Papers by Author: Bo Xue Sun

Abstract: The goal of this paper is to conduct a life cycle inventory (LCI) case study for marble mining in China. The scope focuses on the whole life of marble mining. The functional unit is “per cubic meter of marble block”. The LCI data, including the input of energy and natural resources and the output of pollutant emissions, were collected on-site. The LCI results show that if the waste quarries could be recovered after the exploration, the environmental damages from the marble decorative materials would be much less. The environmental impacts of fresh water consumptions are also discussed. Some suggestions and recommendations on how to improve the environmental performance, at the same time the marble materials can be produced to support the increasing sales, are made. In the future, the land use and the mine recovery should be discussed.

Abstract: With the development of economy, China has become one of the largest cement producers in the world. However, cement industry is a main contributor of global carbon emissions. Substituting calcium carbide sludge for limestone is an effective method for CO₂ emission reduction in cement industry and has developed rapidly in recent years in China. The purpose of this study is to determine the life cycle CO₂ emission of cement clinker produced with calcium carbide sludge as secondary raw material. The results show that compared with general cement clinker, the life cycle CO₂ emission intensity of cement clinker produced with calcium carbide sludge will be decreased by 39.1% when substitution rate is 80%. And the CO₂ emission results from the procedure of cement clinker production accounts for 85.7% of the total emission, in this stage, the CO₂ emission declined by 42.2%.

Abstract: Aerated concrete is a new type of wall material with beneficial features like light weight, heat insulation, fire prevention and low energy consumption. As a key milestone in wall materials innovation and energy-saving of building system, it has been proven to be an ideal wall material which can replace traditional clay brick through years of application and practice. This study calculated the CO₂ emissions in all the stages of life cycle of aerated concrete production. Compared with clay brick, the life cycle CO₂ intensity of aerated concrete block will be decreased by 67.4% with the same insulation effect. Study on the environmental loads of aerated concrete industry will provide theoretical base for the carry out of energy-saving and emission reduction, the formulation of clean production and the development of recycling economy.

Abstract: With the development of materials industry, the problem of water pollution is increasingly serious, and therefore it is important to establish an appropriate characterization model of heavy metals in water in China. This paper provides the human toxicity potential factors of several heavy metals, including Hg, Cd, Cr, Pb and As. The result showed that Chinas HTP factors are partial greater than Europe factors, caused by the different industrial situation and the ratio of total human intake to total emissions.

Abstract: LCI study is short for life cycle inventory study. In the situation of more strict regulation limit of 500 mg NOx /m³ a demonstration project to reduce NOx emissions with clinker production capacity of 2000 t/d in Beijing is supported by the 'Five-twelfth' National Science and Technology Support Program of China Science and Technology Department. A selective catalytic reduction denitration (SCR DeNOx) technology is expected to be applied in this project. LCA models the life cycle of cement manufacturing with SCR DeNOx technology applied as its SCR system. The life cycle is from the coal and raw materials transportation, through the coal and raw meal grinding, to the clinker incineration, and finally the flue gas including NOx to the SCR reactor. The functional unit is 1 ton clinker. Data for cement produced in LNB technology as bench mark is analyzed and the SCR scenarios are to show that the SCR reactor can be established because the additional environmental impact is small due to small consumptions of reducing agent and electricity. SCR technology enable the deNOx efficiency much higher with small environmental impact.

Abstract: With the increasing seriousness of climate change problem, carbon footprint has become a very useful method to measure carbon emissions and has been widely accepted. In modern industry, electricity is almost consumed in all industry processes, and electricity is the first "footprint" of most products. As carbon emissions is always measured by theoretical estimation from input inventory but not experimental data, the input inventory of electricity generation becomes very important in carbon footprint analysis. Electricity generation is a very complex process, where all input items inter-dependant on each other and the whole system is an infinite cycle net. But in the traditional calculation model of input inventory, the interaction effect of production system is usually neglected. The major work of this study is to make clear the carbon emissions of provision 1kWh thermal power generation to consumers in China in 2006, since thermal power generation takes the most proportion of Chinese electricity. This study used a matrix-based model which includes interaction effect of the system to calculate the input inventory of electricity generation, and then the carbon emissions of thermal electricity generation in China in 2006 can be calculated. The final result of this paper can be used in carbon footprint, Life Cycle Assessment or some other related fields.

Abstract: The primary problem of eco-materials is how to judge whether a material is environmentally friendly or not, and the method of life cycle assessment is usually used to evaluate it. The depletion of mineral resources is a very important indicator of LCA, but its characterization is still filled with dispute. At present, the most commonly used method is CML, which is put forward by Leiden University, and its core idea is that using the ratio of exploitation amount and reserves of mineral resources as the degree of scarcity. Although being accepted by most of the scholars at work on LCA, CML doesn’t grasp the essence of the depletion of mineral resources. Recently, a new assessment method, injecting new ideas to the conventional life cycle assessment, combines exergy with LCA is arising, which can be used to solve some specific problems of LCA especially the depletion of mineral resources. In this paper, two results of elements’ exergy calculated by Rivero and Szargut respectively are compared, and the exergy of some natural minerals, which can be used in LCA and other minerals-related research, is calculated based on the data of Chinese mineral resources.