scholarly journals Energy Minimization in Piperazine Promoted MDEA-Based CO2 Capture Process

2020 ◽  
Vol 12 (20) ◽  
pp. 8524
Author(s):  
Bilal Alam Khan ◽  
Asad Ullah ◽  
Muhammad Wajid Saleem ◽  
Abdullah Nawaz Khan ◽  
Muhammad Faiq ◽  
...  
Keyword(s):  
Cost Saving ◽  
Co2 Capture ◽  
Concentration Ratio ◽  
Large Scale ◽  
Energy Requirement ◽  
Base Case ◽  
Co2 Removal ◽  
Reference Case ◽  
Combined Process ◽  
Capture Process

A piperazine (PZ)-promoted methyldiethanolamine (MDEA) solution for a carbon dioxide (CO2) removal process from the flue gas of a large-scale coal power plant has been simulated. An Aspen Plus® was used to perform the simulation process. Initially, the effects of MDEA/PZ concentration ratio and stripper pressure on the regeneration energy of CO2 capture process were investigated. The MDEA/PZ concentration ratio of 35/15 wt.% (35 wt. MDEA and 15 wt.% PZ) was selected as an appropriate concentration. The reboiler duty of 3.235 MJ/kg CO2 was obtained at 35/15 wt.% concentration ratio of MDEA/PZ. It was considered a reference or base case, and process modifications including rich vapor compression (RVC) process, cold solvent split (CSS), and the combination of both processes were investigated to check its effect on the energy requirement. A total equivalent work of 0.7 MJe/kg CO2 in the RVC and a reboiler duty of 2.78 MJ/kg CO2 was achieved in the CSS process. Similarly, the total equivalent work, reboiler duty, and condenser duty of 0.627 MJe/kg CO2, 2.44 MJ/kg CO2, and 0.33 MJ/kg CO2, respectively, were obtained in the combined process. The reboiler duty and the total equivalent work were reduced by about 24.6 and 16.2%, respectively, as compared to the reference case. The total energy cost saving was 1.79 M$/yr. Considering the additional equipment cost in the combined process, the total cost saving was 0.67 M$ per year.

scholarly journals Improved process modifications of aqueous ammonia-based CO2 capture system

2019 ◽  
Vol 268 ◽  
pp. 02004 ◽  
Author(s):  
Christine Ann Obek ◽  
Foster Kofi Ayittey ◽  
Agus Saptoro
Keyword(s):  
Total Energy ◽  
Co2 Capture ◽  
Large Scale ◽  
Energy Savings ◽  
Aqueous Ammonia ◽  
Energy Requirement ◽  
Vapor Compression ◽  
Total Energy Consumption ◽  
Capture Process ◽  
High Volatility

Extensive research works on CO2 capture process using MEA have been carried out and showed promising results. Nevertheless, it has been acknowledged that the use of MEA is associated with high cost, solvent degradation issues and corrosion. The issues above have motivated researchers to explore and test other potential solvents such as aqueous ammonia (NH3). As result, NH3 based CO2 capture systems have recently attracted much attention as an alternative to MEA based counterparts. Despite their encouraging applications, high volatility of NH3 raise concerns on the energy requirement related to the solvent recovery. Consequently, energy efficient NH3 based CO2 capture systems by modifying the process is desirable. This study, therefore, aims to propose and evaluate three different stand-alone process configurations of absorption-desorption processes in a NH3-based system and compare them with the traditional absorption-desorption system in respect to total energy consumption. These modifications include Rich Solvent Split (RSS), Lean Vapor Compression (LVC), and Rich Vapor Compression (RVC). Results indicate that among these three proposed process modifications, LVC led to the highest reboiler energy savings of 38.3% and total energy savings of 34.5% compared to NH3 based conventional configuration. These findings can serve as essential recommendations for further studies on and large-scale implementations of aqueous NH3 as a better solvent.

scholarly journals Biocatalytic CO2 Absorption and Structural Studies of Carbonic Anhydrase under Industrially-Relevant Conditions

2020 ◽  
Vol 21 (8) ◽  
pp. 2918
Author(s):  
Aline M. de Castro ◽  
Elisabete Ferreira ◽  
Carla Portugal ◽  
Luisa A. Neves ◽  
João G. Crespo
Keyword(s):  
Carbonic Anhydrase ◽  
Co2 Capture ◽  
Large Scale ◽  
Rate Increase ◽  
Absorption Capacity ◽  
Co2 Absorption ◽  
Structural Studies ◽  
Kinetic Rate ◽  
Capture Process ◽  
Bovine Erythrocytes

The unprecedently high CO2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g−1) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.

