scholarly journals Performance Analysis of the Perhydro-Dibenzyl-Toluene Dehydrogenation System—A Simulation Study

2021 ◽  
Vol 13 (11) ◽  
pp. 6490
Author(s):  
Farea Asif ◽  
Muhammad Haris Hamayun ◽  
Murid Hussain ◽  
Arif Hussain ◽  
Ibrahim M. Maafa ◽  
...  

The depletion of conventional energy resources has drawn the world’s attention towards the use of alternate energy resources, which are not only efficient but sustainable as well. For this purpose, hydrogen is considered the fuel of the future. Liquid organic hydrogen carriers (LOHCs) have proved themselves as a potential option for the release and storage of hydrogen. The present study is aimed to analyze the performance of the perhydro-dibenzyl-toluene (PDBT) dehydrogenation system, for the release of hydrogen, under various operational conditions, i.e., temperature range of 270–320 °C, pressure range of 1–3 bar, and various platinum/palladium-based catalysts. For the operational system, the optimum operating conditions selected are 320 °C and 2 bar, and 2 wt. % Pt/Al2O3 as a suitable catalyst. The configuration is analyzed based on exergy analysis i.e., % exergy efficiency, and exergy destruction rate (kW), and two optimization strategies are developed using principles of process integration. Based on exergy analysis, strategy # 2, where the product’s heat is utilized to preheat the feed, and utilities consumption is minimized, is selected as the most suitable option for the dehydrogenation system. The process is simulated and optimized using Aspen HYSYS® V10.

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 206 ◽  
Author(s):  
Muhammad Haris Hamayun ◽  
Ibrahim M. Maafa ◽  
Murid Hussain ◽  
Rabya Aslam

In the recent era, hydrogen has gained immense consideration as a clean-energy carrier. Its storage is, however, still the main hurdle in the implementation of a hydrogen-based clean economy. Liquid organic hydrogen carriers (LOHCs) are a potential option for hydrogen storage in ambient conditions, and can contribute to the clean-fuel concept in the future. In the present work, a parametric and simulation study was carried out for the storage and release of hydrogen for the methylcyclohexane toluene system. In particular, the methylcyclohexane dehydrogenation reaction is investigated over six potential catalysts for the temperature range of 300–450 °C and a pressure range of 1–3 bar to select the best catalyst under optimum operating conditions. Moreover, the effects of hydrogen addition in the feed mixture, and byproduct yield, are also studied as functions of operating conditions. The best catalyst selected for the process is 1 wt. % Pt/γ-Al2O3. The optimum operating conditions selected for the dehydrogenation process are 360 °C and 1.8 bar. Hydrogen addition in the feed reduces the percentage of methylcyclohexane conversion but is required to enhance the catalyst’s stability. Aspen HYSYS v. 9.0 (AspenTech, Lahore, Pakistan) has been used to carry out the simulation study.


2019 ◽  
Vol 113 ◽  
pp. 02017
Author(s):  
Mariagiovanna Minutillo ◽  
Alessandra Perna ◽  
Alessandro Sorce

This paper focuses on a biofuel-based Multi-Energy System generating electricity, heat and hydrogen. The proposed system, that is conceived as refit option for an existing anaerobic digester plant in which the biomass is converted to biogas, consists of: i) a fuel processing unit, ii) a power production unit based on the SOFC (Solid Oxide Fuel Cell) technology, iii) a hydrogen separation, compression and storage unit. The aim of this study is to define the operating conditions that allow optimizing the plant performances by applying the exergy analysis that is an appropriate technique to assess and rank the irreversibility sources in energy processes. Thus, the exergy analysis has been performed for both the overall plant and main plant components and the main contributors to the overall losses have been evaluated. Moreover, the first principle efficiency and the second principle efficiency have been estimated. Results have highlighted that the fuel processor (the Auto-Thermal Reforming reactor) is the main contributor to the global exergy destruction (9.74% of the input biogas exergy). In terms of overall system performance the plant has an exergetic efficiency of 53.1% (it is equal to 37.7% for the H2 production).


2003 ◽  
Vol 125 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Afif Akel Hasan ◽  
D. Y. Goswami

Exergy thermodynamics is employed to analyze a binary ammonia water mixture thermodynamic cycle that produces both power and refrigeration. The analysis includes exergy destruction for each component in the cycle as well as the first law and exergy efficiencies of the cycle. The optimum operating conditions are established by maximizing the cycle exergy efficiency for the case of a solar heat source. Performance of the cycle over a range of heat source temperatures of 320–460°K was investigated. It is found that increasing the heat source temperature does not necessarily produce higher exergy efficiency, as is the case for first law efficiency. The largest exergy destruction occurs in the absorber, while little exergy destruction takes place in the boiler.


