1. “Green Chemistry” A greener future…
Prof. Ángela González
Department of Biology, Chemistry and Env. Sciences
Interamerican University of Puerto Rico
San Germán Campus
Angela González -UIA San Germán

2. What to expect from this talk…
Why?
History
What?
Definitions
How?
Principles
Examples
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

3. Remediation Techniques
¿WHY?
70’s – need to improve environmental quality
Control  Laws
Contaminants produced and THEN treated before releasing them to the environment
Excellent idea IF there is good control and handling of environmental laws
It is continuous, slow and expensive
Remediation Techniques
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

4. Angela González -UIA San Germán
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

5. ¿WHY?
1991 – Green Chemistry is promoted by EPA – (Paul Anastas)
Prevention!!!!
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

6. What is Green Chemistry?
… or sustainable/environmentally benign chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

7. What is Green Chemistry?
… principles to reduce or eliminate use or production of dangerous chemicals in the design, manufacture and application of chemical products.
Green Chemistry Theory & Practice, P T Anastas & J C Warner, Oxford University Press 1998
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

8. Green Chemistry Goals Reduction or elimination of Waste
Toxic chemicals or processes
Energy use
Angela González, Ph.D. / UIA-SG

9. Green chemistry is looking to:
Waste
Materials
Danger
Risk
Energy
Environmental Impact
COST! ($$$$)
Reduce
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

10. Green Chemistry vs. Environmental Chemistry
Study of sources, reactions, transport, effects and destruction of chemical compounds in the ground, water and air.
Stanley Manahan, Env. Chemistry, 6th Ed. CRC Press. 2005
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

11. Green Chemistry Environmental Regulations Clean up Research
Monitoring
Prevention
Green
Chemistry
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

12. Green Chemistry Benefits:
Reduced waste, eliminating costly end-of-the-pipe treatments
Safer products
Reduced use of energy and resources
Improved competitiveness of chemical manufacturers and their customers
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

13. What has happened?
1996 Presidential Green Chemistry Challenge Awards -promote non contaminant technologies.
1997 Green Chemistry and Engineering Conference
1999 Journal “Green Chemistry”
Chemical and Engineering News
2000 GCI integrated into ACS
2000 Journal of Chemical Education
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

14. and? 1.2 billions 57 millions 16 billions
Until 2006 all the technologies nominated to the PGCCA had eliminated the use or production of:
1.2 billion pounds of chemicals and solvents per year
Enough to fill 5000 train tanks or a 62 miles long train
57 million pounds of CO2 has been reduced
equivalent to take out circulation cars.
16 billion gallons of water per year have been saved
1.2 billions
57 millions
16 billions
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

15. Twelve Principles of Green Chemistry
Paul Anastas and John Warner in Green Chemistry: Theory and Practice (Oxford University Press: New York, 1998).
Angela González -UIA San Germán

16. Twelve Principles of Green Chemistry: 1. Prevent waste
Design chemical syntheses to prevent waste, leaving no waste to treat or clean up.
Easier than clean up, transport or store them
Transforming chemical reactions that incorporate the largest amount of the starting materials = Less waste!
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

17. ¿What kind of industry is worst?
Products (tons)
Kg byproducts/ Kg products
Petroleum Refinery
106 – 108
<0.1
Chemical Production
104 – 106
1-5
Specialized Chemical Compounds
5 – 50
Pharmaceutical
25 – 100+
Petróleo es la más limpia!!!!... Tiene que ser, ya que los márgenes de ganancia por Kg. son pequeños
New Industries:
Large gain margins $$$
More complex chemistry
More waste production
Angela González, Ph.D. / UIA-SG
R A Sheldon J Chem Tech Biotechnol
Angela González -UIA San Germán

18. Possible sources of waste reduction:
Inputs
“eco-friendly” solvents, high purity reagents, solvent recycling.
Production
Optimization of reaction time, temperature and pressure. New synthesis pathways.
Discharges
Reduce water usage, improve filtering procedures and reuse waste products.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

19. Twelve Principles of Green Chemistry: 2
Twelve Principles of Green Chemistry: 2. Design safer chemicals and products:
Design chemical products to be fully effective, yet have little or no toxicity.
…chemicals that are less hazardous to human health and the environment are:
Less toxic to organisms and ecosystems
Not persistent or bioaccumulative in organisms or the environment
Inherently safer with respect to handling and use
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

