methanol production, biogas, mathematical model, nonlinear programming
The dependence of natural gas may be replaced by renewable sources of second generation - nonfood source. Methanol is produced from synthesis gas, which is produced from natural gas. Natural gas can be replaced by biogas for the production of synthesis gas. We compare the production of methanol from varieties of raw materials - natural gas and biogas. The basic starting point for comparison is the same mass inlet flow rate of both raw materials under the same operating conditions. Methanol production using natural gas and biogas as the material raw was simulated using an Aspen Plus simulator with real chemical thermodynamic, and 16 146 kg/h crude methanol from nature gas and 14 615 kg/h from biogas could be produced. Methanol production from biogas could also increase by 9.7 % with processed operational and parametric modification using nonlinear programming (NLP). The NLP model contains equations which enable methanol and steam productions. The most important is the conversion of methane in the reformer. Optimal methane conversion could take place by operating using the optimal parametric data in a reformer unit. Optimal methane conversion could take place by operating using the optimal parametric data in a reformer unit (temperature=840 oC and pressure=8 bar). Optimal production of methanol from biogas was 16 040 kg/h under optimal parameters.