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Uses of Cogeneration
Published in Bernard F. Kolanowski, Small-scale Cogeneration Handbook, 2021
Often, it may be just as practical to use the cogenerator’s hot-water system as a means to preheat the boiler feed water that is pumped into the boiler to make steam. A Btu is defined as the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit. A boiler that produces 10,000 pounds per hour of steam usually raises the temperature of the incoming water to the boiling point and then adds additional heat for the steam pressure desired. Steam systems can be either once through, meaning the steam is released to atmosphere and lost; or as a return system where most, if not all, of the steam is returned to the boiler as condensate. In those cases, the temperature of the condensate is anywhere from 140°F To 180°F and must be raised to the boiling point and beyond. If the temperature can be raised 30 to 40 degrees by cogeneration, that is less fuel required by the boiler to produce steam. Therefore, a 10,000-pound-per-hour boiler will use 400,000 Btu of energy just to raise the condensate from 150 to 190 degrees Fahrenheit. A cogenerator producing 100 kW of electricity can also produce that 400,000 Btu of thermal energy as well.
Energy Basics/Foundation for Understanding
Published in Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo, Energy Conservation Guidebook, 2020
Dale R. Patrick, Stephen W. Fardo, Ray E. Richardson, Brian W. Fardo
Two measures of heat are the calorie and the British thermal unit (Btu). A calorie is the amount of heat energy needed to raise the temperature of 1 gram of water by 1 degree on a Celsius (C) thermometer. This unit is usually quite small and generally used only in scientific measurements. A Btu is an indication of the amount of heat needed to raise the temperature of 1 pound of water by 1 degree on a Fahrenheit (F) thermometer. Applications of Btu measurements are commonly used in heating systems, air-conditioner ratings, and water heaters. As a measure of heat energy, 1 Btu is equivalent to 252 calories.
Stand-Alone Photovoltaic Systems
Published in Roger Messenger, Homayoon “Amir” Abtahi, Photovoltaic Systems Engineering, 2017
Roger Messenger, Homayoon “Amir” Abtahi
Since it takes 1 BTU to raise the temperature of 1 lb of water by 1°F, and since 1 kWh is equivalent to 3413 BTU, one need simply convert the excess kWh to BTU. For example, in April, the excess 15.6 kWh will generate 53,243 BTU. With a cold water temperature of 55°F, heating a gallon of water to a temperature of 180°F will require 8.35 × 125 = 1044 BTU, since a gallon of water weighs 8.35 lb. Hence, the leftover 53,243 BTU is enough to heat 51 gallons of water to 180°F. Of course, if any heat is lost from the pot, then not all the available BTU will go into heating the coffee water, but even at 80% efficiency, 40.8 gallons of coffee should be enough to keep everyone happy, since this would be almost a gallon per day per person if four people stay 3 days/week.
A roadmap to ammonia economy: The case of Qatar
Published in Energy Sources, Part B: Economics, Planning, and Policy, 2023
Mohammed Al-Breiki, Yusuf Bicer
As part of green NH3 production, H2 is produced by electrolyzing water, which is a well-known technique. In another step, an air separator is used to produce N2 directly from the air, making up 2–3% of the energy consumed. NH3 is generated using the Haber-Bosch process and renewable electricity. The primary green NH3 production’s hurdle to overcome is cost, of which electricity accounts for around 85% since the latter is still more expensive than natural gas in most regions of the world. The IEA estimates that an electrolysis process is comparable to an SMR process in terms of cost, with electricity prices ranging from $0.015–0.05 per kilowatt-hour (kWh) with a carbon capture unit and $0.01–0.04 per kWh without a carbon capture unit, assuming that gas prices are $3–10/Metric Million British Thermal Unit (MMBtu) (IEA 2019). In the last decade, electricity cost has declined significantly in locations with highly renewable energy potential. In places with optimum renewable energy conditions, such as Morocco, Chile, and Saudi Arabia, water electrolysis costs can already compete with steam methane costs, with auction costs of $0.045, $0.032, and $0.023 per kWh for utility-sized solar plants, respectively (IRENA 2017; Kruger, Eberhard, and Swartz 2018). The benefit of such low electricity prices also calls for the affordable mass transport of H2. NH3 can play a significant part in the energy supply chain’s transportation with its high technological readiness (Ash and Scarbrough 2019).
Energy efficiency improvements under conditions of low energy prices: the evidence from Russian regions
Published in Energy Sources, Part B: Economics, Planning, and Policy, 2022
Svetlana Ratner, Andrey Berezin, Bruno S. Sergi
EE indicators are used in modern literature and are calculated based on single-factor and total-factor methods (Zou, Lu, and Cheng 2019). The most commonly used in international statistics’ indicators is the energy-GDP ratio, also known in the literature as energy intensity (Elliott, Sun, and Zhu 2017; Sun et al. 2019). Its inverse is the ratio of GDP to the total energy consumed, which is known as EE. Most often, these indicators relate to the national economy. In order to establish correct comparisons of these indicators, the GDP is brought to the base year purchasing power parity (PPP) and the energy consumption is converted to the oil equivalent or British thermal unit (BTU). Sometimes “per capita energy use” is an indicator of the national economy’s EE, making international comparisons easier (Mishra and Smyth 2014). The effect of energy-saving measures is observable by decreasing energy intensity or vice versa, thereby increasing the economy’s EE.
A systematic review on bio-sequestration of carbon dioxide in bio-concrete systems: a future direction
Published in European Journal of Environmental and Civil Engineering, 2022
Abdullah Faisal Alshalif, J. M. Irwan, N. Othman, A. A. Al-Gheethi, S. Shamsudin
As observed, energy is the highest sector that releases CO2 emissions into the atmosphere. However, the transportation and industrial sectors are second and third in terms of the sources of CO2 emissions, respectively. Therefore, industries such as cement factories are considered one of the largest sources of air pollution (Nejat et al., 2015). Fossil fuel combustion and cement manufacturing are responsible for 88% of all anthropogenic CO2 emissions (Le Quere et al., 2009). The cement production process requires high energy with extreme heat, which releases intensive emissions (Jiang et al., 2016). Around 4.7 million British Thermal Unit (BTU) of energy is required to produce one ton of cement. Therefore, one ton of cement produces almost one ton of CO2 (Benhelal, Zahedi, Shamsaei, & Bahadori, 2013). For more illustration, in the cement factories, the CO2 is released in a direct way during the heating process of limestone and indirectly during the burning of fossil fuels to heat the kiln (Benhelal et al., 2013).