Low-tonnage methanol production plant with obtaining syngas by partial oxidation of natural gas with oxygen when correcting gas composition for optimal methanol synthesis

Relevance. The concept of creating low-tonnage methanol production plants is proposed. They include two main nodes: a synthesis gas production complex by non-catalytic partial oxidation of natural gas with oxygen and a methanol synthesis complex using a direct-flow multi-reactor cascade with the release of condensed methanol after each reactor. The plant can enter a chemical cluster and process methanol into useful products. Aim. Describe the technology and design the installation, determine its main indicators. Methods. Design of the plant, mathematical and numerical modeling of chemical and technological processes. Results and conclusions. The paper describes a new technological process of low-tonnage production for methanols. The main apparatus of the installation is an original small-sized syngas gas generator, which provides: high safety, reliability and maintainability; no need to use a catalyst for partial oxidation and the possibility of carrying out the process at high pressures up to 8.0 MPa, which do not require gas compression during subsequent catalytic synthesis of methanol; transportability and modularity of the installation. The paper introduces the results of numerical simulation of natural gas partial oxidation by oxygen. The authors have determined the rational modes of the process in syngas gas generator. The main parameters of the partial oxidation are: the coefficient of excess oxidizer, which should be in the range of 0.34÷0.36, and the supply pressure of the components in the range of 6.0÷7.0 MPa. The authors carried out the numerical simulation of the methanol synthesis without correction and with preliminary correction of the syngas composition. The data obtained allowed: calculating the degree of conversion of carbon from carbon oxides to methanol; when using a three-reactor cascade with an optimal composition of the gas mixture, the degree of conversion reaches 95%; estimating the maximum specific capacity of the installation up to 1250 kg/hour of methanol per 1000 m3/hour of natural gas and the maximum capacity of the installation up to 20000 tons of methanol per year.