Modeling of Hydrogen Production by Applying Biomass Gasification: Artificial Neural Network Modeling Approach

In order to accurately anticipate the proficiency of downdraft biomass gasification linked with a water-gas shift unit to produce biohydrogen, a model based on an artificial neural network (ANN) approach is established to estimate the specific mass flow rate of the biohydrogen output of the plant based on different types of biomasses and diverse operating parameters. The factors considered as inputs to the models are elemental and proximate analysis compositions as well as the operating parameters. The model structure includes one layer for input, a hidden layer and output layer. One thousand eight hundred samples derived from the simulation of 50 various feedstocks in different operating situations were utilized to train the developed ANN model. The established ANN in the case of product biohydrogen presents satisfactory agreement with input data: absolute fraction of variance (R-2) is more than 0.999 and root mean square error (RMSE) is lower than 0.25. In addition, the relative impact of biomass properties and operating parameters on output are studied. At the end, to have a comprehensive evaluation, variations of the inputs regarding hydrogen-content are compared and evaluated together. The results show that almost all of the inputs show a significant impact on the sm(hydrogen) output. Significantly, gasifier temperature, SBR, moisture content and hydrogen have the highest impacts on the sm(hydrogen) with contributions of 19.96, 17.18, 15.3 and 10.48%, respectively. In addition, other variables in feed properties, like C, O, S and N present a range of 1.28-8.6% and proximate components like VM, FC and A present a range of 3.14-7.67% of impact on sm(hydrogen).