13nastuxxa
19.10.2020 21:22

Прочтите статью и составьте аннотацию к ней: BIO-RENEWABLE PROCESS COULD HELP ‘GREEN’ PLASTIC

Plastics are often derived from petroleum, contributing to reliance on fossil fuels and driving harmful greenhouse gas emissions. To change that, scientists are trying to take the pliable nature of plastic in another direction, developing new and renewable ways of creating plastics from biomass.
When John Wesley Hyatt patented the first industrial plastic in 1869, his intention was to create an alternative to the elephant tusk ivory used to make piano keys. But this early plastic also sparked a revolution in the way people thought about manufacturing: What if we weren't limited to the materials nature had to offer?
Over a century later, plastics are an abundant part of daily life. But these plastics are often derived from petroleum, contributing to reliance on fossil fuels and driving harmful greenhouse gas emissions. To change that, Great Lakes Bioenergy Research Center (GLBRC) scientists are trying to take the pliable nature of plastic in another direction, developing new and renewable ways of creating plastics from biomass.
Using a plant-derived solvent called GVL (gamma-Valerolactone), University of Wisconsin-Madison Professor of Chemical and Biological Engineering James Dumesic and his team have developed an economical and high-yielding way of producing furandicarboxylic
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acid, or FDCA. One of 12 chemicals the U.S. Department of Energy calls critical to forging a "green" chemical industry, FDCA is a necessary precursor to a renewable plastic called PEF (or polyethylene furanoate) as well as to a number of polyesters and polyurethanes.
The researchers published their findings Jan. 19, 2018 in the journal Science Advances.
As the bio-based substitute for PET (polyethylene terephthalate) ‒ its widely used, petroleum-derived counterpart ‒ PEF is rich in potential. PET currently has a market demand of close to 1.5 billion tons per year, and Coca-Cola, Ford Motors, H.J. Heinz, Nike and Procter & Gamble have all committed to developing a sustainably sourced, 100 percent plant-based PET for their bottles, packaging, apparel and footwear. PEF's potential to break into that sizeable market, however, has been hampered by the high cost of producing FDCA.
"Until now, FDCA has had a very low solubility in practically any solvent you make it in," says Ali Hussain Motagamwala, a UW-Madison graduate student in chemical and biological engineering and co-author of the study. "You have to use a lot of solvent to get a small amount of FDCA, and you end up with high separation costs and undesirable waste products."
Motagamwala and colleagues' new process begins with fructose, which they convert in a two-step process to FDCA in a solvent system composed of one part GVL and one part water. The end result is a high yield of FDCA that easily separates from the solvent as a white powder upon cooling.
"Using the GVL solvent solves most of the problems with the production of FDCA," says Motagamwala. "Sugars and FDCA are both highly soluble in this solvent, you get high yields, and you can easily separate and recycle the solvent."
Other features of the process contribute to its robust economics. The system doesn't require costly mineral acids for catalysis, doesn't produce waste salts, and you can separate out the FDCA crystals from the solvent by simply cooling the reaction system.
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The team's techno-economic analysis suggests that the process could currently produce FDCA at a minimum selling price of $1,490 per ton. With improvements, including lowering the cost of feedstock and reducing the reaction time, the price could reach $1,310 per ton, which would make their FDCA cost-competitive with some fossil fuel-derived plastic precursors.
"We think this is the streamlined and inexpensive approach to making FDCA that many people in the plastics industry have been waiting for," says Dumesic. "Our hope is that this research opens the door even further to cost-competitive renewable plastics."
The Wisconsin Alumni Research Foundation is working to license GVL technology for use in bioplastics production.

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Xxxmara
14.03.2020 05:18
1. Living in the city is more exciting than in the country. 2. Listening  to my favorite music makes me happy. 3. Fighting for human rights is very important. 4. Travelling abroad widens professional outlook 5. You have a very beautiful voice; I love your singing a lot.6.This is very sensitive topic: I hope for your understanding.7.You are never on time. You have to do something with your constant lating8. Surfing the Net is not the best pastime on a nice summer day9.  Living is nowadays much faster than 20 years ago. 10. Only having a cup of coffe in the morning really wakes me up
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katyaaaasd
01.02.2022 09:01
Это про выхухоль. Described from Vladimir region In the beginning of XX century the desman was common in the basin. PP. The Dnieper, don, Volga and Ural. The current habitat is in the aquatic systems of the rivers listed and has broken character. Thanks to the artificial resettlement, the muskrat began to meet in bass. R. Ob. In the European part of Russia in the basin. of the Dnieper river meets Iput river (Bryansk region), PP. Vyazma and Dnieper, Oster and Iput the Smolensk region. and over the floodplains of rivers. The diet, Swap the Kursk region, In the basin. Don - on the river Voronezh, Tambov and Lipetsk region., PP. Bityug, Khoper and their tributaries (Voronezh, Tambov, Saratov, Penza, Volgograd region). In the upper reaches of the Volga meets the rivers. The mouth of the Kotorosl in Yaroslavl region and Kostroma region of Snake Observed in the lower reaches of the Klyazma (Vladimir, Ivanovo region). Inhabits all the suitable grounds in the lower reaches of the Moksha river and its tributary the CNA (Ryazan, Tambov region). Common in floodplain wetlands of the lower reaches of the Oka (Vladimir, Ryazan and Nizhny Novgorod region). In the middle part of the Volga meets the river Sura (Penza, Ulyanovsk region) and the river Alatyr in the Republic of Mordovia. Down the Volga river muskrat everywhere rare [1-5]. Issue 74 muskrats in 1961 in Chelyabinsk region was the formation of a new hotbed of muskrat habitat in the West. Siberia. Released animals in the mid 60-ies. settled down the UY river in the Kurgan region. and moved to R. floodplain of the Tobol. Now, here at the junction of three regions - Chelyabinsk, Kurgan, Kustanay (Kazakhstan) formed a stable population of muskrat. Successful works were the first stage in issue 236 muskrats in 1956 in the floodplain R. Tagan Tomsk region 114 and muskrats in 1978 in the floodplain of R. Tortas Novosibirsk region due to high floods and anthropogenic impacts at present the animal in these areas are very rare.
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