Evaluation of a novel multibed heat-integrated vacuum and temperature swing adsorption post-combustion CO2 capture process

Abstract

A novel multibed heat-integrated vacuum and temperature swing adsorption process has been designed to capture 85% of the CO 2 emitted by an advanced supercritical coal fired power plant of 820 MW e taken as reference, and to produce a concentrated product with 95% of CO 2 using a microporous carbon obtained from olive stones. The overall performance of the postcombustion CO 2 capture process has been evaluated from the results of the dynamic simulation of the process at cyclic steady state, using a detailed non-isothermal nonequilibrium dynamic fixed-bed adsorption model that takes into consideration competitive adsorption between the main flue gas components: N 2 , CO 2 and H 2 O. The proposed process operates between 30 °C and 1.05 bar and 80 °C and 0.05 bar. The specific heat duty of the process, 2.41 MJ th kg -1 CO 2 , which is lower than the benchmark amine absorption technology, can be satisfied using waste heat. On the other hand, its electricity consumption, 1.15 MJ e kg -1 CO 2 , is higher. Increasing the pressure of the production step reduces significantly the energy demand of the process, but also its capture rate. Substantial improvements in performance can be expected from adsorbent development. Adsorption is an environmentally benign technology with great potential to mitigate CO 2 emissions from industrial processes with unused waste heat sources.

Development of carbon-based vacuum, temperature and concentration swing adsorption post-combustion CO2 capture processes

“…Water is used as the thermal fluid due to its low cost, lack of toxicity and its adequate properties in the temperature range of operation: 30-80 °C. Thin tubes with a diameter of 3 cm, a thin wall of 1 mm width, and a length of 0.7 m are considered to ensure fast thermal exchange and to facilitate comparison with previous results [14,23].…”

“…The latter are cooled using the reference power plant's cooling water, which is delivered at 20.78 °C and returned at 30.53 °C. These utilities' specifications have been set in agreement with previous studies [14,16,23] to facilitate technology comparison.…”

“…The process performance parameters of the VTCSA post-combustion CO 2 capture process that satisfies the purity and recovery constrains with the lowest specific energy demand are summarized in Table 3. Another three post-combustion CO 2 capture processes have been included in the table for comparison purposes: an advanced absorption case taken as the reference case within HiPercap project (CESAR1) [16], a TCSA process based on structured carbon monoliths [14], and a VTSA process that makes use of the same biomass-based carbon adsorbent [23]. These processes have been developed for the same reference power plant using the common set of assumptions described in Section 2.4.…”

Comparative Investigation of Different CO2 Capture Technologies for Coal to Ethylene Glycol Process

“…Howev little work has studied the effects of different CO2 capture technologies on the perfo mance of the CTEG process. Carbon dioxide is one of the greenhouse gases causing global warming, which contributes more than 60% of the enhanced greenhouse effect, thus reducing CO 2 emissions has become one of the top goals of the world [5]. In addition, after the water gas shift unit, the shifted syngas contains a large amount of CO 2 , which has a significantly negative impact on subsequent ethylene glycol synthesis and refining (EGSR) unit, for example, catalyst poisoning.…”

Evaluation of separation effect for CH4 enrichment from coalbed methane (CBM) under the synergistic action of temperature and pressure based on IAST theory

“…However, the presence of residual condensation water after the cooling step reduces the cyclic adsorption capacity, requiring an additional drying step with hot or cold air. For the postcombustion CO 2 capture, a novel multibed heat‐integrated vacuum and temperature swing adsorption (VTSA) process was proposed by Plaza and Rubiera, 41 and a biomass microporous carbon material obtained from direct oxidation of olive stones was used as adsorbent for separation of N 2 , CO 2 , and H 2 O in this process. Results proved that Increasing the pressure of the production step reduces significantly the energy demand of the process, but also its capture rate.…”