1. Introduction - Firenze University Press

PROCEEDINGS OF ECOS 2012 - THE 25 TH INTERNATIONAL CONFERENCE ON
EFFICIENCY, COST, OPTIMIZATION, SIMULATION AND ENVIRONMENTAL IMPACT OF ENERGY SYSTEMS
JUNE 26-29, 2012, PERUGIA, ITALY
Analysis and Optimization of CO2 Capture in a
China’s Existing Coal-fired Power Plant
Gang Xu a , Yongping Yang b , Shoucheng Li c , Wenyi Liu d and Ying Wu e
a North China Electric Power University, Beijing, China, xg2008@ncepu.edu.cn
b North China Electric Power University, Beijing, China, yyp@ncepu.edu.cn
c North China Electric Power University, Beijing, China, lishoucheng6363@126.com
d North China Electric Power University, Beijing, China, lwy@ncepu.edu.cn
e North China Electric Power University, Beijing, China, 837469236@qq.com
Abstract:
In China, pulverized coal-fired power plants provide over 70% of the total electricity, on the other side, make
up nearly half of the total CO2 emission volume of the whole country. Thus, CO2 capture in these coal fired
power plants will be extremely important to the effort of CO2 reduction made worldwide. However, to retrofit
existing power plant for CO2 capture may encounter many constrains from the layout of original process and
the structure of existing equipments, causing a lot of special problems in process design and bringing deep
influence on system performance, which in turn requiring special considerations in system integration. In
view of these factors, this paper carried out the process simulation, characteristics analysis and system
integration of CO2 capture based on a typical China’s existing coal-fired power plant with supercritical
parameters. The paper analyzes main constrains encountered in retrofitting existing power plant with CO2
capture using monoethanolamine (MEA) solution and puts forward several special system integration
schemes for CO2 capture in an existing 600MW unit of China. The results revealed that, due to the
constrains of the layout of original process and the structure of existing equipments, efficiency penalty of
CO2 capture in a existing power plant will be even higher than a re-design new power plant by 3-5%-points.
However, through the special system integrations, the efficiency of such retrofitting existing power plant can
increase by 2-4%-points. The research of this paper may provide a feasible technology solution for
decarburization retrofits of existing power plants, and promote CCS technologies into application.
Keywords:
CO2 Capture, Existing Coal-fired Power Plant, Retrofit, Thermal Energy Integration.
1. Introduction
Increasing concentration of CO2 and other greenhouse gases (GHG) is the main reason behind
alarming environmental phenomena, such as global warming and sea level rising [1-2]. China, one
of the world’s largest producers of CO2 emissions, is responsible for approximately one fifth of
global CO2 emissions [3].
Different from many industrialized countries, China’s main primary energy is coal, which is a kind
of cheap but carbon-intensive energy resources. And in China, pulverized coal fired power plants,
whose total installed capacity is over 700GW, provide nearly 80% of the total electricity, however,
make up almost half of the total CO2 emission volume of the whole country [4]. Thus, the reduction
of CO2 emissions in the electricity supply sector of China, especially in these pulverized coal fired
power plants, will make a significant contribution to the country and even to the whole world.
Though suffering of high energy and cost penalty, CO2 capture and storage (CCS) is commonly
considered as a technically feasible method of making deep reductions in carbon dioxide emissions
from sources such as energy utilization systems, and attracted great attentions worldwide [5-11]. At
present, there are three basic technologies for capturing CO2 from energy systems: post-combustion
capture, oxy-fuel combustion capture, and pre-combustion capture. As for CO2 separation process,
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