Analysis of CO2 Capture From Power-Plant Flue Gas Using the Membrane Gas Absorption (MGA) Method

2015 ◽  
Author(s):  
Zhien Zhang ◽  
Yunfei Yan ◽  
Junlei Wang ◽  
Li Zhang ◽  
Yanrong Chen ◽  
...  
Keyword(s):  
Power Plant ◽  
Co2 Capture ◽  
Operating Conditions ◽  
Gas Absorption ◽  
Optimum Operating ◽  
Co2 Removal ◽  
Co2 Absorption ◽  
Capture Process ◽  
Gas Concentration ◽  
Liquid Concentration

Currently membrane gas absorption (MGA) is a novel approach for gas separation. In the present work, a wide-ranging 2D mathematical model for CO2 absorption from the N2/CO2 mixture is proposed. Single solvents [H2O, ethylenediamine (EDA), diethanolamine (DEA), monoethanolamine (MEA), piperazine (PZ)] and blended solvents [DEA/PZ] were used as the absorbents. The non-wetting mode for the membrane contactor was considered in the calculations. The effects of gas concentration and velocity, and liquid concentration and velocity on CO2 removal were observed. The simulation results were verified with the experimental data showing a good agreement. The modeling results indicate that gas concentration and velocity have a negative effect on the capture process, while liquid concentration and velocity enhance CO2 capture. Also, it is noted that PZ has the best absorption performance than other single absorbents. The chemical solvents are much better than the physical solvent for the absorption of CO2. For mixed absorbents based on amine solutions, the CO2 removal efficiency could be about 20% higher than that of the single solutions. Thus, this model could provide the optimum operating conditions for acid gas absorption in the hollow fiber membrane module. It is also proved that the MGA approach exhibits a good potential in power-plant waste gas purification.

Analysis of Flexible CO2 Capture Over an Investment Life Using a Dynamic Electric Grid Model

2010 ◽  
Author(s):  
John R. Fyffe ◽  
Stuart M. Cohen ◽  
Michael E. Webber ◽  
Gary T. Rochelle
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emissions ◽  
Co2 Capture ◽  
Energy Requirement ◽  
System Level ◽  
Co2 Removal ◽  
Electric Grid ◽  
Modeling Framework ◽  
Capital Costs ◽  
Co2 Capture Systems

Global focus on greenhouse gas emissions has led the United State’s legislature to discuss various strategies to reduce carbon dioxide (CO2) emissions. With coal-fired plants responsible for roughly half of United States (U.S.) electricity generation and approximately 30% of the nation’s CO2 emissions, coal-fired plants will be largely affected by any future CO2 emission regulations. However, coal-based generation could continue to meet our electricity demands while complying with future CO2 emissions restrictions with the addition of carbon dioxide capture and sequestration (CCS) technology. Most studies of CCS systems have demonstrated a permanent energy requirement of 11–40% of a plant’s output when operating continuously at a 90% CO2 removal rate. This study, however, used a dynamic model of the Electric Reliability Council of Texas (ERCOT) electric grid to consider post-combustion CO2 capture systems that can operate flexibly. Post-combustion CO2 capture systems using chemical absorption and stripping are particularly suited for retrofitting existing plants and operating in a flexible manner. Flexible carbon capture allows plant operators to vary the energy used for CO2 capture and compression in order to regain this generation capacity when desirable. Thus, flexibility can be used to choose the CO2 capture rate that allows the most economical combination of operating costs, electricity price, and output levels. Furthermore, operating at lower CO2 capture energy requirement levels and increasing output capacity during peak demand periods could dramatically reduce the amount of replacement capacity needed to replace potential output lost when CO2 capture systems are in operation. This research uses an existing modeling framework of a dynamic hourly dispatch system to study the economic, environmental, and performance implications of flexible CO2 capture over an investment lifetime. The effects of CO2 prices, natural gas fuel prices, and replacement capacity costs were analyzed along with various operating strategies. The fuel mixture behavior and emissions effects are presented, showing that large emissions reductions can be achieved using the current ERCOT plant fleet with the addition of flexible CO2 capture. An annual system-level cash-flow analysis is used to determine a net present value (NPV) for a group of CO2 capture plants under a range of possible replacement capacity costs. If replacement capacity costs are accounted for, flexibility can improve the NPV of a CO2 capture investment by substantially lowering the associated capital costs to replace output lost to CO2 capture energy requirements.

