Wenjie Liao

Thermodynamic resource indicators in LCA: A case study on the titania produced in Panzhihua city, southwest China

PurposeWhile life cycle assessment (LCA) has standardized methods for assessing emission impacts, some comparable methods for the accounting or impact assessment of resource use exist, but are not as mature or standardized. This study contributes to the existing research by offering a comprehensive comparison of the similarities and differences of different resource indicators, in particular those based on thermodynamics, and testing them in a case study on titania (titanium dioxide pigment) produced in Panzhihua city, southwest China.Materials and methodsThe system boundary for resource indicators is defined using a thermodynamic hierarchy at four levels, and the case data for titania also follow that hierarchy. Seven resource indicators are applied. Four are thermodynamics-based—cumulative energy demand (CED), solar energy demand (SED), cumulative exergy demand (CExD), and cumulative exergy extraction from the natural environment (CEENE)—and three have different backgrounds: abiotic resource depletion potential, environmental priority strategies, and eco-indicator 99. Inventory data for the foreground system has been collected through on-site interviews and visits. Background inventory data are from the database ecoinvent v2.2. Characterizations factors are based on the CML-IA database covering all major methods. Computations are with the CMLCA software.Results and discussionThe scores of resource indicators of the chloride route for titania system are lower than that of the sulfate route by 10–35xa0%, except in terms of SED. Within the four thermodynamic indicators for resources, CED, CExD, and CEENE have similar scores, while their scores are five orders of magnitude lower than the SED score. Atmospheric resources do not contribute to the SED or CEEND score. Land resources account for a negligible percentage to the SED score and a small percentage to the CEENE score. Non-renewable resources have a dominant contribution to all seven resource indicators. The global production of titania would account for 0.12 and 0.14xa0% of the total anthropogenic non-renewable resource demand in terms of energy and exergy, respectively.ConclusionsFirst, we demonstrate the feasibility of thermodynamic resource indicators. We recommend CEENE as the most appropriate one within the four thermodynamic resource indicators for accounting and characterizing resource use. Regarding the case study on the titania produced in China, all the resource indicators except SED show that the sulfate route demands more resource use than the chloride route.

Improved Environmental Life Cycle Assessment of Crop Production at the Catchment Scale via a Process-Based Nitrogen Simulation Model

One of the major challenges in environmental life cycle assessment (LCA) of crop production is the nonlinearity between nitrogen (N) fertilizer inputs and on-site N emissions resulting from complex biogeochemical processes. A few studies have addressed this nonlinearity by combining process-based N simulation models with LCA, but none accounted for nitrate (NO3(-)) flows across fields. In this study, we present a new method, TNT2-LCA, that couples the topography-based simulation of nitrogen transfer and transformation (TNT2) model with LCA, and compare the new method with a current LCA method based on a French life cycle inventory database. Application of the two methods to a case study of crop production in a catchment in France showed that, compared to the current method, TNT2-LCA allows delineation of more appropriate temporal limits when developing data for on-site N emissions associated with specific crops in this catchment. It also improves estimates of NO3(-) emissions by better consideration of agricultural practices, soil-climatic conditions, and spatial interactions of NO3(-) flows across fields, and by providing predicted crop yield. The new method presented in this study provides improved LCA of crop production at the catchment scale.

Investigating impact of waste reuse on the sustainability of municipal solid waste (MSW) incineration industry using emergy approach: A case study from Sichuan province, China

China has become the largest generator of municipal solid waste (MSW) in the world with its rapid urbanization, population growth and raising living standard. Among diverse solid waste disposal technologies, MSW incineration has been becoming an attractive choice. In terms of systematic point, an integrated MSW incineration system should include an incineration subsystem and a bottom ash (BA) disposal subsystem. This paper employed an extend emergy assessment method with several improved indicators, which considers the emissions impact, to evaluate the comprehensive performances of an integrated MSW incineration system. One existing incineration plant in Yibin City, Sichuan Province, China, as a case study, is evaluated using the proposed method. Three alternative scenarios (scenario A: the incineration subsystemu202f+u202fthe BA landfill subsystem; scenario B: the incineration subsystemu202f+u202fthe concrete paving brick production subsystem using BA as raw material; scenario C: the incineration subsystemu202f+u202fthe non-burnt wall brick production subsystem using BA as raw material) were compared. The study results reveal that the ratio of positive output is 1.225, 2.861 and 1.230, the improved environmental loading ratio is 2.715, 2.742 and 1.533, and the improved environmental sustainability index is 0.451, 1.043 and 0.803 for scenario A, B and C respectively. Therefore, reuse of BA can enhance the sustainability level of this integrated system greatly. Comparatively, scenario B has the best comprehensive performance among the three scenarios. Finally, some targeted recommendations are put forward for decision-making.

Non-renewable Resources as Indicator of Thermodynamic Changes in Environment

Natural resources are the non-substitutable biophysical basis for our economy growth. Transforming current unsustainable economies requires changes to technologies that are thermodynamically speaking a conversion of natural resources from the ecosphere into products and services to meet human needs in the anthroposphere. Certain conditions of thermodynamic change should be respected to ensure the environmental sustainability of technologies. This chapter presents how to use natural resources, particularly non-renewable resources, as a basis to formulate such an environmental indicator. Cumulative exergy demand of non-renewable resources is introduced as an environmental indicator that measures the thermodynamic change in the environment caused by technologies in terms of the extraction of exergy of fossil fuels, nuclear fuels, metal ores, and minerals from the environment and the emission of heat to the environment. The case of global liquid biofuel production is studied to demonstrate the feasibility of the environmental indicator.