News Release

HighChem Company Limited (Headquarters: Minato Minato-ku, Tokyo President and CEO: Ushio Taka hereinafter referred to as HighChem), in response to the rising demand for CO2 emission reduction technologies, is enhancing its promotional activities in Japan for the Chinese-manufactured VOC (Volatile Organic Compounds) membrane separation systems. These systems, which have been implemented in over 500 cases worldwide, are pivotal in tackling VOC emissions, thereby contributing to environmental sustainability efforts.      

Traditionally, exhaust gases produced in the manufacturing of polypropylene, polyethylene, and EO/EG are combusted, which is a common practice. However, the company's VOC membrane separation systems allow for the capture and reuse of these gases. This reuse not only significantly reduces CO2 emissions from combustion but also decreases raw material consumption. The systems' economic and social benefits have led to their implementation in over 500 facilities across China, Taiwan, Thailand, Nigeria, and other countries, with operational units also in Japan. The following details the mechanism of exhaust gas recovery and its economic and environmental impacts.

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In the EO/EG manufacturing process, it is necessary to exhaust impurities such as argon gas to maintain safe production, and a large amount of ethylene is lost in the exhaust gas. By introducing Dalian Ouka's VOC membrane separation equipment, it has become possible to recover more than 80% of ethylene from this exhaust gas, which not only reduces CO2 emitted during combustion but also reduces the amount of raw materials used.

EO/EG plant with annual production capacity of 80,000 tons:
Exhaust gas amount: 160 Nm3/h, ethylene concentration: 23.12% (V%), argon concentration: 12.32% (V%), annual operating hours: 8,000 hours

Before the introduction, more than 370 tons of ethylene was lost per year, but after the introduction, the following economic and environmental benefits have been achieved.
・Recovered 300 tons of ethylene per year [Annual economic effect: approximately 20 million yen]
・CO2 reduction of 940 tons per year

During the polypropylene manufacturing process, the polypropylene powder discharged from the reactor contains a large amount of hydrocarbon gas that causes air pollution. Hydrocarbon gases must be removed from polypropylene powder to reduce hydrocarbon gas losses and ensure safe operation of the subsequent granulation process. In addition, exhaust gas mainly contains propylene, propane, ethylene, hydrogen, nitrogen, etc., and the hydrocarbon content is approximately 10 to 20 vol%.

By using Dalian Ouka's VOC membrane separation equipment, the propylene recovery rate is over 90%, and nitrogen gas with a purity of 99 vol% can be reused from hydrocarbons, reducing CO2 emitted during combustion. We can expect high economic effects.

Polypropylene plant with annual production of 200,000 tons (gas phase method):
Propylene amount in exhaust gas: 250 to 450 kg/hr, nitrogen gas: 1200 kg/hr

・Recover more than 2,400 tons of propylene per year [Annual economic effect: approximately 170 million yen]
・Nitrogen recovery rate averages 60%, approximately 5,760 tons per year [Annual economic effect: approximately 20 million yen]
・CO2 reduction of more than 7,500 tons per year

In 2015, Dalian Ouka developed a new process for recovering polyethylene exhaust gas, the Mem-Cryo (CCMC) process. This process makes it possible to recover highly concentrated ethylene, nitrogen, hydrogen, and carbon gases from the exhaust gas released into flares during the polyethylene manufacturing process. The process consists of a gas separation membrane consisting of a VOC membrane and an H2 membrane, and a cryogenic process that liquefies the gas by cooling it to less than -100°C. By passing through each process, it is possible to separate gases at high concentrations. The recovery rate for ethylene is over 80%, the recovery rate for C4 and C5 is over 98.5%, and the recovery rate for nitrogen with a purity of 93vol% is over 80%. Separation is now possible, and very high economic effects can be expected. We already have a track record of more than 20 cases in China, and are currently expanding into overseas markets.

Polyethylene plant with annual production of 300,000 tons:
Annual losses of hydrocarbons and nitrogen in flared gas amounts to US$1.2 million, but once implemented, the system will provide the following economic and environmental benefits:
・Hydrocarbon recovery 197.65kg/hr [Annual economic impact: approximately 1.1 million USD]
・Nitrogen recovery 600 kg/hr [Annual economic effect: approximately 300,000 USD]
・CO2 reduction of more than 5,000 tons per year

Large amounts of VOC gas are generated during storage and transportation of gasoline. This VOC gas is one of the causes of air pollutants such as photochemical oxidants and suspended particulate matter including PM2.5. By applying VOC membrane separation technology and combining an organic vapor membrane and absorption adsorption process, Dalian Oukesha has reduced the concentration of gasoline vapor in exhaust gas and achieved the recycling of gasoline components.

<Effect>
Before introduction: Generally gasoline vapor concentration is 500-1000 g/m3
After introduction: Gasoline vapor concentration is decreased to 120 mg/m3


Related Links:VOC membrane separator

Media inquiries regarding this release
HighChem Co., Ltd. PR Division – Eriko Kuroiwa
E-mail: kuroiwa@highchem.co.jp Phone: +81-3-5251-8580 / +81-90-6539-4213 (Kuroiwa)