Process for the preparation of methanol using renewable feed stocks and / or energy
Patent Information
- Application Number
- EP2024794378
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-10-30
- Filing Date
- 2024-10-21
- Publication Date
- 2026-09-09
AI Technical Summary
The variability in supply of renewable energy and feedstocks for methanol synthesis leads to fluctuations in methanol synthesis gas production, requiring constant addition of make-up gas and necessitating minimum 10% load of power and COx to maintain methanol synthesis.
The process involves cracking a part of produced methanol to generate additional methanol synthesis gas, which is then added to the feed gas in the methanol reactor during shortages, ensuring consistent H2 and COx availability without the need for imported CO2 or excessive power consumption.
This approach reduces power consumption at minimum synthesis load, eliminates the need for imported COx, and maintains methanol synthesis by ensuring consistent H2 and COx availability, even at low power and syngas availability.
Abstract
Description
[0001] Title : Process for the preparation of methanol using renewable feed stocks and / or energy
[0002] The present invention is directed to process for the for the preparation of methanol using renewable feed stocks and / or energy .
[0003] More particular, the invention makes use of cracking of prepared methanol to provide additional methanol synthesis gas in situations when provision of feed stock or energy is short .
[0004] As an example , synthesis gas is conventionally prepared by subj ecting hydrocarbon feed of natural gas or higher hydrocarbons to endothermic steam reforming reactions in a fired tubular steam reformer by contact with a steam reforming catalyst . The primary reformed gas is then fed into a secondary adiabatic reformer, wherein part of hydrogen and residual amounts of hydrocarbons in the gas are partial oxidi zed with oxygen in presence of a secondary reforming catalyst .
[0005] The primary and secondary steam reforming can in large scale methanol synthesis plants be replaced by autothermal reforming (ATR) .
[0006] Recently, use of renewable energy or feed stocks in the methanol synthesis has become more available . As an example , combination of electrolysis of water operated on renewable energy, such as wind power and solar energy to produce hydrogen by electrolysis of water and carbon dioxide from carbon capture or other carbon oxide source . The thus produced hydrogen and carbon dioxide are combined in stoichiometric ratios to form synthesis gas for methanol production .
[0007] The problem when using renewable feed in the methanol synthesis is that the supply of energy and / or renewable feed variates depending on the natural variations of for instance wind and sun or supply of external carbon oxides . As a result , the flow of fresh methanol synthesis gas produced by means of renewable feed can variate substantially .
[0008] To substitute converted hydrogen and carbon oxides in the unconverted synthesis gas , a make-up gas of fresh synthesis gas must constantly be added into the loop recycle gas .
[0009] In case of low power and / or Syngas (H2 + COx ) availability is still required to keep the methanol synthesis at minimum 10% load .
[0010] The term "Cox" means CO and CO2
[0011] Power is needed for hydrogen generation and COx needed for the methanol synthesis . The invention reduces the required power consumption at minimum synthesis load, and it removes the need for import of CO2 , CO . It has been suggested to use the MeOH for power generation either in fuel cell or by burning the MeOH and convert the heat into power . There is no standard solution for loss of Cox .
[0012] We have found that the amount of feed gas to the methanol reactor can be controlled by cracking a part of produced methanol to methanol synthesis gas and adding the thus prepared synthesis gas to the incoming feed gas in case of shortage of the feed gas . This ensures both the availability of H2, and Cox is ensured as opposed to use methanol to produce power and then use that power to produce Hydrogen
[0013] Less power is needed making hydrogen from cracked methanol compared to make power from MeOH and then use this power to produce Hydrogen .
[0014] Furthermore , COx is required in the methanol synthesis gas . I f the COx feed stops , the MeOH production stops . The cracked MeOH gas includes COx and has the correct composition for MeOH synthesis
[0015] Consequently, the invention reduces the required power consumption at minimum synthesis load, and it removes the need for import of COx, by using a methanol cracker to generate the needed synthesis gas . The cracker can be in operation constantly at a load corresponding to 10% of the supported methanol synthesis .
