Variability in structural carbohydrates, lipid composition, and cellulosic sugar production from industrial hemp varieties

• Published in: Industrial crops and products 2020-12, Vol.157 (1), p.112906, Article 112906
• Main Authors: Viswanathan, Mothi Bharath, Park, Kiyoul, Cheng, Ming-Hsun, Cahoon, Edgar B., Dweikat, Ismail, Clemente, Tom, Singh, Vijay
• Format: Article
• Language: English
• Subjects: 09 BIOMASS FUELS; Disk milling; FAME (Fatty acid methyl esters); Hemp; Liquid hot water pretreatment; TAG (Triacylglycerol)
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2020.112906

•Total carbohydrate content of hemp varieties was similar to sugarcane bagasse and corn stover.•Presence of Eicosanoic (20:0) and docosanoic acids (22:0) fatty acids in all hemp samples suggests fatty acid elongation pathway in endoplasmic reticulum.•Approximately 25% of total lipid in hemp plant named CBD was TAG (Triacylglycerol).•High sugar recovery was achieved in all hemp varieties upon low severity pretreatment coupled with disk refining. The aim of this study was to determine carbohydrate recovery from hemp for ethanol production and quantify biodiesel from TAG (Triacylglycerol) present in hemp. The structural composition of five different hemp varieties (Seward County-SC, York County-YC, Loup County-LC, 19 m96136-19 m, and CBD Hemp-CBD) were analyzed. Concentration of glucan and xylan ranged between 32.63 to 44.52% and 10.62 to 15.48% respectively. The biomass was then pretreated with Liquid hot water followed by disk milling and then hydrolyzed enzymatically to yield monomeric sugars. High glucose (63-85%) and xylose (73-88%) recovery was achieved. Lipids were extracted from hemp using hexane and isopropanol and then transesterified to produce biodiesel. Approximately, 50% of total fatty acids in SC, LC, and CBD hemp were linoleic acid. Palmitic acid was present between 32 to 50% in varieties YC and 19 m. Highest TAG concentration at 25% of total lipids was observed in CBD hemp. The analysis on lipid composition and high sugar recovery demonstrates hemp as a potential bioenergy crop for ethanol and biodiesel coproduction.