Advanced post combustion CO2 capture process – A systematic approach to minimize thermal energy requirement

2020 ◽  
pp. 116285
Author(s):  
Haider Sultan ◽  
Thai-Quyen Quach ◽  
Hafiz Ali Muhammad ◽  
Umair H. Bhatti ◽  
Young Duk Lee ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Co2 Capture ◽  
Systematic Approach ◽  
Energy Requirement ◽  
Capture Process

Shand Coal Fired Power Plant Integrating a Post Combustion CO2 Capture Process

2019 ◽  
Author(s):  
Wayuta Srisang ◽  
Teerawat Sanpasertparnich ◽  
Brent Jacobs ◽  
Stavroula Giannaris ◽  
Corwyn Bruce ◽  
...  
Keyword(s):  
Power Plant ◽  
Co2 Capture ◽  
Capture Process

scholarly journals Design of a Low-cost CO2 Capture Process Based on Heat Integration Technology

2014 ◽  
Vol 61 ◽  
pp. 365-368 ◽  
Author(s):  
Chunfeng Song ◽  
Yasuki Kansha ◽  
Masanori Ishizuka ◽  
Qian Fu ◽  
Atsushi Tsutsumi
Keyword(s):  
Co2 Capture ◽  
Low Cost ◽  
Heat Integration ◽  
Capture Process ◽  
Integration Technology

Assessing the risk of corrosion in amine-based CO2 capture process

2016 ◽  
Vol 43 ◽  
pp. 189-197 ◽  
Author(s):  
Alicja Krzemień ◽  
Angelika Więckol-Ryk ◽  
Adam Smoliński ◽  
Aleksandra Koteras ◽  
Lucyna Więcław-Solny
Keyword(s):  
Co2 Capture ◽  
Capture Process

Abstract MP019: Should Global Cardiovascular Risk Guide Treatment of Stage One Hypertension? A Cost-effectiveness Analysis

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Andrew Moran ◽  
Petra Rasmussen ◽  
Rachel Zhao ◽  
Pamela G Coxson ◽  
David Guzman ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Cost Effectiveness ◽  
Cost Saving ◽  
Risk Function ◽  
Annual Number ◽  
Base Case ◽  
Cvd Risk ◽  
Policy Model ◽  
Life Years ◽  
Stage 1

Introduction: Current U.S. hypertension guidelines base treatment on clinic blood pressure (BP) alone. International guidelines recommend adding global cardiovascular disease (CVD) risk to guide treatment. We projected incremental effectiveness and costs of treating stage 1 hypertension based on CVD risk assessment. Methods: We used the Coronary Heart Disease (CHD) Policy Model, a validated state-transition simulation of the CVD epidemic in the US, to model CHD and stroke events, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness (ICE) of increasingly aggressive treatment of hypertensive patients. Census and national survey data were used to estimate joint distributions of risk factors by age and sex; the CVD risk function was based on Framingham. We modeled treatment of BP to an approximate target <140/90 mmHg using standard dose medications, including averaged annual drug costs (e.g., $253 for a systolic BP reduction of 11.5 mmHg; $1,036 for reduction of 36.7 mmHg) and monitoring costs (2 or 4 visits/year for stage 1 or 2 plus 1 lab test/year for all). We compared a strategy in which only stage 2 hypertensives (≥160/≥100 mmHg) were treated to increasingly aggressive strategies in which stage 1 hypertensives (140-159/90-99 mmHg) with successively lower global CVD risk (15%, 10%, 5% risk, then all of stage 1) were also treated. Results: Reaching hypertension treatment targets with any policy simulated would prevent between 389,000 and 478,000 CVD events annually ( Table ). Treating all stage 2 and ≥15% CVD risk stage 1 hypertensives would be cost-saving and treating stage 1 with ≥10% or ≥5% CVD risk would incur modest costs. Treating all stage 1 would cost $161,000/QALY more than treating only ≥5% CVD risk. Conclusions: Treatment of low risk stage 1 hypertensives appears to come at high cost and limited added benefit unless treatment costs can be minimized. Using global CVD risk assessment might allow re-allocation of resources toward controlling hypertension in the highest risk patients. Table Simulated CVD outcomes, costs, and cost-effectiveness, 2010-2011, the CHD Policy Model Scenario Annual number hypertensives treated Annual CVD events Annual QALYs (millions) Annual costs (millions, $US) ICER * Base case, no intervention - 2,387,000 127.67 $827,313 reference Treat only stage 2 23,364,180 1,997,000 128.78 $825,264 cost saving Treat stage 2 + stage 1 >=15% CVD risk 30,654,361 1,943,000 128.93 $824,541 cost saving Treat stage 2 + stage 1 >=10% CVD risk 34,947,200 1,928,000 128.97 $824,898 $9,381 Treat stage 2 + stage 1 >= 5% CVD risk 44,321,985 1,913,000 129.02 $826,433 $28,931 Treat stage 2 + all stage 1 50,863,390 1,909,000 129.04 $828,290 $160,630 *ICER = difference in cost/difference in QALY in comparison with the next less effective strategy

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