scholarly journals Cutting Oxygen Production-Related Greenhouse Gas Emissions by Improved Compression Heat Management in a Cryogenic Air Separation Unit

2021 ◽  
Vol 18 (19) ◽  
pp. 10370
Author(s):  
Miroslav Variny ◽  
Dominika Jediná ◽  
Miroslav Rimár ◽  
Ján Kizek ◽  
Marianna Kšiňanová
Keyword(s):  
Power Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Ambient Air ◽  
Air Separation ◽  
Oxygen Production ◽  
Gas Emissions ◽  
Separation Unit ◽  
Air Separation Unit ◽  
Air Dryer

Oxygen production in cryogenic air separation units is related to a significant carbon footprint and its supply in the medicinal sphere became critical during the recent COVID-19 crisis. An improved unit design was proposed, utilizing a part of waste heat produced during air pre-cooling and intercooling via absorption coolers, to reduce power consumption. Variable ambient air humidity impact on compressed air dryers’ regeneration was also considered. A steady-state process simulation of a model 500 t h−1 inlet cryogenic air separation unit was performed in Aspen Plus® V11. Comparison of a model without and with absorption coolers yielded an achievable reduction in power consumption for air compression and air dryer regeneration by 6 to 9% (23 to 33 GWh year−1) and a favorable simple payback period of 4 to 10 years, both depending on air pressure loss in additional heat exchangers to be installed. The resulting specific oxygen production decrease amounted to EUR 2–4.2 t−1. Emissions of major gaseous pollutants from power production were both calculated by an in-house developed thermal power plant model and adopted from literature. A power consumption cut was translated into the following annual greenhouse gas emission reduction: CO2 16 to 30 kilotons, CO 0.3 to 2.3 tons, SOx 4.7 to 187 tons and NOx 11 to 56 tons, depending on applied fossil fuel-based emission factors. Considering a more renewable energy sources-containing energy mix, annual greenhouse gas emissions decreased by 50 to over 80%, varying for individual pollutants.

Performance of a Semi-Closed Oxy-Fuel Combustion Combined Cycle (SCOC-CC) With an Air Separation Unit (ASU)

2018 ◽  
Author(s):  
Majed Sammak ◽  
Marcus Thern ◽  
Magnus Genrup
Keyword(s):  
High Pressure ◽  
Power Consumption ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Air Separation ◽  
Separation Unit ◽  
Gross Efficiency ◽  
Pressure Oxygen ◽  
Air Separation Unit ◽  
High Pressure Oxygen

The objective of this paper is to evaluate the performance of a semi-closed oxy-fuel combustion combined cycle (SCOC-CC) and its power penalties. The power penalties are associated with CO2 compression and high-pressure oxygen production in the air separation unit (ASU). The paper discusses three different methods for high pressure oxygen (O2) production. Method 1 is producing O2 directly at high pressure by compressing the air before the air separation takes place. Method 2 is producing O2 at low pressure and then compressing the separated O2 to the desired pressure with a compressor. Method 3 is alike the second method, except that the separated liquid O2 is pressurized with a liquid oxygen pump to the desired pressure. The studied SCOC-CC is a dual-pressure level steam cycle due to its comparable efficiency with three pressure level steam cycle and less complexity. The SCOC-CC, ASU and CO2 compression train are modeled with the commercial heat and mass balance software IPSEpro. The paper analyzed the SCOC-CC performance at different combustion outlet temperatures and pressure ratios. The combustion outlet temperature (COT) varied from 1200 °C to 1550 °C and the pressure ratio varied from 25 to 45. The study is concerned with mid-sized SCOC-CC with a net power output 100 MW. The calculations were performed at the selected design point which was at 1400°C and pressure ratio at 37. The calculated power consumption of the O2 separation at a purity of 95 % was 719 kJ/kgO2. The power consumption for pressurizing the separated O2 (method 2) was 345 kJ/kgO2 whereas it was 4.4 kJ/kgO2 for pumping liquid O2 to the required pressure (method 3). The calculated power consumption for pressurizing and pumping the CO2-enriched stream was 323 kJ/kgCO2. The SCOC-CC gross efficiency was 57.6 %. The SCOC-CC net efficiency at method 2 for air separation was 46.7 %. The gross efficiency was reduced by 9 % due to ASU and other 2 % due to CO2 compression. The SCOC-CC net efficiency at method 3 of the air separation was 49.6 %. The ASU reduced the gross efficiency by 6 % and additional 2 % by CO2 compression. Using method 3 for air separation gave a 3 % gain in cycle efficiency.

