scholarly journals CO2 gasification of microalgae (N. Oculata) – A thermodynamic study

2018 ◽  
Vol 154 ◽  
pp. 01002 ◽  
Author(s):  
Muflih Arisa Adnan ◽  
Mohammad Mozahar Hossain

A new model of CO2 gasification has been developed in the Aspen Plus. The potential of microalgae (N. oculata) for CO2 gasification also has been investigated. The present gasification process utilizes the CO2 at atmospheric pressure as the gasifying agent. The steam is also injected to the gasification to enhance the H2 production. The composition of the producer gas and gasification system efficiency (GSE) are used for performance evaluation. It is found that the CO2 gasification of microalgae produces a producer gas with a high concentration of CO and H2. The GSE indicates that the process works at high performance.

2018 ◽  
Vol 10 (1) ◽  
pp. 18 ◽  
Author(s):  
H Hendriyana ◽  
S Suhartono ◽  
Herri Susanto

Thermodynamic study on vapour-liquid equilibrium of toluene and several types of oil as absorbent Gas cleaning system is one of important step in the utilization of biomass via gasification process. The producer gas obtained from the gasification process must be very clean before it is used in an internal combustion engine. In order to gaseous fuel get cleaned with a tar content below 100 mg/Nm3, a gas cleaning system using scrubbing oil is being developed and taking the advantage of a lower vapour pressure of oil than scrubbing water. Study on vapour-liquid equilibrium is being conducted to understand the phenomena taking place in the absorption of tar with oil. In our present study, the producer gas containing tar is represented using air containing toluene. This producer gas model with a toluene or benzene concentration then bubbled with a rate of 27.6 mL/min into a bath of oil at a various temperature. The progress of absorption of tar model in oil measured gas chromatography until saturated condition. Considering that the concentration of toluene in the gas stream is very low, the toluene and oil vapour-liquid equilibrium follows the Henry’s law. Prediction of Henry’s constants is also carried out using UNIFAC-FV model which is known to be suitable for hydrocarbon gases and high-boiling point hydrocarbon solvent. Keywords: tar, oil, Henry’s constant AbstrakSistem pembersihan gas merupakan salah satu langkah penting dalam pemanfaatan biomassa melalui proses gasifikasi. Gas produser yang dihasilkan dari proses gasifikasi harus sangat bersih sebelum digunakan dalam mesin pembakaran internal. Untuk mendapatkan bahan bakar gas yang bersih dengan kandungan tar di bawah 100 mg/Nm3. Sebuah sistem pembersihan gas dengan menggunakan minyak sebagai media penyerap dikembangkan dengan mengambil keuntungan dari tekanan uap minyak lebih rendah air penyerap. Studi kesetimbangan uap-cair yang dilakukan untuk memahami fenomena yang terjadi dalam penyerapan tar dengan minyak. Dalam kami studi ini, gas produser yang mengandung direpresentasikan dengan udara yang mengandung toluena. Model gas produser ini dibuat dengan menggelembungkan konsentrasi benzena atau toluena dengan laju 27,6 mL/menit ke dalam bak minyak pada berbagai suhu. Kemajuan penyerapan model tar dalam minyak diukur dengan cromathograpy gas sampai dengan kondisi jenuh. Mengingat konsentrasi toluena dalam aliran gas sangat rendah, maka kesetimbangan uap-cair toluena dan minyak mengikuti hukum Henry. Konstanta Henry juga dapat diprediksi dengan menggunakan model UNIFAC-FV yang cocok untuk gas hidrokarbon dan pelarut hidrokarbon dengan titik didih tinggi. Kata kunci: tar, minyak, konstanta Henry


Author(s):  
Lin Lin ◽  
Piyadarsha Amaratunga ◽  
Jerome Reed ◽  
Pornkamol Huang ◽  
Bridget Lorenz Lemberg ◽  
...  

Abstract Quantitative analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in oral fluid has gained increasing interest in clinical and forensic toxicology laboratories. New medicinal and/or recreational cannabinoid products require laboratories to distinguish different patterns of cannabinoid use. This study validated a high-performance liquid chromatography-tandem mass spectrometry method for 13 different cannabinoids, including (-)-trans-Δ8-tetrahydrocannabinol (Δ8-THC), (-)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid-A (Δ9-THCA-A), cannabidiolic acid (CBDA), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-Δ9-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THCCOOH), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiorcol (CBD-C1), cannabichromene (CBC), cannabinol (CBN) and cannabigerol (CBG), in oral fluid. Baseline separation was achieved in the entire quantitation range between Δ9-THC and its isomer Δ8-THC. The quantitation range of Δ9-THC, Δ8-THC and CBD was from 0.1 to 800 ng/mL. Two hundred human subject oral fluid samples were analyzed with this method after solid phase extraction. Among the 200 human subject oral fluid samples, all 13 cannabinoid analytes were confirmed in at least one sample. Δ8-THC was confirmed in 11 samples, with or without the presence of Δ9-THC. A high concentration of 11-OH-Δ9-THC or Δ9-THCCOOH (>400 ng/mL) was confirmed in three samples. CBD, Δ9-THCA-A, THCV, CBN and CBG were confirmed in 74, 39, 44, 107 and 112 of the 179 confirmed Δ9-THC-positive samples, respectively. The quantitation of multiple cannabinoids and metabolites in oral fluid simultaneously provides valuable information for revealing cannabinoid consumption and interpreting cannabinoid-induced driving impairment.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1808
Author(s):  
Rosa Tundis ◽  
Carmela Conidi ◽  
Monica R. Loizzo ◽  
Vincenzo Sicari ◽  
Rosa Romeo ◽  
...  

Olive mill wastewater (OMW), generated as a by-product of olive oil production, is considered one of the most polluting effluents produced by the agro-food industry, due to its high concentration of organic matter and nutrients. However, OMW is rich in several polyphenols, representing compounds with remarkable biological properties. This study aimed to analyze the chemical profile as well as the antioxidant and anti-obesity properties of concentrated fractions obtained from microfiltered OMW treated by direct contact membrane distillation (DCMD). Ultra-high performance liquid chromatography (UHPLC) analyses were applied to quantify some phenols selected as phytochemical markers. Moreover, α-Amylase, α-glucosidase, and lipase inhibitory activity were investigated together with the antioxidant activity by means of assays, namely β-carotene bleaching, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) diammonium salts, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and Ferric Reducing Activity Power (FRAP) tests. MD retentate—which has content of about five times greater of hydroxytyrosol and verbascoside and about 7 times greater of oleuropein than the feed—was more active as an antioxidant in all applied assays. Of interest is the result obtained in the DPPH test (an inhibitory concentration 50% (IC50) of 9.8 μg/mL in comparison to the feed (IC50 of 97.2 μg/mL)) and in the ABTS assay (an IC50 of 0.4 μg/mL in comparison to the feed (IC50 of 1.2 μg/mL)).


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.


Nanoscale ◽  
2015 ◽  
Vol 7 (30) ◽  
pp. 13088-13095 ◽  
Author(s):  
Md Mokhlesur Rahman ◽  
Irin Sultana ◽  
Zhiqiang Chen ◽  
Mateti Srikanth ◽  
Lu Hua Li ◽  
...  

A new liquid plasma method is used to fabricate a Co3O4/CNT nanocomposite anode using a nanosecond pulse atmospheric pressure for sodium-ion battery application.


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