The decline in the pressures of natural gas wells is forcing industries to either find more sustainable alternatives or temporarily make up for the shortfall. One such Pakistani gas field is the Mari Gas Field reservoir, from which the natural gas is extracted and used to produce ammonia which is the precursor of urea production. To temporarily cope with the declining pressures, this study proposes that a mixture of exported RLNG (30%) and Mari gas (70%) be used as feed. Material and Energy balances and the reactor designs were carried out and compared with the existing feed. Results showed that the proposed blend of RLNG and Mari gas could be used for ammonia production. However, alterations in the form of increased tube lengths, reactor volumes, and catalyst loading will be required in the main equipment of plants. Nevertheless, these modifications result in 20784-20791a +20.65% increase in hydrogen production, +4.53% increase in ammonia production, and +4.54% increase in urea production. Thus the proposed scheme can be adopted to manage the shortfall of Mari gas.

This paper discusses the performance evaluation and availability analysis of ammonia synthesis unit of a fertilizer plant. The fertilizer plant is a complex and repairable engineering system comprises of various units viz. shell gasification and carbon recovery, desulphurization, co-shift conversion, decarbonation, nitrogen wash and ammonia synthesis etc. One of the most important functionaries of a fertilizer plant is ammonia synthesis unit. This unit consists of five subunits arranged in series and parallel configurations. For the evaluation of performance and analysis of availability, a performance evaluating model has been developed with the help of mathematical formulation based on Markov Birth-Death process using probabilistic approach. The findings of this paper are therefore, considered to be useful for the analysis of availability and determination of the best possible maintenance strategies in a fertilizer plant concerned.

The decline in the pressures of natural gas wells is forcing industries to either find more sustainable alternatives or temporarily make up for the shortfall. One such Pakistani gas field is the Mari Gas Field reservoir, from which the natural gas is extracted and used to produce ammonia which is the precursor of urea production. To temporarily cope with the declining pressures, this study proposes that a mixture of exported RLNG (30%) and Mari gas (70%) be used as feed. Material and Energy balances and the reactor designs were carried out and compared with the existing feed. Results showed that the proposed blend of RLNG and Mari gas could be used for ammonia production. However, alterations in the form of increased tube lengths, reactor volumes, and catalyst loading will be required in the main equipment of plants. Nevertheless, these modifications result in 20784-20791a +20.65% increase in hydrogen production, +4.53% increase in ammonia production, and +4.54% increase in urea production. Thus the proposed scheme can be adopted to manage the shortfall of Mari gas.

Assessment of creep damage and residual creep life of a cast HP 40 Nb Mod reformer tube was performed, wherein the experimental Larson–Miller diagram and area fraction of creep voids were adopted. The state of damage of the tube in service was metallographically analyzed by using light and electron microscopy. Samples from the serviced reformer furnace tube were cut and prepared for void examination and creep test at 940oC-1000oC under 20-30 MPa stress. Microstructural examination was carried out with a Scanning electron microscope with secondary and backscattered electron detectors. Inter-granular voids in the microstructure of the worked tube as a result of a creep phenomenon are ranked relating to the remaining life.

High concentrations of nitrogen compounds, such as ammonia observed in the petrochemical industry, are the major environmental pollutants. Therefore, effective and inexpensive methods are needed for its treatment. Biological treatment of various pollutants is a low cost and biocompatible replacement for current physico-chemical systems. The use of aquatic plants is an effective way to absorb the nutrient pollutants. In this study, the optimal operating conditions in the biological removal of ammonia from the urea-ammonia wastewater of Kermanshah Petrochemical Company by Lemna gibba were determined using the response surface methodology. Lemna gibba was collected from the ponds around Kermanshah and maintained in a nutrient medium. Effect of the main operational variables such as ammonia concentration, residence time and Lemna gibba to surface ratio on optimal conditions of ammonia removal from wastewater has been analyzed using the Box-Behnken model design of experiments. Model numerical optimization was performed to achieve the maximum amount of ammonia removal from wastewater. The ammonia removal percentage varied from 13% to 88%, but the maximum amount of ammonia removal was determined at ammonia concentration of 5 ppm and Lemna gibba residence time of 11 days in wastewater based on the quadratic model. Lemna gibba to surface ratio of 2: 5 was measured at 96. 449%. After optimization, validation of ammonia removal was performed under optimum conditions and measured at 92. 07%. Based on the experimental design and the predicted under model conditions, the maximum amounts of ammonia removal percentage in the experiments were 82. 84% and 88. 33% respectively, indicating the high accuracy of the model to determine the optimum conditions for the ammonia removal from wastewater.

The current study introduces a ground-breaking multi-generation plant utilizing solar and wind energy. This study proposes a hybrid system that combines wind and a steam Rankine cycle for power generation. This integrated system aims to address cooling needs through a dual-effect cooling system and heating requirements through a steam Rankine cycle heat exchanger. Additionally, the system intends to produce hydrogen through a proton exchange membrane electrolyzer and ammonia via a reactor. This comprehensive approach investigates the potential for a more versatile and efficient plant design. This innovative system goes beyond electricity generation, offering a comprehensive solution for power (44.8 MW), heating (20.64 MW), cooling (123.9 MW), hydrogen (263.1 kg/h), and ammonia (106.48 kg/h) production. A thermo-economic-environmental analysis reveals promising performance with high energetic (83.65%) and exergetic (17.97%) efficiencies, an exergo-environmental impact factor (0.91) as well as a total product cost rate of $1.44/s. The parabolic trough solar collector optimization is crucial as it contributes to the majority (57%) of exergy destruction. Amongst investigated parameters, an ambient temperature of 35°C yields the best exergo-environmental performance.

In this work, reactive absorption of gases in aqueous electrolyte solutions has been investigated resulting in the development of a procedure in order to calculate the concentrations of ionic and molecular species in the liquid phase. Two duplicate experiments were conducted to investigate simultaneous reactive absorption of ammonia and carbon dioxide in partially carbonated ammonia solutions. The experiments were carried out employing an absorption pilot plant. The compositions of the electrolytes (ammonia and carbon dioxide groups) have been determined using principle knowledge of electrolyte solutions. The results revealed that the concentrations of ionic and molecular species in the liquid phase drastically influence the absorption rates of ammonia and carbon dioxide.