This review appraises the chemical conversion processes recently reported for the production of hydroxylmethylfurfural (HMF), a key biorefining intermediate, from carbohydrate biomass feedstocks. Catalytic sites or groups required for the efficient and selective conversion of hexose substrates to HMF are examined. The principle of concerted catalysis was used to rationalise the dehydration of fructose and glucose to HMF in non-aqueous media. A survey of reported reaction routes to diesel-range biofuel intermediates from HMF or furfural is presented and self-condensation reaction routes for linking two or more HMF and furfural units together toward obtaining kerosene and diesel-range biofuel intermediates are highlighted. The reaction routes include: benzoin condensation, condensation of furfuryl alcohols, hetero Diels–Alder reaction and ketonisation reaction. These reaction routes are yet to be exploited despite their potential for obtaining kerosene and diesel-range biofuel intermediates exclusively from furfural or hydroxylmethylfurfural.

Fischer–Tropsch synthesis (FTS) occupies a key position in the search for alternatives to petroleum for obtaining liquid hydrocarbons. Hydrocarbons can be produced from alternative carbonaceous resources (natural gas, coal, biomass and waste) through FTS and the use of biomass is particularly attractive from a carbon footprint point of view. However, the nature of biomass resources dictates a different exploration approach compared to fossil fuel resources. Compared to coal and natural gas based FTS processes where economics of scale is an advantage, a Biomass-to-Liquid (BTL) plant is more suited for smaller scale operation. Thus, the BTL process economy will benefit from a condensed FTS processes. Moreover, considering the expected role of FTS in regional and global hydrocarbon supply in the near future, it becomes pertinent to strive towards improving the process economy. This requires molecular and process engineering and detailed knowledge of the reaction is a pre-requisite to engineering the reaction at molecular level. Syngas to hydrocarbon involves consecutive steps of CO activation, C–C coupling, hydrogenation and desorption of the hydrocarbon product. Atomic details of the dynamics of these steps are still unclear. Recently, clearer pictures about activation are now available. However, over the course of ninety years since the first report on an FTS, proposed pathway of C–C coupling has come full cycle from oxygenate to nonoxygenate and back to oxygenate intermediates. To this end, we attempted an X-ray of progress made at providing answers to issues in the chemistry of FTS. The review focuses on product distribution, macro kinetics and the mechanism of FTS. We compare FTS with other C–C coupling reactions of CO, identify catalytic entities for controlling product selectivity and finally we offer an outlook on future directions of fundamental research towards resolving the lingering questions on the mechanism of C–C coupling in FTS.

Efforts has been intensified in the field of research for nanomaterials to bridge the gap for energy supply in this century. A plant- based material that may provide solutions to the current energy crisis may be found in nanomaterials. Green synthesis of nanoparticles using plant extract is gaining importance as an alternative to conventional chemical and physical method of synthesis, because of its simplicity and environmental friendliness. In this research we synthesized Zinc oxide nanoparticle (ZnO.NPs) using plant extracts and deposited using spin- coating technique. The obtained samples were characterized by UltraViolet–Visible spectrophotometer, Fourier Transform Infra-Red spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Solar simulator for electrical properties. The maximum absorption peaks occurred at 235 nm, 250 nm, 270 nm, and 300 nm respectively but lower when compared with the bulk size that occurred at 350 nm and in the visible spectrum of the wavelength band. Band gap energy of zinc oxide nanoparticle at 500 rpm was 3.50 eV. ZnO.NPs FTIR spectrum was recorded in the range of 4000–500 cm⁻¹. The synthesis ZnO NPs FTIR result shows Zn–O functional group was found at low wavenumber. SEM images of the samples give information on the morphology which are spherical and granular nature. The XRD pattern of synthesized nanoparticles shows that the substances only belong to ZnO since there is no diffraction peaks of other impurities and the average grain size of the particles was estimated to be 14.7 nm. ZnO.NPs thin film device under illumination has efficiency of 0.7%. Based on electrical properties of the fabricated thin film device, the parameter shows it could be suitable for photoanode of Dye sensitized solar cell.