This technology is used for the separation of small or trace amounts of water in liquid organic chemical mixtures (and can also be used for gas permeation dehydration). Its outstanding advantage is that it can achieve separation tasks that are difficult to complete by traditional methods such as distillation, extraction, and adsorption with low energy consumption. This technology can also be coupled with biological and chemical reactions to continuously remove the water generated by the reaction, significantly improving the conversion rate of the reaction. In addition, there are significant technological and economic advantages in separating small amounts of organic pollutants from wastewater and recovering high-value organic components from aqueous solutions. Our company will use this technology to provide professional membrane separation services for the pharmaceutical, chemical, and related industries, and make our own contributions to national energy conservation, emission reduction, and related industry upgrading.

Principle and process flow

Zeolite molecular sieve membrane pervaporation is a novel membrane separation technology used for the separation of liquid mixtures. It is a process of separating components using zeolite molecular sieve membrane materials with different selective permeability and diffusion rates, driven by the vapor pressure difference of the components in a liquid mixture. Compared with traditional separation techniques, pervaporation technology has the characteristics of high efficiency, low energy consumption, convenient operation, and easy scaling up. Its separation principle and process flow are shown in Figure 1 and Figure 2.

Application System

This technology product can be used in industries such as energy, environmental protection, biopharmaceuticals, pesticides, fine chemicals, petrochemicals, electronics, and food. The specific application systems are as follows:
Dehydration of alcohol systems, including methanol, ethanol, propanol, isopropanol, butanol, tert butanol, isoamyl alcohol, cyclohexanol, benzyl alcohol, alkyne alcohol, etc
Ether dehydration, including ether, methyl tert butyl ether, diisopropyl ether, etc
Dehydration of ketones, including acetone, butanone, methyl isobutyl ketone, etc
Dehydration of esters, including methyl acetate, ethyl acetate, butyl acetate, vinyl carbonate, etc
Dehydration of hydrocarbons, including methane, ethane, carbon six oil, cyclohexane, etc
Dehydration of halogenated hydrocarbons, including chlorinated hydrocarbons, dichloromethane, vinyl chloride, etc
Dehydration of aromatic compounds, including benzene, toluene, phenol, ethylbenzene, etc
● Separation of multicomponent organic mixtures, such as fusel oils, etc
Dehydration of other systems, such as methylchlorofuran, acetic acid, triethylamine, aniline, pyridine, organosilicon, etc

Industrial zeolite molecular sieve membrane tube and membrane microstructure

A typical zeolite molecular sieve membrane tube and its microstructure are shown in Figures 3 and 4.

Energy consumption and cost accounting

Taking ethanol and isopropanol dehydration as examples, the energy consumption and cost accounting of pervaporation separation process are carried out

1. Ethanol dehydration

Taking the production of cephalosporin drugs or amoxicillin as an example, in the production process, ethanol is used as a solvent for one or more times, and the water content increases. To recycle and reuse, extraction distillation, azeotropic distillation, or salt addition distillation need to be used. These methods have complex processes, high energy consumption, serious pollution, and introduce third components, making it difficult for the product quality to meet the requirements of the pharmaceutical industry. If the pervaporation method is used, it can save 50% to 70% energy compared to traditional methods, as shown in Table 1, and can also avoid product and environmental pollution.
Accounting Example (Annual Processing of 1600 Tons, Ethanol Content Increased from 90% to 99.5%)
▲ Operating costs: Operating costs mainly include electricity, steam, circulating cooling water, and membrane tube replacement costs.
Electricity consumption: 48 yuan/ton. The product is generated by raw material pumps, product pumps, vacuum pumps, circulating water pumps, and refrigeration machines. The refrigeration power consumption is mainly generated by the use of low-temperature refrigerant as the permeate. Calculated at 0.6 yuan/kWh, the electricity consumption is about 80 kWh/ton of product, and the total electricity consumption cost is about 48 yuan/ton of product.
Steam consumption: 110 yuan/ton of product is mainly generated by heating, vaporization, overheating, and system heat loss of raw materials, with a total cost of approximately 0.55 yuan/ton of product. Calculated at 200 yuan/ton of steam, the total cost is approximately 110 yuan/ton of product.
Cooling water consumption: 10 yuan/ton. The product is mainly generated by the condensation of product steam. Calculated at 0.5 yuan/ton of circulating water, a total of about 20 tons/ton of product will be used, totaling 10 yuan/ton of product.
Replacement of membrane tube: The membrane tube used for 124 yuan/ton is 12m2, and the membrane cost per square meter is 16500 yuan. The total membrane cost is 198000 yuan, which is converted to a membrane cost of 124 yuan/ton per ton of product.
Total operating cost: 48+110+10+124=292 yuan/ton.
▲ Create profits
It is possible to increase the price of ethanol (with 90% ethanol and 10% water content) from approximately 3000 yuan/ton to anhydrous ethanol (with no less than 99.5% ethanol content) priced at approximately 6500 yuan/ton.
Profit creation: (6500-3000-292) × 1600=5132800 yuan.
▲ Device cost
The total cost of the entire device is about 850000 yuan.

2. Ethanol dehydration

In the production process of pharmaceutical products, isopropanol is used as an extraction solvent for recycling. After extraction, the water content in isopropanol increases and the solution becomes alkaline. Isopropanol and water are azeotropic, and it is very difficult to recover them using traditional methods.

Accounting example (processing 2000 tons annually, increasing isopropanol content from 85% to 99.9%)

▲ Operating costs: The operating costs mainly include electricity, steam, circulating cooling water, and membrane tube replacement costs.

Electricity consumption: 64 yuan/ton. The product is generated by raw material pumps, product pumps, vacuum pumps, circulating water pumps, and refrigeration machines. The refrigeration power consumption is mainly generated by the use of low-temperature refrigerant as the permeate. Calculated at 0.8 yuan/kWh, the electricity consumption is about 80 kWh/ton of product, and the total electricity consumption cost is about 64 yuan/ton of product.
Steam consumption: 120 yuan/ton of product, mainly generated by heating, vaporization, overheating, and system heat loss of raw materials, about 0.6 tons/ton of product. Calculated at 200 yuan/ton of steam, the total cost is about 120 yuan/ton of product.
Cooling water consumption: 11 yuan/ton of product, mainly generated by steam condensation of the product. Calculated at 0.55 yuan/ton of circulating water, a total of about 20 tons/ton of product will be used, totaling 11 yuan/ton of product.
Replacement of membrane tube: The membrane tube used for 148.5 yuan/ton is 18m2, and the membrane cost per square meter is 16500 yuan. The total membrane cost is 297000 yuan, which is converted to a membrane cost of 148.5 yuan per ton of product.
Total operating cost: 64+120+11+148.5=343.5 yuan/ton.
▲ Pre tax profit:
It can increase the selling price of isopropanol (isopropanol content of 85%, water content of 15%) from about 3500 yuan/ton to isopropanol (isopropanol content of not less than 99.9%) with a selling price of about 9500 yuan/ton
Pre tax profit: (9500-3500-343.5) × 2000=11.313 million yuan
▲ Device cost: The total cost of the device is approximately 950000 yuan

process comparison(Both azeotropic distillation and azeotropic adsorption are traditional processes)