Combining bioenergy and CO2 capture from gas fired power plant

The energy needed for amine based CO2 capture from a natural gas power plant can be provided in several ways, one possibility is to use steam from the low-pressure steam cycle at a reduction in the power plants efficiency. Alternatively an external energy plant dedicated to providing energy for the CO(2)capture can be built. The fuel used will be of interest since the CO2 in the flue gas from this plant should and probably must be captured. Natural gas, coal and biomass can be used as fuel in the energy plant. The use of biomass is interesting because of carbon neutrality. Capture is hence not necessary, and this gives flexibility to the CO2 capture plant. A concept combining a natural gas power plant and CO2 capture where the energy needed is provided by an external energy plant based on biomass is investigated. An assumed location in Porsgrunn, Norway is used as a basis. The concept is compared to alternative solutions through estimations of capital and operating cost. A condition that is put on the estimations of the operational cost is that for every tonne of CO2 released to the atmosphere, which is not bio based, a CO2 quota must be bought, and for every tonne of bio based CO2 captured the value of a CO2 quota is rewarded. The concept proposed is found to be the most expensive alternative with the initial specified conditions. A sensitivity analysis is performed where different scenarios for the following are varied, CO2 quota price, natural gas price and biomass price. Scenarios that include an increased CO2 quota price favor the proposed concept. (C) 2011 Published by Elsevier Ltd.