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Reduced Integration Optimization Model for Coupled Elevated-Pressure Air Separation Unit and Gas Turbine in Oxy-combustion and Gasification Power Plant

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Maojian Wang at The Hong Kong University of Science and Technology
Maojian Wang
Qinli Liu at Xi'an Jiaotong University
Qinli Liu
Yingzong Liang at GuangDong University of Technology
Yingzong Liang
David Hui at The Hong Kong University of Science and Technology
David Hui
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Abstract and Figures

For the promising and green oxy-combustion and gasification power plant, the most efficient and assessable approach for further improvements on the current situation with less investment turned to be process optimization and integration. In this work, the gap of systematic analysis of air separation unit (ASU) and gas turbine (GT) integrations in integrated gasification combined cycle (IGCC) power plant has been fulfilled in the elevated-pressure ASU operation conditions beyond discrete case studies. Based on the conventional rigorous mathematical simulation, a series of model reductions have been proposed and applied to increase the computational flexibility. To validate the reduced model, a base case is built and settled as the benchmark, which is consistent with the industrial experiences. Afterwards, based on the reduced model, the effects of air integration on the thermal performance of IGCC power plant have been explored under the conditions of various nitrogen injection levels. The individual influences of nitrogen injection level on IGCC plant efficiency have been explored as well. To achieve best IGCC performance, the optimization of coupled air integration and nitrogen injection as a whole is completed. Based on the proposed reduced model, the three dimensional figure about systematics analysis of integration optimization for IGCC power plant is generated for the first time. Based on its two-dimensional top view, the feasible regions are identified and optimal solution is generated through nonlinear programming problem solver based on enhanced generalized reduced gradient method.
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ORIGINAL RESEARCH PAPER
Reduced Integration Optimization Model for Coupled Elevated-Pressure
Air Separation Unit and Gas Turbine in Oxy-combustion and Gasification
Power Plant
Maojian Wang
1,2
&Qinli Liu
1
&Yingzong Liang
2
&Chi Wai Hui
2
&Guilian Liu
1
Received: 31 January 2018 /Revised: 22 June 2018 /Accepted: 19 July 2018 /Published online: 7 August 2018
#Springer Nature Singapore Pte Ltd. 2018
Abstract
For the promising and green oxy-combustion and gasification power plant, the most efficient and assessable approach for further
improvements on the current situation with less investment turned to be process optimization and integration. In this work, the
gap of systematic analysis of air separation unit (ASU) and gas turbine (GT) integrations in integrated gasification combined
cycle (IGCC) power plant has been fulfilled in the elevated-pressure ASU operation conditions beyond discrete case studies.
Based on the conventional rigorous mathematical simulation, a series of model reductions have been proposed and applied to
increase the computational flexibility. To validate the reduced model, a base case is built and settled as the benchmark, which is
consistent with the industrial experiences. Afterwards, based on the reduced model, the effects of air integration on the thermal
performance of IGCC power plant have been explored under the conditions of various nitrogen injection levels. The individual
influences of nitrogen injection level on IGCC plant efficiency have been explored as well. To achieve best IGCC performance,
the optimization of coupled air integration and nitrogen injection as a whole is completed. Based on the proposed reduced model,
the three dimensional figure about systematics analysis of integration optimization for IGCC power plant is generated for the first
time. Based on its two-dimensional top view, the feasible regions are identified and optimal solution is generated through
nonlinear programming problem solver based on enhanced generalized reduced gradient method.
Keywords Optimization .Reduced model .Integrated gasification combined cycle .Air separation unit
Introduction
With the progress of science and technology, electricity power
has become the cornerstone of global economic growth and
social development, which leads to its persistently increasing
demand and supply. For example, the electricity generation of
the whole world has been increased more than 30% from
18,358.1 to 24,097.7 TWh in the decasas from 2005 to 2015
(BP global company 2016). As one of the most potential power
generation technologies, integrated gasification combined cycle
(IGCC) power plant has been recognized as a rare existing op-
portunities to fulfill the requirements of energy dissipation and
waste production simultaneously. It’s almost perfect environ-
mental performance has been demonstrated in the last decade,
which mainly attributes to the implement of pre-combustion
cleaning other than common post-combustion cleaning in con-
ventional pulverized coal (PC) plant. However, this promising
and sustainable technology still requires improvements in terms
of process economics to become fully competitive in commer-
cial scale (Christou et al. 2008). The investigations has identified
the cost of electricity (CoE) as the greatest barrier for the global
acceptance of IGCC power plant.
To overcome this bottleneck, the decrements of corre-
sponding capital costs and operational costs are essential and
necessary. Unfortunately, to achieve lower capital cost
through applying advanced technology, market penetration
and economy of scale still needs plenty of efforts and re-
sources as a valuable but difficult long-term task. Therefore,
improving IGCC plant power efficiency and benefiting the
decrement of its operational cost have become only a
*Chi Wai Hui
kehui@ust.hk
*Guilian Liu
guilianliui@mail.xjtu.edu.cn
1
Xi’an Jiao Tong University, Xian Ning West Road No.28,
Xi’an 710049, China
2
Hong Kong University of Science and Technology, Clear Water Bay,
Kowloon, Hong Kong
Process Integration and Optimization for Sustainability (2019) 3:143–156
https://doi.org/10.1007/s41660-018-0060-3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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