Thermo-economic comparative analysis of solar-assisted and carbon capture integrated conventional cogeneration plant of power and process steam

A thermo-economic comparative analysis of steam production using a solar-assisted cogeneration (SACG) and a conventional cogeneration plant (CCG) with and without carbon capture systems has been conducted. The plants considered to produce electricity and process steam of 500 ton/h. Several parametric studies were carried out on the effect of natural gas price, steam quality, gas turbine capacity and solar multiples (SMs) on the Levelized cost of steam (LCS). Results show that in a CCG plant that comprises a 20 MWe gas turbine, the LCS is $8.11/ton of steam and $3.61/ton of steam from a plant with 100 MWe gas turbine capacity for a natural gas price of $3/GJ. The cost analysis of SACG plant with SM of 0.1 shows that 28% of the total annualized costs are solar system related while it contributed only about 9.17% of the annual steam generation. An increase in SM from 0.1 to 0.9 increases the CO₂ avoidance from 61 to 262 ktons/annum for the SACG plant with 20 MWe gas turbine. CCG plants with CO₂ capture technologies were found to have lower LCS in comparison with that of SACG plant. The impact of carbon credit implementation on the LCS has been also investigated and reported in this article.