ELECTRONIC SUPPLEMENTARY MATERIAL This supplementary information document was organized to support the main article, and contains the following sections: Section A Data Collection and Estimation B Methyl Ethylene Glycol (MEG) Synthesis Process C PTA 1 Synthesis through Muconic Acid Pathway D PTA 2 Synthesis through Isobutanol Pathway E PTA 3 Synthesis through Benzene Toluene Xylene Pathway F Polyethylene Terephthalate Resin Production G Sensitivity Analysis for Energy Input H Completeness Check I Consistency Check J Uncertainty Analysis - Pedigree Matrix K Additional References S-1 A- Data Collection and Estimation Literature data and patent data were used. In addition, some estimation based on similar chemical reactions and material processes were used. Therefore, the need to select appropriate benchmark processes was inevitable. Table S-1 shows the order of priority for selecting the appropriate benchmark processes for this study. Each benchmark process used was selected in accord with these priorities. Table S-1. The order of priority for selecting the appropriate benchmark processes. 1. Chemical reaction process Same Similarity Almost the same Slightly different 2. Output material Same Almost the same Slightly different Different 3. Input material Same Almost the same Slightly different Different Different The reason that the use of the same chemical reaction process had the highest priority was that the type of chemical production process is heavily dependent on the type of chemical reaction. When operational energies were estimated from these benchmark processes, they were estimated as proportional to the output materials’ weight. This is because the energy required to operate chemical production processes is typically much larger than the energy involved in the chemical reaction itself. For instance, dehydration of ethanol is an example. This stoichiometry can be written as follows: πΆ2 π»5 ππ» → πΆ2 π»4 (ππ‘βπ¦ππππ) + π»2 π, βπ»π = 42.91(ππ½/πππ) When1 kg of ethylene was produced, this system requires 1.54 MJ of energy (= 1000 g ÷ 28 g/mol × 42.91 kJ/mol × 0.001 MJ/kJ), theoretically. However, it was reported that 7.4 MJ of energy is required to operate this system, which is much higher than that of the theoretically estimated reaction energy demand. This difference seems to come from the operational energy to run the process. Since each target process was assumed to follow the same chemical reaction process as the benchmark, operational energies, which were dominant in each production step, were estimated as proportional to the output materials’ weight. For material amounts (input and S-2 other byproducts in a unit process), the amounts were estimated based on the stoichiometry of those processes. B- Methyl Ethylene Glycol (MEG) Synthesis Process B-1. Bio-Ethanol Production MEG Synthesis Step 1 As previously described in the main text, all three scenarios include the same MEG synthesis processes. A raw material, which has a C6 structure such as a starch or sugar crop, is produced. Raw materials are converted into C6 sugar by fractionation and hydrolysis, and then converted to ethanol by fermentation. Obtained ethanol is dehydrated into ethylene, and then oxidized and hydrated into MEG. MEG is used in condensation polymerization in order to produce bottle grade PET resin. In this study, corn (technically the glucose in the corn) harvested in the U.S. is fractionated and goes through hydrolysis and fermentation to be converted into ethanol. The following equation shows the stoichiometry of this process. πΆ6 π»12 π6 → 2πΆ2 π»5 ππ» (ππ‘βππππ) + 2πΆπ2 Obtained ethanol is then purified to increase its concentration. Table S-2 shows the inputs and outputs for this process. Flow values are for 1 kg ethanol production. In this study, all material weight and energy balances were checked based on the law of conservation of mass and energy, which is consistent with the stoichiometry. S-3 Table S-2. Input/output flows for 1 kg of bio-ethanol Input Corn, at farm/US with US electricity Tap water, at user/CH with US electricity Sulphuric acid, liquid, at plant/RER with US electricity Soda, powder, at plant Ammonium sulphate, as N, at regional storehouse Diammonium phosphate, as N, at regional storehouse Heat, natural gas, at industrial furnace > 1000kW Electricity, medium voltage, at grid/US 3.226 kg 4.224 kg 0.024 kg 0.036 kg 0.010 kg 0.010 kg 4.635 MJ 0.143 kWh Output Carbon dioxide, biogenic Heat, waste Treatment, sewage, from residence, to wastewater treatment, class Bio-ethanol 2.526 kg 3.385 MJ 0.001 m3 1 kg Note: Data was obtained from Ethanol, 99.7 % in H2O, from biomass, at distillation/kg/US (from Ecoinvent) (For the production of 1 kg of purified ethanol). Ethanol 95 % was subtracted from the Ethanol, 99.7% unit process by using the Ethanol, 95 % in H2O, from corn, at distillery/US U (from Ecoinvent) (For the production of 1 kg of ethanol 95 % in H2O). This procedure was necessary since the subsequent process (MEG synthesis step 2) required 99.7 % ethanol for its input material. All transportation-related and facility-related parts in the input were excluded. This same approach was used in all other steps, even if not explicitly mentioned.. S-4 B-2. Ethylene oxide production (MEG Synthesis Step 2) Ethanol is then converted into ethylene by a dehydration process, as shown in the following equation. πΆ2 π»5 ππ» → πΆ2 π»4 (ππ‘βπ¦ππππ) + π»2 O Obtained ethylene is then converted into ethylene oxide by oxidation. 