US 12,278,000 B2
Method for the early estimation of anaerobic degradability of organic substrates
Gianni Ferretti, Cremona (IT); Arianna Catenacci, Milan (IT); and Francesca Maria Alessandra Malpei, Milan (IT)
Assigned to POLITECNICO DI MILANO, Milan (IT)
Appl. No. 17/785,284
Filed by POLITECNICO DI MILANO, Milan (IT)
PCT Filed Sep. 28, 2021, PCT No. PCT/IB2021/058848
§ 371(c)(1), (2) Date Jun. 14, 2022,
PCT Pub. No. WO2022/070035, PCT Pub. Date Apr. 7, 2022.
Claims priority of application No. 102020000023089 (IT), filed on Sep. 30, 2020.
Prior Publication US 2023/0009939 A1, Jan. 12, 2023
Int. Cl. G16C 20/10 (2019.01); B09B 5/00 (2006.01); C02F 3/00 (2023.01); C02F 3/30 (2023.01); G16C 20/70 (2019.01)
CPC G16C 20/10 (2019.02) [C02F 3/006 (2013.01); G16C 20/70 (2019.02); B09B 5/00 (2013.01); C02F 3/30 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for the early estimation of anaerobic degradability of organic substrate, returning an estimate of a final BMP value, wherein a BMP value expresses an amount of methane that can be produced from a unit mass of the organic substrate, comprising the following steps:
starting a BMP test, wherein the BMP test is carried out in a batch reactor where the organic substrate, an inoculum of anaerobic micorooganisms, and nutrients necessary for microbial metabolism are introduced and kept mixed and thermostated;
acquiring and storing a minimum pre-set number of data from the BMP test;
considering that the anaerobic degradability of organic substrates follows the following formula:
Y(t)=B0(1−e−k(t−t0))
where Y (t) is the value of the signal at time t, B0 is the maximum production of methane at infinite time, k is the first-order kinetic constant; t0 is the time at which acquisition of the data begins;
calculating parameters B0 and k, subsequently identified as B0,est and kest, for the pair (t1+Δt), where t1 is a generic test time instant and Δt is a generic time interval,
incrementing the generic time interval Δt, and repeating the calculation of B0,est and kest until Δt reaches a pre-set value Δtmax;
comparing a fit of the decreasing trend of the curve of B0,est as a function of Δt with a homographic function in the first quadrant;
evaluating whether the fit of the decreasing trend of the curve B0,est as a function of Δt with the homographic function has an adjusted coefficient of determination R2adj greater than or equal to a pre-set minimum coefficient of determination R2adj,min;
if yes, then
selecting a result for B0,est, wherein the result is the estimate of the final BMP value which can be used to more effectively monitoring and optimizing the anaerobic digestion process, enabling timely interventions if issues arise; and
stopping BMP data acquisition and storing;
wherein selecting the result comprises analysing the curve of B0,est as a function of Δt, and selecting a value of B0,est corresponding to a slope of the curve that is less than 0.1% for three consecutive Δt;
if no, acquire additional BMP measurements and repeat the previous steps; and
using the result to manage and optimize a process of anaerobic digestion to enable intervention in the event of problems during running of a plant and to exploit chemical energy contained in treated organic substrates.