Màster Oficial - Enginyeria Química

URI permanent per a aquesta col·leccióhttps://hdl.handle.net/2445/66704

Treballs Finals del Màster d'Enginyeria Química de la Facultat de Química de la Universitat de Barcelona.

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Application of circular economy principles to a paper manufacturing process
(2023-02) Valenzuela Aguilera, Javiera; Cardete Garcia, María Alicia
This work is based on the importance of water consumption by paper industries. It has been known by media and physical results which can be observed that it is present a water-stressed in our country. Physically it can be seen that some river levels have reduced their capacity over the last years and MITECO (2022) provides information to quantify the capacity of the global Spanish water reserve which is about an 39,2%. Therefore, it has been studied the water consumption and wastewater that is removed from a wrapping manufacturing process, presented as a case study. Hence, the objective of this work is to apply novel technologies to a wrapping paper manufacturing process in order to reduce the water consumption by the implementation of circular economy principals. This objective will be accomplished by four milestones. First a paper manufacturing process will be defined and represented, secondly water consumers, quantities and qualities will be identified, thirdly wastewater streams, quantities and qualities will be identified and finally it will be presented a wastewater treatment and regeneration operations which the goal of reuse this kind of water in the paper process. The selected wrapping manufacturing process is based on three processes, which are: recycle pulp, wood pulp and papermaking processes. The raw material to produce paper is pulp which will be conform by a 70% or recycled pulp, being the rest from wood. Water is required to different points of the case study presented as demineralized water with high quality, the amount is approximately 12,2m3 of water per paper tonne produced. The principal characteristic of demineralized water is the lower presence of minerals and salts dissolved thus, TDS and TSS should have reduced levels (Vogelzang, 2007 % Real Decreto 1960/2700) in order to have a conductivity less than 1μs/cm (The Distillate Water Company), and the principal bacteria escherichia coli should not be present (Real Decreto 1960/2700. While wastewater represents 10,7m3 per paper tonne being collected from the papermaking process. This kind of water has high amount of organic matter, being the main source wood fibres and/or lignin derivates and hemicelluloses, which is measured by COD and BOD while it has lower impurities of TDS and TSS (Dagar, 2022). Therefore, wastewater is the major concern in this case study in order to have a circular process. Thus, it has been suggested a process to obtain demineralized water from wastewater for a recirculation system. To reach the mentioned process demineralized water treatment will be studied having as input the raw water, supplied by a river Wastewater treatment follows the three phases of a typical WWTP, it will be treated by a clarifier, then by a novel technology, the MBBR system followed by the MF and finally a chlorination. While the demineralized treatment has more operations starting from the chlorination, sand filtration, MF and RO, membrane degasification and finally the mixed bed resin. The RO is a system that can remove a 98% of major contaminants (Advanced Water Filters) mentioned while the MBBR system can remove with a high efficiency the biological matter (Veolia, 2022). The MF system is presented in both treatments allowing to optimize the whole water process. This is possible because it has been found that once the treated water leaves the MBBR system will have lower levels of TSS, COD and BOD, being suitable for the MF system of the demineralized treatment. Furthermore, the residual chlorine will remove the biological matter from the wastewater treatment. By the other side, the wastewater produced in the mixed bed resin in the demineralized treatment is introduced into the MBBR system of the wastewater treatment as the TDS and TSS is assumed to be lower at that point, allowing to avoid the clarifier of the wastewater treatment. Thus, as the main process of paper is based on a recycled one, the wastewater volume will be less than a conventional process. Moreover, the exact number of the reused water has not been possible to know as the information of suppliers and industries is highly confidential. Because of that this work is based on a conceptual manner. Furthermore, the suggested water process can be applied to any paper industry because the main processes are always present, with some variations, and also it can be applied to other non-paper industries that consumes high volumes of water.
Optimization of supported cobal catalysts for the Fischer-Tropsch Synthesis
(2023-06) Lwazzani, Mohamed Amine; Guilera Sala, Jordi; García Blanco, Andrés Alberto
The Fischer-Tropsch synthesis is a process in which synthetic fuel can be produced from syngas. The interest of this fuel lies in its ability to foment a transition in hard to abate sectors such as aviation, heavy duty, and shipping. The main objective of this investigation is to foment and research about the sustainability of synthetic fuels, by optimizing the catalysts and by upcycling CO2 into fuels. These objectives were studied in 2 phases: The first phase focalized in the optimization of supported cobalt catalysts by varying their preparation technique and the cobalt loading, whilst for the second stage, cerium oxide is added to the optimized catalyst as promoter, for studying the effect of the cerium oxide on the conversion of CO/CO2/H2 mixtures. The obtained catalysts were characterized by TPR, N2 Adsorption, SEM, EDX, XRD, ICP-AES and CO chemisorption; and tested for Fischer Tropsch synthesis in a fixed-bed reactor at 2.0 MPa, 230 ºC and a H2/CO ratio of 2.Differences between the supported cobalt catalysts were observed and related to the preparation method. The impregnation of Co2+ and Ce3+ resulted in a uniform distribution on the catalyst pellets. Lower calcination temperatures and unique impregnation led to higher reducibility of the cobalt oxides, and enhanced properties (SBET, Metallic Surface Area, Dispersion, Particle Size) in comparison to the higher calcination temperature. The properties of the catalysts affected the catalytic performance of the catalysts Once selected the optimized catalyst, a new batch of catalysts impregnated with cerium are prepared in the same conditions. These catalysts were tested under 2 syngas mixtures, in which one syngas mixture was enriched with 25 vol% of CO2, and the other one had no CO2 in it. The reaction under a CO2-enriched mixture yields a lower productivity in comparison to the syngas these results are plausible because the CO2 is not as reactive as the CO. Nonetheless, CO2 conversion is detected at lower temperatures whilst for the highest temperature CO2 is produced. Cerium oxide improved the productivity obtained for the CO2-cointaining mixture in comparison to the non-promoted catalyst. Impregnation of the cobalt over the cerium oxide yields in higher CO2 concentrations than cerium oxide impregnated over cobalt
