Energy potential of leafy spurge (Euphorbia esula)

Leafy spurge (Euphorbia esula) is a noxious, perennial weed that infests pastures, rangeland and waste areas in the northern Great Plains. The objective of this study was to determine the productive potential of this species when grown under optimum agronomic conditions. Plants were fertilized and irrigated. Oil, hydrocarbon, total protein, and dry-weight production were measured on 3 harvest dates. Calorimetric analyses were performed to determine the potential of leafy spurge as a fuel crop. The hydrocarbon content of 12 strains of leafy spurge was determined to measure genetic variability for this trait. The addition of fertilizer doubled dryweight production but did not affect percent oil or hydrocarbon content. Oil and hydrocarbon production averaged 6.8 and 0.6% on a plant dry-weight basis. Maximum production of plant biomass, protein, and hydrocarbon was obtained from a mid-July harvest. Oil content increased later in the growing season. The total protein content of leafy spurge averaged 12%. Whole-plant biomass had a caloric value of 4,407 cal/g while the oils contained 10,019 cal/g. Leafy spurge hay can produce 4 times more energy per year than wheat straw; therefore, the immediate potential of leafy spurge whole-plant biomass as a locally grown fuel crop for home-heating purposes is suggested.     

Characterization and viscosity parameters of seed oils from wild plants

The physico-chemical properties of Spondias mombin seed oil and the viscosity-temperature profiles of six seed oils from other plants which grow in the wild: Balanites aegytiaca, Lophira lanceolata, Sterculia setigera, Khaya senegalensis, Ximenia americana and Sclereocarya birrea, were investigated. The oil content of S. mombin seed was significant at 31.5% (w/w). The oil appeared stable as deduced from its low peroxide and acid values of 6.0 mEq kg(-1) and 1.68 mg KOH, respectively. The X. americana oil was denser than the other ones, with a value of 0.9625 g cm(-3) at 30 degrees C. The kinematic viscosities of the oils and their temperature dependence in the range 30-70 degrees C suggested a potential industrial application of the oils as lubricating base stock. Specifically, the kinematic viscosities of the oils were in the range 59.8-938.2 cst at 30 degrees C with X. americana having the highest value. At 70 degrees C, the reduction in viscosities of the oils was marked: reduction by over 70% of their values at 30 degrees C for S. setigera, K. senegalensis, X. americana and S. birrea oils.     

微水体系中荧光假单胞菌脂肪酶催化合成单甘酯

研究了无溶剂微水体系中荧光假单胞菌脂肪酶 (PFL)催化油脂甘油解合成单甘酯的反应因素以及多温程非均相固液反应对单甘酯产率的影响。以初始体系最低共熔点 (PFL)取代临界温度学说中的油脂初熔点 ,通过考察不同IEP体系的甘油解 ,发现PFL酶促油脂甘油解时存在碳链基质特异性的函数关系 ,即反应物油脂中饱和碳残基的质量百分含量 (C₁₆+C₁₈)与单甘酯产率间符合以下多项式:Y =- 0.0006X³ +0.0592X²-0.8909X+26.753(13%<X<76.5%),式中X为C₁₆+C₁₈,Y为40℃时等温反应条件下的单甘酯产率。IEP为40℃时,最适等温反应条件如下：加水量3%～4.5%,加酶量为500μ/g油酯摩尔比1：2.5-5.0(油酯：甘油)反应温度40℃.实验条件下多步等程序降温反应48h后单甘酯最高产率为81.4%.     

Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor

With the application of induction-heating, the pyrolytic experiments have been carried out for three sewage sludges from the food processing factories in an externally heated fixed-bed reactor. The thermochemical characteristics of sludge samples were first analyzed. The results indicated that the calorific value had about 15 MJ/kg on an average, suggesting that it had a potential for biomass energy source. However, its nitrogen concentration was relatively high. From the thermogravimetric analysis (TGA) curves, it showed that the pyrolysis reaction can be almost finished in the temperature range of 450-750 degrees C. The yields of resulting liquid and char products from the pyrolysis of sewage sludge were discussed for examining the effects of pyrolysis temperature (500-800 degrees C), heating rate (200-500 degrees C/min), and holding time (1-8 min). Overall, the variation of yield was not so significant in the experimental conditions for three sewage sludges. All results of the resulting liquid products analyzed by elemental analyzer, pH meter, Karl-Fischer moisture titrator and bomb calorimeter were in consistence with those analyses by FTIR spectroscopy. Furthermore, the pyrolysis liquid products contained large amounts of water (>73% by weight) mostly derived from the bound water in the biosludge feedstocks and the condensation reactions during the pyrolysis reaction, and fewer contents of oxygenated hydrocarbons composing of carbonyl and nitrogen-containing groups, resulting in low pH and low calorific values.     

