Fischer-Tropsch synthesis is a set of catalytic processes that can be used to produce fuels and chemicals from synthesis gas (mixture of CO and H 2 ), which can be derived from natural gas, coal, or biomass. Biomass to Liquid via Fischer-Tropsch (BTL-FT) synthesis is gaining increasing interests from academia and industry because of its ability to produce carbon neutral and environmentally friendly clean fuels; such kinds of fuels can help to meet the globally increasing energy demand and to meet the stricter environmental regulations in the future. In the BTL-FT process, biomass, such as woodchips and straw stalk, is firstly converted into biomass-derived syngas (bio-syngas) by gasification. Then, a cleaning process is applied to remove impurities from the bio-syngas to produce clean bio-syngas which meets the Fischer-Tropsch synthesis requirements. Cleaned bio-syngas is then conducted into a Fischer-Tropsch catalytic reactor to produce green gasoline, diesel and other clean biofuels. This review will analyze the three main steps of BTL-FT process, and discuss the issues related to biomass gasification, bio-syngas cleaning methods and conversion of bio-syngas into liquid hydrocarbons via Fischer-Tropsch synthesis. Some features in regard to increasing carbon utilization, enhancing catalyst activity, maximizing selectivity and avoiding catalyst deactivation in bio-syngas conversion process are also discussed.

No abstract

No abstract

No abstract

No abstract

No abstract

Perfluoroalkyl substances (PFASs) such as perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS) and PFOS-precursors are routinely measured in human plasma and serum, but their relative abundance in the blood cell fraction has not been carefully examined, particularly at the isomer-specific level. Human plasma and whole blood were collected and partitioning behaviors of PFASs and their isomers between plasma and blood cells were investigated. In human samples, mass fraction in plasma (Fp) for PFASs increased among perfluoroalkyl carboxylates as the carbon chain length increased from C6 (mean 0.24) to C11 (0.87), indicating preference for the plasma fraction with increasing chain length. However, among perfluoroalkyl sulfonates, PFHxS (mean 0.87) had a slightly higher Fp than PFOS (0.85). In vitro assays with spiked Sprague-Dawley rat blood were also conducted, and the results showed that PFOS-precursors had lower Fp values than perfluoroalkyl acids, with perfluoroctanesulfonamide having the lowest Fp (mean 0.24). Consistently, linear isomers of PFOS and PFOS-precursors had lower mean Fp than their corresponding total branched isomers. Multiplying by a factor of 2 is not a reasonable method to convert from whole blood to plasma PFAS concentrations, and current ratios could be used as more accurate conversion factors.

Widespread human exposure and associated adverse health effects led to regulations on the usage of bisphenol A (BPA). Several bisphenol analogues (BPs) have been introduced as BPA alternatives in various applications. However, these BPs have been shown to exhibit similar or even stronger endocrine-disrupting activities compared with that of BPA. Currently, information on the human exposure to BPA alternatives remains limited. In this study, nine BPs were quantified in 81 pairs of plasma and red blood cell (RBC) samples from Chinese participants. In human plasma, the predominant BPs was BPA, bisphenol S (BPS), and bisphenol AF (BPAF), with the mean concentrations of 0.40, 0.15, and 0.073 ng/mL, respectively. BPA (accounting for 63% of total BPs) and BPS (18%) were the major BPs in the RBC fraction. Mass fractions in plasma (F) were found to be highest for BPS (mean, 0.78), followed by BPAF (0.71) and BPA (0.67), indicating strong partitioning to the plasma fraction. However, bisphenol AP was more frequently detected in the RBC fraction. Estimated total daily intake (EDI) of BPA was in the range of 0.0048-0.75 μg/kg bw/day for the participants, and adults aged >50 years had comparatively lower EDI. To our knowledge, this is the first study to assess the occurrence and partitioning of BPA alternatives in paired human plasma and RBCs from the Chinese general population.