Electrocatalytic Energy Production from Bioethanol

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Electrocatalytic Energy Production from Bioethanol. Hydrothermal Processing of Bread Waste for the. Production of Hydroxymethylfurfural. Chemicals from ...
Fuels and Value-Added Chemicals from Biomass Nur Atiqah Nasir, Cynthia Kartey, Eleanor O’Doherty, Ahmed Elsheikh, Gareth Davies, James McGregor Chemical and Biological Engineering, University of Sheffield, Sheffield, UK

Biomass utilization has great potential to tackle a number of global grand challenges in energy and the environment. It represents a renewable feedstock which can reduce societal dependence on fossil resources. Biomass has a high energy content which can be converted into fuels or value-added chemicals. Our group investigates, e.g., hydrothermal systems which utilize high temperature water to break down biomass through a series of degradation reactions, exploitation of living organisms and extraction/conversion therein of the chemicals they produce, and effective utilization of bioethanol using fuel cells. Catalytic Synthesis of Organic Chemicals from Black Soldier Fly Larvae (BSFL) Fed on Waste Biomass  Development of a novel waste-to-energy scheme whereby BSFL consume organic waste, e.g. that resulting from the food industry.  Larvae feed on the waste, and bio-catalytically convert it to organic oils - long chain carboxylic acids such as lauric acid - as a biological energy store. Table 1 shows the free fatty carboxylic acids found in extracted raw BSFL oil fed a potato peel diet. Table 1. Saturated and unsaturated free fatty carboxylic acids found in extracted raw BSFL oil fed a potato peel diet Common Name IUPAC Name Chemical Structure Isocaproic acid 4-methylpentanoic acid C6H12O2 Capric acid (n-)Decanoic acid C10H20O2 Lauric acid Dodecanoic acid C12H24O2 Myristic acid Tetradecanoic acid C14H28O2 Ethyl Laurate Dodecanoic acid, ethyl ester C14H28O2 Palmitic acid (n-)Hexadecanoic acid C16H32O2

Figure 1. The life cycle of extracting and processing valuable chemicals from BSFL.

Electrocatalytic Energy Production from Bioethanol

 Bioethanol is produced by fermentation of agricultural biomass feedstocks.  Gaseous H2 presently used in fuel cells is replaced by bioethanol. [1]  Applications include transport vehicles and portable electronics.  Carbon-supported Pd electrocatalyst is used for the oxidation of ethanol. [1]  The efficacy of Pd/C for oxidation of ethanol, tested in a 3-electrode half-cell. (Figure 2) 30

200

Pd/C (0.5M KOH+EtOH)

Pd/C (1M KOH)

 At -0.5 V, the OH is adsorbed on the catalytic sites; the oxidation of adsorbed ethanol generating increasing current.

20

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im / mA.mgPd-1

im / mA.mgPd-1

10 0 -10 -20

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-50 -0.8

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EHg/HgO (V)

-0.6

-0.4

-0.2

0.0

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EHg/HgO (V)

Figure 2. Cyclic voltammetry tests of Pd/C in 1M KOH and 0.5M EtOH+KOH [1]

S. Sun, Z. Jusys, R.J. Behm, J. Power Sources. 231 (2013) 122–133.

Hydrothermal Processing of Bread Waste for the Production of Hydroxymethylfurfural

 Hydrothermal Processing uses high temperature and pressure in an aqueous environment to convert wet biomass into renewable fuels, and structured carbon material.  Bread waste is employed as an exemplar cereal-based feedstock for production of hydroxymethylfurfural (HMF)  HMF is a high value commodity chemical (~$1100/ton) with applications in the synthesis of pharmaceuticals, fuels, solvents etc. [2]  GC-MS was used to quantify the amount of HMF produced. Elemental analysis and bomb calorimetry were used to determine the quality of the hydrochar produced (Figure 3). >10% +Deionized Water Sealed Under 30 Bar CO2 180 °C 30 Minutes

~40% Hydrochar

Figure 3. Average yields for the production of HMF at given conditions. The hydrochar formed has an energy content of 26 MJ kg-1, similar to bituminous coals. [2] A. Mukherjee, M. J. Dumont, and V. Raghavan, Biomass and Bioenergy, vol. 72, pp. 143–183, 2015.

 The oil extracted from BSFL is converted into solvents and liquid fuels via trans-esterification or hydrogenation.  Biofuels, long chain alcohols and green solvents can be synthesised.  The research combats both the issue of depleting fossil fuel resources, and the problem of increasing municipal waste.  Analytical techniques used include FT-IR, and GC-MS.

Liquefaction of Lignocellulosic Biomass Brewers’ Spent Grain (BSG) as a Lignocellulose Source Bio oil

Figure 4. BSG waste is BSG is the main product arising converted into products stream from brewing; > 250 Mt is produced every year in UK. [3] BSG waste Direct liquefaction (particularly hydrothermal processing) take  Valuable place at temperature