Prediction and Optimization of Sulphur Trioxide Yield from Calcination of Aluminium Sulfate Using Central Composite Design

Sulphur trioxides are common toxic gaseous pollutants which can be produced from alternative routes via calcination of aluminum sulfate derived from kaolin clay. Its demand increases geometrically, thus the need to optimize the yield of SO3 from the calcination of alum is essential. The rate of alum decomposition was monitored by the formation of SO3 via thermogravimetric analysis and X-ray fluorescence analysis. This study aimed to evaluate the effect of calcination temperature and curing time on the SO3 conversion and yields using Face Central Composite Design and optimize the process conditions to evaluate the maximum yield of SO3 using response surface methodology and its effects and interactions were investigated between 800–900 °C at 60-180 minutes. Results indicated that experimental data satisfied second order polynomial regression model for SO3 conversion and SO3 yield from TG analysis while XRF analysis satisfied first order model respectively. An increase in SO3 conversion and yields was observed as the calcination temperature and time were increased both independently and simultaneously. The calcination temperature was found to have a stronger influence compared to the calcination time. Validation indicated agreement between experimental and predicted values with a regression value of 97.8 %, 97.77 % and 97.67 % for SO3 conversion, SO3 yield via TG and XRF analyses respectively. Based on the ANOVA, the SO3 yield via XRF produced the best model with R2pred of 91.98% while SO3 yield via TG analysis and SO3 conversion had R2pred of 79.99% and 78.01% respectively. Optimization of the production of SO3 was carried out and the optimal condition for SO3 conversion, SO3 yield via TG and XRF analyes were 90.11 %, 91.67 % and 75.81 % respectively at an optimal calcination temperature of 877.43 oC and time of 155.04 minutes respectively

Prediction of Loss on Ignition of Ternary Cement Containing Coal Bottom Ash and Limestone Using Central Composite Design

The effect of CBA/CBA-L ratio and the cement replacement on the Loss on ignition (LOI) of ternary cement blends was investigated using central composite design approach in the prediction of LOI of ternary cement blend comprising of Ordinary Portland cement, coal bottom ash and Limestone. LOI is an essential technique employed in the determination of the quality of the cement blend which can be achieved by heating a sample strongly at a specified temperature to enable release of volatile components until the weight remains constant. In this study, monitoring of the LOI of the various cement blends conducted dependent on cement replacement and coal bottom ash to coal bottom ash-limestone ratio (CBA/CBA-L ratio) via thermogravimetric analysis (TGA) and X-ray fluorescence (XRF) analysis. The CBA/CBA-L ratio was varied from 0.25-0.75 while the cement replacement ranges from 20-40%. The significance of these factors within the specified ranges considered was evaluated using analysis of variance.The aim of the study was to evaluate the effect of CBA/CBA-L ratio and cement replacement in the prediction of LOI for ternary cement blends by employing Face Central Composite Design. Analysis of variance results indicated that the LOI prediction via XRF analysis was better than that of TG analyses in which both satisfied Two-Level Factorial model. It was observed from the predictive models that the LOI of the ternary cement decreased as the CBA/CBA-L ratio was increased while LOI of the ternary cement blend increased as the cement replacement was increased. An increase in both CBA/CBA-L ratio and cement replacement resulted in a decrease in the LOI of ternary cement. The cement replacement level of the ternary cement blends indicated a stronger influence on LOI compared to the CBA/CBA-L ratio which was indicated by a significantly high F value for cement replacement compared to CBA/CBA-L ratio.The LOI results from XRF analysis were also found to significantly predict the LOI of the ternary cement blend compared to TGA with Regression value of 99.96% against 97.36% respectively. The CBA/CBA-L ratio and cement replacement were found to have a significant and interactive effect on the LOI of ternary cement blend for both XRF and TGA analyses

Synthesis and Application of Porous Kaolin-Based ZSM-5 in the Petrochemical Industry

Zeolites are advanced chemical materials that play a significant role in many petrochemical applications. In recent years, research interest in improving and enhancing the effectiveness of ZSM-5 as a catalyst has grown immensely. In particular, finding cheaper, environmentally friendly alternative starting materials for the synthesis of ZSM-5 has gained much attention. Kaolin has been widely investigated as a zeolite precursor as it comprises the required constituents for an aluminosilicate zeolite material; ubiquitous nature and its benefit in synthesising zeolites are well known as an inexpensive way of obtaining catalysts. This chapter deals with the factors affecting ZSM-5 synthesis when utilising a kaolin precursor. The effects of kaolin crystallinity, kaolinite content and synthesis parameters on ZSM-5 formation and its physicochemical properties are discussed. The potential of kaolin-based ZSM-5 as an oligomerisation catalyst is investigated. Pure, crystalline ZSM-5 could be successfully synthesised from a kaolin precursor. Physicochemical properties such as morphology, porosity and acidity are affected by the kaolin precursor and optimum synthesis conditions are required for synthesis of ZSM-5 from particular kaolin. Kaolin-based ZSM-5 catalyst showed good activity and selectivity to valuable fuel range hydrocarbons

