Steam Reforming - Catalyst Loading

Industrial & Engineering Chemistry Research, 2018

The kinetics and diffusion effects of methanol steam reforming reaction over commercial Cu/ZnO/Al 2 O 3 catalyst was studied for steam to methanol (S/M) ratios of 0 to 1 and pressures below 6 bar. Our objective is the development of a novel high-pressure propulsion technology based on the concepts of thermochemical recuperation (TCR) and onboard hydrogen production. A simple kinetic model assuming methanol decomposition followed by water−gasshift was used to estimate the rate constants (k MD , k WGS). The apparent activation energy of k MD was estimated as 45−55 kJ/ mol for large pellets and S/M = 1.0, 0.5, and 0.0; k MD for S/M = 0 (and the conversions obtained) were smaller than those of S/M = 1, probably due to CO inhibition. At temperatures above ∼500 K, the WGS is at equilibrium. Strong pore-diffusion limitations are evident at 1 bar for the 3 mm catalyst, evident experimentally as well as by analysis; the apparent k MD is almost diffusion free for particles of 0.7 mm in diameter. This resistance increases, of course, with P. The selectivity of CO (dry basis) increases with W/F meth (weight of the catalyst divided by flow rate of methanol in units of kgcat s mmol −1) and increases with decreasing particle size. As the pressure increases, the ratio of CO and CO 2 increases moderately up to 4 bar; at 6 bar the change is drastic. Similar observations were made with S/M = 0.5 and 1.0. Deactivation rates and coke formation were also studied and were found to be marginal under atmospheric pressures over a period of 10 h and became evident only at S/M = 0 and 275°C; at 6 bar the decline was evident already at S/M = 0.5. The source of deactivation was attributed to coking, a conclusion based on TPO of spent catalyst. In the case of S/M = 1 and 0.5, and at 6 bar, there was a shift in the composition from CO 2 to CO with time over a period of 10 h at 275°C. However, the carbon deposition in all cases was estimated to be about the same.

Journal of Chemical Technology & Biotechnology, 1990

The catalytic hydrocarbon steam reforming process for the production of synthesis gas is accomplished using a nickel-based catalyst. The catalyst is designed to suit fixed-bed continuous-flow tubular reactor operation. It is manufactured in cylindrical form and possesses a relatively high crushing strength. The nickel active ingredient is homogeneously dispersed on the carrier surface in its oxide form. The currently applied reformers are vertical continuous-flow reactors consisting of several hundred tubes in which the reactants—hydrocarbon and steam—are introduced at the top of the reactor tubes and the reformed gaseous products are collected at their bottom ends. Performance and long-term uninterrupted operation of hydrocarbon steam reformers are severely affected by the alteration of the crushing strength of catalyst pellets. Changes in the crushing strength of the catalyst along the reformer tube under actual operating conditions were investigated and the results are presented here. The usefulness of the crushing strength as a diagnostic test for catalysts is discussed. This test has direct bearing on the selection of prospective catalyst charge, the reuse of partially used catalyst charge, and the investigation of catalyst failures.

Anti-Corrosion Methods and Materials, 2005

... In contrast, the scale developed by the inner surface was more dense and compact...' Failure analysis of catalytic steam reformer tubes HMTawancy, A. Ul-Hamid, AI Mohammed and NM Abbas ... moderately carburizing but coke is not formed (Blackburn, 1981). ...

High-performance catalysts are critical for synthesis gas processes technology. By partnering with ALVIGO, a leading Russian catalyst supplier, Matros Technologies makes it possible for customers worldwide to benefit from a range of catalysts that incorporate decades long Russian scientific tradition, unparalleled knowledge of our scientists and engineers, ISO 9001 compliant quality management system, and excellent customer service.

This experiment was carried out to investigate the effect of response time of sensors or thermal lag due to apparatus on the accuracy of the measurements of a property. The property in this case was the saturation temperature of water measured under different values of pressure. It was believed that the difference between heating and cooling rates would reveal the effect of thermal lag or response time but this was proved untrue from analysis of the results. It has been concluded, instead, that the accuracy of the results was mostly affected by a systematic error which seemed to have been introduced by the way in which the reading were recorded. However, only further experimentation, with some improvements, can verify this conclusion.

3rd International conference "Research and development in mechanical industry" RaDMI 2003, ISBN: 86-83803-06-6, Herceg Novi, Serbia and Montenegro, 19-23 Sep. 2003, 2003

Steam boiler is a large industrial agregate which is very sensitive to temperature variations. In the period of work the steam production and high temperatures cause displacements of the construction. The consequences are various: construction is flexibile and suspended on the springs, while large displacements lead to the cracks at the weak parts of the steam boiler. In transient startup period, which can be extended on a whole day, steam boiler changes its dimensions. Extremely high elongations occur in the vertical direction, where there are no constrains. Measurements of the displacements of the steam boiler were performed using telemetric equipment and displacement sensors. The measured values discussed in this paper, are result of one-year study of the steam boiler behaviour in thermo power plant. Results are important and were used to manage working parameters of the steam boiler.

With proper design, manufacture and construction, modern steam generating systems are capable of operating efficiently for long periods of service. However, successful operation requires adherence to basic operating principles. These principles begin with the careful monitoring of operating conditions so that a system functions within design limits. Chapter 40 describes the instrumentation for monitoring pressures, temperatures and flows -the key process parameters. (Specialized instrumentation for environmental equipment is covered in Section IV, Chapter 36.) These operating parameters then serve as the inputs to the control system. The fundamentals of control theory and modern integrated control systems are reviewed in Chapter 41. These systems have advanced rapidly during the past few decades to provide greater operator knowledge and flexibility to optimize plant performance.