Microcalorimetric study of iodized and noniodized cells and C-phycocyanin of Spirulina platensis

It was shown that eight stages of transition are observed in the heating process of Spirulina platensis cells in temperature range 5-140 degrees C. The first stage covers the temperature range 5-53 degrees C with maximum approximately 45 degrees C. The heat evolved in this temperature range is equal to 380 +/- 20 J/g of dry biomass, it does not change at scanning rate lower than 0.083 degrees C/min and belongs, mainly, to cell respiration in a stationary regime, in the dark. It was shown that endotherm approximately 66 degrees C belongs to denaturation of C-phycocyanin which denaturates in solutions with Td = 64.2 degrees C, deltaHd = 34.7 +/- 2.1 J/g and for it deltaHd(cal)/deltaH(V.H) is equal to 10.8 +/- 1.2. The endotherms with Td equal to 58 and 88 degrees C are connected with denaturation of phycobilisome proteins and endotherm with Td = 48 degrees C and deltaHd = 4.2J/g of dry biomass-with denaturation of protein which, apparently, is connected with cell respiration.     

Utilization of oil extracted from spent coffee grounds for sustainable production of polyhydroxyalkanoates

Spent coffee grounds (SCG), an important waste product of the coffee industry, contain approximately 15 wt% of coffee oil. The aim of this work was to investigate the utilization of oil extracted from SCG as a substrate for the production of poly(3-hydroxybutyrate) (PHB) by Cupriavidus necator H16. When compared to other waste/inexpensive oils, the utilization of coffee oil resulted in the highest biomass as well as PHB yields. Since the correlation of PHB yields and the acid value of oil indicated a positive effect of the presence of free fatty acids in oil on PHB production (correlation coefficient R ²?=?0.9058), superior properties of coffee oil can be probably attributed to the high content of free fatty acids which can be simply utilized by the bacteria culture. Employing the fed-batch mode of cultivation, the PHB yields, the PHB content in biomass, the volumetric productivity, and the Y _P/S yield coefficient reached 49.4 g/l, 89.1 wt%, 1.33 g/(l h), and 0.82 g per g of oil, respectively. SCG are annually produced worldwide in extensive amounts and are disposed as solid waste. Hence, the utilization of coffee oil extracted from SCG is likely to improve significantly the economic aspects of PHB production. Moreover, since oil extraction decreased the calorific value of SCG by only about 9 % (from 19.61 to 17.86 MJ/kg), residual SCG after oil extraction can be used as fuel to at least partially cover heat and energy demands of fermentation, which should even improve the economic feasibility of the process.     

Investigating the influence of extractives on the oil yield and alkane production obtained from three kinds of biomass via deoxy-liquefaction

The aim of this study is to investigate the influence of extractives on the yield and composition of oil obtained from biomass samples (Artemisia ordosica, corn stalk and wheat straw). Direct deoxy-liquefaction experiments of original and extracted biomass were performed at certain temperature in a stainless steel tubular reactor. Benzene-alcohol solvent extraction had significant effect on the product distribution of biomass, especially on the yield and composition of the product oils. The oil yield of original biomass and alkane content in the oil were in the range of 5.44-9.27% and 8.23-23.64%, while decreased to 3.83-4.45% and 1.07-6.03% for the extracted biomass. This study concludes that most of alkanes in the oil mainly derive from the decomposition of triglyceride and hydrocarbon existed in the extractives of biomass. The results might be helpful to study the origin of alkanes and benzene derivatives in the oil obtained from biomass via direct deoxy-liquefaction.     