[0016] Methanol cracking is a process that involves breaking down methanol to hydrogen and COx . The process of methanol cracking usually involves heating methanol to high temperatures in the presence of a catalyst . The catalyst helps to facilitate the reaction and increase the yield of the cracked methanol synthesis gas .
[0017] The cracked methanol gas includes COx and has the correct composition for methanol synthesis . Preferred embodiments of present invention are the following .
[0018] 1. Process for the preparation of methanol, comprising the steps of
[0019] (a) providing an amount of methanol synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide;
[0020] (b) introducing the amount of methanol synthesis gas into at least one methanol reactor;
[0021] (c) catalytic reacting the at least part of the methanol synthesis gas to methanol;
[0022] (d) withdrawing from the at least one methanol reactor produced methanol and passing the produced methanol to a methanol storage unit
[0023] (e) reducing the amount of methanol synthesis gas introduced into the at least one methanol reactor and passing methanol product from the methanol storage unit to a catalytic methanol cracking unit;
[0024] (f) cracking the part of the withdrawn methanol product in the catalytic methanol cracking unit to a cracked methanol synthesis gas; and
[0025] (g) adding the cracked methanol synthesis gas from step (f) into the reduced amount of methanol synthesis gas in step (e) .
[0026] 2. The process of embodiment 1, wherein the amount of methanol synthesis gas is produced by means of renewable sources .
[0027] 3. The process of embodiment 2, wherein the renewable sources comprise gasified biomass, captured carbon dioxide and electrolytic produced hydrogen. 4 . The process of any one of the preceding embodiments , wherein the amount of methanol synthesis gas introduced into the at least one methanol reactor in step ( e ) is reduced up to at least 80% , such as 85% , 90% , 95% , or up to 100% compared to full methanol synthesis gas load of the at least one methanol reactor
[0028] 5 . The process of any one of the preceding embodiments , wherein in step ( f ) methanol is cracked to provide at least 10% combined methanol synthesis gas plus cracked methanol synthesis gas in step ( g) .
[0029] The term "methanol synthesis gas load" refers to the flow or pressure of synthesis gas used in the production of methanol .
[0030] The "methanol synthesis gas load" speci fies the amount and composition of syngas fed into the methanol reactor . Controlling the methanol synthesis gas load is crucial for maintaining the optimal reaction conditions , such as temperature , pressure , and reactant ratios , to maximi ze methanol production while minimi zing the formation of unwanted byproducts .
[0031] The speci fic requirements for the methanol synthesis gas load will depend on the design of the reactor, the catalyst used, and the desired production capacity . To ensure ef ficient and safe methanol production, it is essential to carefully control and monitor the composition and flow rate of the synthesis gas entering the reactor .
Claims
Claims1. Process for the preparation of methanol, comprising the steps of(a) providing an amount of methanol synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide;(b) introducing the amount of methanol synthesis gas into at least one methanol reactor;(c) catalytic reacting the at least part of the methanol synthesis gas to methanol ;(d) withdrawing from the at least one methanol reactor produced methanol and passing the produced methanol to a methanol storage unit;(e) reducing the amount of methanol synthesis gas introduced into the at least one methanol reactor and passing methanol product from the methanol storage unit to a catalytic methanol cracking unit;(f) cracking the part of the withdrawn methanol product in the catalytic methanol cracking unit to a cracked methanol synthesis gas; and(g) adding the cracked methanol synthesis gas from step (f) into the reduced amount of methanol synthesis gas in step (e) .
2. The process of claim 1, wherein the amount of methanol synthesis gas is produced by means of renewable sources.
3. The process of claim 2, wherein the renewable sources comprise gasified biomass, captured carbon dioxide and electrolytic produced hydrogen.
4. The process of any one of the preceding claims, wherein the amount of methanol synthesis gas introduced into the at least one methanol reactor in step (e) is reduced up to at least 80%, such as 85%, 90%, 95%, or up to 100% compared to full methanol synthesis gas load of the at least one methanol reactor.
5. The process of any one of the preceding claims, wherein in step (f) methanol is cracked to provide at least 10% combined methanol synthesis gas plus cracked methanol synthesis gas in step (g) .