Direct production of ethylene from methane: a new breakthrough in the petrochemical industry

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Direct production of ethylene from methane: a new breakthrough in the petrochemical industry. According to Chemical Industry 707 News Network: More than 30 years of efforts by the chemical industry have finally paid off—abundant and inexpensive natural gas can now be directly converted into ethylene, the most widely used basic chemical raw material in the world. 　　Recently, the U.S.-based Siluria Technologies company (hereinafter referred to as Siluria) held a grand commissioning ceremony for its pilot plant in Texas, becoming the world’s first company to achieve the industrial-scale direct conversion of natural gas into ethylene. The new route could bring about significant changes to the traditional ethylene industry that relies on oil as a raw material. 　　The \"Holy Grail\" of the chemical industry As a basic industrial raw material, ethylene plays a vital role in the petrochemical industry; its production volume is one of the key indicators of the development level of the petrochemical sector. 　　Except for North America and the Middle East, most countries and regions in the world, including my own country, use naphtha as a raw material and the steam cracking process to produce ethylene. This method is not only energy-intensive, generates large amounts of greenhouse gases, and is costly, but it also consumes valuable petroleum resources since its raw materials come from oil. 　　To reduce dependence on oil, countries are conducting research on producing olefins from natural gas, whose main component is methane. The routes for producing ethylene from natural gas are divided into direct and indirect methods. Compared to the lengthy and complicated process of the indirect method, the direct method can convert methane into ethylene in just one step, offering high economic value and thus being highly attractive. 　　However, since the selective activation and directed conversion of methane represent world-class challenges and are regarded as the \"Holy Grail\" of the entire chemical industry, from the 1980s to the early 2000s, the academic community has failed to develop an industrially viable process for directly converting methane into ethylene. 　　The key to breakthrough lies in the catalyst. In 2010, Siluria Company creatively used biological templates to precisely synthesize nanowire catalysts, and employed high-throughput techniques to select the most suitable elemental compositions from a large number of candidate catalysts, thereby developing an industrially viable catalyst for the direct conversion of methane into ethylene. 　　This catalyst can efficiently catalyze the conversion of methane to ethylene at 5–10 atmospheres of pressure, at temperatures lower than those used in conventional steam cracking methods (200°C–300°C), with an activity more than 100 times that of traditional catalysts. 　　The reactor designed by Siluria is divided into two parts: one part is used to convert methane into ethylene and ethane, while the other part is used to crack the by-product ethane into ethylene; the heat required for the cracking reaction comes from the heat released during the methane conversion reaction. This design allows the reactor to be fed either natural gas or ethane, while maximizing energy savings. 　　Advancement of oil substitution strategies The technical advantages of the ethylene production process from natural gas directly developed by Siluria Company (hereinafter referred to as the new route) lie in five main aspects: lower costs compared to traditional ethylene production via naphtha cracking, reduced greenhouse gas emissions, energy efficiency, and high economic value ； Ethylene can be further converted into liquid fuel, further enhancing the economic value of the entire process ； The requirements for raw materials are not stringent; methane can come from natural gas or biomass, and the oxygen source can be pure oxygen, oxygen-enriched air, compressed air, etc ； It can make use of existing ethylene production facilities and recovery equipment, resulting in low retrofit costs ； It holds great strategic value due to its abundant natural gas resources. 　　In addition to its impact on the olefin industry, the new route will also affect the production of liquid fuels including gasoline, diesel, and aviation fuel. Siluria has also developed a technology for producing liquid fuels from ethylene, which provides an additional route for manufacturing liquid fuels starting from natural gas. Compared to the current route based on the Fischer-Tropsch synthesis method, Siluria’s approach does not require the energy-intensive Fischer-Tropsch process, resulting in cost savings of 25% to 30% merely in terms of investment costs. 　　Both ethylene and liquid fuels are traditionally produced from petroleum, and new routes can save precious petroleum resources and advance petroleum substitution strategies. 　　In June 2014, Linde AG, the world’s largest gas and engineering group, reached a cooperation agreement with Siluria Company; the two parties would work together at a test facility in Texas to carry out the final scaling up and validation of this technology. Under the agreement, the two parties will optimize and integrate their respective technologies and solutions into a comprehensive package. Linde Group will be responsible for granting licenses to the petrochemical industry to use this package for upgrading or expanding existing ethylene plants, or for building new world-class ethylene plants; the licensing process is expected to begin in the second half of 2015. 　　In August 2014, Saudi Aramco, the world’s leading integrated energy and chemicals company, invested in Siluria Company and planned to deploy the new process route first in Saudi Arabia. 　　Previously, since the ethane production in the Middle East was not sufficient to support new ethylene plants, new companies were forced to turn to the more expensive naphtha as a raw material. 　　The new route offered by Siluria came like a blessing in disguise, quickly catching the attention of petrochemical companies in the Middle East and becoming a potential market for them. 　　Not only abroad, but the new routes have also caught the attention of the United States**. In March 2014, the CEO of Siluria was invited to attend the high-level \"2020 Energy Policy Forum\" and deliver a speech; it was the only company from the natural gas industry among those invited. Subsequently, senior executives from Siluria were invited to the White House to discuss future U.S. energy policy issues with the U.S. Secretary of Energy and other officials. 　　The United States **has realized that the new route could have strategic significance for its energy and manufacturing sectors, and is considering formulating policies to promote employment and economic development. 　　Experience and lessons learned: In China, naphtha is the main raw material for ethylene production, accounting for about 65% of the total raw materials used. 　　Previously, due to the sharp rise in international crude oil prices and the intensification of supply-demand imbalances domestically, the supply of olefin raw materials became strained, which hindered the development of the ethylene industry. It is estimated that in 2015, China’s ethylene deficit will reach as high as 13.7 million tons. 　　Not only that, but our country faces the problem of high production costs for ethylene and weak competitiveness. In 2013, the production cost of ethylene in the Middle East was only 100 dollars per ton, while in North America it remained around 300 dollars per ton. In China, however, the cost of producing ethylene was over 900 dollars per ton. 　　Therefore, it is necessary for our country to develop new ethylene production routes. In the field of direct conversion of natural gas into ethylene, China has established a solid research foundation, with research institutions such as the Chinese Academy of Sciences and various universities possessing strong research capabilities. 　　Therefore, it is recommended that our country draw on the successful experience gained from the development of methanol-to-olefins production during the 12th Five-Year Plan period, and include research on direct conversion of natural gas into ethylene in the relevant development plans for the 13th Five-Year Plan period. Organize research institutions to carry out R&D cooperation with petrochemical enterprises, so as to accelerate the conversion of basic research results into industrial production, overcome the current bottleneck in raw material supply for the ethylene industry, reduce production costs, and enhance the competitiveness of China’s ethylene industry and its downstream industries.