CHEM F337: Green Chemistry Lecture 08
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Questions and Answers

What is the starting material used in the green route to styrene production?

  • Benzene
  • Xylene (correct)
  • Toluene
  • Ethylene
  • What is the primary concern associated with polyacrylates?

  • Degradability (correct)
  • Chemical stability
  • Toxicity of materials
  • Cost of production
  • Which catalyst is used in the traditional route for styrene production?

  • Alumina catalyst
  • Fe-oxide catalyst (correct)
  • Nickel catalyst
  • Zeolite based catalyst
  • Which of the following is a key characteristic of polyaspartates compared to polyacrylates?

    <p>Biodegradability</p> Signup and view all the answers

    What is one of the by-products generated in the traditional route for allyl alcohol production?

    <p>Hydrochloric acid</p> Signup and view all the answers

    What is the source material for synthesizing polyaspartates?

    <p>L-aspartic acid</p> Signup and view all the answers

    What is the overall selectivity to styrene in the green route using toluene and methanol?

    <p>60%</p> Signup and view all the answers

    Which application is NOT mentioned for polyacrylates?

    <p>Electrical insulators</p> Signup and view all the answers

    In the green route to allyl alcohol, which reactants are used in the first step?

    <p>Propylene, acetic acid, and oxygen</p> Signup and view all the answers

    Which property of polyaspartates makes them a suitable alternative to polyacrylates?

    <p>Similar performance characteristics</p> Signup and view all the answers

    What is a notable property of polyaspartate?

    <p>It is biodegradable.</p> Signup and view all the answers

    What are the components used to synthesize polyaspartate?

    <p>Aspartic acid and NaOH.</p> Signup and view all the answers

    Which organization awarded the Donlar Corporation for its green chemistry innovations?

    <p>Presidential Green Chemistry Challenge.</p> Signup and view all the answers

    What type of award did the Donlar Corporation receive in 1996?

    <p>Presidential Green Chemistry Challenge Award.</p> Signup and view all the answers

    What chemical reaction occurs during the synthesis of polyaspartate?

    <p>Condensation of aspartic acid.</p> Signup and view all the answers

    In which category did the Donlar Corporation win the Presidential Green Chemistry Challenge Award?

    <p>Small business category.</p> Signup and view all the answers

    What role does NaOH play in the synthesis of polyaspartate?

    <p>It serves as a catalyst.</p> Signup and view all the answers

    What is the relationship between polyaspartate and aspartic acid?

    <p>Polyaspartate is a polymer derived from aspartic acid.</p> Signup and view all the answers

    What was the main disadvantage of the Boots process for ibuprofen in the 1960s?

    <p>It generated unwanted chemical waste.</p> Signup and view all the answers

    How many steps did the Hoechst-Celanese process use for ibuprofen synthesis?

    <p>3 steps</p> Signup and view all the answers

    What type of linkage was primarily utilized in Donlar's polyaspartates manufacturing facility?

    <p>70% α-linkage</p> Signup and view all the answers

    In what year did Boots win the Queens Award for Technical Achievement?

    <p>1987</p> Signup and view all the answers

    Which award did the Hoechst-Celanese process win in 1991?

    <p>Kirkpatrick Award</p> Signup and view all the answers

    What temperature range is optimal for microwave processing in high-temperature water reactions?

    <p>100–200 °C</p> Signup and view all the answers

    What is a limitation of pure water in microwave heating as temperatures increase?

    <p>It is difficult to heat above 130 °C.</p> Signup and view all the answers

    What percentage of atom efficiency does the Hoechst-Celanese process claim for its steps?

    <p>100% Atom efficient</p> Signup and view all the answers

    What was a major characteristic of the Boots process compared to the Hoechst-Celanese process?

    <p>More eco-friendly</p> Signup and view all the answers

    What is a common feature of the processes for synthesizing ibuprofen mentioned in the content?

    <p>Both reduced chemical waste.</p> Signup and view all the answers

    Study Notes

    Case Studies - Green Chemical Products

    • Styrene Production

      • Traditional two-step method starts with benzene and ethylene for ethylbenzene, followed by dehydrogenation.
      • Step II uses Fe-oxide catalyst and K2CO3 promoter, achieving 65% conversion and 95-97% selectivity to styrene.
      • Green route utilizes xylene as a less toxic starting material, converting to styrene via toluene and methanol at >400 °C using a proprietary zeolite catalyst.
      • Overall selectivity to styrene in the green process is approximately 60% at 1 atm pressure, making it the cheapest route.
    • Allyl Alcohol Production

      • Traditional method involves alkaline hydrolysis of allyl chloride, producing hydrochloric acid as a by-product.
      • The Shell process uses NaOH, resulting in significant NaCl generation.
      • Green synthesis avoids chlorine by processing propylene, acetic acid, and oxygen in two steps: acetoxylation followed by hydrolysis.
      • Acetic acid from hydrolysis can be reclaimed for reuse, providing a sustainable cycle.
      • An alternative method uses glycerol reacting with formic or oxalic acids.
    • Thermal Polyaspartate as an Alternative to Polyacrylates

      • Polyacrylates are widely used in products like paints, fibers, resins, and cosmetics but raise concerns about degradability.
      • Polyaspartates, developed by Donlar Inc., are biodegradable biopolymers derived from L-aspartic acid with no waste by-products.
      • Exhibit similar properties to polyacrylates, making them suitable for applications as dispersants and superabsorbers.
      • Donlar Corporation won the 1st Presidential Green Chemistry Challenge Award in 1996 and opened the largest polyaspartates facility in 1997.

    Green Reaction Conditions

    • Ibuprofen Production
      • The Boots process from the 1960s involved 6 steps with stoichiometric reactions, leading to chemical waste and high costs.
      • Boots was recognized with the Queens Award for Technical Achievement in 1987 for their contributions.
      • Hoechst-Celanese developed a more efficient green chemistry method with only 3 catalytic steps, achieving 100% atom efficiency.
      • The HC process received the Kirkpatrick Award in 1991 for its innovative use of catalytic processes over traditional stoichiometric methods.

    Green Modes of Activation

    • High-temperature water reactions (100–200 °C) are optimal for microwave processing in sealed vessels.
    • Challenges arise as pure water's absorbance of microwave energy decreases above 130 °C, complicating heating efforts.

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    Description

    Dive into the case studies of green chemical products, focusing on styrene production. This lecture explores traditional and innovative methods, including the use of Fe-oxide catalysts. Learn about the efficiency and environmental impact of these processes.

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