An Advanced Oxy-Fuel Power Cycle with High Efficiency

Abstract

In this article, an innovative oxy-fuel power cycle is proposed as a promising CO 2 emission mitigation solution. It includes two cases with different characteristics in the cycle configuration. Case 1 basically consists of a water steam Rankine cycle and a steam-CO 2 recuperative-reheat cycle. Case 2 integrates some characteristics of Case 1 and a top Brayton cycle. The thermodynamic performances for the design conditions of these two cases were analysed using the advanced process simulator Aspen Plus and the results are given in detail. The corresponding exergy loss analyses were carried out to gain an understanding of the loss distribution. The MATIANT cycle, the CES cycle, and the GRAZ cycle were also evaluated as references. The results demonstrate that the proposed cycle has notable advantages in thermal efficiency, specific work, and technical feasibility compared with the reference cycles. For example, the thermal efficiency of Case 2 is 6.58 percentage points higher than that of the MATIANT cycle.

Oxyfuel combustion for CO2 capture in power plants

“…The remaining flue gas can be further processed to storage conditions. Although the cycle efficiency is considered to be lower or at most similar to other concepts at comparable conditions (Bolland and Saether, 1992;Kvamsdal et al, 2007;Gou et al, 2006), the most demonstrations activities have been performed. Regarding the maturity of the cycle Kvamsdal et al (2006) conclude that despite technological development is necessary, no major breakthrough is required.…”

“…80-105 bar and 600-900 • C. The IP inlet temperature is in the range of 1200-1500 • C and the condenser pressure between 0.05 and 0.15 bar. This results in a net efficiency between 43 and 47% (Martinez-Frias et al, 2002;Gou et al, 2006;Kvamsdal et al, 2007;Haines et al, 2006). Hustad et al (2005) present a cycle configuration within the ZENG project that uses solely state of the art technology.…”

“…Marin et al (2003) show the efficiency gains of cycle options with strong integration of the waste nitrogen stream of the ASU and a second reheat combustor are around 3%-pts. Gou et al (2006) investigate two advanced cycle configurations where pure HP steam is generated and expanded before the internal combustion. These processes are similar to the MATIANT flow sheet but with water/steam as working fluid.…”

High-efficiency low LCOE combined cycles for sour gas oxy-combustion with CO2 capture

“…Sour gas is a type of natural gas that contains significant amounts of both hydrogen sulfide (H 2 S) and CO 2 , with typical compositions of each around 0-30% H 2 S and 0-80% CO 2 (by volume) [8]. 15 The objective of this study is to explore the use of sour gas directly as the fuel in an oxy-combustion power plant with CCS. However, sour gas combustion produces harmful compounds that can cause hot corrosion in turbines (due to SO x ) [9] and acid corrosion in the low temperature equipment (due to H 2 SO 4 ).…”

“…If H 2 O is used as the diluent, the Water cycle [12,13,14,15] is generally used to model this case. For the Graz cycle [12,16,17], both H 2 O and CO 2 are used as diluents.…”