scholarly journals Quantifying air quality co-benefits of climate policy across sectors and regions

2020 ◽  
Vol 163 (3) ◽  
pp. 1501-1517 ◽  
Author(s):  
Toon Vandyck ◽  
Kimon Keramidas ◽  
Stéphane Tchung-Ming ◽  
Matthias Weitzel ◽  
Rita Van Dingenen
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Climate Policy ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Gas Emissions ◽  
Health Related

AbstractThe overlap in sources of greenhouse gas and local air pollutant emissions creates scope for policy measures to limit global warming and improve air quality simultaneously. In a first step, we derive estimates for the air pollution mortality-related component of the social cost of atmospheric release for 6 pollutants and 56 regions in the world. Combining these estimates with emission inventory data highlights that sector contributions to greenhouse gas emissions and air pollution health impacts differ widely across regions. Next, simulations of future emission pathways consistent with the 2 °C and 1.5 °C targets illustrate that strengthening climate policy ambition raises the total value of air quality co-benefits despite lower marginal co-benefits per tonne of greenhouse gas emissions abated. Finally, we use results from a multi-model ensemble to quantify and compare the value of health-related ambient air quality co-benefits of climate policy across sectors and regions. On the global level, overall air quality co-benefits range from $8 to $40 per tonne of greenhouse gases abated in 2030, with median across models and scenarios of $18/tCO2e. These results mask strong differentiation across regions and sectors, with median co-benefits from mitigation in the residential and service sectors in India exceeding $500/tCO2e. By taking a sector- and region-specific perspective, the results presented here reveal promising channels to improve human health outcomes and to ratchet up greenhouse gas reduction efforts to bridge the gap between countries’ pledges and the global targets of the Paris Agreement.

Energetic, exergetic and economic assessment of oxygen production from two columns cryogenic air separation unit

Energy ◽  
2015 ◽  
Vol 90 ◽  
pp. 1298-1316 ◽  
Author(s):  
Armin Ebrahimi ◽  
Mousa Meratizaman ◽  
Hamed Akbarpour Reyhani ◽  
Omid Pourali ◽  
Majid Amidpour
Keyword(s):  
Economic Assessment ◽  
Air Separation ◽  
Oxygen Production ◽  
Separation Unit ◽  
Air Separation Unit

scholarly journals Integrating Energy Demand and Local Renewable Energy Sources in Smart Urban Development Zones: New Options for Climate-Friendly Resilient Urban Planning

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3672 ◽  
Author(s):  
Zach ◽  
Kretschmer ◽  
Stoeglehner
Keyword(s):  
Urban Development ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Ambient Air ◽  
Energy Sources ◽  
Gas Emissions ◽  
Fossil Energy ◽  
Heating And Cooling

In recent years, most cities have experienced rapid population growth. Concurrently, international policies have called for substantial reductions of greenhouse gas emissions. Additionally, the resilience of energy-supply systems has become more important. Consequently, solutions to exhaust locally-available sources must be developed to minimize the fraction of fossil fuels for heating, cooling and electricity. This article shows an example of designing a low-temperature heating and cooling grid based on locally-available renewables and waste heat and introduces general hypotheses concerning smart energy planning in urban development zones. Taking an urban development area in Vienna, Austria, as example, it is shown that wastewater, geothermal and (office) waste heat, solar energy, and the heat content of ambient air can play an important role within a climate-friendly urban energy concept and that heating and cooling demand can be covered completely on-site. From an environmental point of view, the concept is promising, as greenhouse gas emissions and the non-renewable primary energy consumption can be reduced by over 70% compared to conventional gas heating, while, based on current (fossil) energy prices, it is economically not fully competitive. The gap could be closed e.g. by CO2 taxes on fossil energy sources or (temporal) subsidies for renewables. Additionally, reservations of stakeholders in the energy sector against this innovative approach must be dismantled.

