File Name: chemi try project on green chemi try biodie el and bio petrol .zip
- Biofuels, explained
- Sustainable/Green Chemistry and Chemical Technology
- Biofuel: Sources, Extraction and Determination
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Green chemistry is the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances.
Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, use, and ultimate disposal. Green chemistry is also known as sustainable chemistry. Green chemistry reduces pollution at its source by minimizing or eliminating the hazards of chemical feedstocks, reagents, solvents, and products.
This is unlike cleaning up pollution also called remediation , which involves treating waste streams end-of-the-pipe treatment or cleanup of environmental spills and other releases. Remediation may include separating hazardous chemicals from other materials, then treating them so they are no longer hazardous or concentrating them for safe disposal. Most remediation activities do not involve green chemistry.
Remediation removes hazardous materials from the environment; on the other hand, green chemistry keeps the hazardous materials out of the environment in the first place. If a technology reduces or eliminates the hazardous chemicals used to clean up environmental contaminants, this technology would qualify as a green chemistry technology.
One example is replacing a hazardous sorbent [chemical] used to capture mercury from the air for safe disposal with an effective, but nonhazardous sorbent. Using the nonhazardous sorbent means that the hazardous sorbent is never manufactured and so the remediation technology meets the definition of green chemistry. Prevent waste : Design chemical syntheses to prevent waste. Leave no waste to treat or clean up. Maximize atom economy : Design syntheses so that the final product contains the maximum proportion of the starting materials.
Waste few or no atoms. Design less hazardous chemical syntheses : Design syntheses to use and generate substances with little or no toxicity to either humans or the environment. Design safer chemicals and products : Design chemical products that are fully effective yet have little or no toxicity.
Use safer solvents and reaction conditions : Avoid using solvents, separation agents, or other auxiliary chemicals. If you must use these chemicals, use safer ones. Increase energy efficiency : Run chemical reactions at room temperature and pressure whenever possible. Use renewable feedstocks : Use starting materials also known as feedstocks that are renewable rather than depletable.
The source of renewable feedstocks is often agricultural products or the wastes of other processes; the source of depletable feedstocks is often fossil fuels petroleum, natural gas, or coal or mining operations.
Avoid chemical derivatives : Avoid using blocking or protecting groups or any temporary modifications if possible. Derivatives use additional reagents and generate waste. Use catalysts, not stoichiometric reagents : Minimize waste by using catalytic reactions. Catalysts are effective in small amounts and can carry out a single reaction many times.
They are preferable to stoichiometric reagents, which are used in excess and carry out a reaction only once. Design chemicals and products to degrade after use : Design chemical products to break down to innocuous substances after use so that they do not accumulate in the environment. Analyze in real time to prevent pollution : Include in-process, real-time monitoring and control during syntheses to minimize or eliminate the formation of byproducts. Minimize the potential for accidents : Design chemicals and their physical forms solid, liquid, or gas to minimize the potential for chemical accidents including explosions, fires, and releases to the environment.
Download a one-sided or two-sided bookmark showing the twelve principles of green chemistry. To stop creating pollution in the first place became America's official policy in with the Federal Pollution Prevention Act. Green chemistry aims to design and produce cost-competitive chemical products and processes that attain the highest level of the pollution-prevention hierarchy by reducing pollution at its source.
Contact Us to ask a question, provide feedback, or report a problem. Jump to main content. An official website of the United States government. Related Topics: Green Chemistry. Contact Us. Green chemistry: Prevents pollution at the molecular level Is a philosophy that applies to all areas of chemistry, not a single discipline of chemistry Applies innovative scientific solutions to real-world environmental problems Results in source reduction because it prevents the generation of pollution Reduces the negative impacts of chemical products and processes on human health and the environment Lessens and sometimes eliminates hazard from existing products and processes Designs chemical products and processes to reduce their intrinsic hazards Top of Page How green chemistry differs from cleaning up pollution Green chemistry reduces pollution at its source by minimizing or eliminating the hazards of chemical feedstocks, reagents, solvents, and products.
