Modified Regeneration Scheme for Energy Efficient Gas Dehydration

2021 ◽  
Author(s):  
Haseeb Ali ◽  
Saqib Sajjad
Keyword(s):  
Molecular Sieve ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Energy Savings ◽  
Waste Heat ◽  
Fuel Gas ◽  
Additional Advantage ◽  
Gas Processing ◽  
Gas Compression ◽  
Gas Consumption

Abstract Molecular Sieve Dehydration units are used for dehydration of natural gas prior to gas processing or transportation. A molecular sieve dehydration system consists of multiple adsorbers which remove water during adsorption cycle until they get saturated with water. Regeneration of a saturated adsorber is performed by passing a hot regeneration gas stream through the adsorber. The hot regeneration gas after passing though the adsorber is then cooled before sending to regeneration gas compression. If an aircooled exchanger is used to cool the hot regeneration gas, heat available in the hot spent regeneration gas ends up in the atmosphere. In this context, an in-house study was performed to examine techno-economic viability of waste heat recovery from the hot spent regeneration gas using a modified regeneration scheme at one of the gas processing sites. The modified scheme involves installation of a new waste heat recovery (WHR) exchanger to exchange the heat available in the hot regeneration gas with regeneration heater's inlet regeneration gas thereby reducing the fuel gas consumption in the regeneration heater as well as power consumption in regeneration gas cooler fans. The study comprised design and operation data collection and analysis followed by assessment of key challenges. The key challenges include performance of the heater in WHR case (i.e. lower fuel gas consumption), space availability for the new WHR exchanger and modifications in the existing system. A thermodynamic model was developed for running various operating scenarios and estimating the WHR potential, including heater's specific fuel gas consumption analysis at varying temperatures, to establish realistic fuel gas savings. Overall, the study has indicated significant energy savings with good financial indicators for the proposed regeneration scheme. It has also showed reduction of peak heat duty of heater & cooler, thus providing an additional advantage of reduced CAPEX for future projects.

Feasibility Study of a Supercritical Cycle as a Waste Heat Recovery System

2013 ◽  
Author(s):  
Antonio Agresta ◽  
Antonella Ingenito ◽  
Roberto Andriani ◽  
Fausto Gamma
Keyword(s):  
Power Systems ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Energy Savings ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Organic Fluids

Following the increasing interest of aero-naval industry to design and build systems that might provide fuel and energy savings, this study wants to point out the possibility to produce an increase in the power output from the prime mover propulsion systems of aircrafts. The complexity of using steam heat recovery systems, as well as the lower expected cycle efficiencies, temperature limitations, toxicity, material compatibilities, and/or costs of organic fluids in Rankine cycle power systems, precludes their consideration as a solution to power improvement for this application in turboprop engines. The power improvement system must also comply with the space constraints inherent with onboard power plants, as well as the interest to be economical with respect to the cost of the power recovery system compared to the fuel that can be saved per flight exercise. A waste heat recovery application of the CO2 supercritical cycle will culminate in the sizing of the major components.

scholarly journals Review on Energy Efficiency Progresses, Technologies and Strategies in the Ceramic Sector Focusing on Waste Heat Recovery

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6096
Author(s):  
Miguel Castro Oliveira ◽  
Muriel Iten ◽  
Pedro L. Cruz ◽  
Helena Monteiro
Keyword(s):  
Energy Efficiency ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Manufacturing Industry ◽  
Energy Savings ◽  
High Efficiency ◽  
Waste Heat ◽  
Hot Air ◽  
Plant Level

Thermal processes represent a considerable part of the total energy consumption in manufacturing industry, in sectors such as steel, aluminium, cement, ceramic and glass, among others. It can even be the predominant type of energy consumption in some sectors. High thermal energy processes are mostly associated to high thermal losses, (commonly denominated as waste heat), reinforcing the need for waste heat recovery (WHR) strategies. WHR has therefore been identified as a relevant solution to increase energy efficiency in industrial thermal applications, namely in energy intensive consumers. The ceramic sector is a clear example within the manufacturing industry mainly due to the fuel consumption required for the following processes: firing, drying and spray drying. This paper reviews studies on energy efficiency improvement measures including WHR practices applied to the ceramic sector. This focuses on technologies and strategies which have significant potential to promote energy savings and carbon emissions reduction. The measures have been grouped into three main categories: (i) equipment level; (ii) plant level; and (iii) outer plant level. Some examples include: (i) high efficiency burners; (ii) hot air recycling from kilns to other processes and installation of heat exchangers; and (iii) installation of gas turbine for combined heat and power (CHP). It is observed that energy efficiency solutions allow savings up to 50–60% in the case of high efficiency burners; 15% energy savings for hot air recycling solutions and 30% in the when gas turbines are considered for CHP. Limitations to the implementation of some measures have been identified such as the high investment costs associated, for instance, with certain heat exchangers as well as the corrosive nature of certain available exhaust heat.

