Perpustakaan Digital ITB

Methane pyrolysis offers a promising route for producing turquoise hydrogen and marketable solid carbon without direct carbon dioxide formation during the reaction. This study investigates the effects of operating temperature, feed-gas composition, catalyst particle classification, and fluidization number on methane pyrolysis in a fluidized-bed reactor and evaluates the process from a techno-economic perspective. Experiments using Carbon Black N330 were conducted at temperatures of 900 to 1100°C, methane concentrations of 5, 10%, and 62.5%, Geldart Group A and B particles, and fluidization numbers of 1–2. The experimental results were subsequently incorporated into an Aspen Plus process model and combined with capital expenditure, operating expenditure, and LCOH calculations. The results demonstrate that operating conditions significantly influence methane conversion, hydrogen yield, carbon formation, and catalyst stability. The recommended operating condition condition within the investigated range was obtained at 1100°C using a feed containing 10% CH? and 90% N?, Geldart Group B particles with a size of 0.212-0.425 mm, and a fluidization number of 1.5. Under these conditions, the mean methane conversion and hydrogen yield reached 88.03% and 55.19%, respectively. The carbon yield was 39.44%, with carbon deposition of 0.794 g carbon per gram of initial catalyst. The results also show that high methane conversion does not necessarily correspond to high hydrogen yield because partially dehydrogenated hydrocarbons and carbonaceous intermediates may be formed. The techno-economic analysis yielded a minimum hydrogen selling price of USD 4.01/kg H? when solid carbon was not sold. Treating solid-carbon revenue as a coproduct credit reduced the selling price to USD 3.19/kg H?, representing a reduction of approximately 20.4%. These findings demonstrate that appropriate fluidized-bed operating conditions and the marketability of the solid-carbon coproduct are important to the technical and economic feasibility of methane-pyrolysis hydrogen production.