Method and apparatus for producing methanol with hydrocarbon recycling
An apparatus and method of producing methanol includes reacting a heated hydrocarbon-containing gas and an oxygen-containing gas in a reactor; to provide a product stream comprising methanol; and transferring heat from the product stream to the hydrocarbon-containing gas to heat the hydrocarbon containing gas. After removing methanol and CO 2 from the product stream, unprocessed hydrocarbons are mixed with the hydrocarbon containing gas fro reprocessing through the reactor.
1. An apparatus for producing methanol, comprising:
a reactor having a reactor input;
a first hydrocarbon-containing gas supply that provides a first hydrocarbon-containing gas into the reactor input as a first hydrocarbon-containing gas stream;
a source of oxygen-containing gas that provides oxygen-containing gas into the reactor so that in said reactor a reaction of oxidation of heated hydrocarbon-containing gas with oxygen of the oxygen-containing gas takes place to produce a product stream comprising formaldehyde and methanol;
an isobaric condenser that condenses a relatively low volatility component of the product stream for separation from a relatively high volatility component of the product stream, the isobaric condenser operating isobarically;
a scrubber that receives the relatively high volatility component of the product stream from the isobaric condenser and removes a methanol-water stream that includes formaldehyde, water, methanol, and CO 2 ;
a rectification column that receives the methanol-water stream from the scrubber and removes a formaldehyde distillate stream including formaldehyde and CO 2 ;
a flash drum that receives the relatively low volatility component of the product stream from the isobaric condenser; and
a methanol rectifier that receives a liquid stream from the flash drum and separates methanol from ethanol,
wherein the first hydrocarbon-containing gas stream comprises a portion of the product stream.
2. The apparatus according to claim 1 further comprising a second hydrocarbon-containing gas supply providing a cold hydrocarbon-containing gas downstream of the first hydrocarbon-containing gas to be directly mixed with a mixture of a hydrocarbon-containing gas and the oxygen-containing gas to produce the product stream comprising formaldehyde and methanol; and
a heat exchanger for transferring heat from the product stream to the hydrocarbon-containing gas supplied by the first hydrocarbon-containing gas supply.
3. The apparatus as defined in claim 2 and further comprising a heater disposed between the heat exchanger and the reactor input for further preheating the hydrocarbon-containing gas prior to its supplying into the reactor.
4. The apparatus of claim 3 wherein the heat exchanger comprises a downstream portion of the reactor.
5. The apparatus as in claim 2 , wherein said second hydrocarbon-containing gas supply is arranged at a location of said reactor where formation of methanol and formaldehyde is substantially completed.
6. The apparatus as in claim 2 wherein a controller adjusts the second hydrocarbon-containing gas supply based on one or more operating parameters.
7. The apparatus as in claim 6 wherein the one or more operating parameters comprise temperature.
8. The apparatus according to claim 1 further comprising a formalin blender that receives a combined stream comprising the formaldehyde distillate stream from the rectification column and a vapor stream from the flash drum, the combined stream including formaldehyde, methanol, and carbon dioxide.