A Study on Ordinary Portland Cement Blended with Rice Husk Ash and Metakaolin

Abstract. This paper tries to investigate the effect of replacing Ordinary Portland cement (OPC) with Metakaolin (MK) and Rice husk ash (RHA) on the physicomechanical properties such as consistency, setting times, soundness and mortar compressive strength of ternary cement up to 40 % cement replacement. The soundness of the blended cement pastes and compressive strength of the blended mortars were conducted using Le Chatelier apparatus and Tonic Technic compression machine while the initial and final setting times were conducted on the blended cement paste using Vicat apparatus. Nineteen ternary cement mortars were prepared to comprise of OPC, RHA MK at different proportions and tested at 2, 7, 28 and 60 days. Results indicated that as RHA was gradually increased up to 25% at constant MK content, the volume expansion of the ternary cement paste increased gradually. On the other hand, as MK was increased from 5-25% at constant RHA, the volume expansion diminished. The water consistency of ternary cement paste experienced a variation as MK was increased up to 25 wt% at constant RHA up to 10 wt%. However, at 10 wt% constant RHA as MK was increased the water demand gradually increased. Similarly, an increase in RHA at constant MK increased the water demands of the ternary blends. An increase in RHA from 5-25 wt% at 5-25 wt% constant MK resulted in an acceleration in the initial and final setting times of cement blends. These accelerations could be attributed to the pozzolanic activity leading in shorter setting time. Whereas a series of accelerations and retardations of both setting times were experienced as the MK was increased from 5-25 wt% at 5-25 wt% constant RHA. It was observed that increment in the MK or RHA up to 10 wt% at constant RHA/MK up to 10 wt% resulted in improved mortar compressive strength of the ternary blend in comparison with control. This improvement was attributed to the high silica/alumina contribution to the matrix by MK inclusion, the C/S ratio in the cement matrix and RHA pozzolanic reactivity despite its unburnt carbon. All mortar compressive strength of the cement blends and control experienced an increase as the curing days were lengthened from 2 to 60 days. The enhanced strength compared with the control especially beyond 28 days could be attributed to the slow pozzolanic reaction resulting from the formation of additional CSH and CAH from the interaction of the residual CH and the silica available in the MK and RHA. The best compressive strength at 60 days was obtained at cement replaced with 15 wt% and 20 wt% at MK 5 wt% RHA producing a mortar compressive strength of 40.5 MPa

Конверсия этанола и водноэтанольных смесей на промышленном катализаторе HZSM-5

This work is devoted to investigating the effects of ethanol space velocity and the composition of ethanol-water mixture on their conversion to hydrocarbons over the industrial 3%Zn/27%Al2O3/Fe-ZKE-G50 (Si/Fe = 550) catalyst. It was shown that at 350ºC, the relationship between ethanol space velocity and liquid hydrocarbons yield passes through a maximum at around 2h-1. Increasing ethanol space velocity to 5-10h-1 leads to increase in ethylene formation and a loss in selectivity for other hydrocarbons. Increasing the amount of water, drastically reduces the yield of liquid hydrocarbons. A high selectivity for C3-C4 hydrocarbons can be obtained using a mixture with ethanol to water ratio of 2:1. Further increase in water content leads to a decrease in the ethylene oligomerisation rate, consequently resulting in an increase in ethylene formation. Water addition to ethanol plays an important role in the overall process selectivity without altering the catalyst and technological equipment.В работе проведено комплексное исследование влияния объемной скорости подачи этанола и состава водно-этанольных смесей на их конверсию в углеводороды на промышленном катализаторе 3%Zn/27%Al2O3/Fe-ЦКЕ-Г50 (Si/Fe = 550). Установлено, что зависимость выхода жидких углеводородов при 350ºС от объемной скорости этанола проходит через максимум, соответствующий 2 ч-1. Увеличение скорости потока этанола до 5-10 ч-1 приводит к появлению значительных количеств этилена в составе продуктов реакции и, со временем, к потере селективности по другим углеводородам. Введение воды в состав реагентов резко снижает выход жидких углеводородных продуктов конверсии. При использовании этанольно-водных смесей с соотношением 2 : 1 основным продуктом конверсии является пропан-бутановая фракция. При дальнейшем увеличении содержания воды снижается скорость олигомеризации этиленовых фрагментов, приводя к значительному увеличению концентрации этилена в продуктах реакции. Введением дополнительных количеств воды можно варьировать селективность процесса в целом, не меняя катализатора и конструкции всей установки

