Page 38 - Impiantistica industriale

INDUSTRY & UNIVERSITY

from a twelve-steps cycle (adsorption, pres- the operating parameters that define the VPSA
sure equalization, idle, blowdown, evacuation, cycle (e.g. number and type of the steps, duration
evacuation with purge and backfill) and by re- of the single step, ecc.). All these characteristics
fining the time of each step, in a four-column allows to assure high performances in terms of me-
system. thane recovery (potentially up to 99%) and purity
(potentially up to 99,8%).

Conclusions
Among the technologies proposed for the methane Endnotes
enrichment of the biogas mixture (upgrading pro- 1 IPCC, 2022 Intergovernmental Panel on Climate
cess), the PSA process guarantees high purifica- Change Climate Change 2022: Impacts, Adaptation
tion, with low energy consumption, low installation and Vulnerability. Cambridge University Press. [s.n.].
and operating costs, simple and safe operations. 2 COP 26, 2021
However, designing and optimizing PSA processes 3 Bharadwaj Kummamuru Global Bioenergy Statistics,
remains challenging due to the complex nature of 25th European Biomass Conference and Exhibition.-
the process. Stockholm, Sweden: World Bioenergy Association,
The main challenges are to identify the adsorbent 2019.
and to design a cycle, which allows the best pro- 4 Ambaradan A. [et al.] Robust metal-organic frame-
cess performance, by means of dedicated experi- works for dry and wet biogas upgrading [Rivista]//
mental tests in the VPSA laboratory plant. Dynamic Appl. Mater. Today. - 2021.- 22.- pp. 100933.
breakthrough tests can be adopted to characterize 5 Augelletti R., Conti M. e Annesini M.C. Pressure
the performance of adsorbents in terms of adsorp- swing adsorption for biogas upgrading. A new pro-
tion capacity, selectivity and regenerability. cess configuration for the separation of biomethane
While, VPSA tests allow to define a cycle and find and carbon dioxide, Journal of Cleaner Production.
out the optimal operating parameters for the pro- - 2017.- 140.- pp. 1390-1398.
cess. In addition to the evaluation of purity, to verify 6 Grande C.A. Biogas Upgrading by Pressure Swing
the suitability of the produced biomethane for injec- Adsorption, Biofuel’s Engineering Process Technol-
tion into the gas transmission network, recovery in ogy.- 2011.
methane, productivity and energy consumption of 7 Abd A.A. [et al.] Methane enrichment in biogas mix-
the plant allow to verify the effectiveness and eco- ture using pressure swing adsorption: process fun-
nomic feasibility of the technology, for large-scale damental and design parameters, Materials Today
production. Sustainability.- 2021., 11-12, 100063.
The VPSA device set up by Oiltech allows to pro- 8 Santos Monica S., Grande Carlos A. e Rodrigues
ficiently carry out all the necessary operation for Alırio E. New cycle configuration to enhance perfor-
the assessment of the technology. Thanks to its mance of kinetic PSA processes, Chemical Engineer-
versatility and wide field of applicability, it is able ingScience, 2011 .66 - pp. 1590-1599 .
to perform both fundamental adsorption studies, 9 Wu B. [et al.] Assessment of the energy consump-
including both thermodynamic (i.e. adsorption iso- tion of the biogas upgrading process with pressure
therms) and kinetic (i.e. breakthrough curves) tests swing adsorption using novel adsorbents, Journal of
on specific adsorbents, and experimental VPSA Cleaner Production. - 2015. - 101.- pp. 251-261.
tests aimed at the definition of the optimal set of 10 Abd A. A. e Othman M. R. Biogas upgrading to fuel
parameters. grade methane using pressure swing adsorption:
From an operative point of view, this VPSA system Parametric sensitivity analysis on an industrial scale,
assures high working flexibility, as it is possible to Fuel 2022.- 308.- pp. 121986.
run it with a variable number of adsorption co- 11 Canevesi Rafael L. S. [et al.] Towards a design of a
lumns (between 3 and 5), in wide ranges of opera- pressure swing adsorption unit for small scale bio-
tive pressure (1-10 bar), depending on the chosen gas upgrading at, Energy Procedia.- 2019.- 158.- pp.
adsorbent, and it simultaneous allow to adjust all 848-853.

36 36 Impiantistica Italiana - Maggio-Giugno 2022