Novel rubbers from cationic copolymerization of soybean oils and dicyclopentadiene. 1. Synthesis and characterization

Novel thermosetting copolymers, ranging from tough and ductile to very soft rubbers, have been prepared by the cationic copolymerization of regular (SOY) and 100% conjugated soybean oils (C(100)SOY) with dicyclopentadiene (DCP) catalyzed by Norway fish oil (NFO)-modified and SOY- and C(100)SOY-diluted boron trifluoride diethyl etherate (BFE). The gelation time of the reactions varies from 4 to 991 min at 110 degrees C. The yields of the bulk copolymers are essentially quantitative, while the yields of the cross-linked copolymers remaining after Soxhlet extraction with methylene chloride range from 69% to 88%, depending on the monomer stoichiometry and the catalyst used. (1)H NMR spectroscopy and Soxhlet extraction data indicate that these copolymers consist of a cross-linked soybean oil-DCP network plasticized by certain amounts of methylene chloride-soluble linear or less cross-linked soybean oil-DCP copolymers, unreacted oil, and some low molecular weight hydrolyzed oil. The molecular weights of these soluble fractions are in the range from 400 to 10,000 g/mol based on polystyrene standards. The bulk copolymers have glass transition temperatures ranging from -22.6 to 56.6 degrees C, while their tan delta peak values range from 0.7 to 1.2. Thermogravimetric analysis (TGA) indicates that these soybean oil-DCP copolymers are thermally stable below 200 degrees C, with 10% and 50% weight loss temperatures ranging from 280 to 372 degrees C and 470-554 degrees C, respectively. These properties suggest that these biobased thermosets may prove useful alternatives to current petroleum-based plastics and find widespread utility.     

热烟气气氛下生物质在流化床反应器中快速热解制取生物油

在对操作流化速度进行冷态实验以及流化床温度稳定性进行测试的基础上,研制了新型流化床反应器,并使用玉米秸秆为原料,探究了热烟气气氛下快速热解制取生物油的最佳反应温度以及床料。在最佳热解条件下,对糠醛废弃物、木糖废弃物以及海藻进行了实验研究,得到了各产物产率,并对得到的生物油进行了物理特性分析。结果显示,在最佳操作流速下,当温度为500 ℃时使用白云石为床料可以获得最大生物油产率。4种原料中玉米秸秆的生物油产率最高,达到42.3 wt%。在最佳热解条件下获得了4种物料不同含量的重油和轻质油,其中重油的物理特性差别很小,重油的热值比轻质油的热值高很多。不可冷凝气的高位热值是6.5?8.5 MJ/m3,因此不可冷凝气体可以作为一种燃料气被加以利用。     

Efficient lipid production with Trichosporon fermentans and its use for biodiesel preparation

Effects of medium components and culture conditions on biomass and lipid production of Trichosporon fermentans were studied. The optimal nitrogen source, carbon source and C/N molar ratio were peptone, glucose and 163, respectively. The favorable initial pH of the medium and temperature were 6.5 and 25 degrees C. Under the optimized conditions, a biomass of 28.1 g/l and a lipid content of 62.4% could be achieved after culture for 7 days, which were much higher than the original values (19.4 g/l and 50.8%) and the results reported by other groups. T. fermentans could grow well in pretreated waste molasses and a lipid yield of 12.8 g/l could be achieved with waste molasses of 15% total sugar concentration (w/v) at pH 6.0, representing the best result with oleaginous microorganisms on agro-industrial residues. Addition of various sugars to the pretreated molasses could efficiently enhance the accumulation of lipid and the lipid content reached as high as above 50%. Similar to vegetable oils, the lipid mainly contains palmitic acid, stearic acid, oleic acid and linoleic acid and the unsaturated fatty acids amount to about 64% of the total fatty acids. The microbial oil with an acid value of 5.6 mg KOH/g was transesterified to biodiesel by base catalysis after removal of free fatty acids and a high methyl ester yield of 92% was obtained.     

Variations in the energy content of freshwater fish

The calorific value of the three-spined stickleback, Gasterosteus aculeatus , varied with its size, sex and the season. Fish of 16 mg dry weight had a value of 1950 cal/g while for fish of 313 mg the value was 470 cal/g. The califoric value of gravid females was 23% above that of males of comparable size. The califoric value of a tropical cichlid, Tilapia nilotica , with a dry weight of 11 g was 4300 cal/g, the calorific values of the tissues ranged from 2500 cal/g for bone to 5190 cal/g for muscle.     

