Methanol in the oil and gas industry
There are several problems in the oil and gas industry involving production and use of methanol.
One of the problems is associated gas flaring. According to the World Bank, about 150 bcm of associated petroleum gas were flared in the world only in 2019. This is as much as Japan and South Korea jointly imported in the same year. Despite higher awareness of the problem and a number of initiatives aimed at reducing gas flaring, the volume of gas flared in the world is growing every year.
Gas flaring contributes to climate change and effects the environment through CO2 emissions - about 350 million tons annually. A valuable energy resource is wasted in vain, for example, if this volume of gas were used to generate electricity, it could provide about 750 billion kWh of electricity, or more than the current annual electricity consumption by the African continent.
Associated petroleum gas can be used as a feedstock to produce methanol - a chemical product in demand in many industries, the production of which has been developing at the most dynamic rates in recent decades. Methanol is a CO2-binding chemical.
To eliminate flares due to methanol production from APG, small capacity units can be used. When flaring from 100 to 1000 m3/h of gas, the production of methanol will be 1 to 10 thousand tons/year, respectively, while carbon dioxide emissions will be reduced by 3 to 30 thousand tons/year.
There is another problem in the oil and gas industry to be solved through the use of methanol. When producing natural gas, methanol is used as a reagent to prevent the formation of hydrate plugs. Currently, the fields are supplied with methanol from large producers located at a great distance from the fields. Production of methanol on modular plants with a capacity of 3 to 30 tons/day directly at the fields eliminates hazardous logistics and environmental accidents during the transportation of this extremely toxic reagent, saves resources, and, importantly, makes the gas company independent of methanol suppliers.
The oil and gas companies of Ukraine, as well as their colleagues around the world, are forced to solve problems with the use of APG, low-pressure and low-calorific gases, provision of fields with methanol.
Figure 1 M-1 methanol plant, 3 tons/day (1 thousand tons/day)
Severodonetsk enterprise Chemical Technological Company (CTC LLC) offers a solution to such problems. CTC LLC is a scientific division involved in technological engineering for the production of methanol, ammonia, synthesis gas and hydrogen. The company's specialists have many years of experience in technological development and design of chemical plants. The scientific potential of the enterprise is based on the theoretical laws of classical science and the achievements of experimental research carried out at the Methanol Research Institute (GosNIImetanolproekt), which worked in Severodonetsk, and according to the projects of which most methanol and ammonia plants were built in Ukraine and neighboring countries. The enterprise develops technological research and mathematical modeling of chemical processes at the modern level.
Figure 2 M-10 methanol plant, 30 tons/day (10 thousand tons/year)
The company developed a series of compact units of various capacities for methanol production designed to operate directly on oil and gas fields.
The minimum capacity of the unit is 3 tons of methanol/day (1,000 tons/year). The maximum capacity of the plant is not limited, but taking into account the requirements of compact production in block-modular design, the capacity can be up to 60 tons/ day (20 thousand tons/year).
Figure 3. Methanol production flowchart
Traditional technical solutions are applied on plants that are implemented in many existing production facilities and ensure efficient and reliable operation.
Natural gas desulfurization
To prevent irreversible poisoning of catalysts for natural gas conversion and methanol synthesis, purification is used on a bifunctional catalyst combining hydrogenation of organosulfur and zinc oxide adsorption of hydrogen sulfide.
Natural gas conversion
The synthesis gas production process is based on the catalytic conversion of gaseous hydrocarbons with steam in a tube heater at a pressure of about 2.0 MPa and a temperature of 850-900°C. The process comes amid an increase in volume and heat absorption. The heat required for the conversion process is supplied through the walls of the reaction tubes due to the combustion of fuel gas in the tube heater. The technology uses steam obtained directly at the plant.
Methanol synthesis
Methanol synthesis is carried out as per circulation scheme on a copper-containing catalyst in a shaft-type reactor with cold bypasses at a pressure of 5.0 MPa and a temperature of 200-270°C.
The plant can use other types of synthesis reactors - adiabatic radial or isothermal one with steam generation, as well as higher pressure synthesis.
Rectification
The rectification stage is intended for the purification of raw methanol obtained at the synthesis stage. Also, this stage allows for the regeneration of methanol from methanol-containing associated formation water.
The rectification stage provides for the production of commercial methanol that meets the requirements of grade A in accordance with GOST 2222-95 or the requirements and conditions of the Customer, which is suitable for use as an inhibitor of hydrate formation.
Figure 4. Basic layout solutions for the process plant and auxiliary facilities for the M-10 methanol production
Cooperation
The supplier of the methanol plant at the design stage assists the customer in the selection of specialists and is responsible for personnel training. A computer training simulator can be supplied with the equipment.
Duplicate monitors of the plant control system are installed in the developer's office, with the help of which, at the initial stage of the installation, the developer controls the operation of the equipment and the actions of the personnel.
Additional advantages
1 СН3ОН methanol is a chemical that binds carbon found in СН4 methane and other gaseous hydrocarbons. Amidst a carbon tax, a gas company that produces carbon-binding product is granted tax preferences.
2 In case of methanol production in an oil and gas company and its use for its own production needs (as an inhibitor of hydrate formation), a zero rate of excise tax is applied to methanol.
3 Natural gas with a high СО2 content is an excellent feedstock for methanol production.
4 With the enactment of the GTS Code of Ukraine, gas companies will purify the produced natural gas from excess СО2. This waste СО2 can be used as an additive to synthesis gas in the production of methanol, which is used to decrease the consumption index for natural gas, reduce the cost of production. It also provides the possibility of selling quotas for carbon dioxide emissions.
5 The feedstock for the production of methanol can be not only high-methane natural gas, but also a low-calorific gas with high nitrogen content. In this case, the synthesis of methanol is carried out not according to the circulation scheme, but according to the flow cascade scheme, with several reactors.
6 The own production of methanol by the oil and gas company opens up additional promising areas of development for the company. The methanol plant is a basis for its modernization and switch to the "green" methanol production.
"Green" methanol is produced from СО2 and environmentally friendly hydrogen. This hydrogen can be obtained by electrolysis of water using electricity from renewable sources (sun, wind). But for oil and gas companies, the production and use of "turquoise" hydrogen appears to be more interesting. This hydrogen is produced by pyrolysis of methane with no СО2 emissions to obtain solid carbon that does not pollute the environment.
In this case, the oil and gas company will retain its natural gas production capacity and become a member of the green circular economy.
7 Methanol produced using a compact modular plant is a raw material for further chemical processing. By arranging the methanol plant with additional units, it is possible to produce chemical products in market demand:
- formalin;
- carbamide-formaldehyde concentrate (CFC);
- carbamide-formaldehyde resins (CFR);
- gasoline and solvents;
- urotropin.
Trends in the development of the world economy are aimed at the transition to renewable carbon-free energy. At the same time, hydrocarbons will remain a raw material base for the chemical industry. Even today we can observe the rapid construction of large gas processing complexes next to gas production sources - on the coast of the Persian Gulf, in the Caribbean.
The future of the Ukrainian gas industry is thus or otherwise connected with gas chemistry. Own production of methanol for oil and gas companies complies with the current needs for this product and opens up prospects for future development.
CHEMICAL TECHNOLOGICAL COMPANY (CTC LLC)
93400, Ukraine, Severodonetsk, Gagarina Str., building 93, office 10
Tel.: +38 097 3056515, +38 050 3586907 +38 06452 30242
office@chtc.com.ua http://chtc.com.ua