20. Avoid reactions that give dangerous by- products
Twelve Principles of Green Chemistry: 3. Design less hazardous chemical syntheses:
Use and generate substances with little or no toxicity to humans and the environment.
Avoid reactions that give dangerous by- products
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

21. Twelve Principles of Green Chemistry: 4. Use renewable feedstocks:
Use raw materials and feedstocks that are renewable rather than depleting.
Agricultural products
Wastes of other processes;
Reduce dependency from fossil fuels (petroleum, natural gas, or coal) or are mined.
Ejemplo byproduct de fermentacion el CO2 se vende a las companias que envasan refrescos
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

22. Catalysts are used in small amounts
Twelve Principles of Green Chemistry: 5. Use catalysts, not stoichiometric reagents:
They are selective
Catalysts are used in small amounts
Can carry out a single reaction many times.
Improve production and energy consumption
They are preferable to stoichiometric reagents, which are used in excess and work only once.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

23. Twelve Principles of Green Chemistry: 6. Avoid chemical derivatives:
blocking or protecting groups or any temporary modifications if possible.
Derivatives use additional reagents and generate waste.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

24. Twelve Principles of Green Chemistry: 7. Maximize atom economy:
Final product contains the maximum proportion of the starting materials. There should be few, if any, wasted atoms.
Relation between atoms in the products and atoms in the reagents
Addition – good atom efficiency
Elimination – not so good…
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

25. “Because an Atom is a Terrible Thing to Waste”
Atom Economy
Barry Trost, Stanford University
Evaluate the efficiency of the chemical transformation
“Because an Atom is a Terrible Thing to Waste”
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

26. Atom Economy
How many of the atoms of the reactant are incorporated into the final product and how many are wasted?
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

27. How a reactions efficiency is measured?
Reaction Yield
% yield = (actual quantity of products achieved) x (theoretical quantity of products achievable)
Atom Economy*
% atom economy = (MWt of desired products) x (MWt of all products)
Rendimiento:
Cálculo que históricamente se ha utilizado para evaluar eficiencia
No provee información sobre productos colaterales o desechos formados en la reacción
Economía atómica:
Considera el grado en que TODOS los reactantes son incorporados en el producto deseado
Angela González, Ph.D. / UIA-SG
* B M Trost, Science 1991, 254, 1471
Angela González -UIA San Germán

28. % Atom Economy = (FW of atoms utilized/FW of all reactants) X 100 =
H3C-CH2-CH2-CH2-OH + Na-Br + H2SO4  H3C-CH2-CH2-CH2-Br + NaHSO4 + H2O
Reagents Formula
Reagents FW
Utilized
Atoms
Weight of
Unutilized
Weight of
H3C-CH2-CH2-CH2-OH 74
4C, 9H 57 OH 17
Na-Br
103 Br 80 Na 23
H2SO4 98
------
2H, 4O, S
Total
4C, 12H, 5O, Br, Na, S
275
4C, 9H, Br
137
3H, 5O, Na, S
138
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100 =
(137/275) X 100 = 50%
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

29. % Yield vs. atomic economy
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

30. Chemical Reactions and Atomic Economy
Addition > Substitutions > Eliminations
Re-arrangements: 100 % efficient
Ex: Diels-Alder
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

31. USE: innocuous chemicals.
Twelve Principles of Green Chemistry: 8. Use safer solvents and reaction conditions
Avoid:
solvents,
separation agents,
other auxiliary chemicals.
USE: innocuous chemicals.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

32. Solvents Organic solvents = high VOC’s Alternatives
Synthesis without solvents
Water
Supercritical fluids (CO2)
Ionic Liquids
Uso de solventes orgánicos es lo más común
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

33. Dry Cleaning – Greener…
Initially gasoline and kerosene were used
Now use PERC
Future use Supercritical CO2 and CO2 surfactants
Using CO2 eliminates hazardous waste generation of perc.
CO2 does not pose the environmental and human health risks associated with perc (used by 34,000 dry cleaners in US).
Using CO2 reduces environmental regulatory burdens for Hangers operators.
Uses waste CO2 from other processes.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

34. Twelve Principles of Green Chemistry: 9. Increase energy efficiency:
Run chemical reactions at ambient temperature and pressure whenever possible.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

