Recycling of carbon dioxide to produce ethanol

International audienceIn the coming years, a range of technological solutions aimed at reducing CO2 emissions should be developed. The objective of this paper is to study the technical feasibility of CO2 recycling into ethanol using solid oxide electrolysis cells (SOEC) technology, simulate the whole process using Aspen assessment and a carbon footprint. The results of the economic analysis demonstrated that the ethanol production plant can deliver ethanol at a cost of $1.1/kg, assuming an internal rate of return on investment of 8%. Main challenges for this process are improvement of ethanol synthesis reaction catalysts and the SOEC performance

Post Energy Audit of Two Mosques as a Case Study of Intermittent Occupancy Buildings: Toward more Sustainable Mosques

Mosques are buildings with a unique occupancy schedule and special energy and water consumption scheme. Generally, this type of buildings lacks the application of energy efficiency solutions and sustainable guidelines during the conception, construction and the operation phase. Interestingly, these iconic edifices can play a key role in raising awareness for sustainability and promoting cleaner energy technologies. The first aim of this work is to present energy audit results, recommended energy savings solutions for two historical mosques in Marrakech (Morocco). A detailed discussion of the adopted solutions is presented and an economic assessment was performed. Then, a two-year energy savings evaluation was conducted for the two mosques. Conclusions about the adequacy of the proposed solutions is presented. The second part is dedicated to outline some guidelines and sustainable criteria to consider for establishing an international sustainable mosques label. The creation of a such sustainable label will encourage spreading sustainable best practices in mosques and other types of buildings. It will also help to compare sustainable performances of different mosques around the world by establishing an adapted sustainable rating system

Adequacy of air-to-air heat recovery ventilation system applied in low energy buildings

International audienceDwellings represent more than 40% of final energy consumption in France. They also present the highest potential of energy savings, while using technology already substantiated, without huge investments, in contrast to other sectors. Ventilation is one of the main sources of heating loss in buildings, so recovering heat from exhaust air could reduce significantly heating loads. In airtight and well insulated buildings, heat recovery ventilation (HRV) systems are often recommended to save heat energy. However, these savings should be balanced against the electrical power requirements of the fans. A HRV unit is modeled, using TRNSYS, and studied in order to characterize its annual performance when integrated into residential and commercial low energy buildings. The energy performance of HRV is compared to one of the standard ventilation systems. This comparison is based on the heating, cooling and ventilation primary energy consumption for different climatic zones. It is found that the adequacy of using HRV system depends on the building types, the heating loads and ventilation device characteristics. A sensitivity analysis by simulation is undertaken to investigate the influence of exchanger efficiency and specific fan power on the global energy performance of the HRV system

Energy Consumption and Efficiency in Buildings: Current Status and Future Trends

International audienceThe building sector is considered as the biggest single contributor to world energy consumption and greenhouse gas emissions. Therefore, a good understanding of the nature and structure of energy use in buildings is crucial for establishing the adequate future energy and climate change policies. Availability of the updated data is becoming increasingly important in order to allow a rigorous analysis. In this paper, recent data on the world energy consumption in both residential and commercial buildings are reported. Past situation, current status and future trends are discussed and analyzed for selected countries. A breakdown of buildings energy consumption is realized in order to determine the influencing key parameters. A whole section of this paper is dedicated to give an overview of measures and policies adopted by different countries, allowing the monitoring, management and reduction of the energy consumption in buildings. Critical aspects of these policies are discussed based on the feedback of the early adopters