فهرست مطالب ahmed ullah

The problem with waste plastic is that it decomposes after hundreds of years which causes its accumulation on the land. The waste plastic is used in the production of Polymer-Coated Aggregate (PCA) material that is eventually used in the construction of commercial roads. The roads made from PCA material are more efficient and are of greater strength as compared to normal roads. Through previous extensive experimental work, it is concluded that the addition of 12% of plastic in the total mixture provides the optimum results. The chosen process for the research to make PCA is the dry process, which follows by heating the aggregate stone to a certain temperature and on the other hand melting the PCA and coating over the aggregate. This research is mainly based on the fabrication of a machine that eventually produces PCA. The process of production of PCA material includes pre-heating of crushed aggregate, shredding of plastics, melting and coating of plastics, heating bitumen, adding hot molten bitumen, and uniform mixing. The aggregate tests began with each batch sample from the machine to validate the working and product quality of the fabricated mixer. The mean of Marshall stability value, flow value, and % air void are 2651.893kN, 17, and 2.642% respectively. Whereas the mean aggregate crushing and impact value obtained is 9.778 and 7.627. The mean value of specific gravity obtained is 2.569. The produced PCA material has a low water absorption capability is 0.573. The Los Angeles abrasion test, 9.652 is the mean abrasion value observed. The mean value of the stripping test obtained is 0.197%, which shows that there is almost negligible stripping of bitumen from the surface of PCA.  It can be concluded that the fabricated rotary mixer gives us an adequate PCA product with suitable enhancement of binding properties for the pavement of roads.

A plant was developed that uses a sulfur-ammonia thermochemical water-splitting process for H2 production. Hydrogen is beneficial as a fuel in different industries and automobiles. Aspen Plus was used for the simulation of hydrogen plant modeling. This process consists of electrolytic oxidation of ammonium sulfite and the thermal breakdown of potassium pyro sulfate and SO3 in the oxygen production half cycle. The reactions are carried out by solar thermal energy. The inlet stream is water, and the product streams are H2 and O2 gas. This research focuses on scrutinizing the economic strength of hydrogen production by electrolysis. During the research, it is clear that this type of study has great potential to reduce carbon emissions. That there is concluded economic potential for the electrolytic system. The model is for the full-scale operation that will produce approximately 1.3 lac kg H2 / day. It is equal to 370MW. Design specifications were placed in strategic areas of this model to aid in its conversions. Model convergence is complex because of various material and energy recycle loops within the plant. The overall electricity needed to start the process is intramural from squandering heat. The thermal energy storage system will operate continuously without any shutdown. Three substitutes for hydrogen production from solar thermal energy have been inspected from both an efficiency and economic point of view. This observation shows that the possible alternative using solar energy with the help of thermochemical water splitting to manufacture H2 is the best one. The other methods consider the direct conversion of solar energy into electrical energy by Si cells and H2O analysis. The usage of solar energy to power a vapor cycle leads to the production of electrical energy.

Static Mixers (SM), also generally known as inline mixers, form a newly developing industry trend. They have no moving parts, hence have lower energy consumption, lower installation cost, and very low maintenance cost, and are thus an attractive alternative to conventional agitators. Modifications were made to the design to reduce pressure drop and increase the mixing intensity across the mixer and increase the application of inline mixers in the industries. Three hybrid geometries (different combinations of Kenics and LPD) of static mixers were constructed and simulated using Computational Fluid Dynamics (CFD) tools. Kenics is an excellent radial mixing device, and Low-Pressure Drop (LPD) is an excellent axial mixing device. The key design parameter to modify LPD was the slope angle of elliptical plates which affects the mixer performance. Different slope angles from 90º to 120º were simulated. Kenics was modified for different aspect ratios, and the edge of Kenics was curved. Pressure drop, thermal, and Discrete Phase Model (DPM) analysis were performed on these three different classifications of hybrid geometries. The most promising geometry to emerge based on the low-pressure drop and good mixing efficiency was the curved edge Kenics. Keen-sighted these results, further analysis was performed on curved edge Kenics after the modification of the blend radius. It was concluded that for a lower Reynold number, the curved edge with a higher blend radius dominates all other mixers. Result validation was done by comparing the trends and sensitivity of process variables with the established results and standards.

