Browsing by Author "García Pérez, Tsai"

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Biomass carbonization technologies
(Elsevier, 2022) García Pérez, Tsai; Peláez Samaniego, Manuel Raúl; García Núñez, Jesús Alberto; García Pérez, Manuel; Haghighi Mood, Sohrab; Yadama, Vikram
Biomass carbonization is practiced extensively all over the world, with technologies resulting in chars covering a wide range of properties and yields. Although the number of papers published in this area is growing fast, mostly with contributions from Europe, the Unites States, and Brazil, there are very few reviews on the hurdles and challenges of carbonization. Char is mostly used as cooking fuel in developing countries and as a reduction agent for the metallurgical industry in Brazil. Since the 1970s, there has been a lot of interest in producing bio-oil from biomass for transportation fuels, and consequently, fast pyrolysis reactors were developed, scaled up, and deployed. This is an area of great research activity that will not be discussed in this review. More recently, there is a growing global interest in using char as soil amendment for sequestering C to fight global warming. This interest is fueling the development of selective carbonization units maximizing C conversion efficiency. The production of large volumes of cheap chars via selective carbonization could catalyze the growth and deployment of a green C economy resulting in the production of green fuels, green chemicals, and materials. In this chapter, we review old and new carbonization reactor design concepts. Reactions and operation parameters responsible for char yield and properties are also reviewed.
Charcoal from anaerobically digested dairy fiber for removal of hydrogen sulfide within biogas
(2018) Peláez Samaniego, Manuel Raúl; García Pérez, Tsai
Anaerobically digested fibrous solid (AD fiber) is an abundant material that offers potential to produce value-added products such as biochar. The objective of this paper is to better understand how thermochemical processing conditions affect the capacity of biochars derived from AD fiber to adsorb H 2 S from biogas. AD fiber was pyrolyzed in an electric tube reactor at temperatures up to 600° C and 60 min. The chars were employed for H 2 S scrubbing tests from a synthetic biogas. Results showed that the chars' capacity for H 2 S removal is comparable to that of activated carbon. An additional step consisting of impregnation of the chars with Na 2 CO 3 resulted in an improved capacity for H 2 S removal. To study the effect of ash, the AD fiber was also subjected to an alternative thermal treatment, hot water extraction (HWE), at 200° C for 60 min. The resulting HWE material …
Chars from wood gasification for removing H2S from biogas
(2020) Peláez Samaniego, Manuel Raúl; Pérez, Juan Fernando; Ayiania A., Michael A.; García Pérez, Tsai
Biomass gasification is a mature thermochemical process used to produce a gaseous fuel to run burners, engines, and gas turbines. One of the byproducts of biomass gasification is char, which is a residue with low value and sometimes this material is even considered waste. Therefore, options for using gasification chars are required. On the other hand, there is a necessity of making biogas production and use more attractive by employing cheap materials for the biogas cleaning process. One of the promising options for using gasification chars is for cleaning biogas produced via anaerobic digestion (AD). The objective of this work was to assess the use of residual gasification chars from fast growing wood species (Eucalyptus Grandis-EG and Pinus Patula-PP) to remove hydrogen sulfide (H2S) from biogas produced via AD. Gasification chars were produced employing a laboratory scale downdraft gasifier. EG char (EG-C30) was produced by gasification of EG using a 30 L min−1 airflow, whereas the PP chars (PP–C20 and PP-C40) were produced from PP using 20 and 40 L min−1 airflow. Results show that these three chars offer potential for biogas cleaning, although PP-derived chars produced at higher airflow rates are more effective. The H2S removal capacity of the chars is ascribed to their large apparent surface area (up to 517 m2 g−1) and the presence of minerals and metals (e.g., Ca, K, and Fe) in the chars’ ash.