2 πΆ 2 π»4 + π 2 → 2πΆ2 π»4 π(ππ‘βπ¦ππππ ππ₯πππ) The data for this process was obtained from an existing database, Ethylene oxide, at plant/RER with US electricity U (from US-EI). Since the ethylene oxide process has ethanol data as an input stream, we replaced that data with the bio-ethanol data obtained from the previous step in order to obtain Table S-3, which shows the inputs and outputs for this process. Table S-3. Input/output flows for 1 kg of bio-ethylene oxide Input Oxygen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE at grid/UCTE with US electricity Bio-ethanol Output Carbon dioxide, fossil Carbon monoxide, fossil Ethene (ethylene) Ethylene oxide Heat, waste Methane, fossil NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Disposal, catalyst base Eth. Oxide prod., 0% water, to residual material landfill/CH with US electricity Bio-ethylene oxide S-5 0.463 kg 0.33 kWh 0.825 kg 0.21 kg 1.1 x 10-4 kg 2.3 x 10-4 kg 2.0 x 10-5 kg 1.2 MJ 7.5 x 10-5 kg 2.4 x 10-4 kg 1.9 x 10-4 kg 1.9 x 10-4 kg 2.0 x 10-4 kg 2.0 x 10-4 kg 5.0 x 10-4 kg 1.0 kg B-3. Mono ethylene glycol production (MEG Synthesis Step 3) Ethylene oxide is then converted into mono ethylene glycol (MEG) by a hydration process, as shown in the following equation. πΆ 2 π»4 π + 2π»2 π → 2πΆ2 π»6 π2 (ππΈπΊ) The process of Ethylene glycol, at plant/RER with US electricity U (from US-EI) was used. Ethylene oxide data in the input was replaced with bio-ethylene oxide data from MEG synthesis step 2, in order to obtain Table S-4. Table S-4. Input/output flows for 1 kg of bio-MEG Input Water, cooling, unspecified natural origin/m3 Bio-ethylene oxide Bio-ethanol Heat, natural gas, at industrial furnace >100 kW/RER Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Output Heat, waste Ethylene oxide Ethanol Carbon dioxide, fossil BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Bio-MEG 0.024 m3 0.05146 kg 0.538 kg 2.0 MJ 0.333 kWh 1.199 MJ 2.619 x 10-3 kg 2.739 x 10-3 kg 9.245 x 10-2 kg 9.16 x 10-3 kg 9.16 x 10-3 kg 2.86 x 10-3 kg 2.86 x 10-3 kg 1.0 kg C- PTA 1 Synthesis through Muconic Acid Pathway PTA 1- Synthesis Step 1. Muconic acid Production In this PTA scenario, lignin is fermented and degraded to muconic acid as shown in the following reaction. ππππππ → (πππππππ‘ππ‘πππ) → πΆ6 π»12 π4 (ππ’ππππππ ππππ) + πΆπ2 S-6 This process is not available in databases, so it was estimated based on data from Van Duuren et al. (2010) for production of adipic acid from biomass via hydrogenation of muconic acid. The portion of their data from feedstock through fermentation to muconic acid was used. Van Duuren reported on a variety of potential feedstocks; we selected lignin from wheat stover as the feedstock for this study. Table S-5 shows the demands/emissions for the production of 1000 kg adipic acid in their study. Table S-5. Demands/emissions for the production of 1000 kg of adipic acid Demand/emissions Phenol (lignin) feedstock, wheat stover Bioreactor (fermentation) CED, GJ 7.710 0.240 CO2, kg 9.550 0.010 N2O, kg 2.660 0 The Cumulative Energy Demand (CED) used as input for the fermentation step in this study was replaced with electricity, gasoline, and diesel data. Energy required for biomass conversion can be divided into two stages, cultivation and processing. According to Brehmer (2008), 19.6% of energy is typically from electricity, and the rest was thermal energy from fuel. Since the study did not describe the fuel composition used in the cultivation stage, we referred to the LCI data for wheat straw from Ecoinvent (“Wheat straw, at field/kg/US”) in order to estimate the fuel composition as 16% gasoline and 83.9% diesel. This energy ratio was substituted for the lignin CED value, which means 19.6% (1.512 GJ) was electricity, 12.9% (0.995 GJ) was gasoline, and 67.5% (5.203 GJ) was diesel. The CED demand for the bioreactor (fermentation) was replaced with electricity, as no information about its makeup could be found. In addition, feed materials for bacterial growth shown in Table S-6 were required. Van Duuren et al. (2011) used only CED data, which means only energy-related emissions were included and other impacts such as acidification and eutrophication were ignored. Therefore, USEI LCI data for the appropriate amounts of ammonium sulphate, sodium phosphate, sodium hydroxide, and hydrochloric acid were incorporated. Data for potassium phosphate and glucose were not available, so the CED data and the CO2/N2O emission data from Van Duuren et al. were used (potassium phosphate, CED 0.26 GJ and CO2 10.66 kg; glucose, CED 3.62 GJ, CO2 221.26 kg and N2O:10.14 kg). In the absence of other information, the U.S. electricity mix was substituted for the CED values for these compounds. S-7 Table S-6. Feed demands for bacterial growth in the bioreactor, for production of 1000 kg of adipic acid Feedstock Ammonium sulphate Potassium phosphate Glucose Sodium hydroxide Hydrochloric acid Amount 0.070 ton 0.090 ton 0.440 ton 0.560 ton 0.540 ton Adipic acid is made by hydrogenation of muconic acid: πΆ6 π»6 π4 (ππ’πππππ ππππ) + 2π»2 → πΆ6 π»10 π4 (ππππππ ππππ) The weight of muconic acid required to produce 1000 kg of adipic acid therefore is 972 kg (= 1000 kg ÷ 146 g/mol × 142 g/mol). This factor was used to calculate the values in Table S-7, for production of 1 kg muconic acid. Table S-7. Input/Outputs flows for 1 kg of muconic acid Input Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Gasoline, combusted in industrial equipment/US Diesel, combusted in equipment/US Hydrogen Ammonium sulphate Sodium phosphate Sodium hydroxide Hydrochloric acid Output Carbon dioxide Nitrous oxide Muconic acid 5.794 MJ 0.030 L 0.144 L 0.028 kg 0.07202 kg 0.051 kg 0.576 kg 0.556 kg 0.723 kg 0.013 kg 1 kg PTA 1- Synthesis Step 2. Cyclohexa-2,5-diene-1,4-dicarboxylate Production Muconic acid is then converted into cyclohexa-2,5-diene-1,4-dicarboxylate using a Diels-Alder process, as described in U.S. patent 2011/0124911 A1 (2011). Muconic acid and acetylene are charged in a lab scale Parr reactor, and the reactor is then heated to 200β and held at this S-8 temperature for 12 hours. An initial pressure of 3.5 MPa is applied. The following equation shows the stoichiometry of this process. πΆ 6 π»6 π 4 + πΆ 2 π»2 → πΆ8 π»8 π4 (Cyclohexa − 2,5 − diene − 1,4 − dicarboxylate) Since LCI data for this process are not available, the benchmark process used for estimation was production of cyclohexane from benzene. Zhang (2008) compared the inputs and emissions for the production of cyclohexane by solvent-based production and vapor phase industrial production. In this LCA study, LCI data were estimated from Zhang’s vapor phase industrial process data. Table S-8 shows the input and output data for the production of 1 kg of cyclohexane using a vapor phase industrial process. Table S-8. Cyclohexane production data Input Benzene Hydrogen Steam Electricity Catalyst 0.93 kg 0.078 kg 0.1 kg 0.041 kWh 6.2 x 10-5 kg Output Benzene Hydrogen Catalyst Cyclohexane 4.7 x 10-4 kg 1.5 x 10-6 kg 6.2 x 10-5 kg 1 kg To estimate LCI data for the Diels-Alder process for the production of C8H8O4, the energy required for the operation was estimated as proportional to the output materials’ weight ratio (in this case, the ratio was based on the relative mass of cyclohexa-2,5-diene-1,4dicarboxylate and cyclohexane). The required material amounts for the chemical reaction were calculated on the basis of stoichiometry. This same approach was used in all other steps, even if not explicitly mentioned. Table S-9 shows the inputs and outputs production of 1 kg cyclohexa2,5-diene-1,4-dicarboxylate production. Since there no bio-based LCI data was available for acetylene, we used the petrochemical based LCI data available in the US-EI database. S-9 Table S-9. Input/Output flows for 1 kg of cyclohexa-2,5-diene-1,4-dicarboxylate Input Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Steam, for chemical processes, at plant/RER with US electricity Muconic acid Acetylene, at regional storehouse/CH with US electricity Output Muconic acid Acetylene, at regional storehouse/CH with US electricity Cyclohexa-2,5-diene-1,4-dicarboxylate 0.041 kWh 0.10 kg 0.845 kg 0.155 kg 4.27 x 10-4 kg 2.981 x 10-6 kg 1 kg PTA 1- Synthesis Step 3. Purified Terephthalic Acid Production Cyclohexa-2,5-diene-1,4-dicarboxylate is then converted into TPA using dehydrogenation as described in patent US. 2011/0124911 A1 (Burk et al, 2011). According to this patent, subsequent exposure to air or oxygen rapidly converts cyclohexa-2,5-diene-1,4-dicarboxylate to TPA. The following equation shows the stoichiometry of this process. 2πΆ8 π»8 π4 + π2 → 2πΆ8 π»6 π4 (πππ΄) + 2π»2 π Since LCI data for this process are not available, the benchmark process of dehydrogenation of xylene to TPA and its purification to PTA was used for estimation. The required energy was estimated as proportional to the output materials’ weight ratio. The material amounts were estimated based on the stoichiometry. The water mass generated in the chemical reaction was excluded because of its insignificant contribution to environmental impacts. This same approach for water was used in all other steps, even if not explicitly mentioned. The data used for estimation is shown in Tables S-10 and S-11. This information was used to estimate the energy required for conversion of cyclohexa2,5-diene-1,4-dicarboxylate to TPA based on weight ratios, and to estimated the required materials based on stoichiometry, resulting in the inputs and outputs shown in Table S-12. S -10 Table S-10. Para-xylene, at plant/RNA (from U.S. LCI for production of 1 kg of paraxylene from xylene) Input Xylene Electricity, at grid, US Natural gas, combusted in industrial boiler/US Liquefied petroleum gas, combusted in industrial boiler/US Bituminous coal, combusted in industrial boiler/US 1.00 kg 0.1301 kWh 0.1526 m3 7.594 x 10-3 L 2.57 x 10-2 kg Output Para-xylene 1.00 kg S -11 Table S-11. Purified terephthalic acid, at plant/RER with US electricity U (from Ecoinvent for production of 1 kg of PTA from xylene) Input Water, cooling, unspecified natural origin/m3 Xylene Water, completely softened, at plant/RER with US electricity Acetic acid, 98% in H2O, at plant/RER with US electricity Sodium hydroxide, 50% in H2O, production mix, at plant/RER with US electricity Nitrogen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Heat, heavy fuel oil, at industrial furnace 1MW/RER with US electricity Heat, light fuel oil, at industrial furnace 1MW/RER with US electricity Heat, natural gas, at industrial furnace >200kW/RER with US electricity Heat, at hard coal industrial furnace 1-10MW/RER with US electricity Steam, for chemical processes, at plant/RER with US electricity Output Heat, waste Particulates, > 10 um Particulates, > 2.5 um, and < 10 um Particulates, , 2.5 um Hydrocarbons, aromatic NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Suspended solids, unspecified Hydrocarbons, unspecified Disposal, hazardous waste, 0% water, to underground deposit/DE Disposal, average incineration residue, 0% water, to residual material landfill/CH with US electricity Purified terephthalic acid S -12 3.42 x 10-4 m3 0.661 kg 0.425 kg 0.050 kg 1.45 x 10-3 kg 4.88 x 10-2 kg 0.469 kWh 0.637 MJ 0.212 MJ 0.458 MJ 0.323 MJ 0.64 kg 1.69 MJ 2.88 x 10-5 kg 3.87 x 10-5 kg 2.25 x 10-5 kg 3.78 x 10-4 kg 1.10 x 10-4 kg 1.30 x 10-3 kg 1.30 x 10-3 kg 1.22 x 10-5 kg 1.22 x 10-5 kg 2.56 x 10-4 kg 1.40 x 10-5 kg 2.00 x 10-4 kg 6.00 x 10-3 kg 1 kg Table S-12. Input/Output data for the production of 1 kg PTA from cyclohexa-2,5-diene1,4-dicarboxylate Input Water, cooling, unspecified natural origin/m3 Cyclohexa-2,5-diene-1,4-dicarboxylate Water, completely softened, at plant/RER with US electricity Acetic acid, 98% in H2O, at plant/RER with US electricity Oxygen Sodium hydroxide, 50% in H2O, production mix, at plant/RER with US electricity Nitrogen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Heat, heavy fuel oil, at industrial furnace 1MW/RER with US electricity Heat, light fuel oil, at industrial furnace 1MW/RER with US electricity Heat, natural gas, at industrial furnace >200kW/RER with US electricity Heat, at hard coal industrial furnace 1-10MW/RER with US electricity Steam, for chemical processes, at plant/RER with US electricity Electricity, at grid, US Natural gas, combusted in industrial boiler/US Liquefied petroleum gas, combusted in industrial boiler/US Bituminous coal, combusted in industrial boiler/US Output Heat, waste Particulates, > 10 um Particulates, > 2.5 um, and < 10 um Particulates, , 2.5 um Hydrocarbons, aromatic NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Suspended solids, unspecified Hydrocarbons, unspecified Disposal, hazardous waste, 0% water, to underground deposit/DE Disposal, average incineration residue, 0% water, to residual material landfill/CH with US electricity Purified terephthalic acid S -13 3.42 x 10-4 m3 1.012 kg 0.425 kg 0.050 kg 0.096 kg 1.45 x 10-3 kg 4.88 x 10-2 kg 0.469 kWh 0.637 MJ 0.212 MJ 0.458 MJ 0.323 MJ 0.64 kg -0.08598 kWh -0.1009 m3 -5.02 x 10-3 L -0.01699 kg 1.69 MJ 2.88 x 10-5 kg 3.87 x 10-5 kg 2.25 x 10-5 kg 3.78 x 10-4 kg 1.10 x 10-4 kg 1.30 x 10-3 kg 1.30 x 10-3 kg 1.22 x 10-5 kg 1.22 x 10-5 kg 2.56 x 10-4 kg 1.40 x 10-5 kg 2.00 x 10-4 kg 6.00 x 10-3 kg 1 kg D- PTA 2 Synthesis through Isobutanol Pathway PTA 2- Synthesis Step 1. Isobutanol production The benchmark process for production of bio-based isobutanol was the corn to ethanol process as described in MEG step 1, in Table S-2. The stoichiometry of this reaction is as follows. πΆ6 π»12 π6 → 2 πΆ2 π»5 ππ» (ππ‘βππππ) + 2 πΆπ2 The weight of CO2 generated in this reaction was calculated as 957 g (= 1000 g ÷ 46 g/mol × 44 g/mol). Since Table S-2 shows the emission of 2526 g biogenic CO2, it seems 1569 g of CO2 is the extra contribution from the production system (= 2526 g - 957 g). The weight of glucose consumed in this reaction was calculated as 1957 g (= 1000 g ÷ 46 g/mol × 180 g/mol × 0.5), so the conversion loss from corn to glucose was estimated as 1.65 (= 3226 g ÷ 1957 g). The target process stoichiometry is πΆ6 π»12 π6 → πΆ4 π»10 π (ππ πππ’π‘ππππ) + 2πΆπ2 + π»2 π The weight of CO2 generated in this reaction was calculated as 1189 g (= 1000 g ÷ 74 g/mol × 44 g/mol × 2). Since the operational contribution of CO2 must be included, 2758 g CO2 was calculated as the total amount generated in this case (= 1189 g + 1569 g). The weight of glucose required for this reaction was calculated as 2432 g (= 1000 g ÷ 74 g/mol × 180 g/mol); applying the conversion loss resulted in a total amount of corn required of 4013 g (2432 g × 1.65). For the other LCI data, the ratios between the corn mass and the LCI data from the ethanol production model were applied, resulting in the values shown in Table S-13. S -14 Table S-13. Input/output flows for 1 kg of bio-isobutanol Input Corn, at farm/US with US electricity Tap water, at user/CH with US electricity Sulphuric acid, liquid, at plant/RER with US electricity Soda, powder, at plant Ammonium sulphate, as N, at regional storehouse Diammonium phosphate, as N, at regional storehouse Heat, natural gas, at industrial furnace > 1000kW Electricity, medium voltage, at grid/US 4.013 kg 5.255 kg 0.030 kg 0.045 kg 0.012 kg 0.012 kg 5.766 MJ 0.178 kWh Output Carbon dioxide, biogenic Heat, waste Treatment, sewage, from residence, to wastewater treatment, class Bio-isobutanol 2.758 kg 4.211 MJ 0.002 m3 1 kg PTA 2- Synthesis Step 2. Isobutylene Production Isobutanol is then converted to isobutylene by dehydration. Since LCI data are not available, the dehydration of bio-ethanol to bio-ethylene reported by Liptow et al (2009) for the production of polyethylene from sugarcane was used as the benchmark. Table S-14 shows the input and output data for the production of 1 kg of bio-ethylene from bio-ethanol. Table S-14. Input/output flows for the production of 1 kg of bio-ethylene from bio-ethanol Input Bio-ethanol Electricity Fuel 1.70 kg 1.80 MJ 5.60 MJ Output Methane Carbon monoxide Carbon dioxide Nitrous oxide NMVOC NOx Sulfur dioxide Bio-ethylene 1.50 x 10-3 kg 2.0 x 10-4 kg 0.327 kg 1.2 x 10-5 kg 1.1 x 10-5 kg 1.5 x 10-3 kg 1.0 x 10-4 kg 1 kg S -15 For the production of isobutylene, the stoichiometry is πΆ4 π»10 π (ππ πππ’π‘ππππ) → πΆ4 π»8 (ππ πππ’π‘π¦ππππ) + π»2 π The weight of C4H10O required to generate 1 kg of isobutylene is 1.321 kg (= 1.0 kg ÷ 56 g/mol × 74 g/mol). Scaling the data in Table S-14 using stoichiometry for materials and relative weights for energy and emissions resulted in the input/output flows for 1 kg of isobutylene shown in Table S-15. Table S-15. Input/output flows for the production of 1 kg of bio-isobutylene from bioisobutanol Input Bio-isobutanol Electricity, medium voltage, at grid/US Heat, natural gas, at industrial furnace > 100 kW 1.32 kg 1.80 MJ 5.60 MJ Output Methane Carbon monoxide Carbon dioxide Nitrous oxide NMVOC NOx Sulfur dioxide Bio-isobutylene 1.50 x 10-3 kg 2.0 x 10-4 kg 0.327 kg 1.2 x 10-5 kg 1.1 x 10-5 kg 1.5 x 10-3 kg 1.0 x 10-4 kg 1 kg PTA 2- Synthesis Step 3. Isooctene Production LCI data were also not available for conversion of isobutylene to isooctene. The benchmark process used for estimation was conversion of the product of refinery MTBE units to isooctane through dimerization and hydrogenation of C4 components (CDTECH, 2004). Table S-16 shows the input and output data. Table S-16 Input/Output flows for the production of isooctene from C4 component. Input C4 compounds (isobutene 15 wt%) 100,000 lb Oxygen 22 lb Water 40 lb Output Isooctene C4 raffinate 16,680 lb 83,380 lb S -16 Operational energy requirements were based on a study by Croezen and Kampman (2009), which reported that steam consumption of 2 tonnes/tonne isooctene is required based on contractor data, and the process emits 0.3 tonne CO2-eq/tonne isooctene. From the data presented, it appears that conversion from isobutene to isooctene resulted in close to 100% yield. Starting material of 100% isobutylene was used as the input material in this model, and was assumed to have the same 100% process efficiency. Table S-17 presents the input and output flows for conversion of isobutylene to isooctene. Table S-17. Input/output flows for 1 kg of isooctene Input Steam, for chemical processes, at plant/RER with US electricity Oxygen, liquid, at plant/RER with US electricity Isobutylene Water 2.0 kg 1.319 x 10-3 kg 1.00 kg 2.398 x 10-3 kg Output Carbon dioxide Isooctene 0.333 kg 1.00 kg PTA 2- Synthesis Step 4. Isooctane Production Isooctene is then converted into isooctane by hydrogenation. The following equation shows the stoichiometry of this process. πΆ8 π»16 + π»2 → πΆ8 π»18 (ππ ππππ‘πππ) Data for this process also were not available in databases, so hydrogenation of 1-heptene to n-heptane was used as the benchmark (Energetics, Inc., 2006). Table S-18 shows the energy data reported for this process. Table S-18 Energy for production of 1 barrel (bbl) of n-heptane Energy Source Fuel Electricity Total energy input Hydrogen consumed Steam (produced) Amount (BTU) 62,000 19,000 81,000 30,000 -31,100 S -17 The “hydrogen consumed” energy was excluded since it is accounted for separately. Energy produced by steam was assumed to be recovered and used, so was subtracted from the fuel energy amount. The stoichiometry of the benchmark process is πΆ7 π»14 ( 1 − βπππ‘πππ) + π»2 → πΆ7 π»16 (π − βπππ‘πππ) One barrel is 159 L; the density of 1-heptene used was 0.697 g/cm3. Table S-19 shows the inputs and outputs used for production of n-octene, scaling energy to mass and materials to the stoichiometry. Natural gas was substituted for “fuel.” Table S-19. Input/output flows for production of 1 kg isooctane Input Electricity, medium voltage, at grid/US Natural gas, at consumer/RNA with US electricity Isooctene Hydrogen, liquid, at plant/RER with US electricity 0.0483 kWh 0.283 MJ 0.982 kg 0.018 kg Output Isooctane 1.00 kg PTA 2- Synthesis Step 5. Para-Xylene Production Isooctane is then converted into para-xylene by dehydrocyclization. The following equation shows the stoichiometry of this process. πΆ8 π»18 → πΆ8 π»10 (ππππ − π₯π¦ππππ) + 4π»2 As LCI data were not available, the benchmark process used for estimation was dehydrocyclization for the production of toluene from n-heptane. Table S-20 shows the energy data for this process, as described by Energetics Inc., 2006. Table S-20 Toluene production energy data, per barrel Energy Source Fuel Electricity Total energy input Hydrogen consumed Steam (produced) Amount (BTU) 254,000 10,000 264,000 -479,200 -15,400 S -18 As in the previous step, the “hydrogen consumed” energy was excluded in the study since it was accounted for separately. The benchmark process stoichiometry is πΆ7 π»16 (π − βπππ‘πππ) → πΆ7 π»8 (π‘πππ’πππ) + 4π»2 The target process stoichiometry was πΆ8 π»18 → πΆ8 π»10 + 4π»2 Table S-21 shows the input/output flows based on relative amounts and stoichiometry (density of n-heptene is 0.684 g/cm3). As in step 4, it was assumed that the steam energy was recovered and used, so it was subtracted from the fuel energy. Natural gas replaced fuel. Table S-21. Input/ Output flows for 1 kg of para-xylene Input Electricity, medium voltage, at grid/US Natural gas, at consumer/RNA with US electricity Isooctane 0.0293 kWh 2.516 MJ 1.0755 kg Output Hydrogen Para-xylene 0.0755 kg 1.00 kg PTA 2- Synthesis Step 6. PTA Production This process is the same as PTA 1 synthesis step 3, discussed earlier in this document. E- PTA 3 Synthesis through Benzene Toluene Xylene Pathway PTA 3- Synthesis Step 1, through Fast Pyrolysis. The first step in this scenario was production of bio-oil from poplar through fast pyrolysis in a CFB reactor as described by Iribarrena et al. (2012). Table S-22 shows the demands and emissions data reported for the production of bio-oil. S -19 Table S-22. Bio-oil production data Input Poplar Process water Air Electricity Natural gas 5407 kg 89.64 kg 5141 kg 702.4 kWh 1.58 MJ Output Bio-oil Char Ash Oxygen Nitrogen Water Hydrogen Carbon monoxide Carbon dioxide Methane Ethylene Propylene Ammonia 2265 kg 86.75 kg 31.21 kg 365 kg 4028 kg 2690 kg 0.03 kg 7.68 kg 1286 kg 2.99 x 10-6 kg 5.98 x 10-6 kg 8.96 x 10-6 kg 4.48 x 10-6 kg The bio-oil was assumed to be directly converted into BTX through the process of catalytic (zeolite) upgrading (Huber et al. 2006) with a conversion ratio of 0.83. This resulted in the data shown in Table S-23. S -20 Table S-23. Input/Output flows for 1 kg of BTX Input Poplar (chips) Process water, ion exchange, production mix, at plant, from surface water RER Air Electricity, at grid, US Heat, natural gas, at industrial furnace > 100kW/RER with US electricity Output Charcoal, at plant/GLO with US electricity Ash, bagasse, at fermentation plant/BR with US electricity Oxygen Nitrogen Water Hydrogen Carbon monoxide Carbon dioxide Methane Ethylene Propylene Ammonia BTX 2.876 kg 0.04767 kg 2.734 kg 0.3735 kWh 8.403 x 10-4 MJ 0.04614 kg 0.166 kg 0.1941 kg 2.142 kg 1.431 kg 1.595 x 10-5 kg 4.084 x 10-3 kg 0.684 kg 1.59 x 10-9 kg 3.18 x 10-9 kg 4.765 x 10-9 kg 2.383 x 10-9 kg 1.00 kg PTA 3 - Synthesis Step 2. Xylene Mix Production Extractive distillation is used for conversion of BTX to a xylene mix, via the sulfolane process, used to recover high-purity aromatics from hydrocarbon mixtures, with data from Meyers (2003). This process consumes an average 287.5 kcal (1.1932 MJ) of energy per kilogram. The xylene mix weight composition of 33.0% in BTX under the highest yield conditions (upgrading temperature of 550 ºC) and 100 % extraction were assumed, resulting in the flows shown in Table S-24, where electricity was substituted for the required energy. Table S-24 Input/output flows for 1 kg of xylene mixture Input Electricity, medium voltage, at grid/US with US electricity BTX 1.193 MJ 3.030 kg Output Xylene mix 1.00 kg S -21 PTA 3 - Synthesis Step 3. PTA Production The xylene mixture is then converted into para-xylene by an adsorption, separation and isomerization process, and para-xylene is converted into PTA by oxidation and purification. LCI data from Ecoinvent (Purified terephthalic acid, at plant/RER with US electricity U) was used, resulting in the flows shown in Table S-25. S -22 Table S-25. Input/output flows for production of 1 kg PTA from xylene mixture Input Water, cooling, unspecified natural origin/m3 Xylene mixture Water, completely softened, at plant/RER with US electricity Acetic acid, 98% in H2O, at plant/RER with US electricity Oxygen Sodium hydroxide, 50% in H2O, production mix, at plant/RER with US electricity Nitrogen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Heat, heavy fuel oil, at industrial furnace 1MW/RER with US electricity Heat, light fuel oil, at industrial furnace 1MW/RER with US electricity Heat, natural gas, at industrial furnace >200kW/RER with US electricity Heat, at hard coal industrial furnace 1-10MW/RER with US electricity Steam, for chemical processes, at plant/RER with US electricity Electricity, at grid, US Natural gas, combusted in industrial boiler/US Liquefied petroleum gas, combusted in industrial boiler/US Bituminous coal, combusted in industrial boiler/US Output Heat, waste Particulates, > 10 um Particulates, > 2.5 um, and < 10 um Particulates, , 2.5 um Hydrocarbons, aromatic NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Suspended solids, unspecified Hydrocarbons, unspecified Disposal, hazardous waste, 0% water, to underground deposit/DE Disposal, average incineration residue, 0% water, to residual material landfill/CH with US electricity Purified terephthalic acid S -23 3.42 x 10-4 m3 0.661 kg 0.425 kg 0.050 kg 0.096 kg 1.45 x 10-3 kg 4.88 x 10-2 kg 0.469 kWh 0.637 MJ 0.212 MJ 0.458 MJ 0.323 MJ 0.64 kg -0.08598 kWh -0.1009 m3 -5.02 x 10-3 L -0.01699 kg 1.69 MJ 2.88 x 10-5 kg 3.87 x 10-5 kg 2.25 x 10-5 kg 3.78 x 10-4 kg 1.10 x 10-4 kg 1.30 x 10-3 kg 1.30 x 10-3 kg 1.22 x 10-5 kg 1.22 x 10-5 kg 2.56 x 10-4 kg 1.40 x 10-5 kg 2.00 x 10-4 kg 6.00 x 10-3 kg 1 kg F- Polyethylene Terephthalate Resin Production Polyethylene terephthalate (PET) resin is obtained through the condensation polymerization process between MEG and PTA. The PET resin is initially in an almost amorphous state, and its viscosity is not appropriate for bottle grade resin. Therefore, the amorphous resin goes through additional polymerization in the solid state in order to increase its viscosity. Tables S-26 and S27 show the inputs and outputs for these processes, for production of 1 kg PET resin. The Ecoinvent inventory data sources used are “polyethylene terephthalate, granulate, amorphous, at plant/kg/RER” (from Ecoinvent), which covers condensation polymerization in the liquid state, and “polyethylene terephthalate, granulate, bottle grade, at plant/kg/RER” for the solid state polymerization to bottle grade PET resin. S -24 Table S-26. Input/output flows for production of 1 kg amorphous PET Input Water, unspecified natural origin/m3 Water, cooling, unspecified natural origin/m3 Purified terephthalic acid Mono-ethylene glycol Nitrogen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Heat, heavy fuel oil, at industrial furnace 1MW/RER with US electricity Heat, light fuel oil, at industrial furnace 1MW/RER with US electricity Heat, natural gas, at industrial furnace >200kW/RER with US electricity Heat, at hard coal industrial furnace 1-10MW/RER with US electricity Steam, for chemical processes, at plant/RER with US electricity Output Heat, waste Particulates, > 10 um Particulates, > 2.5 um, and < 10 um Particulates, , 2.5 um NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Suspended solids, unspecified Hydrocarbons, unspecified Disposal, hazardous waste, 0% water, to underground deposit/DE with US electricity U Disposal, average incineration residue, 0% water, to residual material landfill/CH with US electricity Disposal, plastics, mixture, 15.3% water, to municipal incineration/CH