Top of Page Green chemistry's 12 principles These principles demonstrate the breadth of the concept of green chemistry: 1. Top of Page Twelve principles of green chemistry bookmarks Download a one-sided or two-sided bookmark showing the twelve principles of green chemistry. Top of Page Green chemistry's roots in the Pollution Prevention Act of To stop creating pollution in the first place became America's official policy in with the Federal Pollution Prevention Act.
The law defines source reduction as any practice that: Reduces the amount of any hazardous substance, pollutant, or contaminant entering any waste stream or otherwise released into the environment including fugitive emissions prior to recycling, treatment, or disposal. Reduces the hazards to public health and the environment associated with the release of such substances, pollutants, or contaminants.
The term "source reduction" includes: Modifications to equipment or technology Modifications to process or procedures Modifications, reformulation or redesign of products Substitution of raw materials Improvements in housekeeping, maintenance, training, or inventory control Section 2 of the Pollution Prevention Act establishes a pollution prevention hierarchy, saying: The Congress hereby declares it to be the national policy of the United States that pollution should be prevented or reduced at the source whenever feasible; Pollution that cannot be prevented should be recycled in an environmentally safe manner, whenever feasible; Pollution that cannot be prevented or recycled should be treated in an environmentally safe manner whenever feasible; an Disposal or other release into the environment should be employed only as a last resort and should be conducted in an environmentally safe manner.
Sustainable/Green Chemistry and Chemical Technology
Green chemistry , also called sustainable chemistry , is an area of chemistry and chemical engineering focused on the design of products and processes that minimize or eliminate the use and generation of hazardous substances. The overarching goals of green chemistry—namely, more resource-efficient and inherently safer design of molecules, materials, products, and processes—can be pursued in a wide range of contexts. Note 1: Modified from ref. Note 2: Green chemistry discusses the engineering concept of pollution prevention and zero waste both at laboratory and industrial scales. It encourages the use of economical and. Green chemistry emerged from a variety of existing ideas and research efforts such as atom economy and catalysis in the period leading up to the s, in the context of increasing attention to problems of chemical pollution and resource depletion.
Biofuel , any fuel that is derived from biomass —that is, plant or algae material or animal waste. Since such feedstock material can be replenished readily, biofuel is considered to be a source of renewable energy , unlike fossil fuels such as petroleum , coal , and natural gas. Biofuel is commonly advocated as a cost-effective and environmentally benign alternative to petroleum and other fossil fuels, particularly within the context of rising petroleum prices and increased concern over the contributions made by fossil fuels to global warming. Many critics express concerns about the scope of the expansion of certain biofuels because of the economic and environmental costs associated with the refining process and the potential removal of vast areas of arable land from food production. Some long-exploited biofuels, such as wood , can be used directly as a raw material that is burned to produce heat.
Biofuel: Sources, Extraction and Determination
Green chemistry is the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, use, and ultimate disposal. Green chemistry is also known as sustainable chemistry.
Biofuels have been around longer than cars have, but cheap gasoline and diesel have long kept them on the fringe. Spikes in oil prices, and now global efforts to stave off the worst effects of climate change , have lent new urgency to the search for clean, renewable fuels. Our road travel, flights, and shipping account for nearly a quarter of the world's greenhouse gas emissions, and transportation today remains heavily dependent on fossil fuels.
What is Green Chemistry?
Nimm deinen FuB weg! - прорычал немец. - Уберите ногу. Взгляд Беккера упал на пухлые пальцы мужчины. Никакого кольца. Я так близок к цели, - подумал .
У вас есть кое-что, что я должен получить. Эти слова оказались не самыми подходящими. Глаза немца сузились.
- Стратмор выдержал паузу. - Какой была твоя первая реакция, когда я сообщил тебе о смерти Танкадо. Сьюзан нахмурилась. - Я подумала, что АНБ его ликвидировало.
Последние слова записки стали для нее сильнейшим ударом. И в первую очередь я сожалею о Дэвиде Беккере. Простите .