Equilibrium thermodynamics of the liquid phase esterification of levulinic acid with octanol over an ion exchange resin
(2023-02) Jurkiewicz Cortada, Marc; Soto López, Rodrigo; Badia i Córcoles, Jordi Hug
The objective of this work is to characterize the thermodynamics of the synthesis reaction of octyl levulinate from levulinic acid and 1-octanol in liquid phase. In the current context of depletion of the traditional resources of raw materials and fuels as well as the fight against climate change, numerous efforts are being carried out to develop material production processes from renewable resources. This is the case of octyl levulinate, a compound that, due to its physical and chemical characteristics such as its density, volatility and viscosity, has a high potential as a substitute for lubricant bases traditionally obtained from crude oil. Octyl levulinate is considered a biomolecule as it is synthesized from levulinic acid, one of the 12 biomassderived molecules with the greatest potential according to U.S. Department of Energy, and 1-octanol, which can also be obtained through bioprocesses. As a previous step to the design of processes for its synthesis, the thermodynamic properties of this esterification need to be determined. Despite the existence of several kinetic studies of the esterification of levulinic acid with 1-octanol, the thermodynamic constant of this reaction is experimentally determined for the first time in this work. Its value at 80, 100 and 120 ºC is compared with those computed via estimation methods. Likewise, the enthalpy change and the entropy change of the reaction are experimentally determined and compared with theoretically estimated values. On the other hand, an experimental purification method of the synthesized octyl levulinate based on the combination of washing the reaction medium with water followed by vacuum rectification is described. Finally, the value of the isobaric heat capacity of octyl levulinate is experimentally determined for the first time at different temperatures, and these values are compared with those obtained via a theoretical estimation method
Bifunctional catalyst synthesis using ion-exchange resins for the methyl isobutyl ketone production
(2023-02) Canadell i Soler, Eloi; Badia i Córcoles, Jordi Hug; Ramírez Rangel, Eliana
This project is focused on the preparation of bifunctional catalysts, using ion exchange resins as a supporting material, for the biomass transformation. The acetone hydrogenation to produce methyl isobutyl ketone (MIBK), under the one-pot synthesis approach was selected as a model reaction. Acidic ion exchange resins, AmberlystTM 15 (A15) and Dowex 50WX2 (Dow2), were selected as the supporting material due to their ability to carry out the reactions at milder conditions. These resins were doped with noble metals (Pd and Ru) and non-noble metals (Cu) by wet impregnation. The catalytic activity test consisted on hydrogenating 40 g of acetone with a 5 wt.% catalyst loading for 4 h at 120 °C, a hydrogen pressure of 30 barg at 300 rpm. Palladium doped resins resulted to be the more catalytically active being able to convert more than 30 % of the acetone being totally selective to the MIBK formation. Similar results were accomplished by a commercial catalyst, namely AmberlystTM CH28 (ACH28). Although Dow2 doped with 1 wt.% achieved the highest yield, 37 %, it was less catalytically active than ACH28 according to the turnover number which were, respectively, 1500 and 1839 mols of acetone converted per mole of metal supported on the catalyst. Cu-based catalyst resulted to be the least catalytically active converting less than 20 % of the acetone with a selectivity towards the product of interest inferior to 10 %. Cu- and Pd-catalysts were characterized. It was observed that the nominal and actual metal content were seen to match at 1 wt.%. Additionally, no acidic sites were lost during the catalytic test, although the Pd-catalyst lost some acidic sites during its preparation. The transmission electron microscope proved that the Dow2-1%Pd catalyst had the smallest size distribution, which makes it a great catalyst while the scanning electron microscopy proved that the metal was homogeneously distributed on the polymeric resin surface. Finally, the Dow2-1%Pd catalyst was assayed at different temperatures (110-130 °C), being able to convert 45 % of the initial acetone without a selectivity loss. However, its reusability is not feasible, although the TON number remains constant, because almost no production of MIBK was observed when tested in three consecutive experimental runs.
Safety Report according to SEVESO regulation in Catalonia
(2023-02) Albiol Burcet, Aina Xiaochun; Giménez Farreras, Jaume; Iglesias Muñoz, Victoria
Although the SEVESO regulation is established in Europe, there are still accidents with catastrophic consequences for people. Therefore, it is necessary to emphasize compliance with this regulation. The SEVESO regulation is European in scope, although its application depends on the different European countries. In the case of Spain, every region can develop its own SEVESO regulation respecting Spanish regulations RD 1196/2003 and RD 840/2015. This project will be focused only on Catalonia. Chemical plants that present hazardous chemical substances are required to submit a series of documents, including the Safety Report. In Catalonia, the Safety Report has to be prepared following the Instruction 11/2010. The main idea of this project consists of presenting a Safety Report, following all the steps dictated by the Instruction 11/2010. Data are used, at regional level, of the chemical plants present in the province of Barcelona. One of the documents presented in the Safety Report is the Risk Assessment. In there, the most representative accidents, associated with the dangerous substances present in the plant are studied. As a result of the study, areas of dangerous are calculated, depending on the scenario design. The most representative initiating events studied are the partial breakage of the equipment or the unloading/loading arm or hose, the catastrophic breakage of a mobile recipient and the confined explosion of a tank. From these initiating events and through the event tree technique, the possible final accidents have been deduced. These have been modelled to assess their possible consequences and vulnerability for people and the environment. Finally, the corresponding risk analyses have been carried out. These accidents are studied considering a statistical study of the chemical plants placed in the province of Barcelona.
