Natural Refrigerants

1998 ◽  
Vol 120 (10) ◽  
pp. 96-99 ◽  
Author(s):  
Yunho Hwang ◽  
Michael Ohadi ◽  
Reinhard Radermacher

This article explains that substances such as air, water, ammonia, hydrocarbons, and carbon dioxide may provide solutions to the problem of finding environmentally acceptable refrigerants. The search for new and environmentally benign refrigerants to replace the existing chlorofluorocarbons (CFC) and hydrochlorofluorocarbons (HCFC) has led to the introduction of hydrofluorocarbons (HFC). HFCs could be useful as short- and mid-term replacements, but may ultimately not be suitable, owing to their high global-warming potential (GWP). Natural refrigerants still have several technical and safety challenges to overcome, and each has its unique advantages and disadvantages. Refrigerant, carbon dioxide offers a clear advantage over CFCs and HCFCs from the environmental impact standpoint. In addition to its environmental advantages, carbon dioxide also offers certain attractive thermal characteristics that can help it provide substantial potential as a long-term replacement if energy efficiency challenges can be addressed.

Author(s):  
Sharmas Vali Shaik ◽  
TP Ashok Babu

This study focuses on energy performance investigation and environmental impact analysis of various new ecofriendly refrigerant blends as alternatives to high global warming potential refrigerant R22 theoretically. In this study, 23 refrigerants were considered at various composition. The present work considered the practical vapour compression refrigeration cycle for the performance assessment of various R22 alternatives. Essential studies such as toxicity, flammability, and total equivalent warming index of various novel refrigerants were also conducted in this study. Results obtained from practical vapour compression refrigeration cycle revealed that the energy efficiency ratio of refrigerants such as R1270 (2.860) and RB03 (R290/R152a of 60/40 in mass %) (2.854) was closer to the energy efficiency ratio of R22 (2.940). Volumetric refrigeration capacity (VRC) of R1270 (3293 kJ/m3) was similar to that of R22 (3297 kJ/m3) whereas VRC of RB03 (2908 kJ/m3) was almost similar to that of R407C (2925 kJ/m3) which was an alternative to R22. Compressor discharge temperature of RB03 was 15.78 ℃ lower when compared to R22. Flammability study revealed that all the new refrigerant blends (RB01 to RB04) were classified into weakly flammable (A2) and flammable (A3) category refrigerants whereas toxicity study revealed that all the investigated refrigerants were classified into non-toxic group (A). Refrigerant blend RB03 was less flammable compared to R1270. Total equivalent warming index analysis revealed that the environmental impact of R422A was 27.88% higher than R22 whereas RB03 has 4.97% lower environmental impact compared to R22. Overall, performance of refrigerant blend RB03 was better compared to 23 investigated refrigerants and it was very nearer to the performance of R22 and hence, it could be considered as an ecofriendly alternative to replace high global warming potential refrigerant R22 used in air conditioners.


2021 ◽  
pp. 68-71
Author(s):  
Igor M. Ageev ◽  
Yuri M. Rybin

The advantages and disadvantages of infrared and electrochemical gas analyzers for carbon dioxide CO2 are described. The possibility of using conductometric sensors with distilled water for monitoring the CO2 content in the air has been investigated. Two identical measuring systems were manufactured, each containing two open-type conductometric cells, a matching device and a personal computer. With the help of these complexes, experiments were carried out on the simultaneous measurement of the CO2 content in the air in two places (a laboratory room and a building in a forest, located at a distance of 15 km from each other) with deliberately different daily dynamics of the CO2 level change. A special experiment was carried out, which made it possible to obtain an estimate of the inertia of conductometric cells and a conversion factor for the values of CO2 content into standard units of measurement. It is shown that the daily dynamics of changes in the electrical conductivity of distilled water in open cells corresponds to the expected dynamics of changes in the CO2 content in the rooms where the measurements were carried out. The operability of the measuring complex and the possibility of creating on its basis a device for long-term monitoring of the CO2 content in the air mixture of gases has been confirmed. The principal high selectivity of the measuring complex to CO2 in relation to other gases of the atmosphere has been established.


Author(s):  
Rina Annisa ◽  
Benno Rahardyan

Geothermal potential in Indonesia estimate can produced renewable energy 29 GW, and until 2016 it still used 5% or about 1643 MW in. From that result, about 227 MW produced by Wayang Windu geothermal power plant. The Input were raw material, energy and water. These input produced electricity as main product, by product, and also other output that related to environment i.e. emission, solid waste and waste water. All environmental impacts should be controlled to comply with environmental standard, and even go beyond compliance and perform continual improvement.  This research will use Life Cycle Assessment method based on ISO 14040 and use cradle to gate concept with boundary from liquid steam production until electricity produced, and Megawatt Hours as the functional unit. Life Cycle Inventory has been done with direct input and output in the boundary and resulted that subsystem of Non Condensable Gas and condensate production have the largest environmental impact. LCI also show that every MWh electricity produced, it needed 6.87 Ton dry steam or 8.16 Ton liquid steam. Global Warming Potential (GWP) value is 0.155 Ton CO2eq./MWh, Acidification Potential (AP) 1.69 kg SO2eq./MWh, Eutrophication Potential (EP) 5.36 gPO4 eq./MWh and land use impacts 0.000024 PDF/m2. Life Cycle Impact Assessment resulted that AP contribute 78% of environmental impact and 98% resulted from H2S Non Condensable Gas. Comparison results with another dry steam geothermal power plant show that impact potential result of the company in good position and there’s a strong relation between gross production, GWP and AP value.Keywords: Life cycle assessment; Geothermal; Continual Improvement; Global Warming Potential; Acidification Potential


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 80 ◽  
Author(s):  
Ricardo Ramírez-Villegas ◽  
Ola Eriksson ◽  
Thomas Olofsson

The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe’s population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.


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