Simulasi Proses dan Optimisasi Superstruktur Multi-Objektif Multi-Periode Strategi Pengembangan Gas Bumi Kaya CO2 menjadi Multi-Produk Kimia dan Bahan Bakar: Studi Kasus Lapangan Gas Natuna Timur = Process Simulation and Multi-Period Multi-objective Superstructure Optimization at Development Strategy of High CO2-content Natural Gas to Multi-Chemicals and Fuels: A Case Study of East Natuna Gas Field