Improvement of the p-xylene and benzene production process through the disproportionation of the toluene
(2022-06) Valldepérez González, Xavier; Bonet i Ruiz, Jordi
This document contains the extension of the thesis carried out during the degree which consisted of the design of a plant to obtain p-xylene and benzene by disproportionation reaction of the toluene that is present in the bottom stream of the hydrocarbon column that is currently sent to the gasoline blend. The expansion of the work consists of the purification of the xylene mixture and maximization of the production of p-xylene, as well as the realization of elements not designed during the reference project. The new unit starts with the modification of the xylene separation column in which previously p-xylene and m-xylene were obtained by means of a 132-tray distillation column, now separating the heavy aromatics from the rest. The stream containing the xylenes is sent to the continuous adsorption column, using hydrated Y-type zeolite as adsorbent, the physisorption is carried out by means of SMB technology, simulated moving bed technology. The stream rich in p-xylene which is separated by means of a distillation column obtaining the product, the desorbent is obtained which is recirculated to the adsorption chamber. The stream that does not contain p-xylene is sent to the desorbent recovery zone and the desorbent-free stream is sent to the reaction zone where the isomerization of the xylenes and the dealkylation of the ethylbenzene is carried out in order to obtain benzene at 10 bar and 420 °C. The output stream from the isomerization unit is sent to the benzene separation zone and then sent back to the adsorption column. Once the process and equipment had been designed, the corresponding P&IDs were drawn up together with the list of pipes. Finally, in order to check the feasibility of the project and its possible implementation, an economic study was carried out. To carry out the process, an initial investment of 108 M€ is required. Considering the current market, assuming that the price of raw materials, products and their demand remains constant and, a IRR of 21.1 % and a NVP of 25.2 M€ are obtained in a period of 5 years. In addition, the payback of the process is 3 years.
Conditioning of waste cooking oil for bioethylene production
(2022-02) Solé Gamell, Alejandro; Cardete Garcia, María Alicia
The cracker is the unit where ethylene and polyethylene, among other products, are produced. The conventional cracker unit has had a feed that comes from crude oil, the main raw material being naphtha, but it is a non-renewable source. For this reason, the aim is to reduce the amount of traditional raw material and add one that is recycled and also comes from a renewable source, such as used cooking oil (WCO). The main disadvantage of using WCO as a raw material is the limitations that the feed has to be processed by the cracker, as the restrictions are aimed at reducing the poisoning of the catalyst present in the cracker, at reducing corrosion, and also at reducing the formation of coke, as if the amount deposited is considerable, the cracker must be stopped. Therefore, it is necessary to develop a pre-treatment to reduce the components limited by the cracker and for this reason, the present project is developed with the objective of developing a process for the pre-treatment of second-generation vegetable oil (called as WCO, waste cooking oil), so that such raw material fulfils the requirements to be processed without limitations in the cracker unit to produce ethylene. To achieve the objective, the WCO has been characterised based on a literature search and with the oil characterised, the necessary pre-treatment operations can be selected to meet the specifications for the cracker feed. The pre-treatment must have operations that remove metals, chlorides, nitrogen, ash and solid particles, free fatty acids, phosphorous, oxygen and water. The processes selected to remove metals are degumming, bleaching, desalting, membrane extraction, ion exchange, and settling with skimming. The processes selected to remove chlorides are degumming, desalting, membrane extraction and settling with skimming. For the removal of nitrogen, they are deodorization and hydrotreating. For the removal of ash and solid particles, the processes are degumming, desalting, membrane extraction and settling with skimming. Free fatty acids are removed by degumming and deodorization. Phosphorus is removed by degumming, bleaching and desalting. Oxygen is removed by bleaching, deodorization and hydrotreating. Finally, to remove water there are the processes of degumming, deodorization, desalting and settling with skimming. The future steps for the development are to check experimentally if the proposed pre-treatment is enough to achieve the requirements of the cracker, furthermore, experimentation will give a clearer picture and it is preferable to do this before industrial scale-up. In addition, an economic study should be carried out to check whether or not the pre-treatment process is viable with the proposed processes. Furthermore, the economic study together with the experimental verification will allow to decide whether all the operations are necessary or not, as the components can be removed by different processes. On the other hand, the economic viability is favoured by the use of processes that are well known in petroleum refining such as desalting, membrane extraction and hydrotreatment.
