Calcium looping combustion for high-efficiency low-emission power generation

Abstract

High-temperature solid looping technologies, such as calcium looping and chemical looping combustion are regarded as emerging CO 2 capture technologies with potential to reduce the net efficiency penalties associated with CO 2 separation. Importantly, high-temperature operation of these technologies allows utilisation of the high-grade heat for power generation. Building on these emerging technologies, this study intended to establish a new class of high-temperature solid looping combustion technologies for high-efficiency low-emission power generation called calcium looping combustion. Such combustion technology comprises a combustor, as a primary source of heat for indirect heating in a calciner, and a carbonator where CO 2 is separated from flue gas leaving the combustor; hence high-grade heat, which can be used for power generation, and a concentrated CO 2 stream, which can be either utilised or permanently stored, are generated. The techno-economic performance of calcium looping combustion was comparable to a conventional coal-fired power plant. Depending on whether the concentrated CO 2 stream is utilised elsewhere or permanently stored, calcium looping combustion was characterised with a net efficiency gain of 0.7% HHV points or a net efficiency penalty of 2.4% HHV , respectively. Additionally, the cost of CO 2 avoided for calcium looping combustion was estimated to be 10.0 €/tCO 2 and 33.9 €/tCO 2 , respectively. Therefore, similarly to chemical looping combustion, calcium looping combustion introduced in this study is a viable high-efficiency low-emission power generation technology that produces a concentrated CO 2 stream with no efficiency penalty associated with CO 2 separation.

Scaling-up the Calcium-Looping Process for CO₂ Capture and Energy Storage

“…Alternatively, calcination could be carried out under partial vacuum (Beruto et al, 2004), which, however, raises the level of complexity to avoid air leakages. Another option is to provide the heat for calcination in an indirect way through a heat transfer wall or heat pipes (Hanak and Manovic, 2017b). This option would avoid the need of oxy-fuel combustion, which contributes to most of the energy consumption in the CaL process (Ortiz et al, 2017b).…”

“…High efficiencies were reached by integrating a supercritical steam Rankine cycle (Stein and Buck, 2017), which is currently commercially used in fossil-based plants with capacities higher than 400 MWe. Several process schemes have been proposed to analyze the potential of integrating a Rankine cycle into the carbonator (Hanak and Manovic, 2017b;Martínez et al, 2011;Ortiz et al, 2016a;Romano et al, 2012;Romano, 2013).…”

Carbon Capture and Storage: A Review of Mineral Storage of CO2 in Greece

“…The calcium looping process separates CO 2 using the reaction CaO + CO 2 → CaCO 3 and the regeneration of CaO using O 2 combustion. The key advantages of this technique are of interest: A large amount of high recoverable heat (600−900 • C); the possible increase in the power plant energy penalty (40−60%); no flue gas cooling and pretreatment (SOx); and finally, it has low emissions and an affordable price [20]. A review of the calcium looping technology and its progress has been presented by Bui et al [4].…”

Efficiency and Energy Analysis of Power Plants with Amine‐Impregnated Solid Sorbents CO2 Capture

“…To design the feasible integration between the power plant, the CO 2 capture system based on AISS and the CO 2 compression installation the following steps have been accomplished: (i) to quantify the heat streams involved in each case, (ii) to classify them into heat sources and heat sinks (as presented in Table 3); (iii) to calculate, according to pinch analysis methodology, the amount of heat that can be internally exchanged, as well as the hot and cold energy requirements that must be externally provided; (iv) to define the corresponding heat exchanger network (HEN), with a similar procedure published elsewhere; [23] (v) to define the amount of energy from the turbine bleeds to satisfy the hot energy requirements of the heat sinks; (vi) to implement the heat exchanger network in the model to calculate the new parameters of the plant; (vii) to define the new streams and to analyse the optimization possibilities; (viii) to restart the process from the beginning. The procedure is repeated until there is no variation between the mass flow results for the bleeds and the HEN is completely designed.…”

“…In high temperature solid sorbent CO 2 capture systems (Ca-looping or CLC), the energy integration plays a key role in the reduction of the penalty of the capture system. [22,23] In the case of AISS, low-grade heat may be recovered from the CO 2 intercoolers in the CO 2 compression train and from the outlet stream after regeneration. However, there is not a clear quantification of the effect of this kind of impregnated sorbents on efficiency penalty and specially, when a full energy integration process is applied.…”