Evaluation of heat transfer in a catalytic fixed bed reactor at high temperatures

Experimental results of fixed-bed heat-transfer experiments with no chemica l reaction are presented and discussed. The runs were carried out in a tubu lar integral reactor heated by an electrical furnace at temperatures in the range of 100 to 500 degrees C. Experimental temperature profiles were dete rmined for the electrical furnace, for the reactor wall, and for the fixed bed center. industrial catalyst for the prereforming of hydrocarbons was em ployed as the packing material. The effects of process conditions (furnace temperature, gas flow rate) on the heat-transfer coefficients were evaluate d. The experimental results were analyzed in terms of the external, wall, a nd internal thermal resistances, associated in series, and compared with mo del predictions. Under the conditions studied, the overall coefficient was mostly a function of the external effective heat-transfer coefficient. An a lternative data treatment was proposed to determine the internal heat-trans fer coefficient in fixed beds when wall temperature is not constant.