Biorefinery Coursework Example | Topics and Well Written Essays - 750 words

Biorefinery - Coursework Example Switch grass is current used for the production of biofuel (Jefferson, McCaughey, May, Woosaree, & McFarlane, 2002). Biomass in Alberta Province of Canada (Jefferson, McCaughey, May, Woosaree, & McFarlane, 2002) Biomass Mean annual yield (Mg/h) Prairie sand reed 9.5 Switch grass 7.0 Big bluestem 5.5 Western wheat grass 8.8 Mammoth wild rye 7.7 Green needle grass 15.8 wheatgrass 7.5 Thick spike 6.7 Question 2 The following bio-products can be obtained from the bio-refinery: bio-diesel, ethanol, modified proteins, adhesives and resins, solvents and lubricants as well as industrial plant-based oil products (such as fertilizers, plastics), and plant-made industrial products (such as composites), Propose conversion technologies that can be applied in the biorefinery to produce the identified products; at least two different paths to ethanol should be included Biomass handling technologies for the production of different bio-products from the biomass listed in the Table above involved harv esting, transportation, storage and pre-processing and fermentation or anaerobic digestion. Pretreatment is carried out by hydrolysis of lignocellulosic material with dilute sulphuric acid (0.7-5% v/v) in two stages to yield fermentable sugars such as D-glucose, D-mannose, D-galactose, L-rhamanose, D-xylose, L-arabinose, and uronic acids. The first stage is carried out at 140 Â °C for 15 min to hydrolyze the hemicelluloses and in the second stage proceeds at 190 Â °C for 10 min to breakdown the cellulose. Any residue cellulose is hydrolyzed enzymatic ally. The bioconversion of D-xylose into ethanol from hemicellulosic materials is limited by the presence of toxic compounds, such as phenol, furfural, 5-hydroxymethylfurfural and acetic acid. These toxic compounds decrease the bioprocess productivity. The toxic compounds are removed by use first adjusting the pH to 9-10 by using Ca(OH)2 to facilitate the removal of the toxic compounds and this is followed by readjusting the pH back t o 5. The hydrolyzed hemicellulosic material will be fermented with S. cerevisiae for ethanol production. Alternatively, ethanol can be obtained from the biomass by carrying the pretreatment process by means of steam explosion at 160-290 Â °C, 0.7-5 MPa. The process depolymerizes the cellulose and the hemicellulosic materials. Detoxification and fermentation processes as describe above is carried out to yield ethanol. For each possible path, estimate how much ethanol can be produced per year. Use theoretical yield if the actual conversion efficiency is unknown. Theoretical yield Percentage of cellulose in Switch grass is 40.2% (Jefferson, McCaughey, May, Woosaree, & McFarlane, 2002) Percentage of hemicelluloses in Switch grass = 32.5% (Jefferson, McCaughey, May, Woosaree, & McFarlane, 2002) Hydrolysis of 1 kg C6 sugar polymers gives 1.11 kg monomer sugars Hydrolysis of 1 kg C5 sugar polymers gives 1.14 kg monomer sugars Fermentation of 1 kg glucose (C6) gives 0.511 kg ethanol Theore tical yield = ([(40.2 *1.11) + (32.5*1.14)] * 0.51) Theoretical yield = 41.65/100 = 0.42 kg/kg feed = 0.55 L/kg feed Comment on the logistic aspect (mainly the transportation of feedstock) of the biorefinery, taking into account the scale of operation, the distribution of feedstock, and