Desarrollo de una ingeniería conceptual para el proceso de pirolisis catalítica de residuos plásticos de polipropeno y poliestireno.

El objetivo del presente trabajo de titulación fue el desarrolló la ingeniería conceptual para el proceso de pirolisis catalítica de residuos plásticos polipropileno y poliestireno, que en los últimos años la demanda de plásticos ha aumentado y luego de cumplir su vida útil son desechados presentando un problema ambiental por la inadecuada disposición final de estos polímeros. Se realizó un estudio bibliográfico y comparativo de las tecnologías existentes del proceso de pirolisis catalítica, para lo cual se construyó matrices comparativas de las variables independientes como son: temperatura de reacción, tiempo de retención de la materia prima en el reactor, tipo de reactor utilizado, tipo de catalizador, analizando las condiciones óptimas y la eficiencia de los productos obtenidos. Se analizó que el proceso realizado por Lin Y.-H., y Yang M.-H (2006), donde se utiliza catalizadores gastados de los procesos de refinación de crudo, en un reactor de lecho fluidizado FCC presenta los mejores rendimientos y las mayores facilidades operacionales, este reactor presenta varias ventajas en relación a otros procesos, mayor contacto polímero catalizador que brindo mayor productos finales deseados, pero a pesar que se necesita grandes cantidades de catalizador, el catalizador es reutilizado ya que este representa un desecho en las industrias petroleras lo que representa una mayor rentabilidad en la utilización de un producto de desecho y finalmente el catalizador puede ser recuperado y reutilizado nuevamente evitando así un gasto innecesario de catalizador.The objective of this research work was development a conceptual engineering for the catalytic pyrolysis process of plastic waste polypropylene and polystyrene, that in the latest years has increased the demand of plastics and after its useful life those are discarded been an environmental problem due to the inadequate final of these polymers. A bibliographic and comparative study about the catalytic pyrolysis process technologies was carried out, from the independent variables some comparative matrices were created such as: temperature reaction, retention time of the raw material in the reactor, type of reactor used, type of catalyst, analyzing the optimal conditions and the efficiency of the products obtained. The process developed by Lin Y.- H., and Yang M.-H (2006) was analyzed, where spent catalysts of crude refining processes are used, in a FCC fluidized litter reactor presents the best yields and some greater operational facilities, this reactor has several advantages in comparison to other ones, higher contact polymer catalyst that provide more desired final products, but although large quantities of catalyst are needed, the catalyst is reused due to it represents a waste in oil industries companies, which represents a greater profitability in the use of a waste product and finally the catalyst can be recovered and reused thus avoiding an unnecessary expenditure of catalyst

Isomelezitose overproduction by alginate-entrapped recombinant E. coli cells and In vitro evaluation of its potential prebiotic effect

In this work, the trisaccharide isomelezitose was overproduced from sucrose using a biocatalyst based on immobilized Escherichia coli cells harbouring the α-glucosidase from the yeast Metschnikowia reukaufii, the best native producer of this sugar described to date. The overall process for isomelezitose production and purification was performed in three simple steps: (i) oligosaccharides synthesis by alginate-entrapped E. coli; (ii) elimination of monosaccharides (glucose and fructose) using alginate-entrapped Komagataella phaffii cells; and (iii) semi-preparative high performance liquid chromatography under isocratic conditions. As result, approximately 2.15 g of isomelezitose (purity exceeding 95%) was obtained from 15 g of sucrose. The potential prebiotic effect of this sugar on probiotic bacteria (Lactobacillus casei, Lactobacillus rhamnosus and Enterococcus faecium) was analysed using in vitro assays for the first time. The growth of all probiotic bacteria cultures supplemented with isomelezitose was significantly improved and was similar to that of cultures supplemented with a commercial mixture of fructo-oligosaccharides. In addition, when isomelezitose was added to the bacteria cultures, the production of organic acids (mainly butyrate) was significantly promoted. Therefore, these results confirm that isomelezitose is a potential novel prebiotic that could be included in healthier foodstuffs designed for human gastrointestinal balance maintenanc

Swine manure management by hydrothermal carbonization: comparative study of batch and continuous operation

Hydrothermal carbonization (HTC) is considered a promising technology for biomass waste management without pre-drying. This study explores the potential for swine manure management by comparing batch and continuous processes, emphasizing the benefits of the continuous mode, particularly for its potential full-scale application. The continuous process at low temperature (180 ◦C) resulted in a hydrochar with a lower degree of carbonization compared to the batch process, but similar characteristics were found in both hydrochars at higher operating temperatures (230–250 ◦C), such as C content (~ 52 wt%), fixed carbon (~ 24 wt%) and higher calorific value (21 MJ kg− 1 ). Thermogravimetric and combustion analyses showed that hydrochars exhibited characteristics suitable as solid biofuels for industrial use. The process water showed a high content of organic matter as soluble chemical oxygen demand (7–22 g L− 1 ) and total organic carbon (4–10 g L− 1 ), although a high amount of refractory species such as N- and O-containing long aromatic compounds were detected in the process water from the batch process, while the process water from the continuous process presented more easily biodegradable compounds such as acids and alcohols, among others. The longer time required to reach operating temperature in the case of the batch system (longer heating time to reach operating temperature) resulted in lower H/C and O/C ratios compared to hydrochar from the continuous process. This indicates that the dehydration and decarboxylation reactions of the feedstock play a more important role in the batch process. This study shows the efficiency of the continuous process to obtain carbonaceous materials suitable for use as biofuel, providing a solution for swine manure managementAuthors greatly appreciate funding from Spanish MCIN/AEI/ 10.13039/501100011033 and European Union "NextGenerationEU/ PRTR" (TED2021-130287B-I00, PDC 2021-120755-I00, and PID 2022- 138632OB-I00) and Grupo Kerbest Company. R.P. Ipiales acknowledges the financial support from the Community of Madrid (IND2019/AMB17092) and Arquimea Agrotech Compan