Effect of particle size and humidity on sugarcane bagasse combustion in a fixed bed furnace

AbstractThe panela industry is one of the most important Agro Industries in Colombia, making it the largest percapita consumer and the second largest producer worldwide. The fuel used in this process is traditionally the sugarcane bagasse (SB) which is a byproduct of milling. However, due to the low efficiency of panela furnaces additional fuel is required such as wood, used rubber tires and coal. The fixed-bed furnaces inefficiency is mainly due to incomplete combustion of SB caused by the influence of process variables. Therefore, the aim of this work was to study the influence of particle size (PS) and moisture content (MC) over the combustion stages of SB in fixed-bed furnaces. A three-level factorial design was proposed for PS and MC of SB where the temperature and gas concentration were considered as response variables to evaluate the furnace performance. The results obtained in this work show that if the MC increases then the SB yield in the combustion is decreased. On the other hand, the increasing PS can counteract the effect of the MC of SB.Keywords: Sugarcane bagasse combustion, influence of particle size, influence of moisture, temperature profiles, concentrations profiles.Efecto del tamaño de particular y la humedad sobre la combustión de bagazo de caña en un horno de lecho fijoResumenLa agroindustria panelera es una de las más importantes en Colombia, convirtiéndolo en el primer consumidor percápita y segundo productor a nivel mundial. El combustible utilizado en el proceso ha sido tradicionalmente el bagazo de caña (SB) subproducto de la molienda. Sin embargo, debido a las bajas eficiencias de los hornos paneleros se requiere de combustibles adicionales como leña, caucho de llanta y carbón. Gran parte de la ineficiencia de los hornos de lecho fijo se debe a una combustión incompleta del SB, ocasionada por la influencia de las variables del proceso. Por lo anterior, el objetivo de este trabajo fue estudiar la influencia de las variables tamaño de partícula (PS) y contenido de humedad (MC) sobre las etapas de combustión del SB en hornos de lecho fijo. Se planteó un diseño factorial de experimentos con tres niveles para el PS y el MC del SB, donde la temperatura y la concentración del gas de combustión fueron consideradas como variables de respuesta para evaluar el desempeño del horno. Los resultados obtenidos muestran que el incremento del MC ocasiona una reducción en el rendimiento de la combustión del SB. Por otra parte, el incremento en el PS puede contrarrestar el efecto del MC del SB.Palabras clave: combustión de bagazo de caña, influencia tamaño de partícula, influencia humedad, perfiles de temperatura, perfiles de concentración

Estudio experimental de las etapas de cremado y separación de un proceso de producción de látex natural cremado

Resumen En este trabajo se muestran los resultados obtenidos en el estudio experimental del proceso de  producción de látex cremado, en el cual se determinó el efecto de algunas condiciones de operación en  la obtención de un producto que satisfaga los parámetros internacionales de calidad. Se seleccionaron  las condiciones de operación que muestran las influencias más importantes en los criterios de calidad  definidos en la norma ASTM 1076. El estudio se realizó utilizando dos tipos de agente cremador (alginato  de sodio, carboximetilcelulosa), dos concentraciones de éste y cuatro tiempos de cremado. Además, se  estudió la influencia de la separación de fases formadas durante el proceso de cremado en la calidad del  producto obtenido, realizando dos tipos de estudio: sin separación de fases y con separación de fases  cada dos días. Como resultado se obtuvo que el experimento que presentó mayor estabilidad, en TSC  y DRC fue el realizado con alginato de sodio a 1,5g/L con tiempo de cremado menor a 2 semanas, con  separación cada dos días. Palabras clave: caucho natural, concentración de látex, alginato de sodio, carboximetilcelulosa. Experimental study of creaming and separation steps a creamed natural latex manufacturing process Abstract This work shows the results obtained in the experimental study of creamed natural latex manufacturing  process. In this study, the effect of some operating conditions on product properties, that must satisfy the international criteria, has been determined. The operating conditions, that allow the most important effect  on the quality criteria proposed by ASTM 1076, were defined. This work was carried out using two different  creamed agents (sodium aliginate, carboxymethylcellulose), two concentration and four creamed times.  Moreover, the effect on the product quality of the two phase’s separation, produced during the creamed  process, has been studied. Finally, two types of studies were done: with or without phase separation. The  test with the best stability, higher TSC and DRC, were obtained using sodium alginate at 1.5g/L, creamed  times lower than two weeks and phase separation of two days. Keywords: natural rubber, latex concentration, sodium alginate, carboxymethylcellulose

Estudio experimental de las etapas de cremado y separación de un proceso de producción de látex natural cremado

