Is carbon sequestration "good" for the environment?: an evaluation based on current technology and methods
Carbon capture and sequestration (CCS) is one of the important mitigation options for climate change. Numerous technologies to capture carbon dioxide (CO2) are in development but currently, capture using amines is the predominant technology. When the flue gas reacts with amines (Monoethanaloamine) the CO2 is absorbed into the solution and forms an intermediate product which then releases CO2 at higher temperature. The high temperature necessary to strip CO2 is provided by steam extracted from the powerplant thus reducing the net output of the powerplant by 25% to 35%. The reduction in electricity output for the same input of coal increases the emissions factor of Nitrogen Oxides, Mercury, Particulate matter, Ammonia, Volatile organic compounds for the same unit of electricity produced. The thesis questions if this tradeoff between CO2 and other emissions is beneficial or not. Three different methodologies, Life Cycle Assessment, Valuation models and cost benefit analysis are used to identify if there is a net benefit to the society on implementation of CCS to a Pulverized coal powerplant. These methodologies include the benefits due to reduction of CO2 and the disbenefits due to the increase of other emissions. The life cycle assessment using ecoindicator'99 methodology shows the CCS is not beneficial under Hierarchical and Egalitarian perspective. The valuation model shows that the inclusion of the other emissions reduces the benefit associated with CCS. For a lower CO2 price the valuation model shows that CCS is detrimental to the environment. The cost benefit analysis shows that a CO2 price of at least $80/tCO2 is required for the cost benefit ratio to be 1. The methodology integrates Montecarlo simulation to characterize the uncertainties associated with the valuation models.