New standards, old problems

Unseasonable weather swept over Beijing during the summer, covering the capital in smog and haze for 18 days during June and resulting in the highest number of high-pollution days in the month for 50 years, according to the China Meteorological Administration.

It's still more than two months before the start of the winter heating season, during which huge amounts of coal are burned and, with ongoing efforts to relocate almost all the polluting industries outside the city, vehicle exhaust fumes have been pinpointed as a key source of pollution during bad weather.

The government has brought forward the timetable for upgrading the quality of both gasoline and diesel fuels. The move came in response to statements by environmental experts that oil-based fuels are the biggest obstacles to solving pollution caused by motor vehicles.

The government will strive to implement phase 5 of the gasoline standard - which stipulates that fuel must contain less than 10 micrograms of sulfur per gram - in a number of key areas, including Tianjin, Hebei province, the Yangtze River Delta region and the Pearl Delta region, by the end of 2015.

The previous timetable had specified the end of 2017, two years later than that stipulated by the Airborne Pollution Prevention and Control Action Plan (2013-17), which was released on Thursday.

In response to concerns about the feasibility of implementing the plan on schedule, some experts said the best way to ensure a stable supply of fuel would be to introduce market-oriented reforms in the domestic fuel market.

"The government is trying to combat airborne pollution caused by vehicle emissions by upgrading vehicles, improving the quality of fuel, and building more roads with the aim of reducing traffic congestion. But currently, the biggest factor hindering progress is the scarcity of high-quality fuel. Domestically refined fuel has failed to keep up with vehicle development," said He Kebin, a professor of environmental science and engineering and the executive dean of Tsinghua University's graduate school.

In 2010, the latest figures available, vehicle emissions of nitrogen oxide nationwide were close to 5.5 million metric tons per annum, accounting for more than 30 percent of total emissions of the gas, according to The First National Pollution Census Bulletin.

Nitrogen oxides, which are toxic and one of the main causes of acid rain, are easily transformed into PM2.5 and ozone when they undergo a series of chemical reactions upon exposure to air. Both pose significant threats to human health.

Nitrogenous organic particles are prevalent in smog and haze, according to a report that studied the thick haze that covered Beijing, Tianjin and Hebei province in January, conducted by a team from the Chinese Academy of Sciences.

He Hong, a leading scientist on the team, said nitrogen oxides are a major source of PM2.5 and ozone, which indicates that motor vehicle emissions play a key role in the formation of smog and haze.

Diesel vehicles, which account for fewer than 18 percent of all those on China's roads, emit almost 70 percent of all nitrogen oxides and 99 percent of particulate matter, according to the 2012 Annual Report on Motor Vehicle Pollution Control, released by the Environmental Protection Ministry.

Measures have been taken to ease the situation. Phase 4 of the emission standards for heavy-duty diesel vehicles came into effect on July 1. In line with the new standard, nitrogen oxide emissions will be reduced by 30 percent, and emissions of particulate matter by 80 percent.

Phase 4 of the emission standards for light-duty diesel vehicles was to have been implemented at the same time, but has been postponed. "There is no new implementation date for some regions," said Tang Dagang, director general of the Vehicle Emission Control Center at the Environmental Protection Ministry. "The reason is that supplies of diesel suitable for new vehicles are insufficient."

This is not the first time the new standard for light-duty vehicles has been postponed. Phase 4 of the emission standards for heavy-duty diesel vehicles was originally scheduled to come into force on Jan 1, 2011, but implementation was postponed for a year, before being deferred again until July 1 this year.

Meanwhile, the new standard for light-duty diesel vehicles was set to come into force on July 1, 2011, having already been postponed for two years.

"The key difference between heavy- and light-duty diesel vehicles under phase 4 of the emissions standards is that heavy-duty vehicles don't have catalytic converters," said Yue Xin, an associate researcher at the Chinese Research Academy of Environmental Sciences.

He said the catalytic converters for light-duty diesel vehicles are more sensitive to the concentration of sulfur in the fuel and the sulfur content of 350 mcg per gram under the current standard is too high for this type of vehicle.

"If the vehicles are loaded with this diesel, drivers may not feel anything unusual when driving, but the catalytic converters will become ineffective, leading to more pollutants in the exhaust fumes, causing the vehicles to fail their annual check," said Yue.

The sulfur content allowed in diesel fuel was reduced to 350 mcg per gram nationwide on July 1. Before that, the figure was 2,000 mcg per gram.

"About 95 percent of all diesel vehicles on the roads have long been loaded with 2,000 microgram-per-gram diesel, which is only supposed to be used for vehicles such as tractors and bulldozers, but drivers can easily find it at gas stations," said Yue.

He said diesel with a sulfur content below 50 mcg per gram, suitable for phase 4 of the emissions standards for light-duty diesel vehicles, will not be available nationwide until Jan 1, 2015.

A unique situation

Environmental experts said that the situation in China is unique because fuel quality upgrades always lag behind vehicle upgrades, irrespective of whether the fuel is diesel or gasoline.

Phase 1 of the gasoline standards was implemented two years after phase 1 of the emissions standards for automobiles. Phase 2 arrived 18 months after phase 2 of the emissions standards, while phase 3 was implemented a year and eight months after phase 3 of the vehicle emissions standards.

In March, Cao Xianghong, a petrochemical expert at the Chinese Academy of Engineering, told China Daily that the fuel quality upgrade has brought an "incomparably greater challenge to Chinese oil refineries than anywhere else in the world".

He said demand for high-quality fuel is growing as the number of vehicles rises, the vehicles become more sophisticated, and the regulations governing the fuel used in them are tightened. A simultaneous upgrade of quality and expansion of production will require a huge equipment upgrade, which will take at least three years.

"For example, a key process in the production of low-sulfur gasoline and diesel is hydrodesulfurization, which requires both high temperatures and high pressure," said Cao. "But very few domestic oil-equipment manufacturers are capable of producing equipment that can create such conditions. So it's impossible to implement a fuel standard as soon as it is released."

Yue from the Chinese Research Academy of Environmental Sciences saw things from a different perspective.

He said the shortage of high-quality fuel could easily be solved by market-oriented reforms that would prevent the cartel formed by Sinopec, China National Petroleum Corporation, China National Offshore Oil Corporation and other major State-owned companies, from setting the standards for fuel provision.

"The markets for both crude and refined oil should be fully opened up to private enterprise and foreign-funded businesses to form an open market like the one in Europe," said Yue.

Wang Jianxin, a researcher at the State Key Laboratory of Automotive Safety and Energy at Tsinghua University, said, "The market should be at least partially opened, perhaps one-half or one-third. That could result in a significant drop in the price of fuel."

Jiang Xueqing and Tang Yue contributed to this story.

wuwencong@chinadaily.com.cn