Resumen En este trabajo se muestran los resultados obtenidos en el estudio experimental del proceso de  producción de látex cremado, en el cual se determinó el efecto de algunas condiciones de operación en  la obtención de un producto que satisfaga los parámetros internacionales de calidad. Se seleccionaron  las condiciones de operación que muestran las influencias más importantes en los criterios de calidad  definidos en la norma ASTM 1076. El estudio se realizó utilizando dos tipos de agente cremador (alginato  de sodio, carboximetilcelulosa), dos concentraciones de éste y cuatro tiempos de cremado. Además, se  estudió la influencia de la separación de fases formadas durante el proceso de cremado en la calidad del  producto obtenido, realizando dos tipos de estudio: sin separación de fases y con separación de fases  cada dos días. Como resultado se obtuvo que el experimento que presentó mayor estabilidad, en TSC  y DRC fue el realizado con alginato de sodio a 1,5g/L con tiempo de cremado menor a 2 semanas, con  separación cada dos días. Palabras clave: caucho natural, concentración de látex, alginato de sodio, carboximetilcelulosa. Experimental study of creaming and separation steps a creamed natural latex manufacturing process Abstract This work shows the results obtained in the experimental study of creamed natural latex manufacturing  process. In this study, the effect of some operating conditions on product properties, that must satisfy the international criteria, has been determined. The operating conditions, that allow the most important effect  on the quality criteria proposed by ASTM 1076, were defined. This work was carried out using two different  creamed agents (sodium aliginate, carboxymethylcellulose), two concentration and four creamed times.  Moreover, the effect on the product quality of the two phase’s separation, produced during the creamed  process, has been studied. Finally, two types of studies were done: with or without phase separation. The  test with the best stability, higher TSC and DRC, were obtained using sodium alginate at 1.5g/L, creamed  times lower than two weeks and phase separation of two days. Keywords: natural rubber, latex concentration, sodium alginate, carboxymethylcellulose

Nickel exsolution driven phase transformation from an n=2 to an n=1 Ruddlesden Popper manganite for methane steam reforming reaction in SOFC conditions

This is the peer reviewed version of the following article: S. Vecino-Mantilla, P. Gauthier-Maradei, M. Huvé, J. M. Serra, P. Roussel, G. H. Gauthier, ChemCatChem 2019, 11, 4631, which has been published in final form at https://doi.org/10.1002/cctc.201901002. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] An original way to perform the exsolution of Ni nanoparticles on a ceramic support was explored for the development of methane steam reforming catalyst in SOFC anode conditions. The n=2 Ruddlesden-Popper (RP) phase La1.5Sr1.5Mn1.5Ni0.5O7 +/-delta has been synthesized by the Pechini method and subsequently reduced with an H-2-N-2 mixture at different temperatures and reducing times to induce the formation of two phases: LaSrMnO4 (n=1 RP) decorated with metallic Ni nanoparticles. Preliminary measurements of catalytic behavior for the steam reforming have been carried out in a reduction-reaction process with a mixture of 82 mol %CH4, 18 mol %N-2 and low steam to carbon ratio (S/C=0.15). The catalyst exhibits a selectivity for CO production (0.97), 14.60 mol % CH4 conversion and around 24.19 mol % H-2 production. Such catalytic behavior was maintained for more than 4 h, with a constant rate of hydrogen production and CH4 conversion rate.The authors acknowledge the financial support of the Colombian Administrative Department of Science, Technology and Innovation COLCIENCIAS (Project #110265842833 "Symmetrical high temperature Fuel Cell operating with Colombian natural gas" (contract #038-2015) and S. Vecino-Mantilla's Ph.D. scholarship (call #647)) and of the Spanish National Research Council CSIC (Project #COOPA20112). The authors are also grateful to UIS' X-Ray Laboratory (Parque Tecnologico Guatiguara) for XRD measurements, UPV's Electronic Microscopy Laboratory for the FESEM analysis, and finally to Margarita Vecino-Mantilla, Carolina Cardenas-Velandia, Santiago Paez-Duque, Ivan Suarez-Acelas (UIS), Maria Fabuel (UPV) and Olivier Gardoll (UCCS) for their contribution to materials synthesis and characterization. As well as Santiago Palencia, Monica Sandoval (UIS) and Caroline Pirovano (UCCS) are warmly acknowledged for useful discussions.Vecino-Mantilla, S.; Gauthier-Maradei, P.; Huvé, M.; Serra Alfaro, JM.; Roussel, P.; Gauthier, GH. (2019). Nickel exsolution driven phase transformation from an n=2 to an n=1 Ruddlesden Popper manganite for methane steam reforming reaction in SOFC conditions. ChemCatChem. 11(18):4631-4641. https://doi.org/10.1002/cctc.201901002S463146411118Ghezel-Ayagh, H., & Borglum, B. P. (2017). Review of Progress in Solid Oxide Fuel Cells at FuelCell Energy. 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Effect of particle size and humidity on sugarcane bagasse combustion in a fixed bed furnace