Combined effect of biochar and fertilizers on andean highland soils before and after cropping
(2022) García Pérez, Tsai; Peláez Samaniego, Manuel Raúl; Delgado Noboa, Jorge Washington; Chica Martínez, Eduardo José
Although a number of works present biochar as a promising material for improving the quality of degraded soils, only a few show the effect of this material in soils from the Andean highlands. The objective of this work was twofold: (a) to study the effect of two types of biochars on two agricultural soils commonly found in the Andean highlands (Andisol and Inceptisol) and the corresponding soil–biochar–fertilizer interactions, and, (b) to assess the response to biochar of two vegetable crops (lettuce and radish) grown in succession in a simulated double-cropping system. Biochar was produced at 400 °C and 500 °C, for 1 h (B400 and B500, respectively), using hardwood residues. Properties of biochar that could potentially affect its interaction with soil and water (e.g., functional groups, surface area, elemental composition) were assessed. Experiments were conducted to test for main and interaction effects of biochar type, soil type, and the addition of NPK fertilizer on the soils’ characteristics. Bulk density and water content at field capacity and permanent wilting point were affected by two-way interactions between biochar and soil type. Biochar impacted bulk density and water retention capacity of soils. Higher available water content was found in soils amended with B400 than with B500, which is a consequence of the higher hydrophilicity of B400 compared to B500. After the lettuce crop was planted and harvested, the soil pH was unaffected by the biochar addition. However, after the second crop, the pH in the Inceptisol slightly decreased, whereas the opposite was detected in the Andisol. The CEC of the Inceptisol decreased (e.g., from 36.62 to 34.04 and from 41.16 to 39.11 in the control and in the Inceptisol amended with B400 only) and the CEC of the Andisol increased (e.g., from 74.25 to 90.41 in the control and from 79.61 to 90.80 in the Andisol amended with B400 only). Inceptisol amended only with biochar showed decrease of radish weight, while a large increase was found in B400 + fertilizer Inceptisol (i.e., from 22.9 g to 40.4 g). In Andisol, the weight of radish after the second crop increased in less proportion (i.e., from 43 g in the control to 59.7 g in the B400 + fertilizer Andisol), showing a visible positive impact of B400. The results suggest that biochar produced at 400 °C performs better than biochar produced at 500 °C because B400 apparently promotes a better environment for bacteria growth in the soils, as a consequence of more OH available groups in B400 and its better interaction with water and the fertilizer.
Improvements of Brazilian carbonization industry as part of the creation of a global biomass economy
(2008-05-04) Peláez Samaniego, Manuel Raúl; García Pérez, Tsai; Cortez L., A. B.; Rosillo Calle, F.; Mesa, J.
Brazil is the largest world charcoal producer. Surface kilns with semi-spherical form built with bricks with or without recovery of by-products called “Tail Quente” are the most important systems used for charcoal production. The un-recovered pyrolysis products released to environment by this technology are major pollutants. Some alternatives integrating existing or improved carbonization units within a global biomass economy are presented. In these alternatives the carbonization reactors can be used for primary biomass conversion, for densification, for power and heat production or as core technology in new bio-refineries. Some of the technical and economical limitations to implement these concepts are discussed.
Potential and impacts of cogeneration in tropical climate countries: Ecuador as a case study
(2020) Peláez Samaniego, Manuel Raúl; Espinoza Abad, Juan Leonardo; Jara Alvear, José Estuardo; Arias Reyes, Pablo Danilo; Maldonado Arias, Fernando Guillermo; Recalde Galindo, Patricia Elizabeth; Rosero Rivera, Pablo Vinicio; García Pérez, Tsai
High dependency on fossil fuels, low energy e ciency, poor diversification of energy sources, and a low rate of access to electricity are challenges that need to be solved in many developing countries to make their energy systems more sustainable. Cogeneration has been identified as a key strategy for increasing energy generation capacity, reducing greenhouse gas (GHG) emissions, and improving energy e ciency in industry, one of the most energy-demanding sectors worldwide.However, more studies are necessary to define approaches for implementing cogeneration, particularly in countries with tropical climates (such as Ecuador). In Ecuador, the National Plan of Energy E ciency includes cogeneration as one of the four routes for making energy use more sustainable in the industrial sector. The objective of this paper is two-fold: (1) to identify the potential of cogeneration in the Ecuadorian industry, and (2) to show the positive impacts of cogeneration on power generation capacity, GHG emissions reduction, energy e ciency, and the economy of the country. The study uses methodologies from works in specific types of industrial processes and puts them together to evaluate the potential and analyze the impacts of cogeneration at national level. The potential of cogeneration in Ecuador is ~600 MWel, which is 12% of Ecuador’s electricity generation capacity. This potential could save ~18.6 106 L/month of oil-derived fuels, avoiding up to 576,800 tCO2/year, and creating around 2600 direct jobs. Cogeneration could increase energy e ciency in the Ecuadorian industry by up to 40%.