Removal of micropollutants from wastewater by rice husk biochar: synthesis, characterisation, and adsorption capacity
(2022-06) Sales Alba, Albert; Bayarri Ferrer, Bernardí
Water is a scarce commodity, continuously exposed to various organic micropollutants, mainly resulting from daily anthropogenic activities. Although these compounds are normally detected in water bodies at very low concentrations, they can also pose a serious threat to the environment and human health. In this regard, pesticides could be considered the micropollutants group with the greatest concern to society. The adsorption process is recognised as a well-known technique for treating pesticide-contaminated waters. However, conventional adsorbents, such as activated carbon from mineral sources, can still considerably harm the environment. In contrast, biochar is a porous, carbonaceous material resulting from the pyrolysis of biomass in oxygen-depleted conditions. The considerable interest in biochar, mainly due to its remarkable physicochemical properties and its low environmental impact, has led to consider it as a promising alternative adsorbent with great potential in wastewater treatment fields. The research derived from this work focuses on the synthesis of biochar from rice husk as feedstock, its characterisation, and its evaluation as an adsorbent material capable of removing different pesticides from wastewater. Biochar was synthesized from pre-treated rice husk feedstock at 500 ºC for 4 h under an N2-H2 (95:5) atmosphere and, subsequently physically activated by CO2 at 800ºC for 1 h. The resulting biochars, both non-activated and activated, were characterised by several techniques to determine their main physicochemical properties. Both presented high alkaline pH values, high ash content and low carbon, hydrogen, and oxygen percentages. The surface area and morphology confirmed the noteworthy change in biochar surface, from 1.22 to 379.95 m2 g -1, upon activation. Moreover, the FTIR spectra confirmed the presence of Si-containing functional groups on activated biochar. Furthermore, it was also evaluated the adsorption performance of activated biochar in the removal of three pesticides with different n-octanol-water partition coefficients (clothianidin, thiacloprid and atrazine). Using a Milli-Q water matrix and assessing the pesticides adsorption individually, the biochar adsorption trend was firstly clothianidin, then thiacloprid and finally, atrazine. On the other hand, when they were evaluated simultaneously from the same aqueous solution, biochar exhibited a greater affinity for thiacloprid, followed by clothianidin, and lastly atrazine. The experimental equilibrium data for thiacloprid and clothianidin was adequately described by the Langmuir model, and the maximum adsorption capacity was quite similar for both, 4068 and 4078 μmol g-1, respectively. In contrast, the atrazine adsorption on biochar was reasonably well adjusted by the Freundlich model, indicating also linear adsorption. Furthermore, in all three cases, the effect of pH on pesticide-biochar adsorption was studied and led to the conclusion that electrostatic interactions were not the main mechanism of adsorption in any case. An experimental study with a real wastewater matrix from a municipal plant was also performed to observe the influence of ions and organic matter on the active sites of biochar. The results evidenced a similar trend of biochar toward clothianidin and thiacloprid, since both achieved around 42-43 % of adsorption at 73 h, whereas for the same time, the adsorption atrazine only was about 23 %. In contrast, for the same conditions but with milli-Q water, the three pesticide adsorption was almost complete within approximately 30 h. In conclusion, the outcomes indicated that CO2-physically activated biochar from rice husk biochar can be used as a readily available adsorbent for the removal of clothianidin, thiacloprid and atrazine from contaminated water, both individually and simultaneously.
Design of a solar thermal installation for the production of domestic hot water
(2020-09) Rovira Mora, Roger; Torres i Castillo, Ricard
In this project, the design of a solar thermal installation for the production of domestic hot water (DHW) for a building in Barcelona has been carried out. Firstly, the energy consumption of the building was determined from statistical data provided by the CTE and meteorological data. Subsequently, the collector model has been selected according to its performance characteristics, area and price. The necessary capture area has been calculated to cover the minimum fraction of demand stipulated by the current law by different methods, heuristics and energy balances of the elements of the installation. The energy balances have been made taking into account the heat losses of different elements of the installation determined from the thermal resistances of the selected equipment, as well as convection losses due to the action of the wind. This has meant an iterative calculation, as it was necessary to know beforehand the appropriate dimensioning of the pipes, including insulation, together with the meters of pipe and the layout of the collectors. The collectors have been arranged on the terrace facing south with a 40 degree slope, and properly separated from the surrounding obstacles to minimize losses due to shading. The final result of the collector system has been represented in a plan for easy understanding. Once the catchment area has been determined, the rest of the elements are sized. The support equipment has been sized based on consumption data of the different elements of the houses applying a simultaneity factor, considering a zero solar contribution of the collectors. The design of the heat exchanger was carried out by determining the useful area of exchange and the overall heat transfer coefficient, considering a counter-current exchange. A return network has been designed for the points of consumption furthest away from the DHW storage tank, based on a partial recirculation of the building's consumption. An exhaustive study has been carried out on the load losses of the elements including the necessary accessories (elbows, valves) in order to size the pumping equipment for each circuit. Once the size of all the elements was known, it was possible to determine the amount of fluid that could be found in each circuit, allowing the sizing of the expansion vessels. With all the elements already designed, an environmental study has been carried out to find out the amount of fuel (natural gas) saved and the CO2 emissions avoided. With the data of fuel savings and the costs of the materials of the installation, the economic viability study of the project is carried out for a useful period of 25 years, with the help of a subsidy from the Barcelona City Council.