AbstractThe panela industry is one of the most important Agro Industries in Colombia, making it the largest percapita consumer and the second largest producer worldwide. The fuel used in this process is traditionally the sugarcane bagasse (SB) which is a byproduct of milling. However, due to the low efficiency of panela furnaces additional fuel is required such as wood, used rubber tires and coal. The fixed-bed furnaces inefficiency is mainly due to incomplete combustion of SB caused by the influence of process variables. Therefore, the aim of this work was to study the influence of particle size (PS) and moisture content (MC) over the combustion stages of SB in fixed-bed furnaces. A three-level factorial design was proposed for PS and MC of SB where the temperature and gas concentration were considered as response variables to evaluate the furnace performance. The results obtained in this work show that if the MC increases then the SB yield in the combustion is decreased. On the other hand, the increasing PS can counteract the effect of the MC of SB.Keywords: Sugarcane bagasse combustion, influence of particle size, influence of moisture, temperature profiles, concentrations profiles.Efecto del tamaño de particular y la humedad sobre la combustión de bagazo de caña en un horno de lecho fijoResumenLa agroindustria panelera es una de las más importantes en Colombia, convirtiéndolo en el primer consumidor percápita y segundo productor a nivel mundial. El combustible utilizado en el proceso ha sido tradicionalmente el bagazo de caña (SB) subproducto de la molienda. Sin embargo, debido a las bajas eficiencias de los hornos paneleros se requiere de combustibles adicionales como leña, caucho de llanta y carbón. Gran parte de la ineficiencia de los hornos de lecho fijo se debe a una combustión incompleta del SB, ocasionada por la influencia de las variables del proceso. Por lo anterior, el objetivo de este trabajo fue estudiar la influencia de las variables tamaño de partícula (PS) y contenido de humedad (MC) sobre las etapas de combustión del SB en hornos de lecho fijo. Se planteó un diseño factorial de experimentos con tres niveles para el PS y el MC del SB, donde la temperatura y la concentración del gas de combustión fueron consideradas como variables de respuesta para evaluar el desempeño del horno. Los resultados obtenidos muestran que el incremento del MC ocasiona una reducción en el rendimiento de la combustión del SB. Por otra parte, el incremento en el PS puede contrarrestar el efecto del MC del SB.Palabras clave: combustión de bagazo de caña, influencia tamaño de partícula, influencia humedad, perfiles de temperatura, perfiles de concentración

Waste-to-energy conversion technologies in the UK: Processes and barriers – A review

This paper reviews the sector of waste-to-energy looking at the main processes and feedstock involved. Within this, incineration, gasification, pyrolysis, anaerobic digestion and hydrothermal liquefaction are named and discussed. Through the discussions and scrutiny, manure is highlighted as a significant source of ammonia, methane, and nitrogen oxides emission, estimated to be 40%, 22.5% and 28% respectively of the total UK's anthropogenic emissions. Manure, and indeed the pollution it poses, are shown to remain largely ignored. In waste to energy processing, manure is capable of providing biogas for a number of pathways including electricity generation. Anaerobic digestion is highlighted as a suitable process with the crucial capability of drastically reducing the pollution potential of manure and slurry compared to no processing, with up to 90% reduction in methane and 50% reduction in nitrogen oxide emissions. If the majority of the 90 million tonnes of manure and slurry in the UK were to be processed through biogas harvesting, this could have the potential of producing more than 1.615 TWh of electricity. As such, the economics and legislation surrounding the implementation of anaerobic digestion for manure and slurry are discussed. In the end, restraining factors that limit the implementation of anaerobic digesters on farms in the UK are discussed. These are found to be mainly capital costs, lack of grants, insufficiently high tariff systems, rather than low gas yields from manure and slurry

Effect of Cooking Conditions on Selected Properties of Biodiesel Produced from Palm-Based Waste Cooking Oils

