China Environ Prot (EP) Industry, Technology, Solid Waste Mgt, Liquid Treat: News & Discussions

[JSCh]

How to Calculate CO2 Emission Factors of Cement Industry in China More Accurately?---Chinese Academy of Sciences
Mar 07, 2019

Cement industry is one of the largest anthropogenic carbon dioxide (CO2) emitters, and China is the biggest cement producer in the world. Therefore it is essential to accurately calculate CO2 emission amounts. The calculation of CO2 emission amount is based on CO2 emission factors (EFs).

Dr. GENG Yuanbo and his colleagues at Key Lab for Resources Use and Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research (IGSNRR) of the Chinese Academy of Sciences (CAS), found that Raw Material Carbonate Method was more accurate and simpler than other methods to calculate CO2 emission factors related to the new suspension pre-heater and pre-calciner kilns, based on inorganic carbon and organic carbon.

The calculation methods of CO2 EFs (process-related emission factors) include two categories: clinker method (the output method) and raw material method ( the input method) in cement production. Clinker method determines the CO2 emission factors according to the amount of calcium oxide (CaO) and magnesium oxide (MgO) in clinker. Though the data is easy to access, the result is hard to guarantee correctness.

"The reason is that the source of calcium oxide (CaO) and magnesium oxide (MgO) are indefinable, and this method usually roughly estimates or ignores either CaO and MgO in cement kiln dust, bypass dust, and coal ash, or the non-carbonates components in the form of CaO and MgO in the raw materials," said Dr. GENG.

In addition, organic and inorganic carbon residues exist in almost all of the clinker due to incomplete decomposition of carbonate and incomplete combustion of fuel, so the carbonate decomposition rate and organic carbon combustion rate should be considered during the process of calculation.

Researchers determined the inorganic carbon (carbonate) in raw materials and the corresponding decomposition rate, calculated the process-related CO2 EFs with raw material carbonate method, measured the organic carbon in coal and the corresponding combustion rate and calculated combustion-related CO2EFs, which improved the accuracy of the two EFs.

The study, published in Journal of Cleaner Production, was supported by the Strategic Priority Research Program – Climate Change: Carbon Budget and Related Issues of the Chinese Academy of Sciences.

Figure: Calculating process of direct CO2 emissions and corresponding CO2 emission factors (Image by GENG Yuanbo et al)

 

[JSCh]

MARCH 11, 2019 / 3:56 PM / UPDATED 4 HOURS AGO
China expands switch from polluting coal heating in 2018: environment minister

BEIJING (Reuters) - China expanded its coal-to-gas and coal-to-electricity projects to 35 cities in 2018 from 12 cities the previous year, China’s environment minister, Li Ganjie, said on Monday, as the world’s second-largest economy stepped up its fight against smog.

China’s winter heating program used to burn an estimated 400 million tonnes of coal a year, and switching it to cleaner types of fuel was identified as a major part of the country’s war on pollution, now in its sixth year.

The program to convert households to low-emission heating ran into difficulties last winter amid widespread natural gas shortages, but 4.8 million households still managed to make the switch from coal to natural gas and electricity last year, up from 4 million households switched in 2017, Li said.

China has also installed ultra-low emissions technology at more than 80 percent of its total coal-fired power generation capacity, Li added.

But, speaking to journalists at a press conference on the sidelines of China’s annual parliamentary meeting, Li warned that despite the strides made in 2018, China’s war on smog was getting harder.

“In reality the pressures are huge and it isn’t easy to be optimistic about the trends,” he said. “The things that could easily be done have already mostly been done, and the things that need to be done afterwards are much harder.”

While China cut the share of coal in its total energy mix to 59 percent last year, down from 68.5 percent in 2012, it remained too high, he said. There were also still regional disparities in the way environmental protection was being enforced, he said.

China said last week that it would implement special emissions restrictions for a third consecutive winter, after Premier Li Keqiang told parliament that the state would continue to strengthen pollution controls in 2019.

China’s economy expanded at its slowest rate since 1990 last year, and the environment ministry has been at pains to state that it would not relent in its efforts to curb pollution.

However, though concentrations of hazardous small particles known as PM2.5 fell overall last year, they rebounded over winter, with averages in 39 smog-prone northern cities up 13 percent over the October-February period.



