Carbon Dioxide Reforming of Methane to Syngas: Modeling Using Response Surface Methodology and Artificial Neural Network

Abstract

Kesan oksigen terhadap mangkin 1% berat Rhodium di dalam Magnesium Oksida (MgO) dikaji untuk proses pembentukan semula metana dengan menggunakan gas karbon dioksida (CORM). Kesan tiga parameter utama: suhu, nisbah reaktan (O₂/CH₄) dan berat mangkin terhadap penukaran metana, kememilihan gas sintesis dan nisbah H₂/CO diselidiki. Dengan bantuan reka bentuk eksperimen, dua pendekatan matematik: polinomial empirik dan rangkaian saraf buatan diterbitkan. Pekali kolerasi model polinomial empirik yang diterbitkan, r, adalah melebihi 85%. Walau bagaimanapun, pekali kolerasi untuk suapan hadapan rangkaian saraf pula melebihi 95%. Oleh itu, suapan hadapan rangkaian saraf adalah lebih efisen daripada model polinomial empirik. Penukaran metana tertinggi sebanyak 95% dihasilkan pada suhu 850°C dengan nisbah O₂/CH₄ sebanyak 0.14 dan 141 mg mangkin. Kememilihan hidrogen secara maksima sebanyak 40% boleh dicapai pada suhu 909°C, nisbah O₂/CH₄ sebanyak 0.23 dan 309 mg mangkin. Nisbah maksima H₂/CO sebanyak 1.6 dihasilkan pada suhu 758°C dengan nisbah O₂/CH₄ sebanyak 0.19 dan 360 mg mangkin digunakan. Kata kunci: Gas sintesis, pembentukan semula metana menggunakan gas karbon dioksida, rhodium, MgO, reka bentuk eksperimen, suapan hadapan rangkaian saraf 1wt% of Rhodium (Rh) on Magnesium Oxide (MgO) catalyst have been investigated for carbon dioxide reforming of methane (CORM) with the effect of oxygen. The effect of temperature, O₂/CH₄ ratio and catalyst weight on the methane conversion, synthesis gas selectivity and H₂/CO ratio were studied. With the help of experimental design, two mathematical approaches: empirical polynomial and artificial neural network were developed. Empirical polynomial models correlation coefficient, r, was above 85%. However, the feed forward neural network correlation coefficient was more than 95%. The feed forward neural network modeling approach was found to be more efficient than the empirical model approach. The condition for maximum methane conversion was obtained at 850°C with O₂/ CH₄ ratio of 0.14 and 141 mg of catalyst resulting in 95% methane conversion. A maximum of 40% hydrogen selectivity was achieved at 909°C, 0.23 of O₂/CH₄ ratio and 309 mg catalyst. The maximum H₂/CO ratio of 1.6 was attained at 758°C, 0.19 of O₂/CH₄ and 360 mg catalyst. Key words: Synthesis gas, carbon dioxide reforming of methane, rhodium, MgO, experimental design, feed forward neural network