National standards have finally been established for coal-to-gas production

Thread Content

A national standard has finally been established for coal-to-gas production. Author/Source: Date: 2017-03-28. Clicks: 80. The obstacle that has plagued domestic companies involved in coal-to-natural gas production for many years has finally been resolved. Recently, the standard for coal-based synthetic natural gas (GB/T 33445-2016)**, developed under the leadership of the Coal-Based Chemicals Sub-committee of the National Coal Chemicals Standardization Technical Committee (referred to as the national standard for conventional natural gas), has been approved for publication by the Standardization Administration Committee (referred to as the National Standards Committee). It will be officially implemented on July 1 this year. As the first **standard in the field of coal-to-natural gas both domestically and internationally, its introduction will rectify the long-standing lack of standards in this area. It will also serve as a bridge for transforming coal-to-natural gas technologies into tangible productive forces, thereby playing a crucial role in guiding and supporting the development of the coal-to-natural gas industry. Process: Repeated discussions. Since the 12th Five-Year Plan period, the domestic coal-to-natural gas industry has developed rapidly, with model enterprises such as Qinghua in Xinjiang and Datang Keqi coming online one after another; however, the corresponding standards and supporting frameworks have lagged far behind. Calls within the industry to expedite the introduction of standards for coal-to-natural gas have never ceased. Sun Xiaoxuan, secretary of the Coal-based Chemicals Sub-committee under the National Coal Chemicals Standardization Technical Committee, told reporters: “Although conventional natural gas already has a comprehensive mandatory standard, GB17820-2012 ‘Natural Gas’ (referred to as the national standard for natural gas), due to some specific characteristics of coal-derived natural gas, this standard cannot be applied entirely in such cases.” Therefore, it is urgent to establish **standards for coal-to-natural gas** in order to address a range of issues, including the classification of product quality, technical requirements for product transportation and blending, as well as product delivery. ”According to the \"13th Five-Year Plan for Demonstrating Advanced Coal Processing Industries,\" it is estimated that by 2020, China’s capacity for producing coal-to-natural gas will reach 17 billion cubic meters per year. With the release and implementation of national standards for coal-to-natural gas, coal-to-natural gas projects now have guidelines and regulations to follow in terms of pipeline transportation, mixed transportation, and consumption. However, it took a full 3 years to develop the national standards for coal-to-natural gas: from December 2013, when the National Standards Committee began working on formulating such standards, until December 2016, when they were finally released. Under normal circumstances, **the standard-setting cycle is two years. “It was quite difficult to establish this standard. ”An industry insider involved in the formulation of national standards for coal-to-natural gas expressed such feelings. It is understood that the entities involved in drafting the national standards for coal-to-natural gas include 11 companies such as Southwest Chemical Engineering Research and Design Institute Co., Ltd., CNOOC Gas & Power Group Co., Ltd., Xinjiang Qinghua Energy Group Co., Ltd., Shanxi Saiding Engineering Co., Ltd., Beijing Gas Group Co., Ltd., and Fuzhou Product Quality Inspection Institute; these companies represent various stakeholders from the upstream and downstream sectors of the coal-to-natural gas industry. “However, there is no consensus on setting the various standard technical parameters. Especially regarding the setting of technical specifications for hydrogen content. ”An industry insider told reporters that it is well known that natural gas does not contain hydrogen, whereas coal-to-natural gas typically contains 1% to 3% hydrogen. The hydrogen content in coal-to-natural gas has a certain impact on users who generate electricity using gas turbines. According to the user’s company, after a certain enterprise’s coal-to-natural gas was used at the Beijing Taiyanggong Power Plant, flame disturbances were observed. A few months later, during a shutdown for inspection, cracks were found on the turbine blades. The main reason is that hydrogen in natural gas burns faster than methane, causing flame disturbance and instability. At the same time, hydrogen also causes the Wobbe index of coal-derived natural gas to differ from that of naturally extracted natural gas. Some gas turbines are very sensitive to changes in the natural gas Wobbe index. For example, while most gas turbine manufacturers claim to be able to tolerate 3% hydrogen content in natural gas, some individual manufacturers state that they can only accept 1% hydrogen content. The coal-to-natural gas plant of a certain company, which is used at the Taiyanggong Power Plant located north of Beijing, employs gas turbines manufactured by Siemens. Therefore, the demand side for coal-to-natural gas proposed that the market should determine the production of the product (referring to a set of quality parameters). An excessively high hydrogen content in coal-to-natural gas can cause damage to gas turbine blades; the hydrogen content should be reduced to 1% (mole/mole). The provider of coal-to-natural gas technology, Saiding Engineering Co., Ltd., along with representatives from two companies that produce coal-to-natural gas, argued that the current production processes for this technology cannot further reduce the hydrogen content; attempting to lower it excessively would impose significant economic pressures on these companies, which would be detrimental to the healthy development of China’s coal chemical industry. They suggested setting the hydrogen content at 4%–5%. After numerous mediations and discussions, the hydrogen content limit for Category 1 was ultimately set at 3.5% (mole/mole). Furthermore, there were intense discussions regarding how to set the high calorific value figure. Some experts suggest that it should be aligned with national standards for natural gas. However, most experts believe that since coal-to-natural gas contains almost no hydrocarbons with two or more carbon atoms, its high calorific value cannot compare to that of natural gas; therefore, they suggest reducing the high calorific value of this type of gas slightly. “Because everyone insists on considering how indicators should be set from the perspective