Effect of energy renovation on indoor air quality in multifamily residential buildings in Slovakia

Buildings are responsible for a substantial portion of the global energy consumption. Most of the multifamily residential buildings built in the 20th century in Central and Eastern Europe do not satisfy the current requirements on energy efficiency. Nationwide measures taken to improve the energy efficiency of these buildings rarely consider their impact on the indoor air quality (IAQ). The objective of the present study was to evaluate the impact of simple energy renovation on IAQ air exchange rates (AER) and occupant satisfaction in Slovak residential buildings. Three pairs of identical naturally ventilated multifamily residential buildings were examined. One building in each pair was newly renovated, the other was in its original condition. Temperature, relative humidity (RH) and the concentration of carbon dioxide (CO2) were measured in 94 apartments (57%) during one week in the winter. A questionnaire related to perceived air quality, sick building syndrome symptoms and airing habits was filled by the occupants. In a companion experiment, the IAQ was investigated in 20 apartments (50%) of a single residential building before and after its renovation. In this experiment, concentrations of nitrogen dioxide (NO2), formaldehyde and total and individual volatile organic compounds (VOC) were also measured. CO2 concentrations were significantly higher and AERs were lower in the renovated buildings. Formaldehyde concentrations increased after renovation and were positively correlated with CO2 and RH. Energy renovation was associated with lower occupant satisfaction with IAQ. Energy retrofitting efforts should be complemented with improved ventilation in order to avoid adverse effects on IAQ

Towards Standardised Measurement of CO2 Transfer in the CCS chain

The global impact of anthropogenic greenhouse gas emissions on climate change is undeniable, with carbon dioxide (CO2) identified as the primary contributor to global warming. Urgent action is required to mitigate global warming by reducing anthropogenic CO2 emissions to achieve net-zero levels. Carbon Capture and Storage (CCS) stands as a proven technology to curtail CO2 emissions from various sources by capturing and sequestering carbon dioxide in geological formations. To address the challenge of deploying CCS on a global scale, it is crucial to accurately quantify the captured, transported, and stored CO2 since quantification underpins regulations and commercial contracts. However, the lack of standardization in CCS projects and measurement methodologies poses a significant challenge, necessitating a common measurement framework to ensure the transparency and reliability of these efforts. This article provides a comprehensive review, with 230 references, of the latest results and operating conditions for current measurement technologies covering the entire measuring system and not just a single instrument. As such, it is a first of its kind effort at establishing a comprehensive framework for CCS measurement. This article serves as a source of references and as a step toward developing an international documentary standard for the transferred CO2 measurement. By addressing measurement challenges and providing comprehensive recommendations for future research, it contributes to the ongoing efforts to mitigate global warming through the widespread deployment of CCS technology.Towards Standardised Measurement of CO2 Transfer in the CCS chainpublishedVersio

Detection of Contaminants in Hydrogen Fuel for Fuel Cell Electrical Vehicles with Sensors—Available Technology, Testing Protocols and Implementation Challenges

Europe’s low-carbon energy policy favors a greater use of fuel cells and technologies based on hydrogen used as a fuel. Hydrogen delivered at the hydrogen refueling station must be compliant with requirements stated in different standards. Currently, the quality control process is performed by offline analysis of the hydrogen fuel. It is, however, beneficial to continuously monitor at least some of the contaminants onsite using chemical sensors. For hydrogen quality control with regard to contaminants, high sensitivity, integration parameters, and low cost are the most important requirements. In this study, we have reviewed the existing sensor technologies to detect contaminants in hydrogen, then discussed the implementation of sensors at a hydrogen refueling stations, described the state-of-art in protocols to perform assessment of these sensor technologies, and, finally, identified the gaps and needs in these areas. It was clear that sensors are not yet commercially available for all gaseous contaminants mentioned in ISO14687:2019. The development of standardized testing protocols is required to go hand in hand with the development of chemical sensors for this application following a similar approach to the one undertaken for air sensors

Report A3.2.1: Literature survey on current state-of-the-art for the material compatibility of vessels for the sampling of CO2 for CCUS