Volatile fatty acids production using waste activated sludge and food waste to produce bioplastics
(2022-02) Peña Picola, Sergi; Dosta Parras, Joan; Astals Garcia, Sergi
Fossil fuel exhaustion, increasing greenhouse gases emissions and population growth, among many other issues, are leading to many environmental problems which require a transformation of the production system and waste management including wastewater treatment plants (WWTPs). Hence, the end-of-pipe processes for organic wastes treatment are being converted into resource recovery facilities that produce value-added products. Anaerobic biological processes using mixed cultures can handle the variability of organic wastes: for example, these wastes could be initially converted to volatile fatty acids (VFAs) through acidogenic fermentation and the remaining part (non-VFA organic matter) could be directed to anaerobic digestion to produce biogas. VFAs have multiple applications and one of them is its use as carbon source for polyhydroxyalkanoates (PHA) production. PHA are value-added products mainly composed by polyhydroxybutyrate (PHB) and/or polyhydroxyvalerate (PHV), that can be obtained using mixed microbial cultures in 4 phases: acidogenic fermentation, selection of PHA-storing microorganisms, accumulation of PHA using selected biomass and PHA extraction. In this Master thesis, the first 3 stages of the PHA production process using organic wastes (namely, the acidogenic fermentation, the selection of PHA-storing microorganisms and the PHA accumulation) are studied. The effect of pH on food waste (FW) and wasted activated sludge (WAS) co-fermentation was studied using batch tests and semi-continuous experiments at mesophilic conditions (35 ºC). The pH control in semi-continuous fermenters was difficulted by continuous foaming events. Moreover, PHA production using VFA-rich wastewater (simulating the effluent resulting from an acidogenic fermentation of the organic fraction of municipal solid wastes (OFMSW)) and different selection strategies (one using aerobic feast-famine with nitrogen depletion during feast and the other applying only aerobic feast-famine regime). Furthermore, the VFA profile obtained along the suitable operation of co-fermenters is compared with the synthetic stream used to assess PHA production. The acidogenic fermentation unit was monitored with VFA profile and distribution, pH, chemical oxygen demand and soluble chemical oxygen demand (COD and sCOD), total ammonium nitrogen (TAN) concentration, total and volatile solids (TS and VS) and alkalinity. Batch tests were performed in glass-bottles filled with 150 mL of fixed proportions of WAS and FW (75:25 on VS basis) and using a lab-scale semi-continuous fermenter’s effluent to test the influence of pH in substrates and an operating fermenter, respectively. Furthermore, 2 semi-continuous fermenters with 1.75 L of working volume were operated for 46 days using fixed proportions of WAS and FW (65:35 on VS basis), organic loading rate (OLR) (11 g VS kg-1 d-1), hydraulic retention time (HRT) (3 d) and mixing at 80 rpm. Main VFAs resulted from batch tests and fermenters were acetic acid (30%), butyric acid (30%) and propionic acid (20%). Higher pH showed an increased VFA yield as the solubilisation of organic matter (hydrolysis) was enhanced. Acetic acid consumption in fermenters was experimented and reduced by changing operational parameters (reduction in FW and HRT). Due to foam formation, pH control in semi-continuous operation could not been studied although different strategies were tested to minimise foam (better homogenisation, discharging foams using effluent tubes and lowering HRT and FW proportion). Regarding to lab-scale PHA production, the monitoring of cycles was performed by recording dissolved oxygen (DO) profile, TAN and VFA concentrations, total and volatile suspended solids (TSS and VSS) and pH. VFA-rich synthetic influent with a concentration of 3.5 g COD L-1 for both selection and accumulation phases was used. Biomass selection was performed with a selection sequential batch reactor (sSBR) at 35 ºC and 80 rpm agitation with aerobic conditions using diffusors connected to air pumps and net-air. Furthermore, for accumulation tests a 1 L capacity glass reactor at 35 ºC, agitation at 80 rpm and air supply system were used. Experimental results showed that if double selection strategy (aerobic feast-famine plus nitrogen decoupling in feast) higher PHA content in purge was obtained (30% on suspended solid (SS) basis) along with higher contents of PHA during accumulation (50% on SS basis) compared to a single selection strategy (only aerobic feast-famine regime) with PHA contents of 11% and 38% (SS basis), respectively. Similar PHA compositions were obtained through selection and accumulation phases with the 90% in PHB and 10% in PHV. To sum up, raising pH increases VFA yields in acidogenic fermentation as consequence of hydrolysis and organic matter solubilisation enhancement. Moreover, increasing pH earlier in fermentation batch tests derives in higher VFA production. Due to PHA production, although both strategies selected the biomass successfully, double selection results in higher PHA accumulation potential. It is expected a suitable PHA production if fermenter’s effluents are used (removing previously the nitrogen content) because of the higher ratios CODVFA sCOD-1 and the similar composition of VFAs.
Kinetics of the isosorbide production from sorbitol using water as solvent and the ion-exchange resin CT-482 as catalyst
(2022-06) Padilla Ortín, María; Soto López, Rodrigo; Tejero Salvador, Xavier
The chemical industry is subject to various trends and requirements. On the one hand, products must be safe for society. On the other hand, they can replace raw materials from oil or coal, reducing the environmental impact of the processes and reducing energy consumption. The use of bisphenol A has been banned because of the endocrine problems it causes in the population. Bisphenol A is a monomer used to produce polymers that coat the inner surface of tin cans, or was present in the heat-sensitive paper on which supermarket tickets are printed, for example. To replace bisphenol A, the use of isosorbide, a monomer that can polymerize to give polymers of equivalent function to bisphenol A derivatives, has recently been proposed. Isosorbide can be obtained by a process that uses fructose or another sugar as a feedstock and can be produced from biomass after hydrolysis of wood or agricultural residues. Fructose is converted to isosorbide in two stages. In the first, fructose is converted to sorbitol by hydrogenation, and in the second, sorbitol, in the presence of an acid catalyst, forms isosorbide. The aim of the present work was to begin the study of the second reaction, verifying that the reaction is possible using acid ion-exchange resins as catalysts and with special emphasis on obtaining kinetic data. These catalysts are suitable to work at moderate temperatures (below 130 ºC) and, therefore, in interesting conditions for energy saving. A reaction device was used that allowed working with sorbitol in aqueous solution. The working conditions that allow to operate selectively towards the isosorbide avoiding the effects of internal and external matter transfer were determined, using a catalyst previously selected by screening. All this, obtaining a good reaction rate. Finally, the kinetic model that best fitted the experimental results was determined.
