Assessment of non-conventional pretreatments for agriculture wastes utilization

Los pretratamientos convencionales de biomasa lignocelulósica involucran el uso intensivo de altas temperaturas, presiones, largos tiempos de residencia sumado a los requerimientos de productos químicos y los elevados consumos energéticos pueden llevar a promover la producción de compuestos inhibitorios así como la degradación de azúcares. Como una alternativa a su uso, dos pretratamientos no convencionales (Pretratamiento asistido con ultrasonido y pretratamiento con fluidos supercríticos) fueron empleados para evaluar los rendimientos de este etapa y la digestibilidad enzimática de materias primas de origen agrícola como la cascarilla de arroz, el tallo de plátano y el pseudotallo de plátano. Algunas variables operacionales como temperatura, amplitud y tiempos de pretratamiento fueron evaluados durante el Pretratamiento asistido con ultrasonido, mientras que el contenido de humedad, presión y temperatura fueron las variables analizadas en el pretratamiento con dióxido de carbono supercrítico. La materia prima que ofreció un mejor comportamiento al ser pretratada con ultrasonido fue el pseudotallo de plátano incrementando la producción de azúcares reductores en ordenes de 2-3 veces comparado con el pretratamiento con ácido diluido (0.78 g azúcares reductores/ g biomasa pretratada recuperada). Este rendimiento fue alcanzado a una temperature de 60°C y 100% de amplitud. Por otro lado, la materia prima que presentó el mejor comportamiento en reducción de índice de cristalinidad y una adecuada redistribución en la matriz lignocelulósica. Finalmente, logró establecerse que diferentes efectos pueden ser alcanzados de acuerdo con las características de las materias primas, estos a su vez pueden generar diferentes impactos a nivel técnico, económico y ambientalAbstract : The current pretreatments of lignocellulosic biomass conventional involve the intensive use of high temperatures, pressures, long times of residence, added to high chemical inputs requirements and elevated energy consumption which sometimes producing inhibitory compounds and sugars degradation. As an alternative to their use two non-conventional pretreatments such as ultrasound assisted pretreatment and supercritical carbon dioxide pretreatments were used to evaluate pretreatment yields and enzymatic digestibility of rice husk, cassava stem and plantain pseudostem. Some operational conditions such as temperature, amplitude, pretreatment time were evaluated during the ultrasound assisted pretreatment whereas the moisture content, pressure and temperature of the pretreatment were evaluated for supercritical carbon dioxide pretreatment. The best performance of ultrasound assisted pretreatment was presented by plantain pseudostem improving the reducing sugars production to 2-3 folds compared the dilute pretreatment (0.78 g total reducing sugars/g of biomass recovered from pretreatment stage). This yield was reached at 60°C and 100% of ultrasound amplitude. By the other hand, for supercritical pretreatment the best performance was presented using rice husk as raw material obtaining reductions in crystallinity index and redistribution of the lignocellulosic matrix. It could be established that different effects according to the raw material specifications can be reached. Finally it was concluded as a first approach that through these pretreatments would be significantly impacted the technological, economic and environmental performance of scalesMaestrí

Assessment of non-conventional pretreatments for agriculture wastes utilization

Los pretratamientos convencionales de biomasa lignocelulósica involucran el uso intensivo de altas temperaturas, presiones, largos tiempos de residencia sumado a los requerimientos de productos químicos y los elevados consumos energéticos pueden llevar a promover la producción de compuestos inhibitorios así como la degradación de azúcares. Como una alternativa a su uso, dos pretratamientos no convencionales (Pretratamiento asistido con ultrasonido y pretratamiento con fluidos supercríticos) fueron empleados para evaluar los rendimientos de este etapa y la digestibilidad enzimática de materias primas de origen agrícola como la cascarilla de arroz, el tallo de plátano y el pseudotallo de plátano. Algunas variables operacionales como temperatura, amplitud y tiempos de pretratamiento fueron evaluados durante el Pretratamiento asistido con ultrasonido, mientras que el contenido de humedad, presión y temperatura fueron las variables analizadas en el pretratamiento con dióxido de carbono supercrítico. La materia prima que ofreció un mejor comportamiento al ser pretratada con ultrasonido fue el pseudotallo de plátano incrementando la producción de azúcares reductores en ordenes de 2-3 veces comparado con el pretratamiento con ácido diluido (0.78 g azúcares reductores/ g biomasa pretratada recuperada). Este rendimiento fue alcanzado a una temperature de 60°C y 100% de amplitud. Por otro lado, la materia prima que presentó el mejor comportamiento en reducción de índice de cristalinidad y una adecuada redistribución en la matriz lignocelulósica. Finalmente, logró establecerse que diferentes efectos pueden ser alcanzados de acuerdo con las características de las materias primas, estos a su vez pueden generar diferentes impactos a nivel técnico, económico y ambientalAbstract : The current pretreatments of lignocellulosic biomass conventional involve the intensive use of high temperatures, pressures, long times of residence, added to high chemical inputs requirements and elevated energy consumption which sometimes producing inhibitory compounds and sugars degradation. As an alternative to their use two non-conventional pretreatments such as ultrasound assisted pretreatment and supercritical carbon dioxide pretreatments were used to evaluate pretreatment yields and enzymatic digestibility of rice husk, cassava stem and plantain pseudostem. Some operational conditions such as temperature, amplitude, pretreatment time were evaluated during the ultrasound assisted pretreatment whereas the moisture content, pressure and temperature of the pretreatment were evaluated for supercritical carbon dioxide pretreatment. The best performance of ultrasound assisted pretreatment was presented by plantain pseudostem improving the reducing sugars production to 2-3 folds compared the dilute pretreatment (0.78 g total reducing sugars/g of biomass recovered from pretreatment stage). This yield was reached at 60°C and 100% of ultrasound amplitude. By the other hand, for supercritical pretreatment the best performance was presented using rice husk as raw material obtaining reductions in crystallinity index and redistribution of the lignocellulosic matrix. It could be established that different effects according to the raw material specifications can be reached. Finally it was concluded as a first approach that through these pretreatments would be significantly impacted the technological, economic and environmental performance of scalesMaestrí

