China Petroleum & Chemical Corporation (Sinopec), China's largest oil refiner, recently announced its success in the industrial application of crude oil steam-cracking technology, which can directly turn crude oil into ethylene and propylene.
The new technology skips the traditional crude-oil refining procedure and shortens the production process. It also reduces production costs and significantly cuts energy consumption and carbon emissions, said Sinopec deputy chief engineer Wang Zizong.
Ethylene is the basic raw material of chemical products and is one of the symbols to measure the development of a country's petrochemical industry. The traditional refining process can turn about 30 percent of crude oil into chemical products.
China produced about 21.6 million tonnes of ethylene in 2020, with a growth rate of 5.25 percent year-on-year, said the National Bureau of Statistics.
Using the new technology, 1 million tonnes of crude oil can produce about 500,000 tonnes of various chemicals, including about 400,000 tonnes of high-value products such as ethylene, propylene, light aromatics, and hydrogen.
The crude oil catalytic-cracking technology, another technical route that Sinopec realized earlier this year, can also turn about 50 percent of crude oil into various chemicals. The combination of the two cracking technologies is expected to raise the turning rate to 70 percent.
The recent achievement of Sinopec is just one example of China's continuous efforts to make the traditional petrochemical and coal chemical industries greener by scientific and technological upgrades.
At a ceremony in Beijing this month to honor China's distinguished scientists, engineers, and research achievements, over ten projects related to petrochemical and coal chemical industries received awards. They included catalytic-cracking processing technology, efficient exploitation of coalbed methane and rock oil, and crude-oil recovery.
Among them, the project of nano-confined catalysis won the first-place prize of the State Natural Science Awards. This project realized the direct and efficient synthesis of light olefins and high-value chemicals such as ethylene, propylene, and butene from coal-synthesized gas, with less water and energy consumption and less carbon emission.
It overturned the Fischer-Tropsch Synthesis process, which has dominated coal chemistry for nearly a century. Nano-confined catalysis now leads the new efficient and water-saving coal chemistry trend.
A kilotonne scale-test plant using technologies based on nano-confined catalysis has been built and accomplished industrial tests to synthesize light olefins.
Besides the greener production process, petrochemistry and coal chemistry produce greener chemical materials.
Yulin Chemical Co Ltd, a China Energy Investment Corporation subsidiary in northwest China's Shaanxi Province, is building an industrial demonstration project to produce polyglycolide (PGA), a degradable chemical material.
According to Tao Long, the manager of PGA installation, a toothbrush made by PGA can degrade within a year. The PGA has remarkable value in fields such as surgical sutures and underground unconventional oil and gas exploitation.
"The gas synthesized from the coal will be made into PGA by multiple processes such as carbonylation and hydrogenation. The demonstration project we are building now can produce 50,000 tonnes of PGA per year," said Tao.
Combined with Yulin Chemical's current production lines, such as coal methanol and coal ethylene glycol synthesis, the PGA project can save about 50 percent raw coal and cut about 65 percent carbon dioxide emission, compared with traditional degradable plastics.
"Modern coal chemistry should accelerate the transformation towards a green and low-carbon direction, and make products that meet market demand and are environment-friendly," said Zhang Xiansong, the chairman of Yulin Chemical.