There is big need for energy efficient CO₂-free Hydrogen production in bio-economy. When using organic feedstock in Chemical Synthesis its intrinsic Hydrogen deficit (<2H₂ : C) either it limits the transformation efficiency or needs to be supplemented externally, putting a lot of pressure on resources and costs. Actually this dilemma is closely related to several barriers:
– Limitation of feedstock supply – while this world squanders our times organic Carbon contained in waste, not usable for compost in agriculture in an amount equivalent to ~25% of Fossil Carbon imports – would just need „Grave-to-Cradle“ recycling for re-use.
– Too high Cost of (fresh) biomass feedstocks – since biomass is a valuable resource for several usage cascades before becoming a waste holding contemporary Carbon recyclable at arm‘s length cost of crude oil Carbon, which originates form Paleozoic residues.
– Limited („Cradle-to-Cradle“) Recyclability – curable by „Grave-to-Cradle“ Carbon Recycling being even more cost-effective than bio-degradability of materials, which over yet to be defined time span would just air Carbon, largely re-usable in Carbon Circularity. Where the Carbon is put back into matter 50% of it is stored over consecutive „Grave-to-Cradle“ life-cycles.
– Non bio-degradability is only a constraint for badly managed disposal of stuff! There are few products holding less than 30%wt Carbon. European 0.5 Tonnes per year per capita household waste hold rather 40%wt. Depending on the countries citizens pay via various cost socialization schemes between €80 – €140 per Tonne for its reduction into ultimately CO₂, approximately equivalent to the crude oil equivalent value of recoverable Carbon content. Therefore there is enough money in the game to incentivize consumers by refund schemes to properly return end of life products for „Grave-to-Cradle“ Carbon recovery.
– Limited availability of funding in early stage & lacking support for scale-up – is primary an issue of reallocation of regularly funded incineration (incl. overhauling) towards Carbon Recycling that consecutively saves ~1.3 times of Carbon Recycling CAPEX in Oil Find & Development Expenditures per crude oil substituted by Recycled Carbon.
– Ongoing need for R&D funding – maybe true for process innovations based on the enhanced possibilities from uniformity of Recycled Carbon feedstock which above and beyond allows processing in cold-wall reactors by kind of micro-wave inducing transformation energy levels electrically. However resulting productivity gains could quickly amortize such Development Expenditures. For products themselves there’s no need to leave well proven Chemical Synthesis paths of combining Carbon and Hydrogen molecules at their appropriate ratios for desired synthesis conditions.
At €0.22/kg sugar price [C₆(H₂O)₅] holding 44.4% Carbon and 6.2% Hydrogen (-56% 2:1 deficit) the making of 1kg polymer [C₂H₄] PE (28g/mol) costs ≈ €1.02/kg PE (not regarding whether the sugar was produced under chemical soil replenishment?).
Recycled Carbon at ~€0.35/kg cost of material for polymers is about ≈ €0.45/kg PE.
Alternatively Celluloses [C₁₂H₂₀O₁₀] (324,28g/mol) about 50%wt of wood (-60% 2H₂:1C deficit) at €90/t 25% moisture. Hence 1kg PE polymer ≈ €0.93/kg PE if residual 20-30% Lignin [C₉H₁₀O₂; C₁₀H₁₂O₃; C₁₁H₁₄O₄] (Carbon rich Black Liquor of 150.18; 180.20; 210.23g/mol) if the ~25MJ/kg was not valorized (≡ €0.08/kg Celluloses). However it could be transformed into Hydrogen for > 2.5 H₂: C mol Celluloses going into Chemical Synthesis brings cost from one and same input down to ≈ €0.47/kg PE.
Hi Steffan, you might found this two articles interesting and perhaps related to further emission calculation reduction potential:
https://www.nature.com/articles/s41612-018-0046-4
https://www.its.ac.id/news/2018/08/20/manfaatkan-sekam-padi-mahasiswa-hasilkan-bioavtur/
Cheers
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