M.G. Plaza

Co-gasification of different rank coals with biomass and petroleum coke in a high-pressure reactor for H2-rich gas production

Four coals of different rank were gasified, using a steam/oxygen mixture as gasifying agent, at atmospheric and elevated pressure in a fixed bed reactor fitted with a solids feeding system in continuous mode. Independently of coal rank, an increase in gasification pressure led to a decrease in H(2) + CO production and carbon conversion. Gasification of the different rank coals revealed that the higher the carbon content and reactivity, the greater the hydrogen production. Co-gasification experiments of binary (coal-biomass) and ternary blends (coal-petcoke-biomass) were conducted at high pressure to study possible synergetic effects. Interactions between the blend components were found to modify the gas production. An improvement in hydrogen production and cold gas efficiency was achieved when the coal was gasified with biomass.

Different Approaches for the Development of Low-Cost CO2 Adsorbents

Different carbon materials were tested as precursors for the production of C O2 adsorbents. The chemical modification of the surface of the prepared adsorbents was studied by means of three different approaches: impregnation with amines, electrophilic aromatic substitution, and heat treatment in the presence of ammonia. The samples were chemically characterized and the porous texture was evaluated from the N2 adsorption isotherms at −196°C . The C O2 adsorption capacities of the adsorbents at 25 and 100°C were evaluated in a thermogravimetric analyzer. In general, the incorporation of basic nitrogen functionalities enhanced the C O2 capture capacities of the modified carbons, but this increase depended on the textural properties of the support and the surface modification methodology. C O2 adsorption capacities of up to 111 mg C O2 ∕g at room temperature were attained. All the tested samples were completely regenerated when subjected to heat treatment at 100°C under inert atmosphere.

Gas-phase simulated moving bed: Propane/propylene separation on 13X zeolite

In the last years several studies were carried out in order to separate gas mixtures by SMB technology; however, this technology has never been implemented on an industrial scale. In the present work, a gas phase SMB bench unit was built and tested for the separation of propane and propylene mixtures, using 13X zeolite extrudates as adsorbent and isobutane as desorbent. Three experiments were performed to separate propane/propylene by gas phase SMB in the bench scale unit with a 4-2-2 configuration, i.e., open loop circuit by suppressing section IV (desorbent regeneration followed by a recycle). Consequently, all the experiments were conducted using an external supply of pure isobutane as desorbent. Parameters such as switching time, extract and raffinate stream flow rates were changed to improve the efficiency of the process. Experimental results have shown that it is feasible to separate propylene from propane by gas phase SMB at a bench scale and that this process is a potential candidate to replace the conventional technologies for the propane/propylene separation. The performance parameters obtained are very promising for future development of this technology, since propylene was obtained in the extract stream with a purity of 99.93%, a recovery of 99.51%, and a productivity of [Formula: see text] . Propane was obtained in the raffinate stream with a purity of 98.10%, a recovery of 99.73% and a productivity of [Formula: see text] . The success of the above mentioned bench scale tests is a big step for the future implementation of this technology in a larger scale.

Water Vapor Adsorption on Biomass Based Carbons under Post-Combustion CO2 Capture Conditions: Effect of Post-Treatment

The effect of post-treatment upon the H2O adsorption performance of biomass-based carbons was studied under post-combustion CO2 capture conditions. Oxygen surface functionalities were partially replaced through heat treatment, acid washing, and wet impregnation with amines. The surface chemistry of the final carbon is strongly affected by the type of post-treatment: acid treatment introduces a greater amount of oxygen whereas it is substantially reduced after thermal treatment. The porous texture of the carbons is also influenced by post-treatment: the wider pore volume is somewhat reduced, while narrow microporosity remains unaltered only after acid treatment. Despite heat treatment leading to a reduction in the number of oxygen surface groups, water vapor adsorption was enhanced in the higher pressure range. On the other hand acid treatment and wet impregnation with amines reduce the total water vapor uptake thus being more suitable for post-combustion CO2 capture applications.

Current status of CO2 capture from coal facilities

Abstract The energy and industrial sectors are dependent on coal, which is an intensive source of CO2 emissions. Carbon capture, use, and storage (CCUS) is the single option to abate coal-related CO2 emissions in a sustainable development scenario. The capture technology is ready: large-scale post-combustion CCUS demonstration projects are currently running on retrofitted coal-fired power plants, and several commercial-scale CCUS projects are running in the industrial sector worldwide. However, some challenges remain as the high penalty in power generation efficiency and the cost of the practice. Second-generation capture processes which are more efficient and environmentally benign continue to develop.