Waste Heat Recovery in LNG Liquefaction Plants

2015 ◽  
Author(s):  
P. Pillai ◽  
C. Meher-Homji ◽  
F. Meher-Homji
Keyword(s):  
Thermal Efficiency ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Combined Cycle ◽  
Capital Outlay ◽  
Fuel Gas ◽  
Lng Liquefaction ◽  
The Impact

High thermal efficiency of LNG liquefaction plants is of importance in order to minimize feed usage and to reduce CO2 emissions. The need for high efficiency becomes important in gas constrained situations where savings in fuel auto consumption of the plant for liquefaction chilling and power generation can be converted into LNG production and also from the standpoint of CO2 reduction. This paper will provide a comprehensive overview of waste heat recovery approaches in LNG Liquefaction facilities as a measure to boost thermal efficiency and reduce fuel auto-consumption. The paper will cover types of heating media, the need and use of heat for process applications, the use of hot oil, steam and water for process applications and direct recovery of waste heat. Cogeneration and combined cycle approaches for LNG liquefaction will also be presented along with thermal designs. Parametric studies and cycle studies relating to waste heat recovery from gas turbines used in LNG liquefaction plants will be provided. The economic viability of waste heat recovery and the extent to which heat integration is deployed will depend on the magnitude of the accrual of operating cost savings, and their ability to counteract the initial capital outlay. Savings can be in the form of reduced fuel gas costs and reduced carbon dioxide taxes. Ultimately the impact of these savings will depend on the owner’s measurement of the value of fuel gas; whether fuel usage is accounted for as lost feed or lost product. The negative impacts include the reduction in nitrogen rejection that occurs with reduced fuel gas usage and the power restrictions imposed on gas turbine drivers due to the increased exhaust system back-pressure caused by the presence of the WHRU. When steam systems are acceptable, a cogeneration type liquefaction facility can be attractive. In addition to steam generation and hot oil heating, newer concepts such as the use of ORCs or supercritical CO2 cycles will also be addressed.

A Novel Flue Gas Heat Recovery System Integrated With Air Preheating in a Utility Boiler

2013 ◽  
Author(s):  
Cheng Xu ◽  
Gang Xu ◽  
Luyao Zhou ◽  
Yongping Yang ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Energy Savings ◽  
Waste Heat ◽  
The Novel ◽  
Air Preheater ◽  
Recovery System ◽  
Condensed Water

Exhaust gas temperature in coal-fired power plants can reach approximately 120 °C to 140 °C, with the thermal energy accounting for approximately 3% to 8% of the total input energy. Therefore, the heat recovery of exhaust flue gas can improve the thermal efficiency of coal-fired power plants. Currently, the waste heat of flue gas can be recovered by installing an extra heat exchanger, also called low-temperature economizer (LTE), at the end of the boiler flue to heat a part of the condensed water. Extra work can then be obtained by saving the extracted steam and using it to heat the condensed water. However, the temperature of exhaust flue gas is only about 130 °C, which causes the flue gas to heat only the condensed water in the #7 and #8 regenerative heaters. Thus, the energy savings are inconspicuous. This paper proposes a novel flue gas heat recovery system to dramatically increase the temperature of flue gas in the LTE by comprehensive optimization of the air preheater and the LTE. A low-temperature (LT) air preheater can be installed after the LTE in the novel system so that the flue gas can be divided into two parts to heat the air. Simultaneously, the LTE can be installed between the two air preheaters, causing the temperature of flue gas in the LTE to reach above 170 °C. Hence, the temperature of condensed water in the LTE can be increased significantly. In addition, the LTE can replace the high-pressure extracted steam from the turbine, resulting in better energy savings. We also conduct case studies based on a typical 1,000 MW supercritical power generation unit in China. The results indicate better performance of the novel system, with a decrease in exergy loss and improvement in heat transfer characteristics. The reduction in standard coal equivalent of the novel system can reach 3.31g/kWh, nearly 2.4 times that of the system that uses conventional waste heat recovery. Our achievements provide a promising waste heat recovery methods of the utility boiler flue gas.

