Exergy and economic analyses of methanol production process

A process that utilized CO2 recovered from thermal power plant flue gas for methanol production was simulated using Aspen HYSYS V8.4 software. Exergy and economic analyses approaches were used to determine the optimum number of trays in the distillation column for economic operation of the process. The results from both approaches showed that the optimum numbers of trays were 20 and further increase in the number of trays did not yield any significant improvement in the process efficiency and quality of methanol produced. The profitability analysis of the plant showed a payback period of 3 years. The study concluded that locating such plant close to the thermal power plant will mitigate the emission of CO2 by providing onsite utilization for the CO2 emitted and captured from the thermal power plant.Keywords: CO2 capture; methanol production; exergy analysis; economic analysi

Evaluation of the emulsifying property of solid phase purified Garcinia kola seed oil

Background:Crude seed oils consist essentially of naturally occurring mixtures of triacylglycerols (˃95%). They are purified to improve their overall quality. Oil purification facilitates elimination of impurities and toxicants.Objective: The objective of the study is to purify Garcinia kola seeds crude oil and to evaluate the purified oil for its emulsifying character.Materials and Methods:Crude seed oil of G. kola, obtained from the dried, powdered seed, was purified by passing the crude oil in n-hexane through silica gel and charcoal arranged in tandem. The crude and refined oils were evaluated by thin layer chromatography and infra-red spectroscopy. Emulsions of the refined oil at 30% and 20% concentrations were prepared and evaluated.Results: With the purification process, there was removal of dissolved polar solutes and pigments in the crude oil relative to the purified oil as revealed by the thin layer chromatographic profile and infra-red spectra. At 20% concentration of the refined oil, a lotion with viscosity of 25.67 ± 1.20 cP was formed while a creamy emulsion was produced with the refined oil at 30% concentration with viscosity of 46.00 ± 1.16 cP. This suggests the suitability of the purified oil as a base in the formulation of lotions and creams.Conclusion: The purified oil of G. kola possesses emulsifying property and could find applications in cosmetic and pharmaceutical industries.Keywords: Garcinia cola, seed oil, solid phase purification, emulsifying propert

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century