A Demonstration of the Consistency of Maize Stover Pretreatment by Soaking in Aqueous Ammonia from Bench to Pilot-Scale
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Soaking in aqueous ammonia (SAA) is a means of pretreating biomass at moderate temperatures and ammonia concentrations (15% w/w). To establish process consistency and scalability, sieved maize stover was pretreated at 50-ml, 300-ml, and 100-l scales. Each scale was carried out through different methods. Sealed reactor tubes were used for 50-ml pretreatment. Fabric dyeing apparatus was used for the 300-ml pretreatment and a commercial Littleford DVT reactor was used for 100-l pretreatment. For each scale, biomass washing and solid-liquid separations were scaled appropriately. Washed pretreated solids were analyzed for composition and recovery of dry biomass and carbohydrates calculated. Nearly 100% of the glucan content was recovered in pretreated solids at all three scales, indicating the viability of SAA pretreatment. Pretreated solids (15% w/w) were hydrolyzed in a 1-l twin Sigma blade mixer using Cellic CTec2 (15 FPU.g-glucan−1) followed by fermentation in shake flasks. Hydrolytic yields ranged 65–70% across scale treatments. In comparison, fermentative yields averaged 95% across scale treatments, indicating saccharification to be a rate-limiting step in effective bioconversion of lignocellulose.
KeywordsPretreatment Soaking in aqueous ammonia Scale-up Lignocellulose Maize stover Sigma mixer Cellulase Hydrolysis
The authors would like to thank the Lab and Engineering staff at NCERC for their invaluable support through the project, and Graduate Assistant Kimia Kajbaf for her assistance.
The study was funded by the Illinois Corn Growers Association (https://www.ilcorn.org/home).
- 1.Zhang X, Athmanathan A, Mosier NS (2016) Biochemical conversion of biomass to biofuels. In: Kumar R, Balan V, Singh S (eds) Valorization of lignocellulosic biomass in a biorefinery, pp 79–142Google Scholar
- 5.Chundawat SPS, Bals B, Campbell T, Sousa L, Gao D, Jin M, Eranki P, Garlock R, Teymouri F, Balan V, Dale BE (2013) Primer on ammonia fiber expansion pretreatment. In: Wyman CE (ed) Aqueous pretreatment of plant biomass for biological and chemical conversion to fuels and chemicals. Wiley, Chichester, pp 169–200CrossRefGoogle Scholar
- 10.Ko JK, Bak JS, Jung MW, Lee HJ, Choi IG, Kim TH, Kim KH (2009) Ethanol production from rice straw using optimized aqueous-ammonia soaking pretreatment and simultaneous saccharification and fermentation processes. Bioresour Technol 100:4374–4380. https://doi.org/10.1016/j.biortech.2009.04.026 CrossRefPubMedGoogle Scholar
- 17.Sarks C, Bals BD, Wynn J, Teymouri F, Schwegmann S, Sanders K, Jin M, Balan V, Dale BE (2016) Scaling up and benchmarking of ethanol production from pelletized pilot scale AFEX treated corn stover using Zymomonas mobilis 8b. Biofuels 7:253–262. https://doi.org/10.1080/17597269.2015.1132368 CrossRefGoogle Scholar
- 22.Fockink DH, Urio MB, Chiarello LM, Sánchez JH, Ramos LP (2016) Principles and challenges involved in the enzymatic hydrolysis of cellulosic materials at high total solids. In: Soccol CR, Brar SK, Faulds C, Ramos LP (eds) Green fuels technology. Springer International Publishing, Cham, pp 147–173CrossRefGoogle Scholar
- 28.Sluiter A, Hames BR, Ruiz R et al (2012) Determination of structural carbohydrates and lignin in biomass: laboratory analytical procedure (LAP), pp 1–18. https://www.nrel.gov/docs/gen/fy08/42621.pdf
- 29.ASABE (2012) Moisture measurement—forages, pp 1–3. https://elibrary.asabe.org/azdez.asp?JID=2&AID=41661&CID=s2000&T=2
- 32.Westman JO, Wang R, Novy V, Franzén CJ (2017) Sustaining fermentation in high-gravity ethanol production by feeding yeast to a temperature-profiled multifeed simultaneous saccharification and co-fermentation of wheat straw. Biotechnol Biofuels 10:213. https://doi.org/10.1186/s13068-017-0893-y CrossRefPubMedPubMedCentralGoogle Scholar
- 47.Liu K, Atiyeh HK, Pardo-Planas O, Ezeji TC, Ujor V, Overton JC, Berning K, Wilkins MR, Tanner RS (2015) Butanol production from hydrothermolysis-pretreated switchgrass: quantification of inhibitors and detoxification of hydrolyzate. Bioresour Technol 189:292–301. https://doi.org/10.1016/j.biortech.2015.04.018 CrossRefPubMedGoogle Scholar