lime in Thailand (1.8 kg lime/t refined sugar) was higher than Japanese sugar refinery factory (0.5 kg lime/ t refined sugar). However comparing to the total amount of CO2 emission from lime use in sugar refinery activity, Thailand CO2 emission rate of 203kg/t is lower than Japanese total CO2 emission rate of 311kg/t. It is assumed that the bagasse regenerated electricity aimed to reduce the CO2 emission rate in Thailand.
There is no bagasse regenerated electricity sugar refinery plant available in Taiwan at the moment. All the electricity is supplied from an electricity company. Therefore, it can be assumed that the amount of CO2 emission will be the same with Japanese refinery company.
ar electricity is 0.3471 kg CO2/kWh.
Then the amount of CO2 emitted from the electricity used at the sugar refinery station was:
6.76 × 104 kWh ×0.3471 kg CO2/kWh = 23454 kg CO2 (4.1.3.22)
③. Fuel
The amount of CO2 emitted from the diesel use at the ethanol production stage was:
5.89 × 106 L diesel ×
L kL
1000 × 0.284 kg-CO2/kL = 1.7 × 103 CO2 kg (4.1.3.23) (5) Bagasse Production
Bagasse produced amount was summed from Taiwan Sugar Statistics (Taiwan Sugar Corporation, 1999). Averaged bagasse produced in sugar milling process stage was 1,021,962 tons (Table 4.13). 4,272,424,000 kg of sugarcane was harvested to this amount of bagasse production. Therefore, it is calculated that 1 kg of sugarcane can produce 0.239 kg of bagasse. Then the total amount of bagasse produced from the 3.30
×107 kg sugarcane is:
0.24 kg bagasse/ kg of sugarcane ×3.30 ×107 kg sugarcane = 7.92 ×106kg bagasse is produced. (4.1.3.24)
Table 4.13 Bagasse Production
Year Amount of bagasse produced (ton) 1999 747,782
An amount of molasses produced in sugar milling process is calculated in this section.
Data is provided from Taiwan Sugar Corporation (1999) as it shown in Table 4.14.
Table 4.14 Amount of molasses produced from 1990-1999 Year Amount of molasses produced
Then approximately 0.01% of loss is considered: assumed that 3000 kL of ethanol will be required as input.
(2) Diesel
① Transporting ethanol prom Kaohsiung Port to the CPC refinery factory
In this section, the amount of gasoline required for transporting from Kaohsiung Port to the CPC refinery factory, Kaohsiung will be assessed.
The traveling distance from Kaohsiung Port to CPC refinery factory, Kaohsiung is approximately 12.85 km (Google Earth). According to Japan Institute of Logistics Systems (2006), the amount of diesel oil required ton kilometer is limit of 17 ton according to Daishou (2004). The amount of ethanol produced was 3000 kL ethanol was transported from Kaohsiung Port to the blending site:
3000 kL ethanol ×
② Transport of E3 from refinery factory to Taipei
After the bioethanol was blended at CPC refinery factory, E3 was distributed to petrol stations in Taipei. Distance form Kaohsiung to Taipei was assumed 340 km. The amount of diesel used to transport E3 from CPC refinery factory at Kaohsiung to Taipei is:
108 L ethanol ×
The density of E3 is adopted from Tanaka (2006).
2. Energy Loss
Energy loss of gasoline for E3 blending will be calculated in this section. Amount of diesel consumed to transport ethanol and E3 was 1.04 ×1033 L diesel + 9.06 ×105 L diesel.
According to Elert (2006), the energy density of diesel was 38.2 MJ/L. Therefore:
diesel
(2) Fugitive loss from tank kg E3/year
When the ethanol is blended with gasoline there is a fugitive loss from tank should be considered. In this section 5% of weight in E3 assumed to be lost:
E3 loss = amount of clean loss can be calculated by times the total amount of E3 blended
100
The amount of E3 produced in subsystem 1 is assumed in this section.
According to Fuels and Lubricant Committee (2006), the density of E3 is 0.794.
