Dimethyl Ether DME 99.9% - Cryogenic Applications & Synthesis

There are two methods for producing DME: one-step method and two-step method. 

The one-step method refers to the synthesis of DME from raw gas in one step, and the two-step method is to synthesize methanol from synthesis gas, and then dehydrate to produce DME.

One-step method of DME production line

This method is to convert natural gas or coal gasification to generate synthesis gas, and then the synthesis gas enters the synthesis reactor, and completes the two reaction processes and conversion reaction of methanol synthesis and methanol dehydration in the reactor at the same time. The product is a mixture of methanol and DME. The mixture is separated by a distillation device to obtain DME, and the unreacted methanol returns to the synthesis reactor.

The one-step method mostly uses a bifunctional catalyst, which is generally a physical mixture of two types of catalysts, one of which is a synthetic methanol catalyst, such as Cu-Zn-Al(O)-based catalyst, BASFS3-85 and ICI-512, etc.; the other is a methanol dehydration catalyst, such as alumina, porous SiO2-Al2O3, Y-type molecular sieve, ZSM-5 molecular sieve, mordenite, etc.

Two-step method

This method is carried out in two steps, namely, methanol is synthesized from synthesis gas first, and methanol is dehydrated under a solid catalyst to produce dimethyl ethre. ZSM-5 molecular sieves made of γ-Al2O3/SiO2 are mostly used as dehydration catalysts at home and abroad. The reaction temperature is controlled at 280~340℃, and the pressure is 0.5-0.8MPa. The single-pass conversion rate of methanol is between 70-85%, and the selectivity of dimethyl ethre is greater than 98%.

The one-step method for synthesizing dimethyl ethre does not have the intermediate process of methanol synthesis. Compared with the two-step method, its process flow is simple, the equipment is small, the investment is small, and the operating cost is low, thereby reducing the production cost of dme and improving the economic benefits. Therefore, the one-step method for synthesizing dme is a hot spot for development at home and abroad. Representative one-step processes developed abroad include: Denmark Topsφe process, the United States Air Products process and Japan NKK process.

The two-step synthesis of dme is the main process for production at home and abroad. This method uses refined methanol as raw material, has few by-products in the dehydration reaction, and the purity reaches 99.9%. The process is mature, the device has wide adaptability, and the post-processing is simple. It can be directly built in a methanol production plant or in other non-methanol production plants with good public facilities. However, this method requires methanol synthesis, methanol distillation, methanol dehydration . The process is relatively long, so the equipment investment is relatively large.

Specification Parameters

Characteristics

· Environmentally Friendly: Combustion produces only carbon dioxide and water, with no sulfur oxides or particulate emissions.

· High Purity: Suitable for use in sensitive applications like aerosol propellants or chemical intermediates.

· Energy Efficient: High calorific value, making it a suitable alternative to traditional fuels.

· Easily Transportable: Can be stored and transported as a liquid under moderate pressure.

Advantages / Selling Points

· Clean Energy: Emits no soot, making it ideal for applications where environmental concerns are paramount.

· Versatile Usage: Compatible with various industrial, automotive, and domestic applications.

· Cost-Effective: An economical alternative to liquefied petroleum gas (LPG) and diesel.

· Safe Storage: Stable under normal conditions, with minimal risk of degradation.

· Reliable Supply: Produced using abundant resources like methanol or natural gas, ensuring consistent availability.

Applications

· Fuel:

o Replacement for LPG in domestic and industrial cooking.

o Alternative diesel fuel for automotive and power generation.

· Aerosol Propellant:

o Widely used in cosmetics, pharmaceuticals, and household sprays.

· Chemical Feedstock:

o Used in the synthesis of dimethyl sulfate, acetic acid, and other intermediates.

· Refrigerant:

o Acts as an efficient cooling agent in refrigeration systems.

· Welding and Cutting:

o Fuel for oxy-DME welding applications.

Technology

The DME project adopts advanced methanol gas-phase catalytic dehydration technology to produce fuel-grade dimethyl ethre with a concentration of more than 99.0%. The fuel-grade DME is further separated through a lightness removal tower (using high-efficiency corrugated rolled perforated plate filler) to obtain refined ethre with a concentration of 99.9% and high-purity ethre with a concentration of 99.99%.

Theory

The chemical stability and low molecular weight of DME make it highly reactive for applications in energy and chemical processes. Its combustion reaction is represented as follows:
CH₃OCH₃ + 3O₂ → 2CO₂ + 3H₂O + Energytext{CH₃OCH₃ + 3O₂ → 2CO₂ + 3H₂O + Energy}CH₃OCH₃ + 3O₂ → 2CO₂ + 3H₂O + Energy

Service

· Customized Solutions: Tailored specifications for different industries.

· Logistics Support: Safe and efficient transport of DME worldwide.

· Technical Assistance: On-site and remote troubleshooting for your specific applications.

· 24/7 Customer Support: Dedicated team to address your queries anytime.

Production Process

The production of DME involves:

1. Methanol dehydration under controlled conditions using advanced solid acid catalysts.

2. Purification of the final product to ensure high purity levels (>99.99%).

3. Storage in pressurized tanks for distribution.

Operation Instructions

1. Handling: Always use DME in well-ventilated areas. Avoid inhalation or contact with the skin.

2. Storage: Store in sealed, pressurized containers away from direct sunlight or heat sources.

3. Transport: Ensure compliance with safety regulations when transporting as a liquefied gas.

Precautions

· Avoid exposure to high temperatures to prevent unintentional vaporization.

· Ensure leak-proof containers and proper safety protocols during handling.

· Use flame arrestors in systems handling DME to prevent flashback.

· Wear appropriate protective equipment (gloves, masks) during use.