COURSE “Introduction to Green and Sustainable Chemistry”

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COURSE “Introduction to Green and Sustainable Chemistry”

Written exam - 13 November 2018 (part I)

1) One of the 12 Principles of Green Engineering is "Targeted durability, not immortality, should be a design goal." Give a specific example of how this principle can be used to prevent pollution.

2) One of the 12 Principles of Green Engineering is "Designers need to strive to ensure that all material and energy inputs and outputs are as inherently non-hazardous as possible." Explain how for You this relates to the concept of Industrial Ecology.

3) Since the start of the industrial age, most of the energy used by humans has come from the burning of coal and oil. In that time the amount of CO

2

in the air has increased from approximately 0.42% by mass to 0.58% by mass.

a) Calculate the additional mass of CO

2

, in kg, that has been added to Earth’s atmosphere since the start of the industrial age, assuming that the total mass of Earth’s atmosphere is 5.15 × 10

¹⁸

kg.

b) Burning coal produces both CO

2

and energy. If half of this additional CO

2

has come from the burning of this coal, calculate the total amount of energy, in kJ, that has been produced, given that

C

(s)

+ O

2(g)

→ CO

2(g)

; ΔH = –394 kJ mol

^–1

. For calculation, assume that coal is pure carbon.

4) The reaction for the production of methylpropene from 2-bromo-2-methylpropane is represented by the following equation :

CH

3

-CBr(CH

3

)

2

+ C

2

H

5

ONa → CH

³

-C(CH

3

)=CH

2

+ C

2

H

5

OH + NaBr

Calculate the Atom Economy and RME of the reaction if an excess of 20% of the base C

2

H

5

ONa is used and an overall yield of 92% is reached.

5) **The GhG carbon dioxide gas brings severe problems of temperature increase on the Earth. Summarize the possible solutions proposed to mitigate the effect of CO

2

increase, including the use of supercritical CO

2

.

6) * The liquid phase hydrolysis of acetic anhydride to form acetic acid is: (CH

3

CO)

2

O + H

2

O → 2 CH

3

COOH

to be carried out in an 1 liter CSTR at a volumetric flow rate of 3.3×10

^-3

dm

³

/s. The reaction follows an elementary rate law with a specific reaction rate of 1.95×10

⁴

dm

³

·mol

^-1

·s

^-1

. The concentration of acetic acid and water in the feed to the reactor are 1 M and 51.2 M. Find the conversion in the SCR and suggest how to improve the process.

7) What are the steps in risk assessment? Give a one-sentence description of what occurs in each step. How is the risk assessment of exposure to carcinogens different that non-carcinogens?

8) Explain the term used in these sentences: “European integrated pollution prevention and control directive (IPPC 96/61) is about minimising pollution from industrial sources throughout the European Union. The application needs to address actual operational conditions demonstrating that Best Available Techniques (BAT) are used at the installation to ensure an acceptable environmental impact. Procedurally, IPPC places a great emphasis on having a good Environmental Management System (EMS) whereby the impacts of operations and environmental performance metrics are fully understood.”

9) Explain the different life cycle phases for a product, process, or system and provide examples of anticipated environmental impacts and risks from each phase. Using the data reported in the following table and figure: a) list the following organic solvents in order of decreasing greenness: ethanol (C

2

H

5

OH); methanol (CH

3

OH); toluene (C

6

H

5

CH

3

); hexane (C

6

H

14

); and tetrahydrofuran (C

4

H

8

O) (b) combining EHS (Environmental, Health and Safety) and LCA methods, which of the five is greenest?

10) Which is Your opinion on the following statement: “Design materials, products, processes, and systems that are inherently safer generate less waste, and use energy efﬁciently.”

11) After defining the concept of Sustainable Development, put in the context the importance of the terms recycling, reuse, remanufacturing and recovery.

12) ** The GhG carbon dioxide gas brings severe problems of temperature increase on the Earth.

Summarize the possible solutions proposed to mitigate the effect of

CO2

increase.

___________________

* Chem. Eng. ** Env. Eng.

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13)**Biopolymers represent a class of polymers different from the one of natural polymers. Provide examples which clarify on which bases these materials are similar and why they differ.

Table – CED data for common solvents.

Solvent CAS-No Solvent production per kg solvent / MJ-eq.

CED Solvent distillation per kg solvent/MJ-eq.

CED Solvent incineration CED per kg solvent/MJ-eq.

Acetic acid 64-19-7 55.9 -34.9 -15.5

Acetone 67-64-1 74.6 -53.6 -33.9

Acetonitrile 75-05-8 88.5 -79.6 -29.7

Butanol(1) 71-36-3 97.3 -74.6 -39.9

Butyl acetate l23-86-4 121.6 -95.9 -34.1

Cyclohexane 110-82-7 83.2 -63.4 -53.5

Cyclohexanone 108-94-1 124.7 -99.7 -40.4

Diethyl ether 60-29-7 49.8 -31.9 -40.2

Dioxane 123-91-1 86.6 -63.8 -27.6

Dimethylformamide 68-12-2 91.1 -67.6 -25.9

Ethanol 64-17-5 50.1 -31.2 -31.7

Ethyl acetate 141-78-2 95.6 -72.0 -27.6

Ethylbenzene 100-41-4 85.1 -64.9 -49.8

Formaldehyde 50-00-0 49.3 -28.8 -15.9

Formic acid 64-18-6 73.9 -50.1 -4.7

Heptane 142-82-5 61.5 -43.7 -54.5

Hexane 110-54-3 64.4 -46.7 -55.2

Methylethylketone 108-10-1 64.2 -44.6 -37.6

Methanol 67-56-1 40.7 -21.7 -22.2

Methyl acetate 79-20-9 49.0 -29.2 -22.8

Pentane 109-66-0 73.2 -54.5 -55.3

Propyl alcohol (n-) 71-23-8 111.7 -87.3 -36.5

Propyl alcohol (i-) 67-63-0 65.6 -46.1 -36.5

Tetrahydrofuran 109-99-2 270.8 -230.7 -37.5

Toluene 108-88-3 80.0 -60.0 -49.3

Xylene 1330-20-7 72.5 -53.1 -49.9

*CED = Cumulative Energy Demand