Cooking conditions affect oil properties and consequently, the quality of the derived biodiesel. Nevertheless, little information regarding the impact of the cooking process on biodiesel properties is currently available, especially for palm biodiesel. Therefore, this study examined the effect of cooking temperature, time of use, and length of reuse, on selected properties of biodiesel produced from palm-based waste cooking oils (WCO). Several WCO collected from restaurants belonging to four categories, namely fried chicken restaurants, fast food restaurants, snack producers, and typical restaurants, were subjected to base-catalyzed transesterification. The biodiesel yield was calculated, and the produced biodiesel was characterized as to its kinematic viscosity, calorific value, and cetane number. As a result, palm-based WCO performed better than other WCO in terms of biodiesel yield regardless of the conditions that they experienced, achieving almost 95% in some cases. The yield decreased as the cooking temperature and length of reuse moved upward, whereas the kinematic viscosity was sensitive only to the length of reuse, rising with increasing reuse. Non-compliance with biodiesel standards and technical requirements was observed in a few cases. The calorific value did not significantly change unless the cooking conditions were severe. The cetane number dropped as use and reuse decreased, remaining better compared to petrodiesel (70.2 ± 3.2 on average). Typical restaurants would generate the most suitable WCO to produce biodiesel, i.e., yield: 93.1 ± 0.2%; kinematic viscosity: 5.0 ± 0.3 mm2/s; calorific value: 39.9 ± 0.1 MJ/kg; density: 919 ± 9 kg/m3; and cetane number: 67.4 on average. This is consistent with the less severe cooking conditions employed at these restaurants

Effect of Cooking Conditions on Selected Properties of Biodiesel Produced from Palm-Based Waste Cooking Oils

Cooking conditions affect oil properties and consequently, the quality of the derived biodiesel. Nevertheless, little information regarding the impact of the cooking process on biodiesel properties is currently available, especially for palm biodiesel. Therefore, this study examined the effect of cooking temperature, time of use, and length of reuse, on selected properties of biodiesel produced from palm-based waste cooking oils (WCO). Several WCO collected from restaurants belonging to four categories, namely fried chicken restaurants, fast food restaurants, snack producers, and typical restaurants, were subjected to base-catalyzed transesterification. The biodiesel yield was calculated, and the produced biodiesel was characterized as to its kinematic viscosity, calorific value, and cetane number. As a result, palm-based WCO performed better than other WCO in terms of biodiesel yield regardless of the conditions that they experienced, achieving almost 95% in some cases. The yield decreased as the cooking temperature and length of reuse moved upward, whereas the kinematic viscosity was sensitive only to the length of reuse, rising with increasing reuse. Non-compliance with biodiesel standards and technical requirements was observed in a few cases. The calorific value did not significantly change unless the cooking conditions were severe. The cetane number dropped as use and reuse decreased, remaining better compared to petrodiesel (70.2 ± 3.2 on average). Typical restaurants would generate the most suitable WCO to produce biodiesel, i.e., yield: 93.1 ± 0.2%; kinematic viscosity: 5.0 ± 0.3 mm2/s; calorific value: 39.9 ± 0.1 MJ/kg; density: 919 ± 9 kg/m3; and cetane number: 67.4 on average. This is consistent with the less severe cooking conditions employed at these restaurants

Methane steam reforming in water-deficient conditions on a new ni-exsolved ruddlesden-popper manganite: coke formation and h2s poisoning

International audienceThis research deals with the catalytic behavior of the methane steam reforming reaction over a new Ni-exsolved Ruddlesden-Popper manganite during prolonged reaction time (up to 100 h) with special focus on the possible carbon deposition and H2S poisoning. La1.5Sr1.5Mn1.5Ni0.5O7±δ material was synthesized and reduced in diluted hydrogen to induce Ni exsolution. Its catalytic behavior in long reaction times was compared to Ni-impregnated manganite and Ni/YSZ cermet. The catalytic measurements for the steam reforming reaction were carried out at 850 °C in low steam-to-carbon conditions. All materials are susceptible to H2S poisoning (50 ppm), forming undesired sulfide compounds with damaging impact on their catalytic activity. In contrast, during tests without H2S, the activity for cermet and impregnated materials drops at relatively short reaction time due to coking formation, as evidenced by TEM and TGA/MS analysis, while the behavior of new exsolved material remains stable throughout the test. This high stability of the new exsolved catalyst over a prolonged reaction time is a noticeable advantage due to its potential use as SOFC anode fed with natural gas free of H2S

Heat transfer metrology issues in two-phase bubble column reactors

International audienceThe metrology and the impact of various parameters and operating conditions on the bulk-to-tube heat transfer coefficients in two-phase bubble columns are investigated on a small-scale mock-up. It is shown that (1) quasi-adiabatic conditions can be reached in the column; (2) the bulk-to-tube heat transfer coefficients for each U-tube downward and upward sections may or may not differ significantly, depending on the way uncertainty of the measurements is estimated; (3) using the different measurements and uncertainty estimates for given conditions, a mean heat transfer coefficient over all tubes is estimated within +/- 5%. The consequences for bulk-to-tube heat transfer coefficient prediction in a larger column are discussed