Review of Carbon Capture and Methane Production from Carbon Dioxide

In the last few decades, excessive greenhouse gas emissions into the atmosphere have led to significant climate change. Many approaches to reducing carbon dioxide (CO2) emissions into the atmosphere have been developed, with carbon capture and sequestration (CCS) techniques being identified as promising. Flue gas emissions that produce CO2 are currently being captured, sequestered, and used on a global scale. These techniques offer a viable way to encourage sustainability for the benefit of future generations. Finding ways to utilize flue gas emissions has received less attention from researchers in the past than CO2 capture and storage. Several problems also need to be resolved in the field of carbon capture and sequestration (CCS) technology, including those relating to cost, storage capacity, and reservoir durability. Also covered in this research is the current carbon capture and sequestration technology. This study proposes a sustainable approach combining CCS and methane production with CO2 as a feedstock, making CCS technology more practicable. By generating renewable energy, this approach provides several benefits, including the reduction of CO2 emissions and increased energy security. The conversion of CO2 into methane is a recommended practice because of the many benefits of methane, which make it potentially useful for reducing pollution and promoting sustainability

Review of Carbon Capture and Methane Production from Carbon Dioxide

In the last few decades, excessive greenhouse gas emissions into the atmosphere have led to significant climate change. Many approaches to reducing carbon dioxide (CO2) emissions into the atmosphere have been developed, with carbon capture and sequestration (CCS) techniques being identified as promising. Flue gas emissions that produce CO2 are currently being captured, sequestered, and used on a global scale. These techniques offer a viable way to encourage sustainability for the benefit of future generations. Finding ways to utilize flue gas emissions has received less attention from researchers in the past than CO2 capture and storage. Several problems also need to be resolved in the field of carbon capture and sequestration (CCS) technology, including those relating to cost, storage capacity, and reservoir durability. Also covered in this research is the current carbon capture and sequestration technology. This study proposes a sustainable approach combining CCS and methane production with CO2 as a feedstock, making CCS technology more practicable. By generating renewable energy, this approach provides several benefits, including the reduction of CO2 emissions and increased energy security. The conversion of CO2 into methane is a recommended practice because of the many benefits of methane, which make it potentially useful for reducing pollution and promoting sustainability

Effect of operating variables on CO2 adsorption capacity of activated carbon, kaolinite, and activated carbon – kaolinite composite adsorbent

Global climate change is currently a major problem and is thought to be due to high levels of CO2 and other greenhouse gases. Several technologies have been built to lower CO2 emissions. Adsorption, a promising technology for CO2 capture, is among these technologies. In addition to adsorbent development, it is essential to determine the influence of operating variables on developed materials. Therefore, in this study, an activated carbon (AC), kaolinite (KAO) and kaolinite-activated carbon (KAC) composite adsorbent characterized was evaluated for CO2 adsorption. The aim of this study was to investigate the effect of operating variables on the CO2 adsorption capacity of each adsorbent (activated carbon, kaolinite, and kaolinite – activated carbon composite) and select the most suitable to serve as the solid anchor in the production of a hydrophobic adsorbent material for CO2 capture. Then, Scanning Electron Microscopy, N2 physisorption and Fourier Transform Infrared were tested for the morphology, surface area and functional groups of the adsorbents, respectively. The CO2 adsorption capacity of the adsorbents was measured using a custom-built 1.0 cm internal diameter adsorption column at of 30 to 70 mL/min bed height, of 3 to 5 cm operating temperature, and of 30 to 70 °C and CO2 feed flow rates. The maximum amounts of AC, KAC and KAO CO2 adsorbed to were found to be 28.97 mg CO2/g, 18.54 mg CO2/g and 12.98 mg CO2/g, respectively

Utilization of quaternary solvent mixtures for extraction of lipids from Scenedesmus obliquus microalgae

Solvent toxicity is of major concern in the extraction of lipid from algae biomass via the solvent extraction technique. This study was carried out to determine the optimal solvent mixture (chloroform, methanol, ethanol, and dichloromethane) composition with less toxicity for the extraction of lipids from Scenedesmus obliquus microalgae. Optimization of the solvent mixture composition was performed using augmented simplex centroid design and the influence of cell disruption on lipid yield was assessed. The eco-toxicity of the solvent mixtures was assessed using thermodynamic prediction model. The optimal lipid yield of 19.4% lipid g-1 DCW (dry cell weight) was obtained using solvent mixture composition (1:5:1:1 v/v) chloroform/methanol/ethanol/dichloromethane. The cost estimation and environmental risk parameter values obtained from the use of proposed quaternary solvent mixture composition indicated that lower cost and less toxicity were achieved when compared with the commonly used chloroform-methanol mixture composition. Microwave-assisted lipid extraction gave 55.67% higher lipid recovery from microalgae and the quality of the extracted lipid was unaffected when compared with the conventional solvent extraction. The fatty acid profile revealed the extracted lipids as an appropriate feedstock for biodiesel production. Applicability of lipid extracted biomass obtained using the proposed technique is confirmed by SEM and FTIR analyses