Biosurfactant production by Pseudomonas aeruginosa A41 using palm oil as carbon source

Biosurfactant production by Pseudomonas aeruginosa A41, a strain isolated from seawater in the gulf of Thailand, was examined when grown in defined medium containing 2% vegetable oil or fatty acid as a carbon source in the presence of vitamins, trace elements and 0.4% NH(4)NO(3), at pH 7 and 30 degrees C with 200 rpm-shaking for 7 days. The yield of biosurfactant steadily increased even after a stationary phase. Under such conditions the surface tension of the medium was lowered from 55-70 mN/m to 27.8-30 mN/m with every carbon source tested. However, types of carbon sources were found to affect biosurfactant yield. The yields of rhamnolipid biosurfactant were 6.58 g/L, 2.91 g/L and 2.93 g/L determined as rhamnose content when olive oil, palm oil and coconut oil, respectively, were used as a carbon source. Among them, biosurfactant obtained from palm oil was the best in lowering surface tension of the medium. Increase in biosurfactant activities in terms of oil displacement test and rhamnose content were observed to be higher with shorter chain fatty acids than that of the longer chains (C12>C14>C16). In addition, we found that C18:2, highly unsaturated fatty acid, showed higher oil displacement activity and rhamnose content than that of C18:1. The optimal oil displacement activity was found at pH 7-9 and in the presence of 0.5-3% NaCl. The oil displacement activity was stable to temperatures up to 100 degrees C for 15 h. Surface tension reduction activity was relatively stable at pH 2-12 and 0-5% of NaCl. Emusification activity tested with various types of hydrocarbons and vegetable oils showed similarity of up to 60% stability. The partially purified biosurfactant via TLC and silica gel column chromatography gave three main peaks on HPLC with mass spectra of 527, 272, and 661 m/z respectively, corresponding to sodium-monorhamnodecanoate, hydroxyhexadecanoic acid and an unknown compound, respectively.     

Preparation and characterization of bio-diesels from various bio-oils

Methyl, ethyl, 2-propyl and butyl esters were prepared from canola and linseed oils through transesterification using KOH and/ or sodium alkoxides as catalysts. In addition, methyl and ethyl esters were prepared from rapeseed and sunflower oils using the same catalysts. Chemical composition of the esters was determined by HPLC for the class of lipids and by GC for fatty acid compositions. The bio-diesel esters were characterized for their physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. Methyl and ethyl esters prepared from a particular vegetable oil had similar viscosities, cloud points and pour points, whereas methyl, ethyl, 2-propyl and butyl esters derived from a particular vegetable oil had similar gross heating values. However, their densities, which were 2 7% higher than those of diesel fuels, statistically decreased in the order of methyl approximately 2-propyl > ethyl > butyl esters. Butyl esters showed reduced cloud points (-6 degrees C to -10 degrees C) and pour points (-13 degrees C to -16 degrees C) similar to those of summer diesel fuel having cloud and pour points of -8 degrees C and -15 degrees C, respectively. The viscosities of bio-diesels (3.3-7.6 x 10(-4) Pa s at 40 degrees C) were much less than those of pure oils (22.4-45.1 x 10(-4) Pa s at 40 degrees C) and were twice those of summer and winter diesel fuels (3.50 and 1.72 x 10(-4) Pa s at 40 degrees C), and their gross heat contents of approximately 40 MJ/kg were 11% less than those of diesel fuels (approximately 45 MJ/kg). For different esters from the same vegetable oil, methyl esters were the most volatile, and the volatility decreased as the alkyl group grew bulkier. However, the bio-diesels were considerably less volatile than the conventional diesel fuels.     

The effect of temperature and pH on ethanol production by free and immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract

The effect of temperature and pH on the kinetics of ethanol production by free and calcium alginate immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract was investigated. With the free cells, the ethanol and biomass yields were relatively constant over the temperature range 25-35 degrees C, but dropped sharply beyond 35 degrees C. Other kinetic parameters, specific growth rate, specific ethanol production rate, and specific total sugar uptake rate were maximum at 35 degrees C. However, with the immobilized cells, ethanol yield remained almost constant in the temperature range 25-45 degrees C, and the specific ethanol production rate and specific total sugar uptake rate attained their maximum values at 40 degrees C. For the pH range between 3 and 7, the free-cell optimum for growth and product formation was found to be ca. pH 5. At this pH, the specific growth rate was 0.35 h(-1) and specific ethanol production rate was 2.83 g/g/h. At values higher or lower than pH 5, a sharp decrease in specific ethanol production rate as well as specific growth rate was observed. In comparison, the immobilized cells showed a broad optimum pH profile. The best ethanol production rates were observed between pH 4 and 6.     