Mass of E3 is calculated by amount of E3 times density of E3 subtracted the volume in item 5 of material loss.
kL L
1000 × 105 kL ×0.794 kg/kL – (3.9 ×106 kg E3 fugitive loss + 7.8 ×105kg clean loss)
= 7.4 × 107 kg (4.1 4.7)
4.1.4.2 Blending and Transportation of E3 - Scenario 2 1. Material inflow
(1) Ethanol
Taiwan would require to import the amount of ethanol of 770kL by the year of 2007 to 2008, 12,000 kL by the year of 2009 and 100,000 kL by the year of 2011 (Su, 2006).
In this study, 3000 kL of ethanol is required to produce 100,000 kL of E3 in Taiwan.
(2) Gasoline
97,000 kL of gasoline is required to blend with 3000 kL of ethanol to the end produce of 105 L E3.
(3) Fuels
In this section, amount of gasoline required for transporting from Chia-yi to the CPC refinery factory, Kaohsiung will be assessed.
The traveling distance from Chia-yi sugar refinery factory to CPC refinery factory, Kaohsiung is approximately 100 km. According to Japan Institute of Logistics Systems, the amount of diesel oil required per kilometer is 0.1870 L. The amount of ethanol required for E3 production is assumed 3,000 kL.
3 ×106 L Ethanol × 0.78
② Transport of E3 from refinery factory to Taipei
After the bioethanol was blended at CPC refinery factory, E3 was distributed to petrol stations in Taipei. Distance form Kaohsiung to Taipei was assumed 340 km. The amount of diesel used to transport E3 from CPC refinery factory at Kaohsiung to Taipei is:
108 L ethanol ×
The density of E3 is adopted from Tanaka (2006).
2. Material outflow (1) Energy Loss
In this section, energy loss by truck should be considered.
According to Elert (2006), the energy of diesel is 32.19 MJ/L. The amount of diesel used to transport ethanol is 8 × 104 L diesel and 9.06 ×105 L (3.2.4.1). Therefore the energy loss from diesel fuel is:
diesel
(2) Fugitive loss from tank kg E3/year
When the ethanol is blended with gasoline, there is a fugitive loss from tank should be considered. In this section 5 % of weight in E3 assumed to be lost:
100
The amount of clean loss from inner surface of pipe is assumed 1%. Then the amount of clean loss can be calculated by times the total amount of E3 blended.
100
(8 × 104 L diesel + 9.06 ×105 L diesel) × L
kg 720 .
0 × 0.284 = 2.01 × 105kg CO2
(4.1.4.13) (4) E3
The amount of E3 produced is assumed in this section.
According to Fuels and Lubricant Committee (2006), the density of E3 is 0.794.
Mass of E3 is calculated by amount of E3 times density of E3 subtracted the volume in item 5 of material loss.
108 L ×0.794 – (3.9 × 106 kg E3 fugitive loss + 7.8 × 105 kg clean loss) = 7.47 × 107kg E3 (4.1.4.14)
4.1.5 Distribution of E3
Electricity and amount of E3 produced at subsystem 4 will be considered as input.
Material out flow, CO2 emissions, energy loss and E3 as output will be assessed.
1. Material inflow (1) E3
At the distribution stage, the amount of E3 is 7.47 × 107kg E3.
(2) Electricity
The amount of electricity for distribution of E3 is considered in this section.
According to ENEOS (2006), the amount of electricity used for distribution of fuel was about 27,500,000 kWh for a year. ENEOS (2004) stated that the amount of oil sold is about 1217000 barrel. Then converting this barrel to liter will be 192,286,000 L. To this amount of oil it can be assumed that 0.14 kWh of electricity is used per liter of oil.
In this study, there is 7.47 × 107kg E3 of E3 is produced. The amount of electricity use can simply be assumed that amount of E3 times amount of electricity consumed per liter of oil. Therefore the amount of electricity used in this section is:
7.4 × 107kg E3 × 0.14 kWh = 1.03 × 107 kWh (4.1.5.1)
2. Material Outflow
Fugitive loss of E3 will be assumed in this section. It can be assumed that when the
Fugitive loss of E3 will be assumed in this section. It can be assumed that when the