Factors Affecting the Profitability of Cement ManufacturingEnterprises in Tuyen Quang Province

This study focuses on analyzing the factors affecting the production and business efficiency of cement manufacturing enterprises in Tuyen Quang province. Production and business efficiency is measured by profitability ratios including return on assets (ROA), return on equity (ROE) and return on sales (ROS). Using a quantitative research method through estimating a linear regression model based on data of two cement manufacturing companies in the period 2019-2021, the research results show that the factors affecting business efficiency of cement manufacturing enterprises in Tuyen Quang province include size of enterprise, cost ratio, average collection period, inventory turnover, fixed assets turnover and debt ratio.

Spatial differences of exergy use of cement manufacturing industry in China based on extended exergy accounting method

Factory-level data from 23 provinces and some national statistical data in cement manufacturing industry and socio-economies in 2012 are used to analyze the spatial distribution of exergy use for China＇s cement manufacturing industry by the Extended Exergy Accounting method. This method takes full account of the inclusion of energy and raw material supply and other external factors （capital, labor and environment） into a comprehensive resource cost assessment. The extended exergy consumption and its intensity quantitatively at the provincial levels of cement production were calculated and then the agglomeration level of exergy use at the regional level was also evaluated. Based on this analysis, their spatial difference in size and efficiency of exergy use at the provincial level were identified. Moreover, their regional characteristics were revealed. Some important results could be drawn as follows. First, the invisible social cost accounted for 1/10 of the total exergy use in cement manufacturing industry, while the energy element shared about 9/10. Second, the gross distribution of exergy use in China＇s cement manufacturing industry was mainly concentrated in the eastern region like Anhui and Shandong provinces, and in the western region like Sichuan province. In terms of exergy use, the coal and electricity were the highest of energy costs in the eastern region, whereas the cost of capital, labor and external environmental factors highlighted the invisible social cost for cement production in the central and western regions to some extent. Third, the efficiency distribution of exergy use in China＇s cement manufacturing industry illustrated an incremental feature from west to east, especially for the energy, labor and capital efficiencies. An evaluation on the environmental efficiency indicated that provinces or regions like Tibet, Xinjiang, Inner Mongolia and Shanxi have undertaken much higher environmental costs. Fourth, the 23 provinces could be classified into eight groups by the Euclidean distance model using the gross and efficiency results of exergy use. Fifth, the high industry concentration degree is the main driving factor of exergy efficiency improvement for cement manufacturing industry in China.

High‑temperature thermal storage‑based cement manufacturing for decarbonization

Cost-effective CO_(2) capture is essential for decarbonized cement production since it is one of the largest CO_(2) emission sources,where 60%of direct emissions are from CaCO3 decomposition and 40%are from fuel combustion.This work presents a low-carbon cement manufacturing process by integrating it with renewable energy for electric heating and thermal storage to replace the burning of fossil fuels in the conventional calciner.The low-carbon renewable energy reduces the indirect CO_(2) emissions from electricity consumption.The high-temperature CO_(2) is employed as the heat transfer fluid between the energy storage system and the calciner.In the proposed basic manufacturing process,the CO_(2) from the CaCO3 decomposition can be directly collected without energy-consuming separation since no impurities are introduced.Furthermore,the remaining CO_(2) from fuel combustion in the kiln can be captured through monoethanolamine(MEA)absorption using waste heat.In the two situations,the overall CO_(2) emissions can be reduced by 69.7% and 83.1%,respectively,including the indirect emissions of electricity consumption.The economic performance of different energy storage materials is investigated for materials selection.The proposed manufacturing process with a few high-temperature energy storage materials(BaCO_(3)/BaO,SrCO_(3)/SrO,Si,etc.)offers a higher CO_(2) emission reduction and lower cost than alternative carbon capture routes,i.e.,oxyfuel.The cost of CO_(2) avoided as low as 39.27$/t can be achieved by thermochemical energy storage with BaCO_(3)/BaO at 1300℃,which is superior to all alternative technologies evaluated in recent studies.