15 research outputs found
A tool for predicting the thermal performance of a diesel engine
This paper presents a thermal network model for the simulation of the transient response of diesel engines. The model was
adjusted by using experimental data from a completely instrumented engine run under steady-state and transient conditions.
Comparisons between measured and predicted material temperatures over a wide range of engine running conditions show
a mean error of 7â—¦C. The model was then used to predict the thermal behavior of a different engine. Model results were
checked against oil and coolant temperatures measured during engine warm-up at constant speed and load, and on a New
European Driving Cycle. Results show that the model predicts these temperatures with a maximum error of 3â—¦C.Torregrosa, AJ.; Olmeda González, PC.; MartÃn DÃaz, J.; Romero Piedrahita, CA. (2011). A tool for predicting the thermal performance of a diesel engine. Heat Transfer Engineering. 32(10):891-904. doi:10.1080/01457632.2011.548639S891904321
Transketolase catalysed upgrading of l-arabinose: the one-step stereoselective synthesis of l-gluco-heptulose
Conversion of biomass using biocatalysis is likely to become a technology that contributes significantly to the future production of chemical building blocks, materials and transport fuels. Here the synthesis of a value-added chemical from L-arabinose, a major component of the carbohydrates in sugar beet pulp (SBP), in a concise and sustainable manner has been investigated. Biocatalytic conversions using transketolase variants have been developed for the efficient, scalable synthesis of a rare naturally occurring ketoheptose, L-gluco-heptulose, from L-arabinose. New active E. coli TK mutants that readily accept L-arabinose were identified using a versatile colorimetric screening assay and the reaction was performed on a preparative scale
An Integrated Biorefinery Concept for Conversion of Sugar Beet Pulp into Value-added Chemicals and Pharmaceutical Intermediates
Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main
by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP
is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including D-glucose
(Glu), L-arabinose (Ara) and D-galacturonic acid (GalAc). This work describes the technical feasibility
of an integrated biorefinery concept for fractionation of SBP and conversion of these
monosaccharides into value-added products.
SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble
pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release
Glu that can then be fermented by a commercial Yeast strain to produce bioethanol with a high
yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or
selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich
streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC)
or ultrafiltration into streams suitable for subsequent enzymatic upgrading.
Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the
conversion of Ara and GalAc into higher value products was explored. In particular the conversion of
Ara into L-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia
and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be
selectively aminated to the corresponding chiral aminopolyol. Current work is addressing upgrading
of the remaining SBP monomer, GalAc, and modelling of the biorefinery concept to enable economic
and Life Cycle Analysis (LCA)
Synthesis and valorization of α hydroxyketones through bio and organocatalysis.
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