Reporting by Meng Meng in Beijing; Writing by Chen Aizhu in Singapore and David Stanway in Shanghai; Editing by Tom Hogue and Christian Schmollinger

China expands switch from polluting coal heating in 2018: environment minister | Reuters

 

[JSCh]

Rubber tyres shed a toxic chemical, but with the help of heat and acid this can be converted into materials with applications in electronics. Credit: Andre Kudyusov/Getty

CHEMISTRY | 05 MARCH 2019
Toxic tyre waste turned into electronic treasure
By-product of rubber tyres is transformed into valuable organic semiconductors.

When the rubber meets the road, it invariably leaves behind traces of the chemicals used to harden it during tyre manufacture. These chemicals, notably 2-(methylthio)-bezothiazole (MTBT), wash into waterways, where they can pose a health hazard if left untreated. The reactions used to break down MTBT just leave behind more waste — benign but useless.

Researchers in China report that they have found a way to not only neutralize MTBT, but also turn it into something valuable: an organic semiconductor. These are cheaper and more flexible than metallic semiconductors, and can be incorporated into items such as mobile-phone displays. Hui Huang at the University of the Chinese Academy of Sciences in Beijing and his colleagues applied a method that relies on a metal catalyst, acid and heat.

The team experimented with different recipes and temperatures to turn the MTBT into several different semiconductor compounds. One could be used to build a field-effect transistor, a key component of electronic devices. From another, the researchers created semiconductor nanoparticles, which can act as fluorescent dyes that allow scientists to image living cells in action.

Angew. Chem. Int. Edn (2019)​

Toxic tyre waste turned into electronic treasure : Research Highlights | Nature

 

[JSCh]

Ni Promoted Ceria-Titanium Oxide Redox Catalysts Enhance Solar Fuel Production
Mar 18, 2019

Solar energy, with tremendous potential as an environmentally sound and sustainable energy source, dwarfs all the derivative sources by a wide margin. The challenge, however, is to take full advantage of the abundant and infinite solar energy and to convert it into readily utilisable and storable forms.

Solar thermochemical CO2 and H2O splitting (STCDS, STWS), tapping sunlight directly and storing solar energy in renewable fuel, are emerging technologies towards meeting this goal. Successful adoption of solar-to-fuel technologies is predicated upon identifying advanced materials with higher efficiency.

Schematic of the proposed reaction mechanism for MDR-STCDS and MDR-STWS processes over 5Ni/CeO2-TiO2 redox catalyst. (Image by RUAN Chongyan)

Recently, a research group led by Prof. WANG Xiaodong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences developed a Ni promoted ceria-titanium oxide catalytic system for highly effective thermochemical CO2 and H2O splitting as well as partial oxidation of CH4 at 900 °C.

The CO and H2 production rates and productivities were 10-140 and 5-50 times higher than the current state-of-the-art STCDS and STWS processes, respectively. Close to complete CH4conversions with high selectivity towards syngas were achieved in the reduction step. Their findings were published online in Energy & Environmental Science.

By combining detailed experimental characterization with density functional theory (DFT) calculations, Prof. WANG Xiaodong and his collaborators from Xi’an Jiaotong University shed light upon the underlying mechanism for the exceptional reaction performance.

It was revealed that the metallic Ni and the Ni/oxide interface manifested the catalytic activity for both CH4 activation and CO2 or H2O dissociation, whereas CeO2-TiO2 enhanced the lattice oxygen transport via the CeO2-TiO2 / Ce2Ti2O7 stoichiometric redox cycle for CH4 partial oxidation and the subsequent CO2 or H2O splitting promoted by catalytic active Ni.

"We anticipate the fundamental understanding on the crucial roles of the catalytic sites for reactants activation and the stoichiometric redox chemistry for enhanced lattice oxygen availability can provide important guidance for the rational design of advanced materials toward solar fuel production," said Prof. WANG.


Ni Promoted Ceria-Titanium Oxide Redox Catalysts Enhance Solar Fuel Production---Chinese Academy of Sciences

 

[JSCh]

SPOTLIGHT * 20 MARCH 2019
The Chinese researcher painting the printing industry green | Nature
Chemist Yanlin Song uses nanomaterials to reduce the pollution caused by conventional lithography.

Sarah O’Meara

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Credit: Stefen Chow for Nature

Chemist Yanlin Song uses nanomaterials to reduce the pollution caused by conventional printing processes. Nature speaks to him about his work at the Chinese Academy of Sciences Institute of Chemistry in Beijing and why it matters to China.

[paste:font size="5"]How does your technology work?
The printing industry uses a high volume of chemicals and produces a lot of waste. These can be hazardous for the environment. We have created a coating, using nanomaterials, to eliminate the need to chemically treat the printing plates that are used to transfer a design to paper.