Development of a SILAR-based technology for the deposition of nanometer layers with controlled thickness for photovoltaic applications
(2022-02) Montes Álvarez, Manuel Eduardo; Dosta Parras, Joan; Sánchez González, Yudaina
The world of renewable energies, more specifically the photovoltaic energy, is a necessary technological source for humans and for the planet, but like all technological sources it is progressing. This progress it's related to a constant development of new materials and new technologies that must comply the photoelectrical requirements demanded by a photovoltaic device. As a booming material and technology, Cadmium Sulfide (CdS) thin films and Successive Ionic Layer Adsorption and Reaction (SILAR) process will be discussed in depth and how to improve and adapt it according to the needs of the device. Due to the fact carrying out this Final Master Project together with the help of the Energy Research Institute of Catalonia (IREC), a detailed study of improvements will be made by SILAR process. Through these experiments, different variables of SILAR will be optimized to obtain a thin layer for place it as a n-buffer and try to be able to replace the previous method used in IREC, Chemical Bath Deposition (CBD). The main objective of this project is to optimize SILAR process for place a CdS n-buffer layer on a photovoltaic device. So, thanks to the bibliographic search and the results of other investigations, certain conclusions have been reached that indicate that the desired objective is well on its way to being achieved.
Methanol synthesis by CO2 hydrogenation using reactive distillation
(2022-02) Meco Morales, Eric; Bonet i Ruiz, Jordi; Bonet Ruiz, Alexandra
Methanol is a very versatile product that can be found in a large number of industrial applications such as it’s use as a solvent or as a raw material for the synthesis of methyl ether, methylamine, etc. Due to the current environmental situation, many research projects are starting to focus on the reduction of greenhouse gases pollution, which directly affects fossil fuels and certain industries that have a large CO2 stream as their major waste (cement plants, thermal power plants, etc.). One of the most studied projects nowadays is the synthesis of carbon-based fuels using CO2 as raw material, which could be used to store the surplus energy obtained from renewable sources in chemical products, to be reused later on. This method has great advantages since with renewable energy and a carbon source (such as CO2) "green" fuels could be produced and these could be easily transported with current logistics and used by many facilities, due to their similarity to fossil fuels. One of the carbon-based fuels with the greatest potential is methanol due to its high energy density. Currently there are several plants producing methanol from CO2 and hydrogen, but they are still too unprofitable to be implemented worldwide. This project studies an intensified process, the reactive distillation process, as an alternative to the current methanol synthesis process to make it more cost effective and efficient. Reactive distillation is an intensified process which allows to reduce the number of equipment required to carry out a process, since several unit operations take place simultaneously inside the column. As it is a process that has not been studied yet, in this project a model has been proposed (simulated using Aspen plus technology) and different points have been evaluated: - Proposal for the process using assumptions and calculation bases. - Process parameters: column reflux, total distillation column stages, feed stages and product obtained by column bottom-head flow stream. - Improvement proposals for the process studied: equipment adjacent to the main column. The different stages of the whole process have been simulated with the ASPEN program and it has been demonstrated that this initial study opens the possibility for future studies since the results are optimistic for the viability of the project in the industrial field
Production of isosorbide from biomass as a substitute for bisphenol A
(2022-06) Mas Novo, Julia; Iborra Urios, Montserrat; Tejero Salvador, Xavier
In order to meet the sustainability criteria demanded by today's society and industry, it is necessary to work with eco-efficient processes, i.e. "producing more with less", in a way that promotes better management of resources and energy while minimising environmental impacts. Hence the importance of the term "biomass". Meeting the growing needs of plastic production while improving sustainability has been a major focus of academic and industrial research. Creating a new generation of sustainable biomass-derived materials as competitive alternatives to petroleum-based plastics can be challenging due to the need for these new materials to match both the performance and cost-effectiveness of commonly used petroplastics. This work aims to cover the most relevant catalytic strategies designed for the conversion of sorbitol, a biomass-derived platform molecule, to isosorbide. Thus, it is shown which is the best pretreatment to separate the lignocellulosic biomass, the subsequent hydrolysis of cellulose to glucose (or other C6 sugars), how from this sugar sorbitol is obtained and how from this sugar the isosorbide molecule is obtained. Isosorbide has been shown to be a good substitute for bisphenol A, as it is a molecule with very similar characteristics but is less toxic to human health and the environment
Optimization of the PERT/CPM project management methodology by implementing the Lean and Agile philosophies
(2021-06) Llach i Porcell, Genís; Cardete Garcia, María Alicia
Companies need to tackle investment projects in order to be more competitive. The proper management of such projects is a key factor for the company’s results. In particular, the construction phase is a critical point since it is the stage where time and/or resources constraints do not often meet, mainly because of the susceptibility to the acceptance of potential changes. In order to comply with such restrictions, project managers are supported by different management techniques, such as the widely implemented PERT/CPM (Program Evaluation and Review Technique/ Critical Path Method) Also, some other novel methodologies are being developed, such as Lean or Agile, in the field of project management. The objective of this study is to assess the impact of an improved, novel combination of such project management methodologies, on the achievement of time and resource constraints. As a methodology, a real case-study has been addressed by showing a comparison of the results obtained with the use of the conventional PERT/CPM methodology to the implemented of the new project management methodology proposed. The case-study focuses on the construction phase of a revamp project in an Ethylene Glycol plant, which consists on changing the existing structured packing from a MEG (monoethylene glycol) distillation column to a high performance one, in order to increase capacity, while keeping the same efficiency. The main constraints that apply this project refer to limited affordable plant shutdown time due to commercial reasons and also to the strictly planned availability of a specialist technician, responsible of the most critical task, to fit in the new structured packing. This study begins with the implementation of the PERT/CPM methodology to programme the construction phase. Although this technique allows to identify the critical path and therefore determine the total duration of the project, it has substantial limitations. The main one, is the lack