Thermochemical characterisation of various biomass feedstock and bio-oil generated by fast pyrolysis

The projected decline in fossil fuel availability, environmental concerns, and security of supply attract increased interest in renewable energy derived from biomass. Fast pyrolysis is a possible thermochemical conversion route for the production of bio-oil, with promising advantages. The purpose of the experiments reported in this thesis was to extend our understanding of the fast pyrolysis process for straw, perennial grasses and hardwoods, and the implications of selective pyrolysis, crop harvest and storage on the thermal decomposition products. To this end, characterisation and laboratory-scale fast pyrolysis were conducted on the available feedstocks, and their products were compared. The variation in light and medium volatile decomposition products was investigated at different pyrolysis temperatures and heating rates, and a comparison of fast and slow pyrolysis products was conducted. Feedstocks from different harvests, storage durations and locations were characterised and compared in terms of their fuel and chemical properties. A range of analytical (e.g. Py-GC-MS and TGA) and processing equipment (0.3 kg/h and 1.0 kg/h fast pyrolysis reactors and 0.15 kg slow pyrolysis reactor) was used. Findings show that the high bio-oil and char heating value, and low water content of willow short rotation coppice (SRC) make this crop attractive for fast pyrolysis processing compared to the other investigated feedstocks in this project. From the analytical sequential investigation of willow SRC, it was found that the volatile product distribution can be tailored to achieve a better final product, by a variation of the heating rate and temperature. Time of harvest was most influential on the fuel properties of miscanthus; overall the late harvest produced the best fuel properties (high HHV, low moisture content, high volatile content, low ash content), and storage of the feedstock reduced the moisture and acid content

Role of mitochondria and C-terminal membrane anchor of Bcl-2 in Bax induced growth arrest and mortality in Saccharomyces cerevisiae

AbstractIn mammalian cells, the Bcl-2 and Bcl-x(L) proteins suppress programmed cell death whereas the topographically similar Bax protein accelerates the apoptotic process. Recently published data suggest that expression of the human Bax-α gene is lethal for the yeast can be overcome by co-expressing Bcl-2 or Bcl-x(L). Our findings corroborate these results. However, we find that although Bax induction invariably stops cell growth under all circumstances, it does not lead to death in ‘petite’ cell. Petites cannot respire because they lack functional mitochondria. It seems that in ‘grande’ cells, which do possess normal mitochondrial DNA, nutritional limitation is critical for increased mortality. Surprisingly, murine Bcl-2 lacking the membrane anchor of human Bcl-2 has no effect on grande cells, but can efficiently rescue petites in rich medium. It has been suggested that the C-terminal membrane anchor of human Bcl-2 may have a crucial role in rescuing apoptosis in mammalian cells. When murine Bcl-2 is fused to the membrane anchor of yeast mitochondrial Mas70 protein, the Bcl-2 variant mBcl-2-mma rescues not only petites but also grandes, just like human Bcl-x(L). The rescuing ability of Bcl-x(L), which contains its own membrane anchor, surpasses that of mBcl-2-mma. Our results indicate that the process involving Bax-induced growth inhibition followed by possible lethality, and the rescuing effect of Bcl-2 or Bcl-x(L) is linked to yeast mitochondrial function. We propose a model which is consistent with these observations

Influence of pre-treatment on grass pyrolysis for high value products

Pyrolysis of biomass is a process which yields high quality, clean, and green products like bio-oil and bio-char. Bio-oil has a wide range of applications and also includes liquid fuels and raw chemical products. Therefore, it will be attractive to tailor the bio-oil properties to improve the yields of specific compounds that are economically interesting. In particular, pyrolytic sugar can be used for fermentation while phenolic compounds have an array of industrial applications such as adhesives; moreover, they can substitute petroleum-based phenols. However, it is difficult to achieve high yields of specific chemicals in the bio-oil without adequate biomass pre-treatments. Please click Additional Files below to see the full abstract

Cellulose valorization in biorefinery: integration of fast pyrolysis and fermentation for building blocks production

A combination of thermochemical and biological conversion of cellulosic materials is a promising alternative for the production of biofuels and building blocks in an integrated biorefinery. Indeed, enzymatic depolymerization is selective but slow and expensive. It would be of interest to associate thermochemical conversion for a fast depolymerization of biomass with biochemical conversion for a selective conversion of depolymerized liquid streams. In this work, cellulose is pyrolyzed to produce sugars that can be used as substrate for a fermentation process. This work is the result of a scientific collaboration between ICFAR (London, Canada) and CNRS (Nancy, France). Pyrolysis was performed in a fluidized bed reactor at 475ᵒC with a bio-oil yield of 73.4 wt.% (Figure 1). Different fractions of bio-oil were recovered with a set of 5 condensers. Levoglucosan and total sugars were quantified by GC-FID-MS and phenol/sulphuric acid method respectively. The maximum yields of levoglucosan (43.7 %) and total sugars (80.4 %) were found in the first condenser that was kept at 70ᵒC. Due to the non-fermentable condition of levoglucosan, all the oil fractions, as well as a mixture of them, were hydrolyzed to obtain fermentable glucose. The different bio-oil fractions and a mixture of all fractions were used as substrate in a fermentation reactor to produce acetone, butanol and ethanol (ABE). The talk will present the mass yields obtained for the integrated process combining pyrolysis, hydrolysis and fermentation (figure 2). The microorganisms were not able to grow in the mixture of all fractions. On the contrary, fractions from condenser 1 and 2 lead to normal bacterial growth and fermentation products pattern. Maximum yields (per gram of oil) of acetone=4.6 %, butanol=13.2 % and ethanol=0.1 % were found for the bio-oil collected in the first condenser. These results put in evidence the importance of pyrolysis with staged condensation as an entry for fermentation processes. The methodology proposed in this work could be applied to other biochemical conversion of bio-oils to produce higher added-value products. Please click Additional Files below to see the full abstract