What results have you had?
We’ve developed a range of green printing applications, from plate-making and electronic printing technology to green printing processes for packaging and 3D printing. Our work has been included in China’s road map for developing the printing industry, and some universities, such as the Beijing Institute for Graphic Communication, have developed a curriculum around our research.

Who funds your lab?
My funding mainly comes from the Ministry of Science and Technology, the Chinese Academy of Sciences, the National Natural Science Foundation of China and the Beijing Municipal Government. I also receive financial support from companies such as Procter & Gamble and Samsung. Last year, my lab received US$3 million in total.

What research obstacles are you facing?
There are still many fundamental problems that need to be solved for green printing technology. Most of the challenges have to do with the way in which liquids behave at very small scales. For example, the nozzles used in conventional inkjet printing can produce droplets only 10 micrometres in diameter or larger. This makes it difficult to print at smaller scales, which in turn limits our ability to produce complex electronic circuits for chips and smart textiles such as wearable sensors.

How is your research being applied?
I’m working with four companies on different applications. There are two main obstacles: fabricating products on a large scale while maintaining quality, and persuading people to buy them. Customers tend to want the most cost-effective product rather than the most high-tech version. This is a challenge for researchers. So far, our green printing-plate technology has been used by China’s national news agency and our electronic printing processes have been used to produce transport tickets in Beijing and Hong Kong.

What are you currently working on?
We’re developing 3D inks that can be printed directly on paper to create braille text. Conventional mechanical processes for printing books in braille are specialized and expensive and the books don’t last long as the embossed dots become flattened by touch. These factors have led to an extremely limited number of braille books in our country. My friend has children who are blind and I’ve been thinking about the problem for a long time. We hope our process will greatly lower the printing costs and improve the printing quality.

 

[JSCh]

China Focus: China on track to cap water usage below 670 bln cubic meters by 2020
Source: Xinhua| 2019-03-22 19:19:18|Editor: Shi Yinglun

BEIJING, March 22 (Xinhua) -- China is set to achieve its target of keeping annual water consumption below 670 billion cubic meters by 2020, a senior official said Friday.

Annual water consumption has been capped below 610 billion cubic meters since 2016, Wei Shanzhong, vice minister of water resources, said at a press conference.

China has long been worried about a water supply bottleneck that could jeopardize future economic growth, thus leading the government to adopt the strictest water management regulations.

The country has witnessed improved efficiency in water consumption over the years. China's water consumption per 10,000 yuan (about 1,492 U.S. dollars) of gross domestic product plunged 30 percent in 2017 compared with 2012.

The amount of water consumed for 10,000 yuan of industrial value added plummeted 32.9 percent during the 2012-2017 period.

As China has striven to develop farmland infrastructure, its irrigation efficiency index rose to 0.54 in 2017 from 0.51 in 2012. The index refers to the ratio of the water that is used by crops against the total irrigated water.

China aims to build the whole country into a water-saving society by 2035.

Thanks to tougher efforts to crack down on polluters, the quality of water in rivers, lakes and reservoirs also improved, Wei said.

However, China still faces serious scarcity of water resources. The country's per capita water resources' share lags far behind the world average.

China is also a country with unbalanced water resources among its regions. North China, which has a population of 168 million, accounts for only 4 percent of the country's total water resources.

Increasing water demand has resulted in groundwater overdraft and water level declines in the North China Plain, Wei added.

He called on efforts to raise water use efficiency, promote water-saving irrigation techniques and limit the development of high water-consuming industries while pledging to continue to transfer fresh water from the country's south to its drought-prone north.

When asked if the government will ease strict controls over water protection amid the economic slowdown, Wei said environmental protection does not contradict with economic development and vowed to strengthen protection and management of water resources to promote green development.

 

[JSCh]

China Develops and Commercializes Aerosol Lidar and Ozone DIAL Products to Relieve the Related Import-Dependence
Mar 22, 2019

A research team with Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science developed and commercialized on their own the aerosol lidar and ozone differential absorption lidar (or DIAL) products that would greatly relieve China’s import-dependence in aerosol and ozone three-dimensional monitoring equipment and thus improves the country’s ability in atmospheric pollution monitoring.

The team made a series of monitoring products that are oriented to both long time field and vehicle portable obervation.

