Metabolism analysis and eco-environmental impact assessment of two typical cement production systems in Chinese enterprises

Abstract

Keywords:Cement production metabolism Industrial metabolism Material and energy flows Use efficiency Environmental emissionsAs one of the primary raw materials in the construction industry, cement production consumes a great deal of resources and has various environmental effects. During the production phase in particular, different procedures play a decisive role in determining the input and output. China has become both the largest producer and the largest consumer of cement worldwide. Together, the two most common production processes in China, the shaft kiln and the NSP (New Suspension Preheater) kiln, account for more than 95% of total production capacity. Although the proportion of NSP kilns continues to increase each year, shaft kilns are still adopted in numerous small and medium-sized enterprises due to their lower costs and quick yields. During the period of technical transformation and the emergence of continuous environmental issues, it is of great importance to quantify the metabolic processes of typical construction materials, particularly in order to conduct a comparative analysis with different production techniques. However, due to the limited availability of data, relevant studies are rare. In this paper, two typical cement enterprises with different production processes were selected in order to investigate material and energy use as well as pollutant emissions. Metabolic processes were then compared and a use efficiency analysis for different procedural phases was conducted using material flow analysis (MFA). The results are as follows: the shaft kiln requires more raw materials, such as limestone, clay, and coal, per unit product. The efficiency of energy consumption (including electric power consumption and overall energy consumption) is also lower for the shaft kiln than for the NSP kiln. As for environmental emissions, the shaft kiln emits more SO 2 , CO 2 , NO X , and dust per unit product than the NSP kiln and has higher eco-environmental impacts.

Analysis on differences of carbon dioxide emission from cement production and their major determinants

“…A life cycle inventory study on China cement industry is conducted by Li et al (2014) to evaluate the environmental damages, including GHG, primary pollution and the hazardous air pollutants. Hu et al (2014) selected two most common production processes in China to investigate material and energy use as well as pollutant emissions. Chen et al's (2015) study addressed pollutants generated by the cement industry in China, the impacts of these pollutants, and the potential for environmental improvement.…”

Life Cycle Assessment of Ordinary Portland Cement (OPC) Using both Problem Oriented (Midpoint) Approach and Damage Oriented Approach (Endpoint)

“…The consequential effect of global warming is the change in the climatic conditions. Several studies that have been carried out estimated the impact of climatic changes from the production of cement within the range of 0.628 kg CO2 eq À0.920 kg CO2 eq (though their evaluation was with respect to 1ton of cement proceed) per kg of cement produced [10,24,35,[48][49][50][51][52]. Ozone formation, Human health and Ozone formation, Terrestrial ecosystem are as a result of 0.00145 kg NOx eq and 0.00147 respectively per kg of OPC.…”

Ecosystem metabolism framework, metrics and indicators towards sustainable society design and management

“…The increasing trend of GHG emission caused by change of the factor for final demand is the main source for the growth of the energy-related emission for most sectors. Hu et al (2015) select two typical cement enterprises with different production processes to investigate material and energy use as well as pollutant emissions. Metabolic processes are then compared and a use efficiency analysis for different procedural phases is conducted using material flow analysis.…”