35. Twelve Principles of Green Chemistry: 10
Twelve Principles of Green Chemistry: 10. 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.
EJEMPLO DE LAS BOLSAS DE PAPEL QUE USSAN EN ESPANA Y QUE SON FOTODEGRADABLES
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

36. Twelve Principles of Green Chemistry: 11
Twelve Principles of Green Chemistry: 11. 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.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

37. PAT: Process Analytical Technologies
Measure quality and execution properties DURING manufacturing
Information is gather continuously to improve process
Diseñando, analizando y controlando fabricación
Se miden atributos de calidad y ejecución durante el proceso de fabricación
Se determinan características de los materiales de partida y de los compuestos formados a lo largo de la producción.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

38. Pre - PAT Analysis of raw materials, intermediates and final products
In case of problems: WHOLE lot rejected = A LOT OF WASTE!... A LOT OF $$$$!!
Tiempo entre toma de muestras y análisis de las mismas, impedía hacer correcciones en condiciones del proceso
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

39. Like you do while cooking…
While you cook you test the food, and apply the needed corrections to improve it:
If it is too salty: …
If it is too bland: ….
If you have extra guest…
If it is too acidic: stop there…
Al cocinar usted:
Prepara los ingredientes (materia prima)
Huele la carne
Si huele raro – esta mala
Si no, procede…
Prepara resto ingredientes
Cebolla tiene hongos – usar otra
Monta el sancocho…
A medida que se va cocinando UD:
Prueba por sal
Si falta sal…
Si tiene de sobra…
Chequea que se cocine la carne
Si las papas ya se cocieron y la carne no:
Saca las papas para que no se deshagan…
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

40. PAT: Process Analytical Technologies
Helps to:
Understand the process
Make corrections in the moment, without waiting for the final product
Develop mitigation strategies.
Inlcuye análisis:
Físico
Químico,
Matemático
Microbiológico
De Riesgo
Diseño y desarrollo de procesos que pueden asegurar consistencia en la calidad del producto.
Reduciendo tiempos de produccion al utilizar mediciones “en-linea”, “fuera de la linea” o “dentro de la linea” de producción
Previene rechazo de productos, producción de productos colaterales y re-procesamiento
Aumenta automatización – mejorando seguridad del operador y reduciendo error humano
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

41. Twelve Principles of Green Chemistry: 12
Twelve Principles of Green Chemistry: 12. Minimize the potential for accidents:
Design chemicals and their forms (solid, liquid, or gas) to minimize the potential for chemical accidents:
explosions,
fires, and
releases to the environment.
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

42. Example of Green Chemistry Synthesis - Ibuprofen
Angela González -UIA San Germán

43. Ibuprofen Synthesis Classic Route
Demand:
13,000 TPY
Developed in 1960
6 steps reaction
reaction:6 pasos con reactivos diferentes en cantidades estequiométricas
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

44. Ibuprofen Synthesis Classic Route
Atomic Economy: 32%
If this synthesis were to be used today, the amount of by-products per year:
27,000 TPY
Angela González, Ph.D. / UIA-SG
MORE WASTE THAN PRODUCT!!!
Angela González -UIA San Germán

45. Boots & Hoechst Synthesis of Ibuprofen – Green Route
Developed to improve production: * 3 steps
* No solvents
* Catalytic vs. stoichiometric reagents
* Recycling, reuse and recovery of
byproducts and reagents (acetic acid
>99%; HF >99.9%)
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

46. Atomic Economy 77% Faster More % yield Less waste produced $$$$$$
Boots & Hoechst Synthesis of Ibuprofen – Green Route
Atomic Economy 77%
Faster
More % yield
Less waste produced
$$$$$$
Angela González, Ph.D. / UIA-SG
And a happier environment
Angela González -UIA San Germán

47. Angela González -UIA San Germán
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

48. Angela González -UIA San Germán
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

49. What is green chemistry looking for?
Waste production minimization from the source
Use of catalysts
Use of non-toxic reagents
Use of renewable sources
Improvement of atomic economy
Use of non-solvent or environmental benign solvents
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán

50. ACS Green Chemistry Institute:
Anastas, P. T.; Warner, J. C. Green Chemistry: Theory and Practice; Oxford University Press: New York, 1998
B M Trost, Science 1991, 254, 1471
PAT:
EPA:
ACS Green Chemistry Institute:
Michael Cann, University of Scranton:
Angela González, Ph.D. / UIA-SG
Angela González -UIA San Germán