Energy use and CO 2 emissions in Mexico's iron and steel industry

Recent trends in Mexican industrial energy use and their impact on carbon dioxide emissions

Using logarithmic mean Divisia index to analyze changes in energy use and carbon dioxide emissions in Mexico's iron and steel industry

Primary aluminium production is energy- and GHG-intensive in which electrolysis is by far the most energy- and GHG-intensive process. This paper’s aim is to study the effects on (1) primary energy use, (2) GHG emissions and (3) energy and CO2 costs when energy end-use efficiency measures are implemented in the electrolysis. Significant savings in final and primary energy use, GHG emissions and energy and CO2 costs can be achieved by implementing the studied measures. Vertical electrode cells and the combination of inert anodes and wettable cathodes are among the measures with the highest savings in all three areas (primary energy use, GHG emissions and energy and CO2 costs). Direct carbothermic reduction is one of the measures with the highest savings in primary energy use and energy and CO2 costs. For GHG emissions, direct carbothermic reduction is the more beneficial choice in regions with a high proportion of coal power, while inert anodes are the more beneficial choice in regions with a high proportion of low-carbon electricity. Although a company potentially can save more money by implementing the direct carbothermic reduction, the company should consider implementing the vertical electrode cells together with other energy-saving technologies since this would yield the largest GHG emission savings while providing similar cost savings as the direct carbothermic reduction. It may be necessary to impose a price on GHG emissions in order to make inert anodes cost-effective on their own, although further evaluations are needed in this regard. There is a potential to achieve carbon-neutrality in the reduction of aluminium oxide to pure aluminium.

Housing sector is one of the important greenhouse gases (GHGs) emissions which result global warming. In order to trace the energy use before and after primary energy factor of electricity adjustment, this paper analyzed the primary energy factor of electricity of the end user in Taiwan from 1982 to 2009 first. Then the compositions of the primary energy use and emissions in Taiwan housing sector were analyzed. The share of electricity use in total energy use of the housing sector was 64.2% at 2009 before primary energy factor of electricity adjustment. By using primary energy factor of the electricity demand of the year as adjustment, the share of the primary energy use of the electricity increased as 84.4%. Results of the research also showed that the annual log growth rate of the primary energy use induced by electricity use was 6.45% in Taiwan housing sector from 1982 to 2009. The total primary energy use of the housing sector in 2009 was about 5.7 times of which in 1982. Respect to emission factor of the housing sector, the research showed that the annual log growth rate of GHG Emissions of the housing sector was 7.81% from 1982 to 2009. The total GHG Emissions of the housing sector in 2009 was about 8.25 times of which in 1982. The shares of emissions from electricity in housing sector were 59.6% in 1982, and 86.6% in 2009. These results showed that the use of electricity was one of the major sources of the housing emissions growth this period.

Primary aluminium production is a highly energy-intensive and greenhouse gas (GHG)-emitting process responsible for about 1 % of global GHG emissions. In 2009, the two most energy-intensive processes in primary aluminium production, alumina refining and aluminium smelting consumed 3.1 EJ, of which 2 EJ was electricity for aluminium smelting, about 8 % of the electricity use in the global industrial sector. The demand for aluminium is expected to increase significantly over the next decades, continuing the upward trend in energy use and GHGs. The wide implementation of energy efficiency measures can cut down GHG emissions and assist in the transition towards a more sustainable primary aluminium industry. In this study, 22 currently available energy efficiency measures are assessed, and cost-supply curves are constructed to determine the technical and the cost-effective energy and GHG savings potentials. The implementation of all measures was estimated to reduce the 2050 primary energy use by 31 % in alumina refining and by 9 % in primary aluminium production (excluding alumina refining) when compared to a “frozen efficiency” scenario. When compared to a “business-as-usual” (BAU) scenario, the identified energy savings potentials are lower, 12 and 0.9 % for alumina refining and primary aluminium production (excluding alumina refining), respectively. Currently available technologies have the potential to significantly reduce the energy use for alumina refining while in the case of aluminium smelting, if no new technologies become available in the future, the energy and GHG savings potentials will be limited.

Gas‐based metalworking fluids (MWFs) have been proposed as alternative coolants and lubricants in machining operations to mitigate concerns surrounding water use and pollution, industrial hygiene, occupational health, and performance limitations associated with water‐based (aqueous) MWFs that are ubiquitously used in the metals manufacturing industry. This study compares the primary energy and water use associated with the consumptive use, delivery, and disposal of aqueous MWFs with three gas‐based MWFs in the literature—minimum quantity lubricant‐in‐compressed air (MQL), liquid/gaseous N, and liquid/supercritical CO. The comparison accounts for reported differences in machining performance in peer‐reviewed experimental studies across several machining processes and materials. The analysis shows that despite the reported improvement in tool life with N and CO‐based MWFs, the electricity‐ and water‐intensive separation and purification processes for N and CO lead to their higher primary energy and water use per volume of material machined relative to water‐based MWFs. Although MQL is found to have lower primary energy use, significant consumptive water use associated with the vegetable oil commonly used with this MWF leads to higher overall water use than aqueous MWF, which is operated in a recirculative system. Gas‐based MWFs thus shift the water use upstream of the manufacturing plant. Primary energy and water use of gas‐based MWFs could be reduced by focusing on achieving higher material removal rates and throughput compared to aqueous MWF instead of solely targeting improvements in tool life. Additionally, the consumptive use of CO and N MWFs could be minimized by optimizing their flow rates and delivery to precisely meet the cooling and lubrication needs of specific machining processes instead of flooding the tool and workpiece with these gases. This article met the requirements for a gold–gold JIE data openness badge described at .