Social representations of marketing work: advertising workers and social media

Purpose: Informed by social representation theory, the study explores how marketing workers represent their activities on social media. Design/methodology/approach: A naturalistic dataset of 17,553 messages posted on Twitter by advertising workers was collected. A sample of over 1,000 unique messages from this dataset, incorporating all external links and images, was analysed inductively using structured thematic analysis. Findings: Advertising workers represent marketing work as a series of fun yet constrained activities involving relationships with clients and colleagues. They engage in cognitive polyphasia by evaluating these productive differences in both a positive and negative light. Research limitations/implications: The study marks a novel use of social representation theory and innovative social media analysis. Further research should explore these relations in greater depth by considering the networks that marketing workers create on social media, and establish how, when and why marketing workers turn to social media in their everyday activities. Practical implications: Marketing workers choose to represent aspects of their work to each other using social media. Marketing managers should support such activities and consider social media as a way to understand the lives and experiences of marketing workers. Originality and value: Marketing researchers have embraced digital media as a route to understanding consumers. This study demonstrates the value of analysing digital media to develop an understanding of marketing work. It sheds new light on the ways marketing workers create social relationships and enables marketing managers to understand and observe the social aspects of effective marketing

The Potent G-Quadruplex-Binding Compound QN-302 Downregulates S100P Gene Expression in Cells and in an In Vivo Model of Pancreatic Cancer

The naphthalene diimide compound QN-302, designed to bind to G-quadruplex DNA sequences within the promoter regions of cancer-related genes, has high anti-proliferative activity in pancreatic cancer cell lines and anti-tumor activity in several experimental models for the disease. We show here that QN-302 also causes downregulation of the expression of the S100P gene and the S100P protein in cells and in vivo. This protein is well established as being involved in key proliferation and motility pathways in several human cancers and has been identified as a potential biomarker in pancreatic cancer. The S100P gene contains 60 putative quadruplex-forming sequences, one of which is in the promoter region, 48 nucleotides upstream from the transcription start site. We report biophysical and molecular modeling studies showing that this sequence forms a highly stable G-quadruplex in vitro, which is further stabilized by QN-302. We also report transcriptome analyses showing that S100P expression is highly upregulated in tissues from human pancreatic cancer tumors, compared to normal pancreas material. The extent of upregulation is dependent on the degree of differentiation of tumor cells, with the most poorly differentiated, from more advanced disease, having the highest level of S100P expression. The experimental drug QN-302 is currently in pre-IND development (as of Q1 2023), and its ability to downregulate S100P protein expression supports a role for this protein as a marker of therapeutic response in pancreatic cancer. These results are also consistent with the hypothesis that the S100P promoter G-quadruplex is a potential therapeutic target in pancreatic cancer at the transcriptional level for QN-302

Blood levels of adiponectin and IL-1Ra distinguish type 3c from type 2 diabetes: Implications for earlier pancreatic cancer detection in new-onset diabetes

BACKGROUND: Screening for pancreatic ductal adenocarcinoma (PDAC) in populations at high risk is recommended. Individuals with new-onset type 2 diabetes mellitus (NOD) are the largest high-risk group for PDAC. To facilitate screening, we sought biomarkers capable of stratifying NOD subjects into those with type 2 diabetes mellitus (T2DM) and those with the less prevalent PDAC-related diabetes (PDAC-DM), a form of type 3c DM commonly misdiagnosed as T2DM. METHODS: Using mass spectrometry- and immunoassay-based methodologies in a multi-stage analysis of independent sample sets (n=443 samples), blood levels of 264 proteins were considered using Ingenuity Pathway Analysis, literature review and targeted training and validation. FINDINGS: Of 30 candidate biomarkers evaluated in up to four independent patient sets, 12 showed statistically significant differences in levels between PDAC-DM and T2DM. The combination of adiponectin and interleukin-1 receptor antagonist (IL-1Ra) showed strong diagnostic potential, (AUC of 0.91; 95% CI: 0.84-0.99) for the distinction of T3cDM from T2DM. INTERPRETATION: Adiponectin and IL-1Ra warrant further consideration for use in screening for PDAC in individuals newly-diagnosed with T2DM. FUNDING: North West Cancer Research, UK, Cancer Research UK, Pancreatic Cancer Action, UK