Producción de azúcares a partir de los residuos de las hojas y cogollos de la caña de azúcar mediante procesos de explosión de vapor e hidrólisis enzimática
(Universidad de Cuenca, 2025-04-03) Duy Ruiz, Adrian Alejandro; Echeverría Mora, Luis Alberto; Delgado Noboa, Jorge Washington; García Pérez, Tsai
The production of biofuels from lignocellulosic biomass represents a sustainable alternative to fossil fuels. In this study, the obtention of fermentable sugars from sugarcane leaf and bud waste was evaluated by means of steam explosion with recirculation and enzymatic hydrolysis. Six recirculation cycles (M0-M6) were applied at 180 °C for 1 second, analyzing the lignocellulosic composition of the solid fraction and performing a mass balance to determine the distribution of compounds in the liquid fraction. From this, total sugars and degradation products are quantified. The results indicated that sample M2 had the lowest lignin content (16.05%) and the highest cellulose concentration (51.94%), which favored enzymatic hydrolysis. The maximum concentration of sugars (72.09 g/L) was reached in M2 at 6 hours, but subsequently decreased due to the presence of inhibitors such as hydroxymethylfurfural (0.71 g/L) and furfural (0.60 g/L), especially in M3. It is concluded that two recirculations optimize the production of sugars, while from M3 onwards, a reduction is observed due to the accumulation of degradation products. These findings evidence the importance of controlling recirculation to maximize process efficiency and reduce inhibitor formation, raising opportunities for future research.
Producción y evaluación de materiales adsorbentes a partir de tusa de maíz por procesos de pirólisis para la remoción sostenible de contaminación por cromo en soluciones acuosas
(Universidad de Cuenca, 2024-11-18) Chuncho Vera, Christian Fernando; León Merino, David Sebastián; García Pérez, Tsai; Vera Cabezas, Luisa Mayra
The growing problem of water pollution from industrial activities, especially tanneries and mining, has prompted a search for friendly and economical solutions to remove pollutants such as chromium. In this study, adsorption is employed as a treatment method, using agricultural residues such as corn stover, for the production of carbonaceous adsorbents. Three materials derived from corn stover were evaluated: untreated corn stover (TM), biochar (BC600) and activated biochar (BCA600). The biochar and activated biochar were produced with a pyrolysis process at 600 °C, in the case of BCA600 phosphoric acid was used as activating agent and the materials were subjected to particle size analysis, BET and zero loading point. The measurement of chromium concentration in aqueous medium was performed by UV-Vis spectrophotometry using diphenylcarbazide as colorimetric agent at pH 2 and 3. The results of the batch adsorption tests determined a removal of 78.16% after 1 hour at optimum pH of 2 for BC600 and an adsorption capacity of 10.12 mg/g, being the best adsorbent of the three. The kinetic tests showed a correlation of 0.951 and 0.998 for the Pseudo First Order and Pseudo Second Order models, while in the equilibrium analysis 0.979 and 0.957 were obtained for the Langmuir and Freundlich model respectively, indicating a composite adsorption process. Finally, an acid regeneration was applied to the BC600 adsorbent using HCl in two adsorption cycles, achieving a regeneration of 79.64% and 57.80%.