The vehicle-based lidar, included in the monitoring products, could realize the mobile measurement to obtain distribution profiles of regional pollution in a very short time and then to quickly analyze its producing and disappearing process as well as the trans-boundary movement.

It is the first real case that the vehicle-based lidar is applied to monitoring the pollution transport in city cluster.

Actually, China has been long time suffering the lack of instrument and data for aerosol and ozone three-dimensional monitoring.

The series of products, developed and commercialized by the team, would not only improve China's air quality, but enhance China’s own capability to produce lidar system, which to a great extent relieve its related import-dependence.

According to the research team, its sales volume have exceeded 200 sets with its market share over 50% till now. And these products form the world’s first PM2.5 and ozone lidar network used in environmental monitoring department.


China Develops and Commercializes Aerosol Lidar and Ozone DIAL Products to Relieve the Related Import-Dependence---Chinese Academy of Sciences

 

[JSCh]

Can China keep it's climate promises?
March 26, 2019 by Marlowe Hood

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China can easily fulfill its Paris climate pledge to peak greenhouse gas emissions by 2030, but sourcing 20 percent of its energy needs from renewables and nuclear power by that date may be much harder

China can easily meet its Paris climate pledge to peak its greenhouse gas emissions by 2030, but sourcing 20 percent of its energy needs from renewables and nuclear power by that date may be considerably harder, researchers said Tuesday.

Tripling the share of non-fossil fuels will require a major overhaul of China's recalcitrant power sector and the full deployment of a fledgling emissions trading system, they said in the journal Nature Communications.

There is a lot at stake.

If the world's top carbon polluter fails to achieve these and other voluntary targets, the 2015 treaty's cornerstone goal of capping global warming at "well below" two degrees Celsius (3.6 degrees Fahrenheit) may remain out of reach.

On current trajectories, the planet is set to warm twice that much by century's end.

China has also pledged to expand carbon-absorbing forests by 4,500 square kilometres before 2030, compared to 2005 levels.

"China is on track to achieve its climate commitments," lead author Kelly Sims, director of The Fletcher School's Climate Policy Lab at Tufts University, told AFP.

"It is not pulling back from implementing the Paris Agreement even though US President Donald Trump signalled his intention to do so."

Over the last decade, China has positioned itself as a global leader on climate action, enacting a raft of policies to slow the growth of its carbon footprint and, eventually, make it shrink.

Global warming, however, has not always been the main—or even the primary—target.​

"The vast majority of China's policies have co-benefits for energy security, economic reform and reduced ground-level pollution," Sims told AFP.

More than a million—up to 2.8 million, according to a recent study—premature deaths in China each year are attributed to foul air.

Room for more ambition

The only major climate policy exclusively aimed at reducing CO2 levels is China's emissions trading scheme (ETS).

Introduced in 2017, it is set to cover more than 1,700 power companies and some three billion tonnes in greenhouse gas emissions.

China's total emissions in 2018 topped 10 billion tonnes of CO2, well over a quarter of the world total.

Driving up the price of carbon within the ETS and boosting the share of renewables in China's electricity grid will both depend on revamping the country's power sector, the study said.

"The main challenge is completing power sector reform," said Sims.

​

Primary energy demand growth by fuel in major energy markets, change from 2017 to 2018

"There is political resistance from owners of existing coal plants, and from the provinces with major coal production and coal use."

To assess China's chances of meeting its carbon-cutting promises, Sims and colleagues canvassed 18 experts, and modelled the implementation of 14 climate policies.

China has come in for sharp criticism from watchdog groups for not setting more ambition carbon-cutting targets.

The Carbon Action Tracker, which evaluates the CO2 reduction efforts in relation to capacity, has labelled Beijing's "highly insufficient."

"Discouragingly, a rise in coal consumption drove Chinese CO2 emissions to a new high in 2017, which will likely be exceeded again in 2018," it noted.

But the experts said that Beijing still has plenty of time to put its emissions curve on a downward track before 2030.

"There is certainly room to be more ambitious in its peaking target," Sims added.

China is also under pressure to bring down—and account for—emissions of the potent greenhouse gas methane, a byproduct of both natural gas and livestock production.

"But China cannot stop climate change alone," Sims said.

"All of the major industrialised countries will need to reduce their emissions, and rapidly developing countries will need to implement alternative growth strategies with the help of wealthier countries."

