COURSE “Introduction to Green and Sustainable Chemistry”
Written exam – March 03, 2014 (part II)
1) What the term process intensification means? Provide a representative example of the concept of hazard reduction through process intensification and another significant example of PI processes which combine reaction and separation stages in a single plant.
2) Justify why the application of green chemistry principles involve a shift of analytical control of the process from traditional system based on final product quality to on-line controls (i.e. process analytical technology - PAT) and a design of quality (quality by design, QbD). In your opinion why these concepts, developed in the frame of pharmaceutical industry, are not jet extensively applied?
3) An accident prevention program must include:
a) regular monitoring
b) formal and regular procedures
c) procedures to ensure and appropriate disposal of chemical waste d) regular controls on safety
e) only previous a and c.
On which bases an accident prevention program is formulated?
4) *Provide schematic example of the intrinsic safety criteria to be adopted and how to activate the inherence concept in a production process of methanol (CH3OH) from CO e H2.
5) **Biocatalysis and metabolic control represents the future of environmentally safe chemicals transformations. Explain the appropriateness and generality of the sentence with appropriate examples, evidencing limits and problems.
6) REACH norm from EU provide for toxic chemicals the substitution with more healthy products. Which are the reasons of the fact that industry is against to adopt these substitutions and prefers to control the exposition? Why international organizations (i.e. EU) are convinced that only adoption of international directives is effective in controlling the use of very dangerous chemicals?
7) Biotechnologies have relevance in the production of first generation bioethanol, but particularly of second generation bioethanol Clarify which are the main differences in the production of this biofuel.
8) After a brief outline of the main family of compounds which can be obtained from biomasses, indicate for each almost one Cn platform chemical (n = 3, 5, 6), arising from them, and its main uses.
9) **Biopolymers and biodegradable polymers belong to two different classes of polymers having different roles, properties, and uses. Which are the main differences between the polyesters RNA, PHA and PLA?
10)**Alkyl polyglucosides and flavonoids are two classes of interesting fully biodegradable materials (used as surfactants and water soluble dies, respectively). From which natural raw material they arise and which reactions are used in their preparation/extraction?
11) Comment the correctness or not correctness of this sentence: "Energy represents the best selection criteria between recycle, reuse or landfill of materials and chemicals".
12) *The diagram below illustrates the Cativa Process for production of acetic acid (ethanoic acid) from methanol (CH3OH) and carbon monoxide (CO) using a Ir/Ru catalyst. What steps are taken to:
a. produce a pure product b. reduce costs
c. protect the environment?
13) *This question is about four reactions which are used in the manufacture of hydrogen:
CH4(g) + H2O(g) a CO(g) + 3H2(g) H = +210 kJ·mol–1 CO(g) + H2O(g) a CO2(g) + H2(g)
K2CO3(aq) + CO2(g) + H2O(l) f 2KHCO3(aq)
2KHCO3(aq) f K2CO3(aq) + CO2(g) + H2O(l)
(i) Discuss, with reasons, the conditions of temperature and pressure that would favor the production of hydrogen in reaction 1. (You should consider the effect of the conditions on both yield and rate).
(ii) State one economic advantage of reaction 4.
(iii) Reaction 3 and 4 contributes to global warming?
(iv) Identify the more toxic compound involved in the sequence of reactions.
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* Responses due by Eng. Chem. Students.
** Responses due by Eng. Environ. students.