Selection of thermotolerant yeast strains for simultaneous saccharification and fermentation of cellulose

A total of 58 yeast strains from 12 genera were assayed for their ability to grow and ferment carbohydrates in standard Durham tube test at 40, 43, and 46 degrees C. Based on the kinetic parameters for glucose fermentation in shaken flask cultures, the strain Fabospora fragilis CCY51-1-1 was chosen for further studies. It reached about 56.0 and 35.0 g ethanol/L from approximately 140 g glucose/L at 43 and 46 degrees C in less than 48 h, respectively. Trichoderma reesei cellulase preparation (400 FPU/L) had not distinct effect on the ethanol yield and biomass production by the selected strain in the first 12 h fermentation at 46 degrees C. Later a negligible decrease in both yields was observed. It was found that Fabospora fragilis did not grow or produce ethanol at 46 degrees C as tho initial ethanol concentration overcame 40 g/L.     

Estimation of a novel method to produce bio-oil from sewage sludge by microwave pyrolysis with the consideration of efficiency and safety

This paper presented a feasible method to produce bio-oil from sewage sludge by microwave pyrolysis. The results showed that oils derived under 400 W obtained an attractive yield (49.8 wt.%) with favorable characteristics such as high calorific value (35.0 MJ/kg), low density (929 kg/m3) and preferable chemical composition (29.5 wt.% of monoaromatics). A model to study the relationship between microwave power and mass balance of product fractions was developed, and the results indicated that the power range of the highest transforming efficiency for organics in sludge into oils was 400-600 W, the subsequent increase of power to the range of 600-800 W favored gases formation at the expense of oils, and increase of power to above 800 W led to the conversion of solids into gases, while oils remained unchanged. The analysis of sulfur and nitrogen compounds in oils showed that bio-oil should be extracted before being used as fuel.     

Effect of structural features on enzyme digestibility of corn stover

Corn stover was pretreated with excess calcium hydroxide (0.5 g Ca(OH)2/g raw biomass) in non-oxidative and oxidative conditions at 25, 35, 45, and 55 degrees C. The enzymatic digestibility of lime-treated corn stover was affected by the change of structural features (acetylation, lignification, and crystallization) resulting from the treatment. Extensive delignification required oxidative treatment and additional consumption of lime (up to 0.17 g Ca(OH)2/g biomass). Deacetylation reached a plateau within 1 week and there were no significant differences between non-oxidative and oxidative conditions at 55 degrees C; both conditions removed approximately 90% of the acetyl groups in 1 week at all temperatures studied. Delignification highly depended on temperature and the presence of oxygen. Lignin and hemicellulose were selectively removed (or solubilized), but cellulose was not affected by lime pretreatment in mild temperatures (25-55 degrees C), even though corn stover was contacted with alkali for a long time, 16 weeks. The degree of crystallinity slightly increased from 43% to 60% with delignification because amorphous components (lignin, hemicellulose) were removed. However, the increased crystallinity did not negatively affect the 3-d sugar yield of enzymatic hydrolysis. Oxidative lime pretreatment lowered the acetyl and lignin contents to obtain high digestibility, regardless of crystallinity. The non-linear models for 3-d hydrolysis yields of glucan (Y(g)), xylan (Y(x)), and holocellulose (Y(gx)) were empirically established as a function of the residual lignin (L) for the corn stover pretreated with lime and air.     

Influence of temperature and pH on xylitol production from xylose by Debaryomyces hansenii

