Demonstration of CO2 conversion to synthetic transport fuel at flue gas concentrations

A mixture of 1-and 2-butanol was produced using a stepwise synthesis starting with a methyl halide. The process included a carbon dioxide utilization step to produce an acetate salt which was then converted to the butanol isomers by Claisen condensation of the esterified acetate followed by hydrogenation of the resulting ethyl acetoacetate. Importantly, the CO 2 utilization step uses dry, dilute carbon dioxide (12% CO 2 in nitrogen) similar to those found in post-combustion flue gases. The work has shown that the Grignard reagent has a slow rate of reaction with oxygen in comparison to carbon dioxide, meaning that the costly purification step usually associated with carbon capture technologies can be omitted using this direct capture-conversion technique. Butanol isomers are useful as direct drop-in replacement fuels for gasoline due to their high octane number, higher energy density, hydrophobicity, and low corrosivity in existing petrol engines. An energy analysis shows the process to be exothermic from methanol to butanol; however, energy is required to regenerate the active magnesium metal from the halide by-product. The methodology is important as it allows electrical energy, which is difficult to store using batteries over long periods of time, to be stored as a liquid fuel that fits entirely with the current liquid fuels infrastructure. This means that renewable, weather-dependent energy can be stored across seasons, for example, production in summer with consumption in winter. It also helps to avoid new fossil carbon entering the supply chain through the utilization of carbon dioxide that would otherwise be emitted. As methanol has also been shown to be commercially produced from CO 2 , this adds to the prospect of the general decarbonization of the transport fuels sector. Furthermore, as the conversion of CO 2 to butanol requires significantly less hydrogen than CO 2 to octanes, there is a potentially reduced burden on the so-called hydrogen economy

Occupational exposure to bisphenol A (BPA) in a plastic injection molding factory in Malaysia

Objectives: The purpose of this study has been to assess ambient bisphenol A (BPA) levels in workplaces and urine levels of workers and to establish a BPA database for different populations in Malaysia. Material and Methods: Urine samples were collected from plastic factory workers and from control subjects after their shift. Air samples were collected using gas analyzers from 5 sampling positions in the injection molding unit work area and from ambient air. The level of BPA in airborne and urine samples was quantified by the gas chromatography mass spectrometry – selected ion monitoring (GCMS-SIM) analysis. Results: Bisphenol A was detected in the median range of 8–28.3 ng/m³ and 2.4–3.59 ng/m³ for the 5 sampling points in the plastic molding factory and in the ambient air respectively. The median urinary BPA concentration was significantly higher in the workers (3.81 ng/ml) than in control subjects (0.73 ng/ml). The urinary BPA concentration was significantly associated with airborne BPA levels (ρ = 0.55, p < 0.01). Conclusions: Our findings provide the first evidence that workers in a molding factory in Malaysia are occupationally exposed to BPA. Int J Occup Med Environ Health 2017;30(5):743–75

Electrochemical Capture and Storage of CO2 as Calcium Carbonate

A carbon dioxide capture, conversion, and utilization technology has been developed that can be powered by renewable energy with the potential to mitigate CO2 emissions. This relies on an electrochemical process whereby the dissolution of carbon dioxide into carbonate ions is accelerated by a locally induced pH change at the cathode. The carbonate ions can then complex with metal cations, such as Ca2+, Sr2+, or Mn2+, present in solution to form their respective metal carbonates, which precipitate out of solution. To ensure the cathode is not fouled by deposition of the insulating metal carbonate, the process is operated under hydrogen evolution conditions, thereby alleviating any significant attachment of the solid to the electrode. This process is demonstrated in CO2-saturated solutions while the possibility of direct air capture is also shown, where the precipitation of CaCO3 from atmospherically dissolved CO2 during electrolysis is observed. The latter process can be significantly enhanced by using 5 vol.% of monoethanolamine (MEA) in the electrochemical cell. Finally, the process is investigated using seawater, which is also successful after the initial precipitation of metal sulfates from solution. In particular, the use of renewable energy to capture CO2 and create CaCO3 while also generating hydrogen may be of particular interest to the cement industry, which has a significant CO2 footprint.</p

Enhancement of the Efficiency and Selectivity for Carbon Dioxide Electroreduction to Fuels on Tailored Copper Catalyst Architectures

The electroreduction of CO2 is one of the most promising strategies for the production of fuels, energy vectors, and chemicals from CO2. Recently, we have described the realization of an electrochemical reactor based on the use of a Cu cathode for the CO2 electroreduction reaction. Here, three Cu electrodes were prepared by different techniques that generate different surface structures and morphologies. These three Cu cathodes, employed in the electrolysis cell, are compared in terms of Faradaic efficiency (FE) and product selectivity to a reference Cu foil electrode. The higher active surface area of these samples produced an improved total FE versus the Cu smooth plate. In terms of product selectivity, Cu electroplating onto a Cu foil enhanced HCOOK production strongly; the electrofaceting treatment of the Cu foil drove selectivity towards the production of CH4. In the third electrode, the deposition of Cu onto carbon cloth favors the formation of C2H4

Nanotechnology makes biomass electrolysis more energy efficient than water electrolysis

The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg(-1)H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg(-1)H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis