IMPROVEMENT OF LIFE CYCLE ASSESSMENT SOFTWARE AND ITS APPLICATIONS. Keywords: Life cycle assessment, Life cycle inventory, Sustainable process design

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1 IMPROVEMENT OF LIFE CYCLE ASSESSMENT SOFTWARE AND ITS APPLICATIONS Yodsathorn Chavewanmas a, Pomthong Malakul* a, Rafiqul Gani* b a The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok, Thailand b Department of Chemical and Biochemical Engineering, Technical University of Denmark, Lyngby, Denmark Keywords: Life cycle assessment, Life cycle inventory, Sustainable process design ABSTRACT Nowadays, sustainable process has become the challenges for developing chemical process designs. It is necessary to consider both technically and economically feasible together with environmental aspects. Life Cycle Assessment (LCA) is a tool for analysing and evaluating environmental impacts through the entire life cycle of products and processes in order to improve the environmental hotspot and/or select optimal design among various alternatives. For this purpose, LCSoft software has been developed with ability to perform LCA and integrate with other process design tools such as process simulation software, economic analysis tool, and sustainable process design tool. In this research, new version of LCSoft has been presented with improvements in terms of performance and application range. The development framework consists of four tasks: (1) improvement for LCIA calculation; (2) extension of the Life cycle inventory database; (3) development of new LCSoft features endpoint indicator, parameter sensitivity analysis, normalization, and data quality indicator; (4) validation of the integrated software. The assessment results for para-xylene production by toluene methylation are compared with LCA software, SimaPro, as a case study. Therefore, LCSoft can provide reliable calculations with systematic analysis and features to help sustainable process design very efficiently. *pomthong.m@chula.ac.th INTRODUCTION In the present, our society needs the better living standard along with environmental friendly trend. Many industries are needed to concern about their activities that have negative effect on the environment, which is environmental impact. Plenty of techniques have been developed to deal with this issue. One of effective technique is Life cycle assessment (LCA), a technique to evaluate environmental impacts through life cycle assessment of the products and/or processes, starting from the raw materials acquisition to the product disposal. With overall consideration, LCA can identify environmental deficiency (process hotspot) of the process and evaluate improvement option to minimize the problem. According to ISO (ISO International Standard, 2006), the LCA framework is consists of four main steps: (i) Goal and scope definition: The goal of LCA and the system boundary are clearly defined, also the functional unit, such as, 1 kg product. (ii) Life Cycle Inventory (LCI): all relevant input flows (natural resources, raw materials, energy) and Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 1

2 output flows (emissions to air, water, and soil; waste; products; and by-products) are compiled in terms of defined functional unit. (iii) Life Cycle Impact Assessment (LCIA): The LCI data are classified into each impact category based on their effect on environment, such as, acidification, climate change, eutrophication, etc. The environmental impact potentials of each category are evaluated by multiplying the LCI data with characterization factor (CFs) that represent their potency. (iv) Interpretation: the results from all previous steps are evaluated and analyzed with several methods, for example, contribution analysis, sensitivity analysis, and uncertainty analysis, to get the conclusion and recommendation of the study. A plenty of data are included in LCA, and it is time consuming. Therefore, software is needed to perform LCA. As a result, several commercial software are available such as SimaPro (PRé Consultants, 2016), Gabi, and Umberto. However, in the view of process synthesis-design, there is still need for software, which has ability to connect with other process design tools. LCSoft (Petchkaewkul et al., 2016) has been developed for this purpose under the user-friendly concept. That is, user can perform LCA easily and efficiently in LCSoft and be able to integrate with process simulation software (PROII/ASPEN), economic analysis tool (ECON), and sustainable process design tool (SustainPro) for process analysis and/or improvement. LCSoft is a stand-alone tool which can provides both Life Cycle Inventory (LCI) and Life Cycle Impact Assessment (LCIA) calculation options by systematically calculating from input data (stream and utility data of processes), and evaluate to environmental impact results in 21 midpoint impact categories with respect to the production stage. The environmental impact categories includes: Acidification, Aquatic toxicity, Global warming potential, Photochemical oxidation, Ozone depletion, Terrestrial toxicity, Human toxicity by exposure, Human toxicity by ingestion, Fresh water ecotoxicity, Human toxicitycarcinogenics, Human toxicity-noncarcinogenics, Energy resource consumption, Mineral extraction, Deposited waste, Water resource consumption, Photochemical ozone formation, Marine eutrophication, Freshwater eutrophication, Terrestrial eutrophication, Ionizing radiation, and Particular matter. The characterization factor data of these impacts are collected from U.S. Environmental Protection Agency (USEPA), USEtoxTM database, Ecological Scarcity 2013, Cumulative Energy Demand, CML-IA method and implemented them with Group-Contribution+ property models (Hukkerikar et al., 2012) to cover wider range of organic substances. The software also has features to evaluate carbon footprint, shows the LCI and LCIA contributions of processes, and interpretation, such as, sensitivity analysis, alternative comparison, and eco-efficiency. The objectives of this research are to develop and improve the new version of LCSoft with new features, and validate their applications through case studies. EXPERIMENTAL The research framework consists of four tasks: (1) Improvement of LCIA calculation; (2) Extension of LCI database; (3) Development of new features in LCSoft (4) Validation of LCSoft through case study. Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 2

3 A. Task 1: Improvement of LCIA calculation In order to cover wider range of applications and increased flexibility of the software, new feature to select the design methodology is added in LCSoft. New methodology that has been implemented is International Reference Life Cycle Data System (ILCD) 2011 midpoint method, which is a recommended characterization factor for impact assessment, as stated in the ILCD Handbook (EC-JRC, 2011). In addition, allocation function is added in LCSoft to calculate the processes with multiple products or multifunctional processes. B. Task 2: Extension of LCI database LCI data in LCSoft are gathered from U.S. LCI (U.S. Life Cycle Inventory Database, 2012), ELCD (European reference Life Cycle Database, 2006) and other available opensources. The raw data are calculated by matrix algebra approach (Heijung et al., 2002) and stored in LCSoft LCI database. However, with these data, some of environmental impacts cannot be calculated in specific process. In this research, extended database are provided by adopting partial inventories for similar process from different sources, in order to cover calculation of all environmental impact categories. C. Task 3: Development of new features in LCSoft The objective of this task is to extend the capability of the software by adding new applicable features into the software, including: Data Quality Indicator, the rating indicator where users can estimate the quality of his/her data collection. Normalization features, which provides the relative environmental impact results compared to a reference value. Parameter sensitivity analysis, an option to investigate the influence of changing selected parameter value (design-controlled) on impact assessment results. Uncertainty calculation, which calculate the environmental impacts result with fluctuation from uncertainty. D. Task 4: Validation of LCSoft through case study In order to identify efficiency, reliability, and deficiency of the software, LCSoft is validated by comparing assessment results from case study with commercial software, SimaPro. The calculations in LCSoft consist of five main steps and several optional steps in order to analyse LCA: (1) existence of LCI data checking; (2) retrieve LCI data; (3) impact assessment; (4) contribution analysis; and (5) interpretation. The details of calculation steps and new features in LCSoft are summarized in Table 1. RESULTS AND DISCUSSION A. Task 1: Improvement of LCIA calculation ILCD calculation method has introduced as new pathway for calculation, which has fifteen impact categories includes: Global warming potential, Ozone depletion, Human toxicity cancer effect, Human toxicity non-cancer effect, Fresh water ecotoxicity, Particular matter, Ionizing radiation, Photochemical ozone formation, Acidification, Water resource consumption, Terrestrial eutrophication, Freshwater eutrophication, Marine eutrophication, Mineral extraction, and Land use. Characterization factor of these new environmental impacts categories are based on ILCD For allocation, the model has been added in Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 3

4 this version of LCSoft, which user could specify the allocation of the process in the database management section. Environmental load of the inputs and outputs from the process are divided by allocation value among the product and co-product. Table 1 Calculation steps and new features in LCSoft Calculation step Step1: Check LCI data Step2: Retrieve LCI data Step3: Impact assessment Step4: Contribution analysis Step5: Interpretation Previous development The LCI data of related products or processes are checked with permission to add or modify LCI data. LCI results could be obtained by the LCI calculation function contained in software. Calculation model: Heijungs and Suh (2002). Resource and raw material consumption, and emission of related products or processes are received from LCI KB for calculations in step3 The LCI results are classified and characterized for each impact category based on their effect on environment. LCSoft provides data on 21 midpoint environmental impact categories. The process, LCI results, and impact assessment results are shown for each production stage. Optional steps which are helpful features for analyzing the results and archiving the goal of study are provided. - Carbon footprint calculation - Source Sensitivity analysis - Alternative comparison - Eco-efficiency evaluation New features in LCSoft - Allocation is used to calculate LCI results for multifunction process. - Data Quality Matrix is available to qualify the quality of LCI data. New pathway for calculation, 15 midpoint impact categories from ILCD method are available to calculate. New optional steps are added. - Normalization - Parameter Sensitivity analysis - Uncertainty analysis B. Task 2: Extension of LCI database LCSoft LCI database is extended by adopting partial inventory from available sources in order to cover the all impact categories assessment. Production of 1 kg benzene at plant RNA from US.LCI database is used as case study for checking the missing impact categories. As a result, nine impact categories results are missing, which are Deposited Waste, Mineral Extraction, Water Consumption, Non-renewable energy from nuclear consumption, Renewable energy from biomass consumption, Renewable energy from wind, solar, geothermal consumption, Renewable water, Freshwater eutrophication, and Ionizing radiation. The relative substances that effect to the missing impacts have been checked and adopted the lacking inventories in to LCSoft LCI database. C. Task 3: Development of new features in LCSoft Four new features have been highlighted in this research. Data Quality Matrix (DQM) is introduced into LCSoft, where users can check the quality of their data by rating with the guideline (Wang and Shen, 2013). The indicator is used to estimate shape parameter of beta function and determined the distribution of the data. Normalization features is introduced, which users can specify the normalization factor that compatible with their goal. Parameter sensitivity analysis is introduced to investigate the effect from variation of parameter. And Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 4

5 calculation with uncertainty features option is included, where user can specify the uncertainty range that associates with their study as a boundary in each inventories value. D. Task 4: Validation of LCSoft through case study Production of para-xylene from toluene methylation is taken to validate the new version of LCSoft with SimaPro The process is cradle-to-gate, which is analyzed in production of feedstock, transportation, and manufacturing. The data are taken from the simulation results (Nateetorn, 2016) where the input toluene is 569 tons/day, methanol input is 318 tons/day, and para-xylene product is 513 tons/day. For LCA study, 1 kg of pure para-xylene is considered as the functional unit. The impact assessments are based on the process and material data in LCSoft LCI database (collected from US.LCI database) and compare with similar process in SimaPro. A comparison of environmental impacts result for fifteen impact categories, which are calculated by ILCD 2011 midpoint method from both software, are given in Table 2. Table 2 Comparative results of para-xylene process between LCSoft and SimaPro Impact Categories Unit LCSoft Simapro Difference Percentage Difference Global Warming kg CO2 eq Ozone Depletion kg CFC-11 eq 1.35E E E Human toxicity, cancer effect CTUh 4.65E E E Human toxicity, non-cancer effect CTUh 1.69E E E Fresh Water Ecotoxicity CTUe Particulate matter kg PM2.5 eq Ionizing radiation kg U235 eq Photochemical Ozone Formation kg NMVOC eq Acidification molc H+ eq Terrestrial eutrophication molc N eq Freshwater eutrophication kg P eq 4.28E E Marine eutrophication kg N eq Water Resource Consumption m3 water eq Mineral Extraction kg Sb eq 4.64E E Land use kg C deficit The validation results from new version of LCSoft and SimaPro show the same trend of calculations. LCSoft give a slightly different result than SimaPro in most impact categories which indicate that the calculation model and boundary definition of them are the same. In addition, the differences are in the acceptable range. The major differences are come from the different set of emission factors. US.LCI database in the SimaPro model has larger sets of combustion fuels and petroleum feedstock emission factor compared with those in the LCSoft model, result in to high percentage difference in Fresh Water Ecotoxicity and other categories. Also, the different emission factor in methanol process, SimaPro model did not include the carbon monoxide emission. Therefore, LCSoft yield higher global warming Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 5

6 potential than SimaPro. However, LCSoft and SimaPro, have nearly the same results for the rest impact categories. CONCLUSIONS The new version of LCA software, LCSoft, that can evaluate the environmental impacts of products and/or processes, together with the ability to cooperate with other process simulation tools, has been presented together with their validation results from a case study. New methods for calculation have been added in order to widen the range of applications. Likewise, new features of data quality indicator, normalization, and parameter sensitivity analysis have been added to allow better analysis of results. With these additions, LCSoft has become a reliable and very efficient tool to analyse either new, existing and/or intensified processes. Future development plan of LCSoft is to improve the uncertainty analysis, and continuing extension of the LCI database. ACKNOWLEDGEMENTS The authors would like to thank the Petroleum and Petrochemical College, Chulalongkorn University, Thailand; and Department of chemical and biochemical engineering, Technical University of Denmark, Denmark REFERENCES EC-JRC (2011). ILCD Handbook. IES, Joint Research Centre, Ispra. ELCD data sets (2006). European Commission (accesed ). Guinée, J. M., Gorrée, M., Heijungs, R., Huppes, G., Kleijn, R. de Koning, A., van Oers, L., Wegener -Sleeswijk, A., Suh, S., de Haes, H. A. U., de Bruijn, van Duin, R., Huijbregts, M. A. J. (2002). Handbook on Life Cycle Assessment. Kluwer Academic Publishers, Dordrecht, The Netherlands. Hukkerikar, A. S., Kalakul, S., Sarup, B., Young, D. M., Sin, G., Gani, R. (2012). Chemical Information and Modeling. 56, Nateetorn, A., Uthaiporn, S., Deenesh, K. B. (2016). A computer-aided approach for achieving sustainable process design by process intensification). MSc-thesis. The Petroleum and Petrochemical College (PPC), Chulalongkorn University, Bangkok, Thailand. Petchkaewkul, K., Malakul, P., Gani, R. (2016). Study for the Improvement of LCSoft Program and Its Applications (Phase II). MSc-thesis. The Petroleum and Petrochemical College (PPC), Chulalongkorn University, Bangkok, Thailand. PRé Consultants (2016). SimaPro LCA Software. (accessed ). U.S. Life Cycle Inventory Database (2012). National Renewable Energy Laboratory. (accessed ). Wang, E. and Z. Shen (2013). A hybrid Data Quality Indicator and statistical method for improving uncertainty analysis in LCA of complex system application to the wholebuilding embodied energy analysis. Journal of Cleaner Production, 43, Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 6