1. The contribution of chemical engineering to biotechnology
Professor Howard Chase FREng
Professor of Biochemical Engineering
Department of Chemical Engineering

2. Definitions
Biotechnology - “the application of scientific and engineering principles to the processing of materials by biological agents to provide goods and services”
Biochemical engineering - “the contribution of chemical engineering to biotechnology”.

3. Where can biotechnology be applied?
All applications benefit from an input of chemical engineering principles although the scales may not be the same as that encountered in the traditional oil and chemical industries. Some scales are smaller (e.g. healthcare) and some larger (environmental).

4. Biological cells: the source of sustainable molecules and more
H2, CH4, O2, CO2
Ethanol, butanol, acetone, propane-diol, biodiesel
Organic acids, amino acids, flavourings
Pharmaceuticals (e.g. antibiotics
Biopolymers (plastics and rheology)
Proteins: enzymes and therapeutics
Gene therapy products (packaged nucleic acid sequences)
Vaccines
Microbial cells (environmental clean-up; waste treatment)
Human cells (stem cells; tissue replacements)
Hybrid products: bio/electrical/optical/mechanical (e.g. biosensors)

5. Why not chemical engineering? The chemical engineer’s tool-box
Material and energy balances
Thermodynamics and equilibria
Separation principles and selectivity
Heat and mass transfer
Modelling
Measurement techniques
Processes
Microstructure engineering
Product design

6. Some outcomes for biotechnology
Bioreactor design and optimization (fermenter mixing and aeration; biocatalysis)
Separation and purification of (complex) biomolecules/molecular entities
Controlled drug release; targeted drug delivery
Scaffolds for tissue culture
P &ID, Hazop/Hazan, Batch process scheduling; debottle-necking
Systems’ biology

7. Biotechnology is not new to Chemical Engineering @ Cambridge
Peter King: 1953 photosynthethic Chlorella with PVD
John Davidson: 1980 member of committee for Spinks Report
Deep shaft waste treatment processes & ICI’s Pruteen bioreactor
Nigel Kenney: Packed bed processes for antibiotic purification.
Nigel Slater: Maintenance of sterility in valves and pipes attached to fermenters

8. What has this department done recently? Healthcare
Purification of molecules and biological assemblies produced in biological systems
Targeted delivery of pharmaceuticals to cells.
Purification of viruses and constructs for gene therapy.
Separation of different types of human blood cells.
Bioreactors for the growth of stem cells
Separation of differentiated from non-differentiated stem cells.

9. Energy and the environment
Biodiesel production from vegetable oils and algae
Gasification of sewage sludge
Oil production by pyrolysis of cellulosic materials.
Reduced sludge production in activated sludge waste water treatment
Biofilm reactors for degrading toxic compounds in aqueous wastes

10. Case study. Expanded bed adsorption for protein purification.
A quasi-packed bed through which particulates in non- clarified feeds can pass U
Segregation of beads via distributions of size and density
Umf < U < Ut
 ~ 0.4
 ~
Fluidised Bed Well mixed Poor adsorption
Packed Bed Blocks with particulates
Expanded Bed

11. Simplified Downstream Processing Flow Sheets
Conventional Process :
50-80% total production costs
cascade of 5-6 stages
decreasing yield with increasing number of stages
Expanded Bed Adsorption :
clarification, concentration and purification in one stage
increase in yield through reduction in stages

12. The expanded bed in action: purification of enzymes from yeast cells

13. Expanding the bed

14. Applying the feedstock

15. Washing to remove particulates

16. Desorbing the desired enzyme

17. The future of biotechnology: a personal vision
New therapeutics; gene therapy; personalized medicine; replacement organs
Novel diagnosis
Renewable feedstocks for the (petro)-chemical industries
Direct biological energy production; photosynthesis
Biological information storage: DNA versus silicon
Improved environmental clean-up

18. The future of Chemical Engineering and Biotechnology
Chemical engineering has a pivotal role in the delivery of biotechnological discovery and innovation for the benefit of society
Biotechnology will continue to provide intriguing challenges for chemical engineers as the range, variety and extent of applications proliferates.
Chemical engineers have the appropriate ‘wherewithal’ to meet and surpass those expectations.
The right combination at the right time in the right place.