Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : absorption


Absorption of Carbon Dioxide into Aqueous Ammonia Solution using Blended Promoters (MEA, MEA+PZ, PZ+ArgK, MEA+ArgK)

Farah T. Al-Sudani

Engineering and Technology Journal, 2020, Volume 38, Issue 9, Pages 1359-1372
DOI: 10.30684/etj.v38i9A.876

Absorption of CO2 into promoted-NH3 solution utilize a packed column (1.25 m long, 0.05m inside diameter) was examined in the present work. The process performance of four different blended promoters monoethanolamine (MEA)+ piperazine (PZ), piperazine (PZ)+ potassium argininate (ArgK) and monoethanolamine +potassium argininate was compared with unpromoted-NH3 solution by evaluated the absorption rate (φ_(CO_2 )) and overall mass transfer coefficient (K_(G,CO_2.) a_v) over the operating ranges of the studied process variables (1-15Kpa initial partial pressure of CO2, 5-15 Liter/min gas flow rate, 0.25-0.85 Liter/min liquid flow rate). The results exhibit that the absorption behavior and efficiency can be enhanced by rising volumetric liquid flow rate and initial CO2 partial pressure. However, the gas flow rate should be kept at a suitable value on the controlling gas film. Furthermore, it has been observed that the (PZ+ArgK) promoter was the major species that can accelerate the absorption rate and reached almost 66.166% up to123.23% over that of the unpromoted-NH3 solution.

Dynamic Study of Carbon Dioxide Absorption Using Promoted Absorbent in Bubble Column Reactor

Safa A. Al-Naimi; Farah T. Jasim; Ahmed N. Kokaz

Engineering and Technology Journal, 2019, Volume 37, Issue 1C, Pages 70-78
DOI: 10.30684/etj.37.1C.11

The most common process to remove carbon dioxide from natural gas and the flue gasses is absorption into suitable solvents. Absorption of carbon dioxide are studied experimentally in this work using bubble column reactor (glass cylindrical (QVF) of 7.5 cm i.d. × 140 cm height), where different types of absorbent (30%MEA, 30%K2CO3), promoter types (organic(piperazine)and inorganic(amino acids)) and concentrations were examined over a wide range of gas flow rate cover homogeneous to transition flow regime at ambient temperature and atmospheric pressure. The results showed that the dissolved gas undergoes a pseudo-first order reaction, and the optimum superficial velocity of gas given a higher conversion and rate of reaction at Ug=0.025 m/sec, at this velocity the reaction rate of monoethanolamine with carbon dioxide (94.1% conversion and RA = 7.75*10-3 Kmol/m3 .sec) is higher than reaction rate of potassium carbonate with carbon dioxide(29.3% conversion and RA = 2.73*10-3 Kmol/m3 .sec). Furthermore, the addition of promoters to the 30%K2CO3 absorbents enhanced the reaction between potassium carbonate with carbon dioxide and increased the reaction rate when increasing the concentration of promoters to the critical concentration. The results show that the piperazine is a better promoter from other types of the amino acid promoter used was 52.1% increase in carbonate conversion with carbon dioxide

Effect of Temperature and Concentration on the Optical Properties of PVC Solutions

Esam A. Tawfiq; Shams. M. Abdul kareem

Engineering and Technology Journal, 2018, Volume 36, Issue 2B, Pages 170-174
DOI: 10.30684/etj.36.2B.14

In this paper, effects of temperature and concentration on the
absorption spectra for Polyvinyl chloride solutions are studied at wavelengths
from 200 to 400 nm and with the range of temperature 20, 30, 40, 50, and 60
degrees (Co). Electronic absorption spectra were examined over the
wavelength range 200-400 nm by different concentrations (1x10-3, 8x10-4,
6.5x10-4, 5x10-4 and 3x10-4)[M]. The UV spectra shifted slightly towards
large wavelength with increasing the temperature. The values of the energy
gap of polyvinyl chloride are decreasing as concentration and temperature
increased. The data shows that the refractive index of the polymer decreases
with increasing the wavelength and temperature. The relationship between the
absorption coefficient and photon energy of the PVC solutions are calculated.

Perovskite Thin Film Preparation and Energy Band-Gap Determination for Solar Cell Applicatiosn

Thaira Z. Altayyar; Shubhra Gangopadhyay

Engineering and Technology Journal, 2016, Volume 34, Issue 14, Pages 2611-2620
DOI: 10.30684/etj.34.14A.6

Using Perovskite is a promising approach for upgrading the performance of an established low-bandgap Si photo voltaic (PV) solar technology because Perovskite is a high bandgap polycrystalline semiconductor compared with bulk Si and other semiconductors such as GaAs. In this work, Perovskite-structured methyl ammonium lead triiodide CH3NH3PbI3 uniform one-step planar thin films nanoparticles (NPs) have been developed from the reaction process of methylammonium iodide with PbI2 and deposited on a glass substrate by Aerosol Assisted Chemical Vapor Deposition (AACVD) to minimize the size of the solar cell and to reduce the cost and increase efficiency. This aims at the study and investigation of the energy bandgap (Eg) of nano-architectured solar cells absorber film as light harvesters. The X-ray diffraction (XRD) patterns of a CH3NH3PbI3 film on glass substrates are recorded by X' Pert Ultima IV X-ray diffractometer. Optical band gap of CH3NH3PbI3 is estimated by UV−Vis absorption spectroscopy and extracted from the absorption spectrum of the Tauc plot to be 1.63 eV. The Perovskite deposited on glass appears efficient to absorb most of the light with wavelength below 800 nm with a refractive index (n): 2.75. The film thickness was measured by an optical profile-meter to be about 200 nm, giving small reflectivity of 0.23 and resulting in efficiency enhancement of 15.7 %.