2018 ◽  
Vol 20 (2) ◽  
pp. 216-225

The aim of this study is to investigate the performance of the solar photocatalyst of TiO2/ZnO/Fenton process to treat the refinery wastewater and remove inorganic carbon (IC) which potentially toxic to human, aquatic and microorganism life. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, Fe2+ dosage, H2O2 dosage, and pH to identify the optimum operating conditions. Quadratic models for inorganic carbon (IC) removal and residual iron prove to be significant with low probabilities (<0.0001). The (IC) removal rates and residual iron correspond well with the predicted models. The maximum removal rate for IC and residual iron was 92.3% and 0.013, respectively at optimum operational conditions of a TiO2 dosage (0.3 g/l), ZnO dosage (0.58 g/l), Fe2+ dosage (0.02 g/l), H2O2 dosage (2.7 g/l), and pH (7). The treatment process achieved higher degradation efficiencies for IC and reduced the treatment time comparing with other related processes.


1983 ◽  
Vol 105 (2) ◽  
pp. 163-167 ◽  
Author(s):  
M. Fujiwara

The optimum control and performance evaluation of solar collectors are analyzed from the standpoint of exergy. The pressure drop inside the collector is introduced to the analysis using the Hottel-Whillier model. By treating the friction process as exergy loss, the optimum operating conditions are presented in a simple statement. The maximum capability of collectors is determined and expressed by a relationship among the collector parameters and the environment in which they operates.


2016 ◽  
Vol 72 (7) ◽  
pp. 435-447
Author(s):  
Fatih Tornuk ◽  
Mustafa Tahsin Yilmaz ◽  
Ismet Ozturk ◽  
Osman Sagdic ◽  
Muhammet Arici ◽  
...  

Response surface methodology was used to optimize conditions (e.g., Thyme oil concentration [0.0–0.57%] and storage temperature [0.0-14.14ºC]) for inhibiting the growth of L. monocytogenes (log cfu/g) in ground meat. Additionally, the effect of the variables; namely, temperature and concentration on µmax (maximum specific growth rate, ln cfu/g/h) values was also evaluated using a proposed combined model. The best fitting second order polynomial models were developed for each response using multiple linear regression analysis with backward elimination regression (BER) procedure. In this paper, multi-response surfaces using desirability function approaches were successfully applied to determine optimum operating conditions. Under these optimum treatment and storage parameters, L. monocytogenes populations at hours 6, 24, 48, 72 and 96 were 6.12, 5.96, 5.88, 5.81 and 5.41 log cfu/g and 0.001 ln cfu/g/h, respectively and μmax value 0.001 ln cfu/g/h. At the end, the proposed combined model is described numerically and experimentally.


Energy ◽  
2021 ◽  
Vol 216 ◽  
pp. 119264
Author(s):  
Xiaohui Lu ◽  
Bing Li ◽  
Lin Guo ◽  
Peifang Wang ◽  
Nasser Yousefi

2021 ◽  
Vol 10 (4) ◽  
pp. 891-900
Author(s):  
Selvaganapathy Thambiyapillai ◽  
Muthuvelayudham Ramanujam

Plastic wastes are necessary to recycle due to their disposal issues around the world. They can be recycled through various techniques i.e., mechanical reprocessing, mechanical recycling, chemical recycling and incineration. Most recycling techniques are expensive and end up in producing low-grade products excluding chemical recycling; it is an eco-friendly way to deal with plastic waste. Catalytic cracking is one of the chemical recycling methods, for converting waste plastics into liquid fuel same as commercial fuels. An experimental investigation of polystyrene catalytic cracking process was conducted with impregnated fly ash catalyst and 88.4% of liquid product yield was found as a maximum at optimum operating conditions 425 ̊C and 60 min. The liquid fuel quality was analyzed using FTIR spectra analysis, GC/MS analysis and Physico-chemical property analysis. The GC/MS analysis shows that the fly ash cracking of polystyrene leads to the production of gasoline fuels within the hydrocarbon range of C3-C24, and the aliphatic and aromatic functional compounds were detected using FTIR analysis. Moreover, the Aspen Hysys simulation of polystyrene catalytic cracking was conducted in a pyrolytic reactor at 425 ̊C and at the end of the simulation, 93.6% of liquid fuel yield was predicted. It was inferred that the simulation model for the catalytic cracking is substantial to fit the experimental data in terms of liquid fuel conversion


2016 ◽  
Vol 74 (6) ◽  
pp. 1312-1325 ◽  
Author(s):  
Dheeaa al deen Atallah Aljuboury ◽  
Puganeshwary Palaniandy ◽  
Hamidi Bin Abdul Aziz ◽  
Shaik Feroz ◽  
Salem S. Abu Amr

The aim of this study is to investigate the performance of combined solar photo-catalyst of titanium oxide/zinc oxide (TiO2/ZnO) with aeration processes to treat petroleum wastewater. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, air flow, pH, and reaction time to identify the optimum operating conditions. Quadratic models for chemical oxygen demand (COD) and total organic carbon (TOC) removals prove to be significant with low probabilities (&lt;0.0001). The obtained optimum conditions included a reaction time of 170 min, TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), and pH 6.8 COD and TOC removal rates of 99% and 74%, respectively. The TOC and COD removal rates correspond well with the predicted models. The maximum removal rate for TOC and COD was 99.3% and 76%, respectively at optimum operational conditions of TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), reaction time (170 min) and pH (6.8). The new treatment process achieved higher degradation efficiencies for TOC and COD and reduced the treatment time comparing with other related processes.


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