In recent years, lots of research has been done on effective usage of natural gas; the first step in these processes is conversion of natural gas to Syngas. Natural gas reforming process by refomer furnace is commonly used for syngas and hydrogen production. In this paper, windows based software, RIPI-RefSim, is introduced. By using proper heat, mass, kinetic and thermodynamic models as well as effect of catalyst shape, the software has been developed for the REFORMER furnace SIMULATION for syngas and hydrogen production. RIPI-RefSim could be used in three different modes (Rating, SIMULATION and Design) and provides user a detailed understanding of furnace performance, product characteristics, temperature, reaction rates and pressure drop profiles, heat loss, effect of catalyst shape, and etc.

Micro-REFORMERs used for producing hydrogen with a high surface-tovolume ratio in small-scale fuel cells were investigated. To this end, scrutinizing and exploiting all areas of micro REFORMERs is very important. Parallel micro-channels have shown good performance in eliminating dead volumes. Inlet/outlet configuration has great effect on the velocity distribution through micro-channels. In this study, four configurations (1 inlet/1 outlet on the same and opposite sides; 1 inlet/2 outlets on the same and opposite sides) were studied through SIMULATION and 1 inlet/2 outlets on opposite sides were found to have the lowest velocity difference, hence having the best configuration. SIMULATIONs were carried out at 600 ° C, 1 atm, with S/C=3 and feed flow rate of 100 mL/min. Three channel patterns (i. e., parallel, splitting-jointing and pin-hole) were compared in terms of Figure of Merit (FoM) and specific conversion. Parallel channel design revealed a high value of specific conversion to be about 5. 36× 10 − 5 2 𝑘 𝑘 𝑘 𝑘 𝐶 𝐶 𝐶 𝐶 4 𝑚 𝑚 ⁄ , while splitting-jointing and pin-hole were 5. 33× 10 − 5 and 4. 91× − 5 10, respectively. Based on FoM, pin-hole design had a high value of − 5 1. 34× 10 2 𝑘 𝑘 𝑘 𝑘 𝐶 𝐶 𝐶 𝐶 4 𝑚 𝑚 ⁄ . 𝑃 𝑃 𝑃 𝑃 , while the values of splitting-jointing and parallel designs were 0. 037× 10 − 5 − 5 and 1. 28× 10, respectively.

Considering improved heat transfer, uniformity of catalyst distribution and virtual elimination of diffusion limitations as the major advantages of fluidized beds, it seems preferable to employ such a reactor for reforming of natural gas. In this study, by considering the presented simulators and hydrodynamic structure of the fluidized beds, a SIMULATION model is developed in order to predict the performance of the fluidized bed reactor of steam methane reforming in a complex process. The results obtained from the SIMULATION of this model in Hysys 3.1 environment are compared with other models and experimental data. Better agreement is found between the model predictions and experimental data than the recent studies.

For the production of synthesis gas utilized in Midrex direct reduction plants, catalytic steam/CO2 reforming of hydrocarbons in tubular reactor is commonly used. Owing to the high heat flux through the wall of REFORMER tube, the endothermic nature of reforming reactions, low mass velocity of feed gas and large tube diameter, the catalyst bed is exposed to the considerable axial and radial temperature gradients. These radial gradients of concentration and temperature may create local areas with potency of carbon formation. In this investigation, a two dimensional model is developed for simulating the operation of a Midrex REFORMER. In this model, a thermodynamic approach is used to recognize zones inside the REFORMER tubes in which the risk of carbon formation is high. The SIMULATION results are in good agreement with available data of Mobarake Plant, in Esfahan, Iran. The results show that the first half of tubes, both in center and near the wall, is critical in point of view of carbon formation.

Nowadays, the destructive phenomenon of desertification and wind erosion is one of the most important environmental crises in the world, which are serious challenges to sustainable production and agricultural land management. In the present study, the effect of microbial precipitation of calcium carbonate has been studied as a biological REFORMER and compatible for controlling wind erosion and soil stabilization. For this purpose, erosion rate of bio-cemented samples was investigated through … . in a wind tunnel under the condition of wind velocity of (0 to 98 km hr-1) in two soil types with sandy and silty texture in a completely randomized design in three replications. Investigation of the threshold velocity of soil particle movement revealed that air dried soil particles begin to move at the velocity of 8 and 10 km hr-1 in the silty and sandy soils respectively, however, in all biological samples (MICP) particles did not move at 97 km. hr-1. The results also indicated that the weight loss of all MICP treatments at different wind velocities were significantly reduced as compare to the control. The amount of the soil loss among biological cemented samples and control treatments were dramatically different at higher velocities. So that, at velocities more than 57 km/h, soil losses indicated significantly enhancement in control, whereas in the soils which are treated by bacteria, soil losses were insignificant and approximately 2. 5 kg. m-2. hr-1. The results also showed that the equal's amount of calcium carbonate and the penetration resistance of the soil surface increased significantly in MICP treatments as compare to control treatments, this event indicated the formation of a surface-resistant layer on bio-treated cement samples. In this study, the comparison of used bacteria also showed that Bacillus infantis and Paenibacillus sp3 have high efficiency in controlling wind erosion. Therefore, it seems that cementation by biological methods could be an effective way to stabilize surface particles and control soil erosion.

Micro-structural failure analysis of the heat resisting HP40 Nb modified alloy was studied by light and electron methods. Samples from the failed REFORMER furnace tube were cut and prepared for metallographic examination. Examination with electron microscope was carried out with secondary and backscattered electron detectors; x-ray analysis was conducted at the grain boundary areas. In tubes, which are filled with a supported nickel catalyst, methane reacts with steam, carbondioxide and oxygen into synthesis gas. The overall heat of reactions may be positive, zero, or negative, depending on the process conditions.The catalyst plays a key role in developing overheating in the tubes. The catalyst deactivation caused by feeding is heavier than that designed hydrocarbon. Using an unsuitably designedhydrocarbon causes a thin layer of carbon coating on the catalyst surface. Overheating due to catalyst poisoning caused creep failure. The presence of intergranular voids in the microstructure of the failed tube seemsto be the result of creep phenomenon.