Godwin Severa

LiSc(BH4)4: A Novel Salt of Li + and Discrete Sc(BH4)4 - Complex Anions

LiSc(BH4)4 has been prepared by ball milling of LiBH4 and ScCl3. Vibrational spectroscopy indicates the presence of discrete Sc(BH4)4(-) ions. DFT calculations of this isolated complex ion confirm that it is a stable complex, and the calculated vibrational spectra agree well with the experimental ones. The four BH4(-) groups are oriented with a tilted plane of three hydrogen atoms directed to the central Sc ion, resulting in a global 8 + 4 coordination. The crystal structure obtained by high-resolution synchrotron powder diffraction reveals a tetragonal unit cell with a = 6.076 A and c = 12.034 A (space group P-42c). The local structure of the Sc(BH4)4(-) complex is refined as a distorted form of the theoretical structure. The Li ions are found to be disordered along the z axis.

Corecovery of Bio-Oil and Fermentable Sugars from Oil-Bearing Biomass

The applicability of ionic liquid-methanol cosolvent system to both extract bio-oil and simultaneously pretreat the carbohydrate fraction of jatropha and safflower biomass for enzymatic hydrolysis to fermentable sugars is presented. Although pretreatment with either the cosolvent or pure ionic liquid yielded comparable hydrolysis kinetics and fermentable sugar yields on safflower whole seeds, the addition of alcohol to the ionic liquid was necessary to optimally recover both bio-oil and fermentable sugars. The ionic liquid [C2mim][Ac] was far more effective than [C2mim][MeSO4] with optimum processing conditions occurring at a cosolvent concentration of 70–30 wt% of [C2mim][Ac] to methanol and a processing temperature of 120°C. Under these conditions, the majority of the bio-oil was extracted and 25.4 wt% (safflower) and 14.3 wt% (jatropha) of the whole seed biomass were recovered as fermentable sugars. The recovery of fermentable sugars from the carbohydrate fraction was as high as 74% and 78% for jatropha and safflower seeds, respectively, when using [C2mim][Ac] cosolvent. A preliminary theoretical analysis of two potential oil seed processing pathways using the cosolvent system suggested that the corecovery of bio-oil, fermentable sugars, and a protein rich meal can recover a majority of the energy contained in the original biomass—a result that improves upon the traditional approach of solely extracting bio-oil.

Corecovery of lipids and fermentable sugars from Rhodosporidium toruloides using ionic liquid cosolvents: application of recycle to batch fermentation.

This work evaluates the ability of an ionic liquid‐methanol cosolvent system to extract lipids and recycle fermentable sugars recovered from oil‐bearing Rhodosporidium toruloides grown in batch culture on defined media using glucose and xylose as carbon sources. Growth on the recycled mixed carbon substrate was successful with glucose consumed before xylose and overall cell mass to lipid yields (YP/X) between 57% and 61% (w/w relative to whole dried cell mass) achieved. Enzymatic hydrolysis of the delipified carbohydrate fraction recovered approximately 9%–11% (w/w) of the whole dried cell mass as fermentable sugars, which were successfully recycled as carbon sources without further purification. In total, up to 70% (w/w) of the whole dried cell mass was recovered as lipids and fermentable sugars and the substrate to lipid yields (YP/S) was increased from 0.12 to 0.16 g lipid/g carbohydrate consumed, highlighting the promise of this approach to process lipid bearing cell biomass.

Bio-oil extraction of Jatropha curcas with ionic liquid co-solvent: Fate of biomass protein

The fate of oil-seed biomass protein has been tracked through all steps of a multi-phase extraction process using an ionic liquid based co-solvent system previously demonstrated to extract bio-oil and phorbol esters and to recover fermentable sugars from Jatropha oil seed. These analyses, however, did not address the fate of biomass protein. This work demonstrated that the majority of protein (∼86%) tracked with the biomass with the balance lost to co-solvent (∼12%) and methanol (∼2%) washes. A significant portion of the ionic liquid remained with the treated biomass and required aggressive methanol washes to recover. A system analysis showed a net-positive energy balance and thus the potential of this system to produce both bio-oil and protein-rich toxin-free biomass. While these results further support Jatropha as an oil seed crop, the additional costs of solvent recovery will need to be addressed if commercialization is to be realized.