Sci­en­tists get green light for a cleaner world

China Daily (Hong Kong) - - FRONT PAGE - By CHENG YINGQI chengy­ingqi@chi­

Stum­bling out of bed in the morn­ing, your thoughts turn to a wakeup cup of tea or cof­fee. You know what you want to drink, but what about the cup. What’s the green choice: pa­per, china or poly­styrene?

Many might say the china cup. But what if we count in the en­ergy spent to make it and the wa­ter used to wash it?

You would have to use a china cup at least 1,000 times be­fore it would be en­vi­ron­men­tally bet­ter than poly­styrene.

A new op­tion might help en­vi­ron­men­tal­ists sleep bet­ter at night, ac­cord­ing to a lead­ing sci­en­tist. Not just sweet dreams, but green dreams.

“We need green chem­istry, which re­duces or elim­i­nates the use and gen­er­a­tion of haz­ardous sub­stances and makes chem­i­cal in­dus­try more sus­tain­able,” said Han Bux­ing, who chaired the In­ter­na­tional Union of Pure and Ap­plied Chem­istry’s sub­com­mit­tee on green chem­istry for five years.

Green chem­istry is be­com­ing in­creas­ingly pop­u­lar in China.

In Fe­bru­ary, a green en­ergy en­gi­neer­ing re­search cen­ter got, par­don the pun, the green light in Qing­dao, Shan­dong prov­ince.

Within five years it hopes to be­come a bridge be­tween biomass en­ergy re­search and in­dus­try.

Also in Fe­bru­ary, Yueyang, a ma­jor petro­chem­i­cal hub in Hu­nan prov­ince, opened a green chem­istry park. And other green parks are ap­pear­ing across the na­tion.

One sec­tor that is turn­ing green is the print­ing in­dus­try.

An am­bi­tious plan was un­veiled to make 30 per­cent of the print­ing sec­tor use green tech­nol­ogy by the end of the 12th Five-Year Plan (2011-15).

Print­ing has long used a process called plate-mak­ing, which re­lies on toxic photo-sen­si­tive ma­te­ri­als and alu­minum. This process can be re­placed by a nano-coat­ing tech­nol­ogy that greatly re­duces the chem­i­cal process in print­ing.

“This is a rev­o­lu­tion­ary method that could make our print­ing in­dus­try in China the most en­vi­ron­men­tally friendly in the world,” said Song Yanlin, who de­vel­oped the tech­nol­ogy, which has seen 51 patents taken out in China and 14 patents ap­plied for un­der the Patent Co­op­er­a­tion Treaty.

Plas­tic film

Green chem­istry is not only about cut­ting down on the use of toxic ma­te­ri­als, but also de­sign­ing chem­i­cals and prod­ucts to de­grade af­ter use. De­vel­op­ing biodegrad­able plas­tic films for agri­cul­ture is one ex­am­ple.

In China, a huge amount of poly­eth­yl­ene mulch film is used for bet­ter growth and crop yield. The plas­tic, of­ten seen on farms, is laid in strips and re­tains wa­ter while of­fer­ing pro­tec­tion from the ele­ments.

In June, Xin­hua News Agency re­ported that a sur­vey in 20 coun­ties in the Xin­jiang Uygur au­ton­o­mous re­gion showed an aver­age of 253 kg of torn plas­tic film re­mained on each hectare of land.

“Af­ter har­vest, th­ese thin poly­eth­yl­ene films can eas­ily break down to small frag­ments, and they are hard to col­lect and re­cy­cle,” said Zhang Jun, a sci­en­tist who spe­cial­izes in nat­u­ral poly­mers.

To solve this prob­lem, Zhang and his team are de­vel­op­ing tech­nol­ogy to make plas­tic film from plant cel­lu­lose, which is re­new­able and biodegrad­able.

“Most in­dus­trial plas­tics are made from petro­chem­i­cals and con­sume a huge amount of pe­tro­leum re­sources. More­over, al­most all of th­ese plas­tics are non-biodegrad­able.

“In con­trast, plant cel­lu­lose is abun­dant, re­new­able and it ex­ists in all plants. More im­por­tant, it de­grades to car­bon diox­ide and wa­ter and re­turns to na­ture af­ter be­ing used,” he said.

Re­cently, plant cel­lu­lose film has been suc­cess­fully pre­pared through a sim­ple and “green” method in Zhang’s lab­o­ra­tory. A Chi­nese com­pany is in­vest­ing about 10 mil­lion yuan in de­vel­op­ing the tech­nol­ogy for in­dus­trial pro­duc­tion, Zhang said.

New cat­a­lyst

Green chem­istry tar­gets the use of haz­ardous sub­stances and points the way to the fu­ture, said Fan Qinghua, an or­ganic chem­istry spe­cial­ist.

“Chemists hope to in­vent ‘ per­fect chem­i­cal re­ac­tions’. The de­sired prod­uct is ob­tained with­out form­ing any waste. This is the ul­ti­mate goal of green chem­istry,” he said.

Green chem­istry is not just an aca­demic mat­ter, ex­perts said, and it must be tar­geted well.

“Only if re­search com­bines with need will the new meth­ods pro­duce ben­e­fits for the en­vi­ron­ment,” said Zhang De­qing, di­rec­tor of the In­sti­tute of Chem­istry at the Chi­nese Acad­emy of Sciences.

To en­cour­age green chem­istry re­search, the CAS has launched a dozen projects that al­low re­searchers to iron out tech­no­log­i­cal prob­lems, and th­ese projects are also open to com­pa­nies.

Newspapers in English

Newspapers from China

© PressReader. All rights reserved.