Simulation Analysis of Primary Energy Ratio for Air-Source Gas Engine-Driven Heat Pump

2014 ◽  
Vol 953-954 ◽  
pp. 692-697
Author(s):  
Xiao Feng Ren ◽  
Shu Xing Zhao ◽  
Zhi Chao Wang ◽  
Yi Tao Zhou ◽  
Ying Jie Zhang
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Simulation Analysis ◽  
Waste Heat ◽  
Primary Energy ◽  
Energy Ratio ◽  
Gas Engine ◽  
Gas Consumption

Based on the simulation of the air conditioning construction dynamic load and simulation calculation of air-source gas engine-driven heat pump (GEHP), the air-source GEHP air conditioning in winter, summer and the annual primary energy ratio are analyzed in simulation with the combination of a hotel building in Tianjin. Firstly, DeST software is used to simulate all-year hourly air conditioning load of the building. Then air-source GEHP simulation model [1] is used to calculate the annual hourly gas consumption and the amount of GEHP's gas consumption in winter, summer and a total year afterwards can be got. At the same time, by the analysis of waste heat recovery of gas engine-driven, primary energy ratio for air-source GEHP in Tianjin is given under the different waste heat recovery of winter, summer and the annual.

scholarly journals Waste Heat Recovery Technologies Revisited with Emphasis on New Solutions, including Heat Pipes, and Case Studies

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 384
Author(s):  
Paul Christodoulides ◽  
Rafaela Agathokleous ◽  
Lazaros Aresti ◽  
Soteris A. Kalogirou ◽  
Savvas A. Tassou ◽  
...  
Keyword(s):  
Case Studies ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Energy Savings ◽  
New Technologies ◽  
Waste Heat ◽  
Cost Savings ◽  
Energy Performance ◽  
The European Union ◽  
Target Energy

Industrial processes are characterized by energy losses, such as heat streams rejected to the environment in the form of exhaust gases or effluents occurring at different temperature levels. Hence, waste heat recovery (WHR) has been a challenge for industries, as it can lead to energy savings, higher energy efficiency, and sustainability. As a consequence, WHR methods and technologies have been used extensively in the European Union (EU) (and worldwide for that matter). The current paper revisits and reviews conventional WHR technologies, their use in all types of industry, and their limitations. Special attention is given to alternative “new” technologies, which are discussed for parameters such as projected energy and cost savings. Finally, an extended review of case studies regarding applications of WHR technologies is presented. The information presented here can also be used to determine target energy performance, as well as capital and installation costs, for increasing the attractiveness of WHR technologies, leading to the widespread adoption by industry.

Solution Proposal for Utilization of the Waste Heat in Refrigeration Systems

TEM Journal ◽  
2021 ◽  
pp. 177-182
Author(s):  
Halima Hadžiahmetović ◽  
Rejhana Blažević ◽  
Emina Peco
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Food Industry ◽  
Energy Savings ◽  
Waste Heat ◽  
Cost Savings ◽  
Primary Energy ◽  
Industrial Processes ◽  
Industrial Companies ◽  
Simplified Solution

The possibility for utilization of waste heat from processes in the food industry is presented in this paper. The need for reuse of waste heat comes from the fact that energy consumption in industrial companies is uneconomical and that environmental pollution has increased. Therefore, one of the method of reuse of waste heat that is applicable in industrial processes is presented in the paper. Potential primary energy savings is presented by implementing the waste heat recovery in the food factory. The paper presents a simplified solution proposal for installation of heat exchangers with the aim of utilizing the waste heat of the refrigerant. The results showed that by the implementation of simple heat recovery significant annual fuel energy savings can be achieved as well as fuel cost savings.

scholarly journals Heat Exchangers for Waste-Heat Recovery

1993 ◽  
Vol 4 (3) ◽  
pp. 284-306 ◽  
Author(s):  
O.M. Al-Rabghi ◽  
M. Akyurt ◽  
Y.S.H. Najjar ◽  
T. Alp
Keyword(s):  
Heat Exchangers ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Energy Savings ◽  
Waste Heat ◽  
Careful Selection

A survey is made of the equipment used for heat recovery and utilization. Types and merits of commonly employed heat exchangers are presented, and criteria for selecting heat exchangers are summarized. Applications for waste heat recovery are emphasized. It is concluded that careful selection and operation of such equipment would be expected to result in energy savings as well as problem-free operation.

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