of tools to optimize the planning either to meet the project constraints or even to make it more reliable. The study reveals that just applying the conventional PERT/CPM methodology based on timings experienced in previous similar projects does not allow to accomplish with the required constraints. For that reason, a novel methodology is developed to ensure the accomplishment of time and resources constraints. A SWOT analysis is run to identify weaknesses and potential threats which are overcome through the introduction of Lean and Agile techniques. As a result, a modified PERT/CPM with Agile and Lean methodologies have been developed. Whereas PERT/CPM sets the operative basis for the project management, its upgrade with the philosophies Agile and Lean provides a combined framework, which not only addresses the timely organization of the activities, but also provides tools to deal with time and resources constraints. The report reveals that this innovative combined technique ensures compliance with the established deadlines while increasing the reliability of the project's results. Finally, the present study proposes the implementation of a risk assessment as an objective and rigorous methodology for the proper resource assignment, an issue which in today’s project tends to be done either arbitrarily or on the background of previous project experiences, resulting in inefficient resource management and high financial losses In conclusion, because of the flexible framework provided by this innovative methodology, it can also be applied in small improvement projects, in other sectors different from the chemical industry and even in maintenance activities that have to be organised on a daily basis in production plants.
Contribution to the Study of Heat Integration of Pressure Swing Distillation
(2022-02) Gutiérrez Campos, Eva; Bonet i Ruiz, Jordi; Manso, Victor
Separation processes of mixtures are one of the most important operations in the chemical industry due to the need of product purification or components recovery. Distillation is a widespread method of purification for liquid mixtures. The basis of this process is the selective boiling and condensation of the components. When it concerns an azeotropic mixture, the separation is limited to the azeotropic composition, so from this point it is impossible to continue with the purification and an alternative method must be used. Pressure swing distillation (PSD) process is an enhanced distillation method to break the azeotrope of azeotropic mixtures which are pressure sensitives. Heat integrated pressure swing distillation (HIPSD) is an improvement to overcome the high operating costs generated in the PSD process exchanging heat between hot and cold streams of the process in order to minimise the external energy requirements. In this project, the mixture to be separated is composed of methyl acetate (MetAc) and methanol (MeOH). This mixture is obtained in the synthesis of polyvinyl alcohol (PVA), and the purification of the components is useful as MeOH is a raw material for the PVA process, and to sell / use MetAc as a solvent in production processes such as glue or paint production. The PSD process is designed according to heuristic rules for distillation, and using Aspen Plus as simulation software. The process consists of two columns. MeOH is obtained in the first one (operating at 1 atm) and MetAc is obtained in the second one (operating at 10 atm), both by bottoms and with a 99.45 % of purity. Once the design is done, partial and full HIPSD are studied to achieve energy costs savings. This is done by means of Aspen Energy Analyzer complement, included in Aspen Plus. Since this is the first time using this tool in the department, the designs are also developed by a traditional method (Temperature-Interval) to compare the results and see how it works. For the partial HIPSD the feasible heat exchange between the first column reboiler and the second column condenser is performed, but the heat duties are not equal, hence an auxiliary reboiler is needed. The energy costs savings achieved are 37.47 %. For the full HIPSD, the PSD process is modified to equalise the heat duties, so that an auxiliary reboiler is not needed, and to minimise the second column reboiler heat requirements. The energy costs savings for this case are 46.27 %.
Checking kinetic modeling enhancement of the catalyzed BTBE synthesis reaction through Hansen solubility parameters
(2020-02) González Ramón, Andreu; Fité Piquer, Carles
The prediction of reaction rates of the BTBE synthesis reaction is enhanced by including the reaction medium effect in the kinetic model, as demonstrated in a previous study based on experimental kinetic data. The Hildebrand solubility parameter was used to predict such interaction. The aim of the present work is to check if the use of the Hansen solubility parameters presents an advantage over Hildebrand solubility parameters in the kinetic modelling of the studied reaction, because it is based on a more accurate description of intra- and intermolecular forces. Several estimation methods will be considered to find Hansen solubility parameters. The method which provides the best accurate results, will be used to find Hansen solubility parameters of BTBE. Different tests are carried out to check if Hansen solubility parameters depend significantly on temperature. At this point, the kinetic equation obtained from the previous work and other kinetic equations will be tested to find the best results that describe the kinetics of the BTBE synthesis
Design of a batch plant for azithromycin manufacture
(2021-02) Gil Pallares, Isidro; Gutiérrez González, José María, 1953-
Azithromycin is a drug that is used in the presence of a large number of bacterial infections or as a reducer of viral symptoms. Due to the exceptional situation of COVID-19, its potential to treat the symptoms of a wide range of respiratory diseases has been further investigated. This led to it being classified as a key drug in stopping the first waves of future infectious threats. Therefore, the production of azithromycin may be of interest to new manufacturers who want to take advantage of this market opportunity. The objective of this project is the development of a novel process for the large-scale industrial production of azithromycin, by studying the different industrial solutions available, based on market needs. The selection of the synthesis recipe is the starting point from which the process design is elaborated. Including the appropriate adaptations, scaling is carried out to obtain a process design according to the industrial production capacity. This project addresses the specification of the stages, operations and equipment that constitute the process is made, as well as detailing the conditions and work needs. Based on the original distribution of the tasks in the different equipment of the process, planning and optimization strategies are applied to obtain a reorganization that allows a planning of the process that achieves the established production objectives. Bearing in mind that it is a widely studied process, this stage is fundamental, if a certain economic return is to be obtained, since increases of up to four times the production capacity of the original distribution are achieved. Finally, to complete the objective of the project with the design of an industrially viable process, a selection is made of the main equipment in the commercial catalogue available, looking for the most appropriate technology according to the needs of the process, but also taking into account the economic viability of the project.