Análisis tecno-económico de una biorefinería a partir de residuos del plátano

El pseudotallo de pl tano es un residuo lignocelul sico disponible en grandes cantidades en Colombia debido a la amplia demanda que se tiene del fruto de pl tano. Este material es desaprovechado y dispuesto de manera incorrecta generando contaminaci n en suelos y fuentes acu feras. El presente trabajo describe la simulaci n y evaluaci n tecno-econ mica bajo el concepto de biorefiner a de la producci n de etanol, furfural, cido l ctico y xilitol utilizando pseudotallo de pl tano como materia prima considerando dos escenarios: el caso base (producci n de los compuestos mencionados) anteriormente y un segundo escenario que emplea los s lidos remanentes del primer escenario a trav s de un sistema de cogeneraci n. El an lisis de costos y m rgenes de ganancia obtenidos muestran la viabilidad de la producci n de furfural, xilitol y cido l ctico a partir de pseudotallo de pl tano, lo cual permitir a alcanzar m rgenes de ganancia positivos.Banana pseudostem is a lignocellulosic material highly available in Colombia due to the large demand of plantain bunches. This material is incorrectly wasted and disposed causing both soil and water source contamination. The present work describes the simulation and techno-economic evaluation of furfural, ethanol, xylitol and acetic acid production under biorefinery concept, by using banana pseudostem as raw material in two process stages: base case in which only previous chemicals production is made, and another where besides raw material remainder solid fraction is used for energy cogeneration through gasification system. The cost obtained and gain margin analysis show furfural, xylitol and lactic acid production viability from banana pseudostem; and energy cogeneration positive influence inside banana pseudostem s biorefinery.Cuencanúmero 1

Integral Analysis of Liquid-Hot-Water Pretreatment of Wheat Straw: Evaluation of the Production of Sugars, Degradation Products, and Lignin

Developing sustainable biorefineries is an urgent matter to support the transition to a sustainable society. Lignocellulosic biomass (LCB) is a crucial renewable feedstock for this purpose, and its complete valorization is essential for the sustainability of biorefineries. However, it is improbable that a single pretreatment will extract both sugars and lignin from LCB. Therefore, a combination of pretreatments must be applied. Liquid-hot-water (LHW) is highlighted as a pretreatment for hemicellulose hydrolysis, conventionally analyzed only in terms of sugars and degradation products. However, lignin is also hydrolyzed in the process. The objective of this work was to evaluate LHW at different conditions for sugars, degradation products, and lignin. We performed LHW at 160, 180, and 200 °C for 30, 60, and 90 min using wheat straw and characterized the extract for sugars, degradation products (furfural, hydroxymethylfurfural, and acetic acid), and lignin. Three conditions allowed reaching similar total sugar concentrations (~12 g/L): 160 °C for 90 min, 180 °C for 30 min, and 180 °C for 60 min. Among these, LHW performed at 160 °C for 90 min allowed the lowest concentration of degradation products (0.2, 0.01, and 1.4 g/L for furfural, hydroxymethylfurfural, and acetic acid, respectively) and lignin hydrolysis (2.2 g/L). These values indicate the potential use of the obtained sugars as a fermentation substrate while leaving the lignin in the solid phase for a following stage focused on its extraction and valorization

Recovery of Salts from Synthetic Erythritol Culture Broth via Electrodialysis: An Alternative Strategy from the Bin to the Loop

Sustainability and circularity are currently two relevant drivers in the development and optimisation of industrial processes. This study assessed the use of electrodialysis (ED) to purify synthetic erythritol culture broth and for the recovery of the salts in solution, for minimising the generation of waste by representing an efficient alternative to remove ions, ensuring their recovery process contributing to reaching cleaner standards in erythritol production. Removal and recovery of ions was evaluated for synthetic erythritol culture broth at three different levels of complexity using a stepwise voltage in the experimental settings. ED was demonstrated to be a potential technology removing between 91.7–99.0% of ions from the synthetic culture broth, with 49–54% current efficiency. Besides this, further recovery of ions into the concentrated fraction was accomplished. The anions and cations were recovered in a second fraction reaching concentration factors between 1.5 to 2.5 times while observing low level of erythritol losses (<2%), with an energy consumption of 4.10 kWh/m3.1181