of their own fields, the time it takes to establish national standards has increased from usually 2 years to 3 years now. However, the final result was still good. ”The industry insider said. Content: Strict standards. The national standards issued this time set technical specifications for key performance indicators in coal-to-natural gas, including high calorific value, hydrogen, hydrogen sulfide, carbon monoxide, carbon dioxide, solid particles, and water dew point (see Table 1). Based on differences in higher heating value, hydrogen content, and carbon dioxide content, coal-to-natural gas is classified into category 1, category 2, and category 3. For coal-to-natural gas outside these three categories, the supply and demand parties can use contracts or agreements to determine their specific requirements. “Setting technical specifications requires balancing the need to meet users’ demands to the greatest extent possible with the practical constraints that companies can operate under – it is a difficult dilemma. ”Sun Xiaoxuan explained. It is understood that, thanks to advantages in raw materials and technology, the various coal-to-natural gas projects currently under construction are generally able to meet the standard requirements. The standards for Xinjiang Qinghua Energy Group’s coal-to-natural gas project are even higher than the current **standards** for coal-to-natural gas. Sun Xiaoxuan also provided a set of data for a horizontal comparison between the national standards for coal-to-natural gas, industry standards, Xinjiang’s local standards, and the national standards for conventional natural gas (see Table 2). http://img.yf116.cn/image/img/20170328/155720574403.jpg “By comparing these 3 key indicators, it is easy to see that, compared with the conventional natural gas standards, the standards for coal-derived natural gas differ in 3 aspects: its high calorific value is slightly insufficient, its hydrogen content is high, and its sulfur compound content is extremely low.” This is mainly determined by different process flows. And this is precisely why conventional natural gas standards cannot be applied, and why special national standards for coal-derived natural gas must be established. Furthermore, compared with the industry standards for coal-to-natural gas and the local standards of Xinjiang, the differences between them lie mainly in slight variations in the specifications. The national standard for coal-to-natural gas is closer to the natural gas standard in terms of high calorific value, and it has stricter requirements regarding hydrogen sulfide levels than the other two standards. This is beneficial for environmental protection. At the same time, due to chemical production processes, the national standards for coal-to-natural gas include ammonia specifications in order to prevent potential damage to natural gas transmission pipelines. It is thus found that national standards are more scientific and environmentally friendly. ”Sun Xiaoxuan said. Impact: Standardized development – The introduction of national standards for coal-to-natural gas is definitely a good thing for projects and companies. ”This is how a staff member from the coal-to-natural gas project of Xinjiang Qinghua Energy Group commented. One of the advantages is that the national standards for coal-derived natural gas are relatively close to those for conventional natural gas, which facilitates the mixed transportation of coal-derived natural gas and conventional natural gas through long-distance pipelines. How to transport coal-to-natural gas has always been a concern for companies involved in this industry. In the future, major coal-to-natural gas projects will operate in accordance with national standards, and their technical specifications will be very similar to those of conventional natural gas, thereby preventing issues such as damage to pipelines, gas turbines, and nozzles in traditional thermal power boilers. The official also revealed, “The introduction of national standards will also have a positive impact on coal-to-natural gas in terms of its ability to secure pricing power when mixed in long-distance pipelines.” ” At the same time, due to the process characteristics of coal-to-natural gas methanation, strict purification steps must be employed during production. Therefore, coal-to-natural gas contains almost no hydrogen sulfide and other various forms of sulfides that are common in conventional natural gas and are harmful to natural gas transportation; it also has a lower carbon dioxide content, and particulates are removed during the dehydration process of coal-to-natural gas. This is highly advantageous for the long-distance pipeline transport of coal-derived natural gas. The second advantage is that the release of national standards for coal-to-natural gas facilitates the export of China’s advanced coal chemical technologies overseas. It is reported that on December 14, 2014, China Qinghua Energy Group Co., Ltd. officially signed a cooperation agreement for a project aimed at the comprehensive utilization of coal-based clean energy, in collaboration with Kazakhstan’s Oil Processing and Sales Company, Albat Joint Venture Company, and Guzhnesky Coal Mine Co., Ltd. This project will take advantage of Kazakhstan’s abundant resources, as well as Qinghua Group’s extensive experience and technical expertise in the field of modern coal chemical processing, to produce coal-to-natural gas and other products. Given that China leads the world in coal chemical technology, there are no corresponding standard-setting organizations abroad, nor any international or advanced standards available for use. Therefore, when introducing China’s advanced coal chemical technologies overseas, it is essential to have advanced standards to provide support. The implementation of national standards for coal-to-natural gas is of great practical significance in promoting cooperation in the local processing and conversion of energy resources in Central Asia, in establishing an integrated industrial chain for such energy resource activities, and in facilitating the export of China’s coal chemical technologies, equipment, and engineering services. “As the implementation date of July 1 approaches, the technical specifications of existing, under-construction, and planned coal-to-natural gas projects need to be adjusted. To this end, companies must be willing to invest in technological advancements in order to meet the required standards. It should be noted in particular that new coal-to-natural gas projects must reduce the hydrogen content to 1% or less; when this standard is revised in the future, lowering the hydrogen limit will be inevitable. ”Sun Xiaoxuan reminded.