Study and design of a multiproduct plant of vegetable beverages
(2022-02) Pozo Pòrtulas, Víctor del; Maestro Garriga, Alicia; Chamarro Aguilera, María Esther
The current project is focused on the development of several plant-based beverages in a multiproduct plant. The high percentage of lactose intolerant people, the great contribution of livestock to global warming and the increasing cow’s milk allergies makes it crucial to find an alternative to the classical cow milk. Furthermore, people are becoming more aware about their fitness and lifestyle and these types of beverages are perceived as healthier as bovine milk, gaining importance in the market. Other reasons to bet for these types of products are their sustainability and their impact on the environment. As bovine milk needs a lot of water and huge areas of land for its production, plant-based milks don’t require such amounts of water and land. In addition, CO2 emissions are another problem of cow’s milk and another reason why people decided to change to vegetable beverages. This work is based on the development of formulated products, including all steps of this procedure: market study, product conceptualization, quality criteria, product formulation, design the manufacturing process and a scheduling to plan the production. Three different types of plant-based milks have been selected to produce due to their popularity and consumption here in Catalonia. These beverages are soya milk, almond milk and oat milk. There is a general production process for all types of milk but obviously modifications have been made depending on the raw material used and the aims of the present thesis. Two main quality criteria have been stablished to make this product especially appealing, which are their nutritional value and the flavor. When it comes to flavor, lipoxygenase and its oxidation reaction plays an important role when designing the production process and specially the equipment. In the present work one of the aims is to avoid the activation of this enzyme to improve the final flavor of the milk. On the other hand, to launch an alternative to cow’s milk, the substitute must have similar qualities in terms of nutritional value. Depending on the raw material, amounts of these nutrients differ from each other but in all of them there is a specific way to make the addition of nutrients in order to enrich the beverages. Finally, to plan the production and operate properly it has been made a scheduling. Firstly, a batch size of 6000kg is stablished according to the total production wanted per year, the way milks are delivered and considering a production unit of six carboards of one liter of milk each. Afterwards, time required for each stage is estimated to plan the number of batches carried out every month. In this amount of time, it is included not only the main operation but also other operations such as the charging of the product or the cleaning. Taking into consideration the time and the total production to be carried out, it is estimated how to operate in the plan.
Design of a plant for polylactic acid polymer manufacture
(2020-02) Canzobre Silva, Andrea; Gutiérrez González, José María, 1953-
Over the last decades, plastic demand has grown increasingly at a level such that it is unavoidable for current society. Plastics versatility and unique properties makes them suitable for all kind of industries, which currently suppose a threat to both environment and human health at every stage, right from their production to their end-of-life scenario. Bioplastics stand out in this way as a greener solution able to reduce carbon footprint, with high recycling value and complete biodegradability or compostability. In this regard, polylactic acid constitutes a biodegradable and bio-based bioplastic which is gaining attention in the recent years, as it possesses the potential to replace conventional fossil-based plastics in food packaging and other applications. Continuous research and development in this field has made possible the polylactic acid mass production at a competitive cost, promising a sustainable future and overcoming the accumulation of plastic waste in landfills. The purpose of this project is the development of the Master’s Degree Final Project with which it is intended to apply for the Master Degree in Chemical Engineering by the “Universidad de Barcelona” The project is focused on the design of a plant for polylactic acid polymer manufacture from lactic acid solutions. Based on a comparison among different polylactic acid market players and the increasing demand reflected in the market analysis, the plant has a fixed annual production capacity of 60,000 tonnes and operates 330 days per year. A selection of the most adequate synthesis of the manufacturing process, according to product necessities, is conducted through a bibliographic research. By means of mass and energy balances, stream flows and operating conditions of each equipment are determined in order to carry out the basic design of the plant, in which the main design parameters and dimensions are detailed. A falling film evaporator type of reactor is selected for the condensation polymerization of lactic acid into polylactic acid of low molecular weight, as it provides the advantages required to optimize the polymer production due to its high surface area to volumetric hold up ratio, which reduces evaporation residence time. A detailed design of this equipment, based on heat transfer and mechanical design, is carried out and reflected in the equipment lay-out. As a final point, the control system of the plant is studied in order to supress the influence of external disturbances, ensuring the stability of the chemical process and the optimization of the process performance. The control system stands for the discussion of the control philosophy and the establishment of the control loops of the plant, described through a P&I diagram which includes the engineering details of the equipment as well as instruments, piping, valves and fittings.

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