Explore further: 2018 spike in energy demand spells climate trouble: IEA

More information: Kelly Sims Gallagher et al. Assessing the Policy gaps for achieving China's climate targets in the Paris Agreement, Nature Communications (2019). DOI: 10.1038/s41467-019-09159-0



Read more at: https://phys.org/news/2019-03-china-climate.html

 

[JSCh]

Fridges made from plastic crystals could help cut carbon emissions
PHYSICS 27 March 2019

It’s hard to keep your cool
Description:Tetra Images, LLC / Alamy

By Donna Lu

A fridge that runs on plastic crystals could solve a big problem: our need to stay cool is warming the planet.

Refrigeration equipment, air conditioners and heat pumps are estimated to consume between 25 and 30 per cent of the world’s electricity – and many rely on greenhouse gases to transfer heat.

Bing Li at the Chinese Academy of Sciences’ Institute of Metal Research in Shenyang and his colleagues have used an alternative cooling material known as plastic crystals, which they believe could use less energy and be better for the environment.

Conventional fridges rely on compressing a material so it changes from gas to liquid. The liquid absorbs heat from its surroundings, in this case the inside of the fridge, causing it to turn back into a gas and beginning the cycle anew.

These refrigerant materials are fluids that absorb and release heat efficiently, but are problematic because they contribute to global warming.

One type, chlorofluorocarbons (CFCs), are known to deplete the ozone layer and have been mostly phased out, but their more ozone-friendly replacement, hydrofluorocarbons (HFCs), are also powerful greenhouse gases.

Developed countries began reducing HFCs this year, but exactly what chemicals refrigerators and air conditioners will use instead is still unclear – carbon dioxide has been considered as a possible replacement.

Solids that change temperature in response to external pressure have been floated as greener alternatives. Plastic crystals, soft and mouldable solids with a powder-like appearance, were created decades ago and have been used in a range of products, including cosmetics, paints and plastics.

Some have been considered as a material to store energy, but Li and his colleagues found that they work surprisingly well as a refrigerant.

Plastic crystals have a disordered structure, says Li, meaning they don’t have a regular lattice formation. “A tiny pressure can switch the materials between the disordered state and the ordered state,” says Li, resulting in a large change in energy.

One type of plastic crystal, neopentylglycol, has an energy change tens of times greater than other potential solid refrigerants, meaning it has a far greater cooling effect when the same pressure is applied.

“We identified plastic crystals as promising materials for solid-state refrigeration,” says Li, but the team needs to do more work to reduce heat loss and maximise the energy efficiency of the process in order to match that of existing liquid-to-gas refrigerants.

Journal reference: Nature, DOI: 10.1038/s41586-019-1042-5


Fridges made from plastic crystals could help cut carbon emissions | New Scientist

 

[TaiShang]

Inner Mongolia sees mass return of rare birds

Xinhua, April 8, 2019

Over 800 relict gulls migrated to Ordos wetlands in early April in north China's Inner Mongolia Autonomous Region, marking the first mass return of this migratory birds in 13 years, local authorities said Sunday.

The gull, featuring a black-hooded head and white body, is an endangered species and a national first-class protected animal. Most of its populations winter in Bohai Bay in China.

"In spring, the birds fly to northwestern China, Mongolia and Kazakhstan, nesting generally on islets in the lack of deserts," said Xing Xiaojun, director of the administration of the Ordos Relict Gull Reserve in the city of Ordos.

An island in the Taolimiao-Araxan Lake of the reserve is renowned as a vital habitat for gull breeding.

"There were once over 10,000 breeding gulls, accounting for over half of the whole population," said Xing. However, since 2006 few nests of the species can be seen as the island disappeared as the Lake shrank.

Ordos has adopted a series of measures to protect the wetland in recent years, such as dam removal and water diversion from the Yellow River.

At present, the lake, with its water area up to 7 square km, has seen boosted diversity of the birds. "Over 20,000 migrant birds came here last autumn, as the wetland's environment has improved," said Ren Yongqi, a chief of a protection station in the reserve.

The wetland is also home to 15,000 other birds, according to Xing. More efforts have been made to protect the breeding birds from disturbances.

The Ordos Relict Gull Reserve, as the world's only natural reserve for relict gulls, was listed an internationally recognized wetland reserve in 2002.

http://www.china.org.cn/china/2019-04/08/content_74656184.htm

 

[JSCh]

Carbon-negative power generation for China | Harvard John A. Paulson School of Engineering and Applied Sciences
Reducing CO2 concentrations and air pollution in the atmosphere

By Leah Burrows
April 8, 2019

If we’re going to limit global temperature increases to 2 degrees above pre-industrial levels, as laid out in the Paris Climate Agreement, it’s going to take a lot more than a transition to carbon-neutral energy sources such as wind and solar. It’s going to require carbon-negative technologies, including energy sources that actually reduce carbon dioxide levels in the atmosphere.