The production of xylitol from concentrated synthetic xylose solutions (S(o) = 130-135 g/L) by Debaryomyces hansenii was investigated at different pH and temperature values. At optimum starting pH (pH(o) = 5.5), T = 24 degrees C, and relatively low starting biomass levels (0.5-0.6 g(x)/L), 88% of xylose was utilized for xylitol production, the rest being preferentially fermented to ethanol (10%). Under these conditions, nearly 70% of initial carbon was recovered as xylitol, corresponding to final xylitol concentration of 91.9 g(P)/L, product yield on substrate of 0.81 g(P)/g(S), and maximum volumetric and specific productivities of 1.86 g(P)/L x h and 1.43 g(P)/g(x) x h, respectively. At higher and lower pH(o) values, respiration also became important, consuming up to 32% of xylose, while negligible amounts were utilized for cell growth (0.8-1.8%). The same approach extended to the effect of temperature on the metabolism of this yeast at pH(o) = 5.5 and higher biomass levels (1.4-3.0 g(x)/L) revealed that, at temperatures ranging from 32-37 degrees C, xylose was nearly completely consumed to produce xylitol, reaching a maximum volumetric productivity of 4.67 g(P)/L x h at 35 degrees C. Similarly, both respiration and ethanol fermentation became significant either at higher or at lower temperatures. Finally, to elucidate the kinetic mechanisms of both xylitol production and thermal inactivation of the system, the related thermodynamic parameters were estimated from the experimental data with the Arrhenius model: activation enthalpy and entropy were 57.7 kJ/mol and -0.152 kJ/mol x K for xylitol production and 187.3 kJ/mol and 0.054 kJ/mol x K for thermal inactivation, respectively.     

Interactions among water content, rapid (nonequilibrium) cooling to -196 degrees C, and survival of embryonic axes of Aesculus hippocastanum L. seeds

This study investigated the interactions among water content, rapid (nonequilibrium) cooling to -196 degrees C using isopentane or subcooled nitrogen, and survival of embryonic axes of Aesculus hippocastanum. Average cooling rates in either cryogen did not exceed 60 degrees C s(-1) for axes containing more than 1.0 g H(2)O g(-1)dw (g g(-1)). Partial dehydration below 0.5 g gg(-1) facilitated faster cooling, averaging about 200 and 580 degrees C s(-1) in subcooled nitrogen and isopentane, respectively. The combination of partial drying and rapid cooling led to increased survival and reduced cellular damage in axes. Electrolyte leakage was 10-fold higher from fully hydrated axes cooled in either cryogen than from control axes that were not cooled. Drying of axes to 0.5 g g(-1), reduced electrolyte leakage of cryopreserved axes to levels similar to those of control material. Axis survival was assayed by germination in vitro. Axes with water contents greater than 1.0 g g(-1), did not survive cryogenic cooling. Between 1.0 and 0.75 g g(-1), axes survived cryogenic exposure but developed abnormally. The proportion of axes developing normally after being cooled in isopentane increased with increasing dehydration below 0.75 g g(-1), reaching a maximum between 0.5 and 0.25 g g(-1) after being cooled at > or =300 degrees C s(-1). Cooling rates attained in subcooled nitrogen did not exceed 250 degrees C s(-1), and normal development of axes was observed only at < or =0.4 g g(-1). These results support the hypothesis that rapid cooling enhances the feasibility of cryopreservation of desiccation-sensitive embryonic axes by increasing the upper limit of allowable water contents and overall survival.     

Effects of ecotypes and morphotypes in feedstock composition of switchgrass (Panicum virgatum L.)

Switchgrass (Panicum virgatum L.) is a C4 grass with high biomass yield potential and is now a model species for the Bioenergy Feedstock Development Program. Two distinct ecotypes (e.g., upland and lowland) and a range of plant morphotypes (e.g., leafy and stemmy) have been observed in switchgrass. The objective of this study was to determine the influence of ecotype and morphotype on biomass feedstock quality. Leaf and stem tissues of leafy and stemmy morphotypes from both lowland and upland ecotypes were analyzed for key feedstock traits. The leaf : stem ratio of leafy morphotype was more than 40% higher than the stemmy morphotype in both upland and lowland ecotypes. Therefore, the stemmy morphotype has significant advantages over leafy morphotype during harvesting, storage, transportation and finally the feedstock quality. Remarkable differences in feedstock quality and mineral composition were observed in switchgrass genotypes with distinct ecotypic origins and variable plant morphotypes. Lignin, hemicelluloses and cellulose concentrations were higher in stems than in the leaves, while ash content was notably high in leaves. A higher concentration of potassium was found in the stems compared to the leaves. In contrast, calcium was higher and magnesium was generally higher in the leaves compared to stems. The upland genotypes demonstrated considerably higher lignin (14.4%) compared with lowland genotypes (12.4%), while hemicellulose was higher in lowland compared with upland. The stemmy type demonstrated slightly higher lignin compared with leafy types (P < 0.1). Differences between the ecotypes and morphotypes for key quality traits demonstrated the potential for improving feedstock composition of switchgrass through selection in breeding programs.