This report was written as part of activity A3.2.1 from the Partnership on Metrology project Metrology for the support for Carbon Capture Utilisation and Storage (MetCCUS). The three-year European project started 1st October 2022. In the report, we have reviewed the current state of the art for the material compatibility of the vessels (including cylinders, bags and sorbent tubes) that are used to sample CO2. The choice of vessels depends on many parameters, including the pressure and temperature of the gas at the sampling point, safety aspects, requirements/ recommendations in standards, transport regulations and the suitability of the vessel. It is crucial to ensure that the sample provided to the laboratory is representative, which requires knowledge about the stability of the impurities in the carbon dioxide stored in sampling vessels. Risks of reaction inside the vessel or adsorption on the wall of the vessel must be avoided. Stability studies performed in adequate conditions (careful choice of the concentration, pressure for cylinders, possible interaction with other impurities) are often needed to ensure the suitability of any given vessel for a given impurity. The MetCCUS project will perform stability studies in bags in activity A3.2.3 and information on cylinder´s suitability will be obtained from the activities performed in task 3.1

Methods for Sampling Biogas and Biomethane on Adsorbent Tubes after Collection in Gas Bags

Biogas is a renewable energy source with many different production pathways and numerous excellent opportunities for use; for example, as vehicle fuel after upgrading (biomethane). Reliable analytical methodologies for assessing the quality of the gas are critical for ensuring that the gas can be used technically and safely. An essential part of any procedure aimed at determining the quality is the sampling and transfer to the laboratory. Sampling bags and sorbent tubes are widely used for collecting biogas. In this study, we have combined these two methods, i.e., sampling in a gas bag before subsequent sampling onto tubes in order to demonstrate that this alternative can help eliminate the disadvantages associated with the two methods whilst combining their advantages; with expected longer storage stability as well as easier sampling and transport. The results of the study show that two parameters need to be taken into account when transferring gas from a bag on to an adsorbent; the water content of the gas and the flow rate used during transfer of the gas on to the adsorbent

Need for a protocol for performance evaluation of the gas analyzers used in biomethane conformity assessment

Biomethane may contain trace components that can have adverse effects on gas vehicles performances and on the pipelines when injected in the gas grid. Biomethane quality assurance against specifications is therefore crucial for the integrity of the end-users’ appliances. Analytical methods used to assess biomethane conformity assessment must be validated properly and possibly, new methods specifically for biomethane should be developed. This paper provides an overview of the biomethane quality assurance infrastructure and the challenges faced with focus on sampling, analysis methods, reference gas mixtures, and performance evaluation. Currently, requirements for analytical method validation and fit-for-purpose assessments do not exist for biomethane. The industry is in urgent need of a protocol to evaluate the fit-for-purpose of methods in a harmonized manner. Reference gas mixtures to check the accuracy of the instrument and to determine the traceability of the measurement are also urgently required. The project has received funding from the European Partnership on Metrology, co-financed by European Union Horizon Europe Research and Innovation Program and from the Participating States.Funder name: European Partnership on Metrology, Funder ID: 10.13039/100019599, Grant number: 21NRM04 BiometCAP.</p

Ultrafine particles produced by ozone/limonene reactions in indoor air under low/closed ventilation conditions

Formation of ultrafine particles, dp<100 nm, from gas-phase reaction of limonene with O3 was studied. The concentration of reactants was chosen as close to realistic indoor conditions as possible. Two reaction chambers (1 and 14 m3) were used. Particle number concentrations were measured using a CPC and size distributions by using a scanning mobility particle sizer (SMPS) system. Rapid formation of new particles was observed at low concentrations of reactants and close to zero ventilation rates. The maximum number of particles was correlated with the initial rate of formation of reaction products. An excess of O3 tends to give higher maximum particle concentrations. Modeling work lead to the conclusion that significant nucleation starts when the mixing ratio of “product” from the reaction Limonene+O3→productox exceeds 0.5–1 ppb. The secondary particles formed by atmospheric chemistry in indoor air contribute to the total particulate matter indoors and should be considered in terms of low-dose long-term exposure