with US electricity Disposal, municipal solid waste, 22.9% water, to municipal incineration/CH with US electricity Amorphous PET S -25 1.63 x 10-4 m3 6.40 x 10-3 m3 0.875 kg 0.334 kg 0.0298 kg 0.194 kWh 0.494 MJ 0.165 MJ 0.665 MJ 0.306 MJ 0.94 kg 0.70 MJ 3.20 x 10-7 kg 4.30 x 10-7 kg 2.50 x 10-7 kg 9.00 x 10-4 kg 1.60 x 10-3 kg 1.02 x 10-3 kg 2.62 x 10-4 kg 2.62 x 10-4 kg 1.00 x 10-6 kg 4.99 x 10-4 kg 9.00 x 10-5 kg 4.00 x 10-4 kg 2.31 x 10-3 kg 8.8 x 10-4 kg 1 kg Table S-27 Input/output flows for production of 1 kg of bottle-grade PET resin Input Water, unspecified natural origin/m3 Water, cooling, unspecified natural origin/m3 PET, amorphous PTA Mono-ethylene glycol Nitrogen, liquid, at plant/RER with US electricity Electricity, medium voltage, production UCTE, at grid/UCTE with US electricity Heat, heavy fuel oil, at industrial furnace 1MW/RER with US electricity Heat, light fuel oil, at industrial furnace 1MW/RER with US electricity Heat, natural gas, at industrial furnace >200kW/RER with US electricity Heat, at hard coal industrial furnace 1-10MW/RER with US electricity Steam, for chemical processes, at plant/RER with US electricity Output Heat, waste Particulates, > 10 um Particulates, > 2.5 um, and < 10 um Particulates, , 2.5 um NMVOC, non-methane volatile organic compounds, unspecified origin BOD5, Biological oxygen demand COD, Chemical oxygen demand DOC, Dissolved organic carbon TOC, Total organic carbon Suspended solids, unspecified Hydrocarbons, unspecified Disposal, hazardous waste, 0% water, to underground deposit/DE with US electricity U Disposal, average incineration residue, 0% water, to residual material landfill/CH with US electricity Disposal, plastics, mixture, 15.3% water, to municipal incineration/CH with US electricity Disposal, municipal solid waste, 22.9% water, to municipal incineration/CH with US electricity Bottle-grade PET S -26 1.43 x 10-5 m3 4.84 x 10-3 m3 0.78 kg 0.194 kg 0.0761 kg 0.0366 kg 0.189 kWh 0.284 MJ 0.0946 MJ 0.379 MJ 0.172 MJ 0.100 kg 0.68 MJ 3.20 x 10-7 kg 4.30 x 10-7 kg 2.50 x 10-7 kg 1.00 x 10-6 kg 6.31 x 10-4 kg 6.31 x 10-4 kg 6.41 x 10-7 kg 6.41 x 10-7 kg 9.00 x 10-6 kg 1.00 x 10-6 kg 4.30 x 10-4 kg 1.81 x 10-3 kg 6.30 x 10-4 kg 4.00 x 10-54 kg 1 kg G- Sensitivity Analysis for Energy Input Process Energy Demand Since this study contains a number of estimations, a sensitivity check on energy data uncertainty was performed. We tentatively assumed if there was over a 10% total output change (total sensitivity %) in the case of a 20% input energy change in a particular step, that step would be identified as highly sensitive. Sensitivity (%) was expressed as the absolute deviation (%) of the results. Table S-28 shows the results for 1 kg of PET bottle grade resin made with the muconic acid pathway. Input energy amounts were reduced 20% for each PTA production step. Although significant change (larger than 10 %) was not observed, the PTA 1 step 1 process (muconic acid synthesis) appeared to have the greatest sensitivity in this study since its sensitivity value of 6.8% was the highest among the three PTA production scenarios. More accurate LCI data should be procured for this step in a future study. Table S-28 Results of the sensitivity analysis for uncertainty of PTA scenario 1: Effects of 10% reduction in energy required in each PTA step Step with 10% reduction PTA step 1 PTA step 2 PTA step 3 Overall reduction in process energy 6.8% 1.7% 2.0% Table S-29 shows the reduction in energy in the production of PET bottle grade resin resulting from a 20% reduction in energy for each step in the isobutanol process for PTA. Significant change (over 10 %) was not observed. Table S-30 shows the results for 1 kg PET bottle grade resin made with the BTX pathway to PTA. No significant change (over 10 %) was observed. S -27 Table S-29 Results of the sensitivity analysis for uncertainty of PTA scenario 2: Effects of 10% reduction in energy required in each PTA step Step with 10% reduction PTA step 1 PTA step 2 PTA step 3 PTA step 4 PTA step 5 PTA step 6 Overall reduction in process energy 3.4% 1.9% 0.8% 0.1% 0.2% 2.3% Table S-30 Results of the sensitivity analysis for uncertainty of PTA scenario 3: Effects of 10% reduction in energy required in each PTA step Step with 10% reduction PTA step 1 PTA step 2 PTA step 3 Overall reduction in process energy 1.2% 1.0% 4.3% H- Completeness Check ISO14044 requires that LCA results be checked for completeness. The completeness check is the process of verifying whether information from the phases of a LCA is sufficient for reaching conclusions in accordance with the goal and scope definition. As discussed, some processes were omitted from this study: transportation, processing, use, and end of life. Completeness of the material production and energy requirements were verified. For PTA 2 step 3, energy required was assumed to be the same as in the benchmark process. In PTA 3 step 2 for material production, the conversion efficiency was assumed to be the same as in the petrochemical case. I- Consistency Check LCA results must also be checked for consistency. Tables S-31, S-32 and S-33 show the results of the consistency check. As can be seen in the tables, some processes are not consistent, but these steps were the targets of this report, so no corrective action was needed. S -28 In the data accuracy entry, “caution” means that some of the LCI data were based on stoichiometric estimation. In the technology coverage entry, “commercial” means technology used in the specific process is already available at an industrial