Air Gasification of Banana (Musa spp.) Residues to Produce Biofuels

Thermochemical conversion of biomass is a technique used in recovering its energetic content and for the production useful biofuels. A lot of wastes/residues are generated from the harvesting and consumption of banana fruits. This study developed an ASPEN Plus model for the gasification of banana (Musa Spp.) residues pseudo-stem, the peels and the leaves. The model will be used to study the effect of gasification temperature, gasification pressure and air-fuel ratio (AFR) on the selectivity of the chemical species in the product stream. For all three residues, the selectivity of hydrogen increases with temperature with temperature. At the optimum temperature, the hydrogen molar selectivity in the product stream is 56% (900oC), 55% (900oC) and 53% (700oC) for pseudo-stem, peels and leaves respectively. At the optimum atmospheric pressure, the hydrogen molar percentage in the product stream was 48%, 49% and 50% for pseudo-stem, peels and leaves respectively. At the optimum AFR, the hydrogen selectivity in the product stream is 55%, 52% and 46% for pseudo-stem, peels and leaves respectively. All three residues are reasonably good feedstock for the gasification process but the pseudo-stem possesses a marginal advantage over the others.

Effect of ionic liquids as entrainers on the dynamic behavior of ethanol-water extractive columns

Ionic liquids (ILs) have been recently considered as potential entrainers for extractive distillation. The use of ILs may affect the vapor-liquid properties to aid the separation of azeotropic mixtures. In particular, their effectiveness has been observed for ethanol dehydration, showing promising perspectives for their industrial implementation. However, there is still a lack of information about the effect of ILs on the system controllability. The objective of this work is to explore the dynamic implications of the use of two types of ionic liquids on the ethanol dehydration process. An equimolar feed mixture of ethanol and water was considered, and different IL concentrations were tested. The results show that changing the IL concentration affect the degree of stabilization of the product stream, even when smooth dynamic responses were in many cases observed.

Design and simulation of high purity biodiesel reactive distillation process

Biodiesel is a promising energy substitute of fossil fuels since it is produced from renewable and biodegradable sources. In the present work, reactive distillation (RD) process is designed and simulated using Aspen Plus process simulator to produce biodiesel of high purity through esterification reaction. The simultaneous reaction and separation in same unit enhances the biodiesel yield and composition in RD process. Two flowsheets are proposed in present work. In the first flowsheet, the unreacted methanol is recycled back to reactive distillation column. Biodiesel with 99.5 mol% purity is obtained in product stream while the byproduct stream comprises 95.2 mol% water, which has to be treated further. In the second flowsheet, a part of methanol recycle is split and purged. In this case, the biodiesel composition in product stream is 99.7 mol% whereas water composition is 99.9 mol% in byproduct stream, which can be reused for other process without treatment.

A Microfluidic Split-Flow Technology for Product Characterization in Continuous Low-Volume Nanoparticle Synthesis

A key aspect of microfluidic processes is their ability to perform chemical reactions in small volumes under continuous flow. However, a continuous process requires stable reagent flow over a prolonged period. This can be challenging in microfluidic systems, as bubbles or particles easily block or alter the flow. Online analysis of the product stream can alleviate this problem by providing a feedback signal. When this signal exceeds a pre-defined range, the process can be re-adjusted or interrupted to prevent contamination. Here we demonstrate the feasibility of this concept by implementing a microfluidic detector downstream of a segmented-flow system for the synthesis of lipid nanoparticles. To match the flow rate through the detector to the measurement bandwidth independent of the synthesis requirements, a small stream is sidelined from the original product stream and routed through a measuring channel with 2 × 2 µm cross-section. The small size of the measuring channel prevents the entry of air plugs, which are inherent to our segmented flow synthesis device. Nanoparticles passing through the small channel were detected and characterized by quantitative fluorescence measurements. With this setup, we were able to count single nanoparticles. This way, we were able to detect changes in the particle synthesis affecting the size, concentration, or velocity of the particles in suspension. We envision that the flow-splitting scheme demonstrated here can be transferred to detection methods other than fluorescence for continuous monitoring and feedback control of microfluidic nanoparticle synthesis.

Controlling the product selectivity in the conversion of methanol to the feedstock for phenol production

A product stream for phenol production along with p-xylene and alkenes was achieved using 1.5 wt% Zn/Si/HZSM-5.