초록 ▼

A process starting from a hydrocarbon feedstock, and aiming to produce a synthesis gas suitable either for methanol synthesis or for other applications requiring a low H2/CO ratio. In this process, the feedstock, supposed to be desulfurized, is divided into two fractions; a first fraction undergoes

A process starting from a hydrocarbon feedstock, and aiming to produce a synthesis gas suitable either for methanol synthesis or for other applications requiring a low H2/CO ratio. In this process, the feedstock, supposed to be desulfurized, is divided into two fractions; a first fraction undergoes a primary steam reforming at high pressure and moderate temperature; the gas effluent from said primary steam reforming, as well as the second fraction of the feedstock, are combined and subsequently undergo a secondary reforming by reaction with a free-oxygen rich gas in a reactor operating under essentially adiabatic conditions. The synthesis gas, obtained as effluent from said secondary reforming, has a composition adjustable at will in a wide range, and therefore can be made as close as necessary to the stoichiometric composition required for methanol synthesis, or it can be made with a low H2/CO ratio for other applications. The synthesis gas is available at high pressure, and can therefore feed directly, without compression, the synthesis loops downstream. The process of the present invention is particularly suitable for methanol production on a very large scale.

대표청구항 ▼

A process for producing, from a desulfurized hydrocarbon-containing feedstock, a synthesis gas having essentially the stoichiometric composition required for methanol synthesis and low CO2 content, consisting essentially of: (a) dividing said feedstock into two fractions, the first fraction represen

A process for producing, from a desulfurized hydrocarbon-containing feedstock, a synthesis gas having essentially the stoichiometric composition required for methanol synthesis and low CO2 content, consisting essentially of: (a) dividing said feedstock into two fractions, the first fraction representing 30 to 95 per cent of the total feedstock, (b) subjecting the first fraction from (a) to a primary steam reforming reaction under a pressure higher than 40 atmospheres, by mixing said fraction with steam, and heating the mixture thereof by indirect heat exchange, in the presence of a reforming catalyst, to form a gaseous effluent including hydrogen to a temperature between 700°and 850°C., (c) preheating the second fraction from (a), by indirect heat exchange, to a temperature such that, after mixing said fraction with the gas effluent from (b) in the subsequent step, the mixture thereof is at a minimum temperature of 600°C., (d) combining effluent gas streams from (b) and (c) to obtain a gas mixture at a minimum temperature of 600°C. and containing a minimum of 35 per cent methane equivalent, (e) providing a free oxygen-rich gas, (f) reacting in a single step the gas mixture from (d) with the oxygen rich gas from (e) in a single stage secondary reforming reactor operating under essentially adiabatic conditions, and consisting essentially of a gas mixing zone and a reaction zone, the total amount of free oxygen injected in said mixing zone constitutes the total amount of free oxygen supplied in the process for reaction with the combined effluent gas stream mixture from (d) to produce the synthesis gas and being sufficient to initiate therein the partial oxidation reaction, and the mixing of the reacting gases in said mixing zone being accomplished through a mixing apparatus designed to obtain quasi-instantaneously a homogeneous mixture before the partial oxidation reaction proceeds significantly, and said reaction zone containing a single bed of catalyst or catalysts, whereby the total homogeneous mixture is passed only once through the whole catalyst bed thus producing a synthesis gas containing a per cent methane equivalent of less than one-tenth of that of the gas mixture from (d), and a CO2 content of less than 8 per cent by volume.