Optimization Strategy for Contradiction Between Intermitting Oxygen Consumption in Converter Steelmaking and Continuous Oxygen Production by Air Separation Unit

2019 ◽  
Author(s):  
Lige Tong ◽  
Yuxin Liu ◽  
Yang Hao ◽  
Shaowu Yin ◽  
Chuanping Liu ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Supply ◽  
Distillation Column ◽  
Air Separation ◽  
Converter Steelmaking ◽  
Pipe Network ◽  
Oxygen Production ◽  
Separation Unit ◽  
Air Separation Unit ◽  
Liquid Vapor

Abstract In order to solve the problem of overpressure release of oxygen supply network caused by the contradiction between continuous oxygen production by air separation unit (ASU) and intermitting oxygen consumption in converter steelmaking, a pressure balance strategy for pre-adjusting liquid-vapor ratio of ASU was proposed. Used Aspen Plus software, a full-compression model of an ASU in an iron and steel enterprise was established. Before stopping oxygen consumption in the converter steelmaking, method of pre-adjusting liquid-vapor ratio from the low-pressure distillation column to reduce the oxygen production of the air separation unit was calculated. This strategy consists of two steps. First step is pre-adjusting liquid-vapor ratio from the low-pressure distillation column to reduce the oxygen production of ASU, before stopping oxygen consumption in the converter steelmaking. The second step is the reduction of the supply oxygen production pipe network pressure, when stopping oxygen consumption in the converter steelmaking. The pre-adjusting oxygen production and the starting time are the key of the strategy. The energy consumption analysis of the strategy is carried out. The results show that the strategy reduces the pressure of the oxygen supply pipe network by 1.3% and reduces the large amount of oxygen release, while increase of the energy consumption of ASU is neglected.

Greenhouse Gas Emissions Due to Power Consumption of Household Whitegoods Appliances

2002 ◽  
Vol 13 (6) ◽  
pp. 833-850
Author(s):  
Caleb Stewart ◽  
Mir-Akbar Hessami
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Power Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Carbon Dioxide Emissions ◽  
Total Carbon ◽  
Gas Emissions ◽  
Household Appliances ◽  
Actual Energy Consumption

This paper presents information related to greenhouse gas emissions due to the power consumption of the following household appliances: refrigerators, clothes washers, clothes dryers, freezers, and dishwashers; a possible extension to this analysis would include heaters and air-conditioners. Actual energy consumption data for the period 1993 to 1999 were used to estimate the total carbon dioxide emissions for 1994 to 2009 incremented at 5 years; these data can also be used to estimate the energy consumption of these appliances for 2008–2012 with reference to 1990 for reasons of comparison under the Kyoto Protocol. The total carbon dioxide equivalent emissions for the above household appliances show a peak of 29.6 mega-tonnes CO2 around 1999 with a decreasing trend post 1999 to 27.4 mega-tonnes CO2 in 2009. Details of the analysis for selected appliances show that refrigerators account for over half of total emissions, decreasing from 60.1% in 1994 to 51.6% in 2009. The aggregate trend activity was found to highly depend on the trend activity for emissions for refrigerators. The trend activity for freezers, clothes dryers and clothes washers is increasing for consecutive years from 1994 to 2009 defying the trend exhibited by refrigerators and dishwashers. The reason for this discrepancy is the relatively higher decreases in kWh/annum for refrigerators and dishwashers in contrast to other appliances. The energy consumption curves for each appliance take this differential into account. The energy consumption curve for refrigerators predicts a much faster decrease in kWh/annum than for other appliances thus causing the downward trend post 1999.

Methodologies for Assessing the Use-Phase Power Consumption and Greenhouse Gas Emissions of Telecommunications Network Services

2012 ◽  
Vol 47 (1) ◽  
pp. 485-492 ◽  
Author(s):  
Chien A. Chan ◽  
André F. Gygax ◽  
Elaine Wong ◽  
Christopher A. Leckie ◽  
Ampalavanapillai Nirmalathas ◽  
...  
Keyword(s):  
Power Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Network Services ◽  
Gas Emissions ◽  
Telecommunications Network ◽  
Use Phase
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