مولانا محمد شاہد فاخری
افسوس ہے کہ گزشتہ ماہ مولانا محمد شاہد فاخری نے وفات پائی، وہ الہ آباد کے مشہور مذہبی خانوادہ دائرہ شاہ اجمل سے تعلق رکھتے تھے، مذہبی کاموں کے ساتھ ان کو ملک کے سماجی اور سیاسی مسائل سے بھی دلچسپی تھی، وہ جمعیۃ علمائے ہند کے نائب صدر تھے، انھوں نے آزادی کی جدوجہد میں نمایاں حصہ لیا تھا اور قیدوبند میں بھی مبتلا ہوئے تھے، آزادی کے بعد بھی وہ ملک و ملت کی خدمت میں لگے رہے اور اس راہ میں مشکلات و مصائب برداشت کرتے رہے، وہ دارالمصنفین کے کاموں کے بڑے قدرداں اور مداح تھے، اﷲ تعالیٰ ان کی مغفرت فرمائے اور انھیں اپنی رحمتوں سے سرفراز فرمائے۔ (عبد السلام قدوائی ندوی، اکتوبر ۱۹۷۵ء)
According to traditional-religious-culture the early age marriages are very common custom especially in rural areas. The act of marring girls in early ages is considered to be a good practice in these constituencies; in contrast, the holy Quran has provided some logical guidelines to reject this idea. In the holy Quran “men” are instructed to marry as per their choice, which reveals, it is necessary for a “man” to be adult (Baligh) for marriage. Considering this fact, how it is possible that a man can be permitted to have a non-adult (Nabaligh) life partner? In this regard, marriages between Adult and Non-adult, Non-adult and Non-adult are not permitted because it is against the right of equality. Further, the holy Quran instructs the guardians of the orphans to return them their valuables when reach to the age of Nikah; which reveals that there is a particular standard of age set for Nikah, if it is not so, why the holy Quran has made this bounding for the guardians of the orphans? As per the guidance of the holy Quran, it is clear that Nikah requires both man and women not only to be physically adult/mature but also mentally adult/mature. In this connection, it has been highlighted that Nikah which is a physical contract requires a particular age for man and woman which however cannot be an age of Non-adult.
Fossil fuels are a major contributor to the today’s world energy demand as well as greenhouse gases causing global warming. The idea to reduce the dependence on fossil fuels for a green future needs a stepwise transition from fossil fuels to renewable sources. Among the various renewable sources hydrogen is probably the most promising alternative due to its availability, high heating value per unit weight, and zero emissions. The only challenge associated with hydrogen is its safe and feasible storage. The methylcyclohexane-toluene-hydrogen (MTH) system is the one that is considered safe and economical option for hydrogen production, storage and transportation, and utilization. The dehydrogenation reaction of the MTH system is highly endothermic and requires considerable amount of heat energy at a fast rate to have high equilibrium conversions. The successful utilization of hydrogen economy based on the MTH system therefore requires a highly active, selective, and stable dehydrogenation catalyst with its associated reaction kinetics. An intensified dehydrogenation reactor design that supplies high rates of heat transfer to the catalyst bed is also desired. A comprehensive review of the literature regarding kinetics of the methylcyclohexane (MCH) dehydrogenation over Pt containing catalysts has revealed that there is no consensus among the researchers on describing the reaction mechanism, rate-determining step, and inhibition offered by a product. Different researchers have suggested different reaction chemistry and developed different kinetic rate equation. There is hardly a study on the design and simulation of an intensified dehydrogenation reactor that is capable of being used on commercial scale applications. In the present study, an attempt is made to address the discrepancies in the kinetics of the MCH dehydrogenation that exist in the literature. The experimental data of 5 different Pt containing catalysts over a wide range of operating conditions is used to conduct a detailed kinetic study of the dehydrogenation reaction. Various kinetic models are developed based on the power law, Langmuir-Hinshelwood-Hougen-Watson (LHHW), and Horiuti-Polanyi reaction mechanism. The developed kinetic model equations are analyzed both kinetically and statistically and the best fitted kinetic model for each of the catalysts is worked out. The kinetic model based on single-site LHHW kinetics where loss of first hydrogen is the rate limiting step is found appropriate in representing the data of all the catalysts. This leads to report a unified kinetic model for the methylcyclohexane dehydrogenation reaction over any Pt containing catalyst. In addition to that, a new reaction mechanism called associative adsorption of methylcyclohexane is proposed and a kinetic model equation developed based on this mechanism is found successful in representing the relevant experimental data. A 2.0 MW power plant, working on the methylcyclohexane dehydrogenation reaction to yield hydrogen gas as fuel for the power production, is proposed and simulated in Aspen Hysys. The operating conditions such as stream flowrates, temperatures, pressures, and thermal efficiency are worked out. It is found that 17.4148 kmol/h methylcyclohexane are required to produce 2.0 MW net power output. Also, it is found that there is enough energy in the exhaust gases of the turbine that can carry out the dehydrogenation reaction. Using the best-fit kinetic model and the simulation data obtained for 2.0 MW power plant, a novel reactor-heat exchanger design is mathematically modeled and simulated. The proposed reactor configuration is found highly appropriate in carrying out the dehydrogenation reaction.