DOI: 10.5281/zenodo.7255076
title: Microchannel steam reforming reactors with enhanced heat transfer for conducting simultaneous endothermic and exothermic reactions

description: <strong>Microchannel steam reforming reactors with enhanced heat transfer for conducting simultaneous endothermic and exothermic reactions</strong> Junjie Chen Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: komcjj@gmail.com It has been described a compact multiple tube steam reformer. The design consists of multiple packed tubes, of small diameter, being placed in intimate contact with a heat generating flame. The arrangement leads to improved heat transfer and therefore chemical conversion. However, the packed tube results in a significant pressure drop and the author states the process is still heat transfer limited. Therefore, a reactor design which minimizes the process side pressure drop and does not suffer from heat transfer limitation is required. It has been described a method to modify a monolithic structure into a combined heat exchanger reactor. The method describes the mechanical process to transform the structure into a structure consisting of two discrete volumes. It is proposed that the arrangement can either be used as a heat exchanger, where energy is transferred from one stream to another via conduction through the wall or it is suitable as a chemical reactor where the second set of channels allow the introduction of a heat transfer fluid. In the second case, the energy required or generated through the reaction is removed via a heat transfer fluid in the second channel. It is noted that the reaction can be a catalytic process and the catalytically active material can be coated onto the monolith passage walls to minimize pressure drop. In this arrangement, the heat transfer from the process catalyst to the dividing wall will be highly efficient, however, the uptake of the energy by the heat transfer fluid will suffer from all of the limitations of traditional heat transfer operations. In this case, the boundary layer will provide a significant resistance to heat transfer and will severely limit the rate of the process. Also, for this arrangement to successfully supply or remove heat and maintain a near isothermal longitudinal profile considerable heat transfer fluid velocities must be utilized. The high velocities will reduce the characteristic thickness of the boundary layer and ensure that a sufficient mass of heat transfer fluid is available to absorb the heat of reaction without significantly changing temperature. These requirements will lead to excessive pressure drop through the coolant channels. Therefore, a reactor design which minimizes the heat transfer fluid side pressure drop is required. The method does not teach about combining endothermic and exothermic reactions on opposing sides of dividing walls of adjacent channels as an efficient method of heat transfer. Streamwise distance (meters), Heat flux (watts per square meter) 0 28082.8 0.00025 139648 0.0005 111616 0.00075 93312 0.001 81920 0.00125 74112 0.0015 68096 0.00175 62976 0.002 58752 0.00225 55168 0.0025 52096 0.00275 49152 0.003 46336 0.00325 44032 0.0035 41984 0.00375 40064 0.004 38400 0.00425 36864 0.0045 35328 0.00475 33920 0.005 32512 0.00525 31360 0.0055 30336 0.00575 29184 0.006 28288 0.00625 27392 0.0065 26496 0.00675 25728 0.007 24832 0.00725 24192 0.0075 23680 0.00775 23040 0.008 22400 0.00825 21760 0.0085 21376 0.00875 21120 0.009 20608 0.00925 20224 0.0095 19968 0.00975 19456 0.01 19072 0.01025 18688 0.0105 18432 0.01075 18176 0.011 17920 0.01125 17792 0.0115 17536 0.01175 17280 0.012 17024 0.01225 16768 0.0125 16640 0.01275 16512 0.013 16384 0.01325 16256 0.0135 16128 0.01375 16000 0.014 15872 0.01425 15744 0.0145 15488 0.01475 15488 0.015 15360 0.01525 15104 0.0155 15104 0.01575 14976 0.016 14848 0.01625 14720 0.0165 14720 0.01675 14720 0.017 14592 0.01725 14336 0.0175 14336 0.01775 14464 0.018 14336 0.01825 14336 0.0185 14336 0.01875 14208 0.019 14080 0.01925 14080 0.0195 14080 0.01975 14080 0.02 13952 0.02025 13824 0.0205 13824 0.02075 13952 0.021 13952 0.02125
description: Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: komcjj@gmail.com, Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China