Percorrer por autor "Matos, Henrique A."
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- Analysis of integrated calcium looping alternatives in a cement plantPublication . Amorim, Ana; Filipe, Rui; Matos, Henrique A.Calcium looping is a promising post-combustion CO2 capturing technology, highly compatible with the cement industry, one of the major industrial sources of CO2 emissions. Limestone, a raw material for clinker, forms lime, a calcium looping adsorbent. Thus, it is possible to maximize the synergies between a cement plant and a calcium looping unit by establishing an integrated configuration. Nevertheless, the integration of calcium looping in cement plants has not yet been thoroughly studied. This study examines different integration alternatives, developing models for the preheater and calciner using Aspen Plus, validated with operational data, alongside an entrained-flow carbonator model considering adsorbent deactivation. By combining these models, six integrated configurations are proposed and compared with the tail-end calcium looping configuration. The integrated configurations show a reduction in fuel consumption and net energy consumption for the same CO2 avoided emissions. The most promising configuration was identified and a comparative techno-economic analysis was conducted.
- Decision-making based on sustainability analysis using GREENSCOPEPublication . Dias, Ricardo N.; Filipe, Rui; Matos, Henrique A.Current economic and environmental pressure encourages companies to invest and reform processes in a sustainable way. However, the decision on the best sustainable investment in a given industry may not be as straightforward as given by the independent economic and environmental indicators. Analyzing such indicators for investment in process alternatives is a complex multi-objective decision-making process. Many methods can help solve multi-objective problems, GREENSCOPE suggests using the Addictive Utility Method, which may have some shortcomings. In this work, the Analytic Hierarchy Process and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) are applied to the indicator scores obtained with the GREENSCOPE methodology. The Analytical Hierarchy Process is applied with Marginal Rate of Substitution, to obtain the priority matrices. MATLAB was used to apply the methods and through an algorithm, to determine the adequate number of indicators to be used. Three cases were studied, namely a biorefinery plant, and two academic case studies on the production of acetaldehyde from ethanol and propylene glycol from glycerol. The two academic cases were modeled in Aspen Plus, to obtain process data, and linked to GREENSCOPE using MATLAB. The methodology was applied to some proposed alternatives where the sustainability improvement of energy integration and material recycling was tested. The new methodology was able to identify the more sustainable case among the alternatives. This methodology based on TOPSIS proved to be the best choice, avoiding the weighting of indicators, and providing an expected analytical decision among alternatives.
- Fatty acid content in biomasses: state-of-the-art and novel physical property estimation methodsPublication . Sousa, Ana; Andrade, Thalles; Errico, Massimiliano; Coelho, Jose; Filipe, Rui; Matos, Henrique A.In line with the growing environmental awareness developed along the last decades, modern societies are urged to evolve into sustainable economics where the reuse of organic wastes represents the key feedstock for a green transaction. The oil phase obtained from different biomasses has the potential to be a source of food supplements, medicines, cosmetics, or feedstock for biofuel production. In the present work, the composition of 104 different biomasses including seeds, peels, flowers, plants, and leaves has been reviewed for the lipid content. Based on the most frequent fatty acids screened, experimental data for normal boiling point temperature, normal melting point, critical properties, and acentric factor were collected and compared with the most common estimation methods, which are functions of the molecular structure and interaction between different functional groups. New predictive equations have been proposed to reduce the estimation deviation and to provide simple correlations to be used in simulation software when dealing with biomass processes. For all the properties, the estimations proposed have an absolute average deviation equal to or lower than 4.6%.
- Modeling the deactivation of CaO-based sorbents during multiple Ca-looping cycles for CO2 post-combustion capturePublication . Abreu, Miguel; Teixeira, Paula; Filipe, Rui; Domingues, Luís; Pinheiro, Carla; Matos, Henrique A.A novel model is presented for the estimation of natural CaO-based sorbents carbonation reactivity decay during Calcium Looping carbonation-calcination cycles. The model consists of a cyclic framework of two sub-models, the Overlapping Grain Model and the novel proposed modified Rate Theory for the Pore Size Distribution model. The model was implemented in gPROMS ModelBuilder (R) and parameter estimation was used for model validation using experimental data from three CaO-based sorbent precursors. The carbonation profile for the three sorbents was simulated with average deviations under 5%. The calcination sub-model predicted the evolution of total porous volume and total surface area for the calcination and sintering of dolomite, with an error of 3%. The cyclic framework successfully predicted the carbonation behavior of dolomite for 20 carbonation-calcination cycles. The model can be used for other CaO-based sorbents and the flexible modular structure allows the integration of other modules or approaches.