Worldwide the broad usage of plastic has resulted in the massive production of plastic pollution, which is incinerated, and put in landfills and oceans. The technique of coating road aggregate with plastic has a good potential to deal with this global issue. The unique physical, mechanical and thermal properties of polymer offers effective binding, less moisture retention, and less susceptibility to void formation. This research will ultimately reflect plastic waste management and road enhancement. The main purpose of this experimental study is to predict and highlight the effect of varying plastic composition coating on an aggregate and select the best-performing sample. For this study, samples of polymer-coated aggregates of different ratios are created, and further tested for their enhancement in properties. To create polymer-coated aggregate, we have used recycled aggregates, Grade 70 bitumen, and polyethylene bags from waste. To coat the aggregates used the "dry-mix process". The effectiveness of the coating with varying plastic compositions was measured using seven different tests. It was hypothesized that incorporating plastic would enhance the properties of aggregate and increase the durability and workability of road materials. The test results supported the hypothesis. Standard ranges were used to perform a comparative study between polymer-coated aggregate and conventional aggregate. Nearly all tests' plastic compositions>8% and less than 15% have shown good results, but the optimum value for all tests is achieved by a sample with 12% plastic coating. Although this study supports that plastic incorporation is a better idea to enhance the longevity of roads, more research is required to explore the underlying mechanism of plastic coating and its long-term outcomes.

Waste thermal energy is enough energy that is rejected to the atmosphere in the form of flue gases, streams of air, and liquid rejected from industries. It arises from the equipment, less efficient processes, and limitations due to thermodynamics' laws on operations. It is obvious that it is not possible to regenerate all waste energy, but most of the time, some waste heat can be used to achieve useful purposes. Waste heat recovery is the most important key to carrying out most of the research areas. The major areas of research and it is necessary to make the process more energy-efficient in chemical industries. To save energy, Heat Exchanger Network’s (HEN) synthesis is essential. They are designed to reach energy targets. HEN design is the thermal integration between cold and hot utilities by pinch analysis at minimum temperature difference. HENs are important for utility saving because it helps in recovering heat from hot streams to others which reduces utility consumption and requirements. The heat exchangers are designed with simplified models for different industries using pinch technology. Most thermal recovery is obtained, and then some HEN network is required for a particular targeted area. In this research, improvements in energy recovery systems and HENs, and synthesis helps in capital savings, and pollutant emission can also be reduced.

In a refinery flare system is the last defense line for controlling the over-pressurization of process vessels. Mostly power failure is the worst contingency in the refinery, and the flare capacity is evaluated for this case. The data of Pressure Safety Vessels (PSVs), header network, knockout drums, flare stack, and flare tip is to utilize for simulating the flare system of the Oil Refinery Complex (ORC-II). In power failure contingency out of fourteen PSVs, four were found to have higher back pressures than the allowable limits, those PSVs were resized and new models have been proposed. Carbon dioxide (CO2) is a significant benefactor of global warming stances a severe hazard to the environment. The danger of natural contamination might be diminished by downstream usage of post-combustion vent gases which principally originate from power plants, gas, or oil fields, and the cement industry with the essential spotlight on CO2 catch. Post-combustion is a broadly utilized system as a result of its similarity with the existing force plant framework. The procedure was conveyed using 30 wt. % monoethanolamine (MEA) dissolvable and Hollow-fiber cellulose acetic membrane framework. This research consists of two sections. In the initial segment, the capacity evaluation of the flare framework was finished utilizing Aspen Flare System Analyzer V8.4 and the rating of the flare framework was conveyed in which to break down the necessary parameters like Mach number and back weight in the system and the adjustments in the flare framework were made as per API 520. In the second part chemical absorption and membrane separation innovations were looked at for post-combustion carbon catch. The research focuses on conveying a relative investigation of the above-expressed methods for the flow rate of vent gas runs between 1 to 200 MMSCFD. The goal is to accomplish 90% recuperation of CO2 with carbon decrease from 10.66 mole % to 2 mole %. The absorption technique is simulated by ASPEN HYSYS V8.4 and a program for membrane framework is created by connecting values from ASPEN HYSYS to Microsoft EXCEL. For membrane separation, the operating expense is seen as lower than the absorption process, yet from the results, it was concluded that the absorption technique is superior to the membrane technique until the problems concerning the degradation of the membrane and high capital expense would be settled.