Optimization Of ph For Acidogenic Digestion Of Willow To Mixed Organic Acids
Open Access
- Author:
- Shafer, Michael Dovin
- Area of Honors:
- Chemical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Thomas Lehman Richard, Thesis Supervisor
Dr. Wayne Roger Curtis, Thesis Honors Advisor - Keywords:
- biofuel
acid
acidogenic
renewable
sustainable
anaerobic
willow
lignocellulosic - Abstract:
- The carboxylate platform is a promising route for biofuels production, capable of converting a variety of biomass materials to liquid fuel without either sterile conditions or costly enzymes. Earlier work has investigated acidogenic digestion on material such as corn stover. Willow wood is less well-studied biomass. An acidogenic digestion of pretreated willow was conducted at multiple pH treatments from pH 4.5 to 6.5. Compositional analysis was conducted on pretreated starting material as well final solid residue. The digestion products quantified were mixed organic acids from C1 to C6. Steam explosion pretreatment was employed, with temperature at 190ºC and residence time at 50 seconds. A non-specified, mixed bacterial culture was used. High organic acid concentrations were achieved of up to 29.75 ± 0.80 g/L. Lower pH treatments produced low acid concentrations; production of acid was maximized at pH 6. Six organic acids accounted for greater than 99% of the acids produced: hexanoic, butyric, propionic, acetic, formic, and lactic acid. A correlation between concentration of acetic acid and pH treatment was observed to exist with 95% confidence. The digestion optimized reactor pH for a lignocellulosic biomass that shows promise for use in biofuel production. Development of a system for in-situ removal of acid products is a candidate for future studies.