level. “Pilot” means the technology is not yet available at a mass production level. Table S-31. Results of consistency check for PTA scenario 1 Data source MEG PTA1 Step 1 Step 2 Step 3 PET resin Comparison Database, literature Literature Data accuracy Good Caution Database, literature Database, literature Database Caution Not consistent Not consistent Good Good Data age Within 6 yrs Within 6 yrs Within 6 yrs Within 6 yrs Within 6 yrs Consistent Technology coverage Commercial Geographical coverage US Pilot (estimation) Pilot (estimation) Pilot (estimation) Commercial US Not consistent Consistent Technology coverage Commercial Geographical coverage US Pilot (estimation) Pilot (estimation) Pilot (estimation) Pilot (estimation) Pilot (estimation) Commercial US Commercial US Not consistent Consistent US US US Table S-32. Results of consistency check for PTA scenario 2 Data source MEG PTA2 PET resin Comparison Data accuracy Good Step 1 Database, literature Literature Step 2 Literature Caution Step 3 Literature Caution Step 4 Literature Caution Step 5 Literature Caution Step 6 Database, literature Database Good Not consistent Not consistent Caution Good S -29 Data age Within 6 yrs Within 10 yrs Within 10 yrs Within 10 yrs Within 10 yrs Within 10 yrs Within 10 yrs Within 6 yrs Consistent US US US US US Table S-33. Results of consistency check for PTA scenario 3 Data source MEG PTA3 Step 1 Step 2 Database, literature Literature Data accuracy Good Caution Database, literature Database Caution PET resin Database Good Comparison Not consistent Not consistent Step 3 Good Data age Within 6 yrs Within 6 yrs Within 6 yrs Within 6 yrs Within 6 yrs Consistent Technology coverage Commercial Geographical coverage US Pilot (estimation) Pilot (estimation) Commercial US Commercial US Not consistent Consistent US US J- Uncertainty Analysis - Pedigree Matrix Table S-34 shows the basic pedigree matrix for this study, with temporal information modified to this study time. The table provides data quality scores and provides an objective analysis of the quality of each production step as discussed by Weidema and Wesnæs (1996). Table S-34 shows the summarized pedigree matrix, indicating the data quality values determined for each step. The standard deviation (SD) values in Table S-35 were calculated using the following equation as implemented in SimaPro (SimaPro 7, 2010): 2 2 2 2 2 2 SD = exp√[ln(U1 ) ] + [ln(U2 ) ] + [ln(U3 ) ] + [ln(U4 ) ] + [ln(U5 ) ] + [ln(U6 ) ] U1 = score for reliability. U2 = score for completeness. U3 = score for temporal correlation. U4 = score for geographical correlation. U5 = score for technological correlation. U6 = score for sample size. S -30 Table S-34. Pedigree matrix with the scores used to assess the quality of data sources (modified from Weidema and Wesnæs, 1996) Score U1 Reliability U2 Completeness U3 Temporal correlation U4 Geographical correlation U5 Further technological correlation U6 Sample size 1 Verified data based on measurements 2 Verified data partly based on assumptions OR non-verified data based on measurements 1.05 Representative data from >50% of sites relevant for market considered over adequate period to even out normal fluctuations 1.02 2007-2010 1.03 Average data from larger area including area under study 3 Non-verified data partly based on qualified estimates 4 Qualified estimate; data derived from theoretical information 5 Non-qualified estimate 1.10 Representative data from only some relevant sites (<<50%) OR >50% of sites but from shorter periods 1.20 Representative data from only one relevant site OR some sites but from shorter periods 1.50 Representativeness unknown or data from a small number of sites AND shorter periods 1.05 2003-2006 1.10 Data from smaller area than area under study, or from similar area 1.10 1998-2002 1.20 - 1.00 Data from enterprises, processes and materials under study (i.e. identical technology) 1.00 >100, continuous measurement 1.01 - 1.02 Data from processes/materials under study but different technology Data from laboratory scale processes and same technology 1.20 Before 1997 1.50 Data from unknown OR distinctly different area 1.10 Data from laboratory scale and different technology >20 1.50 ≥3 2.00 unknown 1.00 1.02 1.20 >10, aggregated data in environmental report 1.05 1.10 1.20 1.00 Representative data from all sites relevant for market considered over adequate period to even out normal fluctuations 1.00 2011-2013 1.00 Data from area under study S -31 Table S-35. Scores used to assess the quality of data sources and further run the uncertainty analysis U1 U2 U3 U4 U5 U6 PTA 1 Muconic acid Step 1 Energy/ 3 4 1 Materials Step 2 Energy 5 4 2 Materials 4 4 2 Step 3 Energy/ * * * Materials PTA 2 Step 1 Energy/ 4 4 1 Butanol Materials Step 2 Energy/ 4 4 2 Materials Step 3 Energy 3 3 3 Materials 4 3 3 Step 4 Energy 2 1 3 Materials 4 1 3 Step 5 Energy 2 1 3 Materials 4 1 3 Step 6 Energy/ * * * Materials PTA 3 Step 1 Energy/ 2 3 1 BTX Materials Step 2 Energy/ 2 3 3 Materials Step 3 Energy/ * * * Materials * Data was used from SimaPro containing standard deviation values S -32 Calculated SD2 3 3 5 1.063 3 3 3 3 5 5 1.273 1.116 * * * * 3 3 3 1.081 3 3 4 1.090 3 3 1 1 1 1 3 3 3 3 3 3 3 3 1 1 1 1 1.058 1.084 1.046 1.078 1.046 1.078 * * * * 3 3 4 1.049 3 3 3 1.051 * * * * K- Additional References ANL (Argonne National Laboratory) (2010) Life-Cycle Assessment of Corn-Based Butanol as a Potential Transportation Fuel.Available at: http://www.transportation.anl.gov/pdfs/AF/448.pdf. 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