The main objective of the research is to analyze the impact of financial sector development indicators and financial institutions access on primary energy use based on a sample of European Union transition members over 20 years period (1996–2017) through panel cointegration and causality tests that allow for cross-section dependence. The causality analysis revealed that the direction of the causality among financial development indicators, financial institutions access, and primary energy use varied among the countries. On the other side, panel cointegration coefficients disclosed that the financial development index positively affected the primary energy use, but private credit did not have a significant effect on the primary energy use. Furthermore, financial institutions’ access had a significant negative impact on primary energy use. However, country-level cointegration coefficients indicated that the financial development index positively affected the primary energy use in Bulgaria, Croatia, Czechia, Hungary, and Slovenia, and private credit also had a positive impact on primary energy use in Bulgaria, Czechia, Estonia, Hungary, Lithuania, Poland, and Slovakia, but the effect of financial development index on primary energy use was found to be very higher than that of private credit. Moreover, financial institutions’ access negatively affected the primary energy use in Croatia, Estonia, Hungary, Poland, and Romania.

Effect of Energy Efficiency Requirements for Residential Buildings in Sweden on Lifecycle Primary Energy Use

In recent years, several comparative life cycle analyses have shown that increasing the use of wood in buildings can reduce the life cycle primary energy use and carbon emission of buildings. This study reviews the life cycle inventory methodology of primary energy use and carbon emissions, based on ecoinvent database, considering different modelling choices for (i) materials heating values; (ii) biogenic carbon; (iii) calcination and carbonation processes; (iv) electricity production scenarios; (v) impact distribution of multi-functional processes; (vi) post-use benefits. The analysis relates to the standards while the implication of different modelling choice is shown by comparing the primary energy use and carbon emission in the production and end-of-life stages of a multi-storey residential building with concrete, cross laminated timber and modular timber structures, respectively. The results highlight the displacement between different modelling choices in terms of primary energy use and carbon emissions. Such modelling options especially influence the LCA results in the product stage and beyond the end of life stage, and especially wood- and/or cement-based materials.

A system perspective on the heating of detached houses

Primary energy use in buildings in a Swedish perspective

Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building

Life cycle primary energy analysis of residential buildings

Low temperature (<25 °C) Aquifer Thermal Energy Storage (ATES) systems have a world-wide potential to provide low-carbon space heating and cooling for buildings by using heat pumps combined with the seasonal subsurface storage and recovery of heated and cooled groundwater. ATES systems increasingly utilize aquifer space, decreasing the overall primary energy use for heating and cooling for an urban area. However, subsurface interaction may negatively affect the energy performance of individual buildings with existing ATES systems. In this study, it is investigated how aquifer utilization levels, obtained by varying well placement policies, affect subsurface interaction between ATES systems and how this in turn affects individual primary energy use. To this end, a building climate installation model is developed and integrated with a MODFLOW-MT3DMS thermal groundwater model. For the spatial distribution and thermal requirements of 26 unique buildings as present in the city centre of Utrecht, the placement of ATES wells is varied using an agent-based modelling approach applying dense and spacious placement restrictions. Within these simulations ATES adoption order and well placement location is randomized. Well placement density is varied for 9 scenarios by changing the distance between wells of the same and the opposite type. The results of this study show that the applied dense well placement policies lead to a 30% increase of ATES adoption and hence overall GHG emission reduction improved with maximum 60% compared to conventional heating and cooling. The primary energy use of individual ATES systems is affected at varying well placement policies by two mechanisms. Firstly, at denser well placement, ATES systems are able to place more wells, which increases the capacity of their ATES system, thereby decreasing their electricity and gas use. Secondly, aquifer utilization increases with denser well placement policies and thus interaction between individual ATES increases. At subsurface utilization up to 80%, individual primary energy use does not change significantly due to subsurface interaction. At aquifer utilization level > 80%, both negative and positive interaction is observed. Negative interaction between wells of the opposite type leads to an increase of gas or electricity use up to 15% compared to spacious well placement. On the other side, buildings may experience a maximum decrease of 15% electricity use at dense well placement due to positive interaction between wells of the same type. Local conditions like building location, plot size, distance to other buildings and heating/cooling demand determine the specific effect per building. The optimal well placement policy result from the aquifer utilisation levels discussed above. Maximum GHG emission reduction while maintaining individual ATES system performance, is achieved with well distances of 0.5–1 times the yearly average thermal radius for wells of the same type (cold-cold and warm-warm). Opposite well types (cold-warm) should be placed apart ∼2 times the thermal radius to prevent negative subsurface interaction.

Sectoral trends in global energy use and greenhouse gas emissions