Lecture 4+5 biorefinery ex. and ethanol production Flashcards
What is the project BioBUF?
Upgrading of renewable domestic raw materials to value-added bulk and fine chemicals for a biobased economy: technology development, systems integration and environmental impact assessment.
What challenges are they addressing?
- replacing fossil-based raw materials with biobased raw materials
- smarter use of raw materials by developing a highly
integrated biorefinery concept, including technology for using all parts of the raw material for simultaneous
production of several bulk and fine chemicals - careful analyses of the environmental impact and the economic performance of suggested processes
What can adipic acid be used for?
As a platform chemical used for production of
nylon and a broad range of chemicals
What is GROT?
The waste from the forestry industry (grenar och toppar)
How can GROT be used?
It can be converted into lignin, hemicellulose and carbohydrates. Lignin can be converted to aromatic compounds which can create valuable biochemicals. Sugars from GROT can possibly also be used to create adipic acid.
Whats the main substrates in 1st generation bioethanol production?
sugars and starch
What is Dry milling VHG SSF?
A typical industrial process for fuel ethanol production. Creates Ethanol and DDGS (=Dry matter/cereal bi-product from the process, also includes yeast and enzymes).
VHG = Very high gravity
SSF= simultaneous saccharification and fermentation
Are cells metabolic active if they do not grow?
Usually no. If they do not grow they are generally not metabolically active. E.g. If yeast stop growing ethanol production decreases a lot
What are the substrates of 2nd generation ethanol production derived from?
Cellulose, hemicellulose and lignin
How does the typical 2nd generation ethanol production look like?
Enzymatic hydrolysis to degrade the polymers to create fermentable sugars-> fermentation -> product
What challenges are there to high solid loadings? e.g. using lignocellulose
Separation/enzymatic hydrolysis costs
water economy (it holds a lot of water)
Creates a viscous media - mixing problems
higher levels of inhibitory compounds
What strategies can you use to get a more robust 2nd generation process?
- Pretreatment for detoxification (=less inhibitors)
- More cells and nutrients (yeast extract)
- Evolve the strain to perform better
- Optimization of the process schemes
What is a hydrolysate?
Any product formed from hydrolysis
How can you use evolutionary engineering?
Example: improve hydrolysate conversion and inhibitor tolerance. Can be done by adapting the yeast to e.g. lignocellulosic hydrolysates during propagation to improve their performance.
What’s the multi-feed SSCF process?
Pretreated wheat straw (or similar) is divided into liquid and solid fractions. Yeast cultivation on the liquid fraction then cells feed to SSCF. In the fed-batch SSCF enzymes and the solid/dry feed are added. This process improves mixing and reduces inhibition!
