In coal-based chemical looping combustion (CLC) technology, relatively cheap metal oxides, referred to as oxygen carrier materials (OCMs), are required because some of the OCMs will be removed together with the residual ashes after combustion. CLC technology will have an estimated loss in efficiency of around 2% compared to standard combustion technology without capture if a proper OCM is found that can give full combustion, removing the need of an air separation unit (ASU). Materials with a chemical looping oxygen uncoupling (CLOU) effect will even give further benefits in faster gasification and combustion of the fuel. One can already find produced materials that can give such a desirable effect, but fabrication and material cost are still an issue in these cases. If such a material can be delivered by the mining industry, cost savings and plant efficiency will be high. Before selection of the natural minerals with strong inert inherent support that contain Fe and Mn, the need for a better understanding of the Fe−Mn system is needed. This pre-study combined with other literature findings of the Fe−Mn system shows that a Mn content of up to 25−33% will increase the CLOU effect, increase the conversion of CH 4 , and give possibilities for full combustion in a CLC plant.

No abstract

This work focuses on the study of a pressure swing adsorption (PSA) process for biogas upgrading using a carbon molecular sieve adsorbent. Adsorption equilibrium and diffusion data of pure components were used to predict the multicomponent behavior. To validate the prediction of multicomponent adsorption at different concentrations, breakthrough curve experiments were performed for a gas mixture at different pressures (0.25, 0.5, 1, and 5 bar). Based on basic information, a model was used to predict the performance of a two-column PSA unit. The mixture used as feed was 60% CH 4 and 40% CO 2 with pressure swings between 5 bar in adsorption mode to 0.1 bar in blowdown. Experimental data demonstrated that the model could describe the PSA performance with good accuracy. We have evaluated the influence of different feed times in the biomethane recovery and purity. Biomethane purity higher than 97.5% with recovery higher than 90% was obtained.

No abstract

No abstract

Structured packings are important elements to enhance mass and heat transfer in the chemical industry. New techniques of manufacturing, like 3D printing, can create completely new families of solids used for this purpose. In this work the effect of different 3D printing techniques in the manufacture of packings with triply periodic minimal surfaces (TPMS) geometry was analyzed and the influence of different 3D printing techniques in the final properties of packings produced with TMPS topologies, both numerically and experimentally, were studied.

No abstract

Reactions of CaO, MgO, and decarbonated dolomite (CaOMgO) with CO 2 and added water have been studied with the goal of understanding fundamental issues related to these materials' performance as CO 2 sorbents. We used a fixed bed reactor, in situ XRD, and DRIFTS to monitor the extent and kinetics of carbonation, surface reactions, and performance loss during repetitive adsorption−desorption cycles at industrial relevant conditions. From reactor and in situ XRD experiments, we found that water is essential to reach high carbonation levels (solid conversion >40%) of CaO and CaOMgO, which is in contrast to a situation where only a small fraction (<10%) of the capacity is used. Water has a more pronounced effect when applying CaOMgO as sorbent as compared to CaO, both when considering solid conversions and carbonation rates. DRIFTS shows that water together with CO 2 do in fact react at the MgO surface into carbonates species. Furthermore, H 2 CO 3 may be important for exploiting CaO and CaOMgO materials because hydrogen carbonate is observed as a surface species only during reactions with water.