- Multi-scale modelling and simulation of Ca-looping cycle process for CO2 post-combustion capturePublication . Pinheiro, Carla; Filipe, Rui; Torres, Miguel Abreu; Silva, João; Matos, Henrique A.The present work focuses on one of the more promising new post-combustion technologies using calcium-based materials, known as the “Ca-looping cycle” process, which endeavors to scrub CO2 from flue gases and syngases by using natural lime-based sorbents and which appears to potentially offer limited CO2 capture costs. So, the major driving force is to improve overall efficiency, reduce the cost, and minimize adverse environmental impacts of post-combustion Ca-looping cycle CO2 capture, as compared to more conventional technologies (e.g., amine-based solvent scrubbing). There is a large energy penalty with amine scrubbing, the closest to market technology. The main objective of this work is to develop a first principles model to simulate different natural sorbents looping cycle performance in a fixed bed reactor laboratory scale system. A rigorous non-linear dynamic model of the looping cycle process was developed in gPROMS, based on the multiscale concept. The multiscale modeling is an emerging technique, where the characteristic length for each phenomena that occurs is taken into consideration, leading to a set of submodels with different scale lengths. These submodels when coupled together allow the simulation of a macrosystem (Hangos and Cameron, 2001). After the identification of the characteristic dimensions involved in the models, the first step is the development of a single particle model, which takes into account the energy and material transport, undergoing reactions (carbonation and calcination) and structural changes inside the particle. The material and heat transport inside the particle take into account the structural changes. Detailed models of single particle undergoing cycles of calcination and carbonation are developed. An improved decay approach is introduced in the model for those sorbents exhibiting carbonation decay with the number of cycles. The experimental characterization of the samples gave vital information on the physicochemical changes occurring during testing that need to be described in the model in the carbonation decay function. The conversion decay does not only depend on the number of cycles, but also on the conditions of the previous cycles, temperature, pressure, gas phase composition and characteristics of the material used for the carbonation. Model parameters are estimated from experimental results obtained for different sorbents tested (Santos et al., 2012)(Pinheiro et al., 2016). Several simulations for different sorbents and operating conditions were performed and the model was validated with experimental data obtained in a fixed bed reactor. It was also important to ensure that the model is numerically stable within a large range of values.
- Optimization studies through simulation of a methanol/water/glycerol distillation columnPublication . Palmeira, José; Silva, João; Matos, Henrique A.This paper presents an optimization study of a distillation column for methanol and aqueous glycerol separation in a biodiesel production plant. Considering the available physical data of the column configuration, a steady state model was built for the column using Aspen-HYSYS as process simulator. Several sensitivity analysis were performed in order to better understand the relation between the variables of the distillation process. With the information obtained by the simulator, it is possible to define the best range for some operational variables that maintain composition of the desired product under specifications and choose operational conditions to minimize energy consumptions.
- Phex: a computational tool for plate heat exchanges design problemsPublication . Palmeira, José; Fernandes, Cristina; Matos, Henrique A.; Silva, JoãoThis paper presents a computational tool (PHEx) developed in Excel VBA for solving sizing and rating design problems involving Chevron type plate heat exchangers (PHE) with 1-pass-1-pass configuration. The rating methodology procedure used in the program is outlined, and a case study is presented with the purpose to show how the program can be used to develop sensitivity analysis to several dimensional parameters of PHE and to observe their effect on transferred heat and pressure drop.
- ProGreS 2nd Workshop: from biomass characterization to process synthesis (book of extended abstracts)Publication . Coelho, Jose; Matos, Henrique A.; Filipe, Rui; Robalo, Maria Paula; Braz, Catarina G.
- A strategy to extend reactive distillation column performance under catalyst deactivationPublication . Filipe, Rui; Matos, Henrique A.; Novais, Augusto Q.This work addresses the effects of catalyst deactivation and investigates methods to reduce their impact on the reactive distillation columns performance. The use of variable feed quality and reboil ratio are investigated using a rigorous dynamic model developed in gPROMS and applied to an illustrative example, i.e., the olefin metathesis system, wherein 2-pentene reacts to form 2-butene and 3-hexene. Three designs and different strategies on column energy supply to tackle catalyst deactivation are investigated and the results compared.
- Sustainability analysis of a solar-driven calcium looping plant for thermochemical energy storagePublication . Dias, Ricardo N.; Filipe, Rui; Matos, Henrique A.Sustainable development is essential to ensure that future generations enjoy the same or better standard of living as today's society. Clean energy will play an important role in this. Concentrated solar power is one of the cleanest ways to harness solar power and convert it into useable energy like electricity. However, due to the intermittent nature of solar power production, concentrated solar power needs to be coupled with energy storage to ensure the ability to produce and release electricity during peak demand periods. Calcium looping for thermochemical energy storage is an emerging technology that uses calcium carbonate, a highly abundant and inexpensive material, to store energy in the form of calcium oxide and carbon dioxide. A sustainability analysis of a solar-driven calcium looping plant for thermochemical energy storage process is performed in this work. Several process alternatives, previously modelled in Aspen Plus (R), are assessed using three sustainability analysis tools, GREENSCOPE, SimaPro, and OpenLCA. Nine process alternatives are considered, including the use of sorbent purge, water vapor as fluidization fluid at the calciner, and different operating temperatures in the calciner. All the analysis tools identified the process alternative using total sorbent purge, water vapor as fluidization fluid and a calciner temperature of 800 degrees C as the best overall performer. This work contributes through a sustainability analysis to the decision-making on which process configuration and conditions should be used, building on a previous technical analysis of a calcium looping for thermochemical energy storage process.