While most climate researchers and activists agree that carbon-negative solutions will be needed to meet the terms of the Paris Agreement goal, so far most of these solutions have been viewed as impractical in the near term, especially for large, coal-reliant countries like China.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences and the Harvard-China Project on Energy, Economy and Environment, in collaboration with colleagues from Tsinghua University in Beijing and other institutions in China, Australia and the U.S., have analyzed technical and economic viability for China to move towards carbon-negative electric power generation.

The research is published in the Proceedings of the National Academy of Sciences.

“This paper is making a bold suggestion that not only can China move towards negative carbon power but that it can do so in an economically competitive way,” said Michael McElroy, the Gilbert Butler Professor of Environmental Studies at Harvard and a senior co-author of the paper.

“The system we describe not only offers a carbon-negative alternative to generate electricity in the long run but also brings significant near-term co-benefit to reducing air pollution in China,” said Xi Lu, Associate Professor in the School of Environment at Tsinghua University and first author of the paper. Lu is also a former SEAS graduate student and postdoctoral fellow.

The strategy McElroy, Lu and their colleagues lay out involves the combination of two forms of green energy: coal-bioenergy gasification and carbon capture and storage.

Bioenergy one of the most important tools in the carbon-negative toolbox.

Bioenergy comes from the best CO2 scrubbers on the planet — plants. As most of us learned in grade school, plants use photosynthesis to convert CO2into organic carbon and oxygen. The carbon stored in plants can be converted back into energy through combustion (a.k.a., fire); fermentation, as in the production of ethanol; or through a process known as gasification, which converts carbon-rich materials into carbon monoxide, hydrogen and carbon dioxide for fuels and industrial chemicals.

The process of converting biomass into energy and then capturing and storing the waste CO2 is one of the most talked-about strategies for negative carbon power. It’s known as BECCS, bioenergy with carbon capture and storage. The problem is, in most applications BECCS is not very efficient and requires massive amounts of land to grow the plants needed to power the planet, which would likely result in global food and water shortages.

But what if there was a way to make the process more practical and efficient?

Lu, McElroy and their international team turned to an unlikely solution for green energy: coal.

“If you try to do this with biofuel alone, it’s not very effective,” McElroy said. “The addition of coal provides an energy source that is really important. If you combine biofuel with coal and gasify the mixture, you can essentially develop a pure source of hydrogen in the process.”

By modeling different ratios of biofuel to coal, the researchers found that as long as at least 35 percent of the mixture is biomass and the waste carbon is captured, the power generated would actually reduce CO2 in the atmosphere. At that ratio, the researchers found that the levelized cost of electricity would be no more than 9.2 cents per kilowatt hour. A carbon price of approximately $52 per ton would make this system cost-competitive with current coal-fired powerplants in China.

A key component to this strategy is the use of crop residue — the remains of plants after fields have been harvested — as biofuel.

Seasonal agricultural fires, when farmers set fire to their fields to clear stubble after a harvest, are a major source of air pollution in China. Collecting that stubble and using it as biofuels would not only reduce CO2 but significantly improve air quality in the country. Gasification also allows easier removal of air pollutants from the waste stream.

The researchers acknowledge that developing a system to collect the biomass and deliver it to powerplants will take time but they argue that the system doesn’t need to be implemented all at once.

“Because we’ve investigated the whole range of coal-to-biomass ratios, we’ve demonstrated how China could move incrementally towards an increasingly carbon-negative energy source,” said Chris P. Nielsen, Executive Director of the Harvard-China Project and co-author of the study. “First, small amounts of biofuel could be used to reduce the net positive carbon emissions. Then, the system could grow toward carbon neutrality and eventually to a carbon-negative system. You don’t have to accomplish everything from the get-go.”

“This study provides critical information for policy makers seeking to implement carbon-negative energy opportunities in China,” said Lu.

The research was co-authored by Liang Cao, Haikun Wang, Wei Peng, Jia Xing, Shuxiao Wang, Siyi Cai, Bo Shen, and Qing Yang; lead author Lu and three other China-based co-authors are alumni of the Harvard-China Project. It was supported in part by a grant from the Harvard Global Institute.

