Carbon Dioxide Utilization

Transcription

1 [ 2016 IEAGHG CCS Summer School] Carbon Dioxide Utilization Dr. David Wassell BDPS Senior Chemist July 20, 2016

2 Imagine an industrial chemical that: Readily biodegrades. Is available in large quantities. Is cheap. Has tunable solvent properties. Can be used as a C1 chemical precursor. Is well understood. Has very low toxicity. 2

3 Rehabilitation of a maligned molecule Geochemical and biogeochemical history: Early atmosphere consisted of nitrogen and carbon dioxide. Most carbon dioxide locked in sedimentary and metamorphic rock (~80% as carbon). Some is dispersed as organic carbon in sedimentary rock (biological activity) and unavailable. Very small remainder exists as CO 2 (~0.001%) in the atmosphere in equilibrium with carbonates in the ocean (0.04%). Traces exist as biomass (0.0007%) 3

4 Biological background Plants convert carbon dioxide and water to carbohydrates using the sun as an energy source. CO 2 fertilization is used extensively in the greenhouse industry. Estimates of the effect of CO 2 fertilization on field crops range from no effect to up to 15% of the historical increase in yield (depending on who you believe). Carbon dioxide is released when food is metabolized. At CO 2 concentrations below ~150 ppm, (C3) plant growth nearly ceases. 4

5 Safety and toxicity Time weighted average (TWA) limit of 5000 ppm (7000 ppm for NASA SMAC limits), ppm short term exposure limit (13000 NASA). Acute health effects noted above ppm, lowest concentration reported to cause death is ppm. Odourless, colourless, and non-flammable. 5

6 Physics Easily accessible liquid and supercritical region. 6

7 Chemistry Fully oxidized. D h symmetry (linear). Low reactivity, must be activated to react. Can be used as a chemical feedstock. 7

8 Utilization 8

9 Some existing markets include Decaffeination Drycleaning Horticulture Botanical Extractions Urea Manufacture 9

10 Some emerging markets include Methanol synthesis Electrochemical formic acid synthesis Dimethyl ether synthesis via syngas Polycarbonate synthesis Dimethylcarbonate synthesis Sabatier reaction/ reverse water gas shift Accelerated mineralisation 10

11 Utilisation Categories These can be divided into the following broad categories: Storage (EOR and mineralisation). As solvent (botanicals, drycleaning, processing fluid). Fuels. Chemical precursors. 11

12 Storage Enhanced oil recovery CO 2 is used to flood oil formation. Approx. 90% is trapped underground in pores. Mineralisation The conversion of metal oxides and silicates to carbonates. Use of alkaline waste (slag, flyash, etc) most advanced. E.g. cement curing (conversion of, primarily, calcium hydroxide to calcium carbonate) can be accelerated by enriched carbon dioxide atmosphere. 12

13 Solvent Dry-cleaning fluid, parts degreaser. Botanical extracts. Textile dyeing and wood preservative impregnation 13

14 scco 2 as a solvent Solvent polarity is a function of pressure and temperature. Solute recovery is achieved by decompression. Fractionation can be achieved by successive pressure drops. The reverse process can be used to infuse wanted chemicals to substrates. 14

15 scco 2 as a process adjunct Can be used as a pre-process step on cellulose and lignins. Decompression disrupts biopolymer structure. This allows much more efficient fermentation or enzyme catalysis 15

16 Examples: One decaffeination processor treats 60,000 tonnes per annum. DyeCoo textile dyeing. Essential oil extraction. Parts cleaning. Biowaste pre-processing. 16

17 Chemical Precursor Fuels: Methane synthesis. Dimethylether (DME) synthesis. Ethylene synthesis. Energy storage, not energy production. 17

18 Chemical Industry: Methanol, ethylene, dimethylcarbonate, syngas. All require reduction of CO 2. Can be produced by a combination of Sabatier, Fischer- Tropsch, reverse water-gas shift, etc. 18

19 Combination of water, energy, and carbon dioxide can reproduce most of the fuel and plastic industries. Current plans are to use Sabatier and RWGS reactions to produce methane and oxygen for Mars missions (NASA, SpaceX, etc.). 19

20 Reactions: Reverse water-gas shift reaction Sabatier CO 2 + H 2 CO 2 + 4H 2 CO + H 2 O CH 4 + 2H 2 O Fisher-Tropsch + (2n+1)H 2 nco C n H 2n H 2 O 20

21 The use of Carbon dioxide in the chemical industry assumes a source of hydrogen: Currently most hydrogen is produced by steam reforming of methane. The other options include electrolytic reduction of water or thermal decomposition of water. Both require an energy source. 21

22 Utilisation Pathways Multiple pathways for the utilization of CO 2 EOR, mineralisation. scco 2 as solvent. scco 2 as process adjunct. Potential use as fuel and chemical precursor assuming chemical or electrochemical reduction of CO 2. 22

23 Useful References Accelerating the uptake of CCS: industrial use of captured carbon dioxide. Global CCS Institute, Parsons Brinckerhoff, Dec. 20, Morais, A.R.C; da Costa Lopes, A. M.; Bogel-Łukasik, R*, Carbon Dioxide in Biomass Processing: Contributions to the Green Biorefinery Concept, Chem. Rev. 2015, 115, pp Styring, P.; Quadrelli, E. A.; Armstrong, K., Carbon Dioxide Utilisation: Closing the Carbon Cycle, Elsevier, Sep 24,

24 Questions? 24