Xi Lu, Liang Cao, Haikun Wang, Wei Peng, Jia Xing, Shuxiao Wang, Siyi Cai, Bo Shen, Qing Yang, Chris P. Nielsen, Michael B. McElroy. Gasification of coal and biomass as a net carbon-negative power source for environment-friendly electricity generation in China. Proceedings of the National Academy of Sciences, April 8, 2019; DOI: 10.1073/pnas.1812239116​

 

[JSCh]

Chinese scientist creates machine that can track PM2.5 within hours
2019-04-12 16:39:18
CGTN

With China's air pollution blamed for a wide range of environmental and health issues, the government is taking actions. Levels of the pollutant PM2.5 are down in most Chinese cities. Now, an online PM2.5 detection system has been installed in over 100 cities to find out what's contaminating the air.

A group of scientists from South China's Jinan University, headed by Professor Zhou Zhen, in 2012 invented a machine which is capable of identifying air pollutants, most notably PM2.5. And over some seven years of research, the machine has been upgraded and widely used in China.

The expanding database the team has developed over the past years enables the machines, scattered across China, to monitor the PM2.5 pollution sources with more precision.

“This is the only method to detect the sources of PM2.5 in the event of heavy air pollution. It plays an important role in setting guidelines to solve air pollution and addressing the public's concerns. It can also save the Chinese government a great amount of money in preventing air pollution,” said Professor Zhou Zhen, Head of Institute of Mass Spectrometry and Atmospheric Environment, Jinan University.

Zhou added that the machine has been sold to several developed countries, including the United States, and in the near future they are eyeing the markets of the Belt and Road participating countries.

Our crew boarded a van equipped with the detecting machine, which just finished its mission in the east of Guangzhou. Unsurprisingly, the main source of air pollution was car emissions.

“This is the online air pollution spectrum. In the pie chart, we can tell the pollution is mainly comprised of car emissions. Second is coal. Now it's around 15 percent. But in the winter in northern China, it would move up to be the main pollution source,” said Bi Yanru, a Hexin Mass Spectrometry engineer.

PM 2.5 pollution and chronic disease in China

China in 2013 introduced the Air Pollution and Control Action Plan with the hope of improving air quality nationwide, most notably reducing the concentration of PM2.5.

PM 2.5 concentration in eastern China, which is relatively more developed, fell nearly 40 percent in 2018, according to research jointly conducted by the John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Nanjing University of Information Science & Technology (NUIST).

Regardless, the country's air quality is still shy of meeting the World Health Organization's (WHO) standard of 10 micrograms per cubic meter of PM2.5 and 20 micrograms per cubic meter of PM10.

Many Chinese cities still suffer from suffocating air, especially in the wintertime, when the heating season starts in northern and parts of central China. And in the spring, farmers in the countryside are used to burning straw left in the farmland, which contributes to the already toxic air. Local governments are ramping up efforts to curb such behaviors.

More than 1,000 air quality monitoring stations have been established across China over the years, collecting environmental data. Researchers from SEAS and NUIST, however, found out with the concentration of PM2.5 falling, harmful ground-level ozone pollution is on the rise, mostly in large Chinese cities.

 

[JSCh]

Synergy of Anthropogenic Emissions and Atmospheric Processes May Cause Severe Haze in Northern China
Apr 17, 2019

Regional severe haze in northern China is characterized by exceedingly high concentrations of fine particulate matter and exhibits extensive temporal and spatial coverage, thus influencing air quality, human health, and ecosystems. The causes of these severe haze events, however, are very complex and still debated.

A study led by AN Zhisheng from the Institute of Earth Environment (IEE), Chinese Academy of Sciences, published online in PNAS on April15, reviews and synthesizes recent advances in the causes and formation mechanisms of severe haze pollution in northern China.

"The severe haze events in northern China can be regarded as synergetic effects from the interactions between anthropogenic emissions and atmospheric processes," said AN.

Researchers found that the seasonally enhanced emissions of pollutants from residential heating and efficient secondary aerosol formation and transformation could cause severe haze.

Unfavorable meteorological conditions, for example, enhanced air static stability and shallow planetary boundary layer due to aerosol-radiation and aerosol-cloud interactions could also exacerbate the formation of severe haze, according to AN.

"In addition, the regional East Asian winter monsoon and westerly circulation, which are influenced by various factors including variations of Arctic sea ice and the Siberian High, the topography of the Tibetan Plateau, and ElNi？o - Southern Oscillation, may also have significant influence on the formation of severe haze in northern China," AN said.

Schematic representation of the climatic factors affecting the regional East Asian winter monsoon and westerly circulation and therefore the severe haze formation in northern China (Image by IEE)

Severe haze pollution in northern China provides a unique scientific platform for gaining insights into many aspects of the relevant atmospheric chemistry and physics.

The scientists call for additional research, including on the mechanisms leading to secondary aerosol formation and the chemical/physical transformation of primary and secondary aerosols during haze development as well as the interactions and feedback cycles between haze and meteorological/climatic conditions.

This work was supported by the National Research Program for Key Issues in Air Pollution Control, the National Natural Science Foundation of China, the State Key Laboratory of Loess and Quaternary Geology, and the Robert A. Welch Foundation.



Synergy of Anthropogenic Emissions and Atmospheric Processes May Cause Severe Haze in Northern China---Chinese Academy of Sciences

 

[JSCh]

China Focus: Chinese scientists use rice straw to desalinate seawater
Source: Xinhua| 2019-04-18 21:07:45|Editor: zh

BEIJING, April 18 (Xinhua) -- Chinese scientists have developed an innovative desalination technology that uses rice straw and sunlight for clean water production.

Solar steam generation is considered a promising strategy for purification of wastewater and seawater. Scientists from the Ningbo Institute of Materials Technology and Engineering have developed a solar steam-generation device from wasted rice straw.

The device is composed of a photothermal membrane and water pumps. Rice straw leaves are carbonized and composited with bacterial cellulose to function as a photothermal membrane and the lower culms of straw are designed as water pumps.

The solar rice straw-derived desalination achieves a daily clean water yield of 6.4 to 7.9 kg per square meter on sunny days and 4.6 to 5.6 kg on cloudy days. The water yielded reached safe drinking water standards with over 99.9 percent of saline ions removed.

Besides seawater desalination, the device can also be used for extracting clean water from various water-bearing areas such as tidal flats, wetlands and marshes.

The research was published in the journal ACS Applied Materials and Interfaces.

As fresh water scarcity is one of the most compelling global concerns, scientists are exploring innovative desalination technologies to increase water productivity and bring down the overall desalination cost.

According to Liu Fu, the leading researcher, there is a great need to reduce energy consumption in desalination technology and solar-driven steam generation has attracted wide attention.

"As green and inexhaustible energy, solar energy can be harnessed in desalination and water purification, leading to low-cost and sustainable technologies that address the water crisis worldwide," Liu said.

To utilize solar energy, solar thermal materials are needed. Since it is complex and costly to prepare traditional solar thermal materials such as plasmonic materials, carbon nanotubes and graphene-based materials, they are not suitable for large-scale applications.

Liu's team explores new materials and new engineering designs to improve the efficiency of solar thermal conversion and reduce the cost of desalination.

Stepping out of the lab, learning from nature, he found rice straw was the most suitable candidate for photothermal desalination, as it possesses a high transpiration coefficient and a superior water delivery capability through its culms.

China has an abundance of rice straw. Chinese farmers traditionally burn straw after harvest, which causes air pollution and has been banned in many places.

"If this agricultural waste can be used for extracting clean water, it will be an environmentally friendly and sustainable technology," Liu said.

The technique can be used in remote islands or mountainous regions lacking water. It can be used during emergencies such as floods, earthquakes and severe environments such as in the wilderness for obtaining clean water, according to the team.

Liu's team is also researching other solar thermal materials, which are expected to be commercialized in large-scale desalination projects in three years.

An expert in solar-thermal desalination, Professor Zhu Jia from Nanjing University said the research was a new and creative exploration in using solar energy to desalinate sea water.

"By using rice straw as solar thermal materials, the cost for desalination can be further reduced," Zhu said.

 

[JSCh]

Alipay Has Planted 100 Million Trees in China's Badlands, It Announces on Earth Day
ZHANG YUSHUO
DATE : APR 22 2019/SOURCE : YICAI

(Yicai Global) April 22 -- Alipay has planted 100 million real trees with 500 million Ant Forest users to establish forestation of an area of 1.4 million hectares, China's largest online payment firm announced today in commemoration of Earth Day.

The Alipay mobile payment of Hangzhou-based tech titan Alibaba Group Holding's Ant Financial finance arm started the Ant Forest Program in August 2016 and encouraged people to pay with the third-party app to amass credit to grow virtual trees.

It then conjured these virtual trees to life by planting real ones in barren areas of the country's northern Inner Mongolia Autonomous Region and northwestern Gansu province under threat of desertification.