06:41 07 Aug 20
I-DEV0318: Calculation of BFi,y: Quantity of biomass combusted in the project plant based on measured data.
|Submitted by||SGS (08 Jun 2010)|
|Project activity||258: Nueva Aldea Biomass Power Plant Phase 1|
|Selected monitoring period||01 Oct 2007 - 30 Sep 2008|
|Title/subject of deviation||Calculation of BFi,y: Quantity of biomass combusted in the project plant based on measured data.|
SGS verified the third monitoring period (01 Oct 2007 - 30 Sep 2008) of the project ref 0258 Nueva Aldea Biomass Power Plant Phase 1 (ref 0258) against the applicable methodology ACM0006 Version 01.
The request for deviation is being submitted because the Quantity of biomass combusted in the project is determined based on measured and calculated data and not directly measured as required by the approved revised monitoring plan page 2 and ACM0006 version 1 page 39 requires: BFi,y: Quantity of biomass type i combusted in the project plant during the year y (mass or volume unit) is to be measured.
The total biomass combusted by the project only corresponds to biomass waste from forestry/industrial operation; it is a combination of bark and sawdust which is according to the information reported in the registered PDD section A2 and also consistent with the rest of the document.
During the site visit of the third monitoring period (from October 01st, 2007 to September 30th, 2008) it was verified that the biomass combusted arrives from outside the complex (sawmill and forestry plantation operations inside the defined area of influence established within the 200 Km radius around the power plant, as per ACM0006 version 1 page 35) in trucks. Each truck has its load weighed (by calibrated weigh bridges) and measured (volume is measured in m³stereo: it refers to a m3 of biomass that also contain air and moisture in between) / Annex 3/ at the entrance of the complex before leaving the load at the storage site next to the power plant. But there is also biomass residues that come from the different forestry industrial production lines located inside the Nueva Aldea Complex, where the project is located, (pulp mill, sawmill and plywood plant) arriving to the storage area through belts, excepting the case of the wood sander dust that go directly from the plywood mill source to the power plant boiler through a pipeline because of safety reasons, the power plant boiler is fed with a belt that obtains the biomass from the storage area as it was verified on site./Annex 1/
During the site visit it was verified that the quantity of biomass residues that come from the different production lines of the complex to the power plant is reported to the power plant manager through dispatch orders related to invoicing. This information is daily monitored and entered in the information database (called SCR) and it was also further verified that the quantities of biomass that come from pulp mill, sawmill and plywood plant are determined by applying specific factors to the measured volume of logs processed which are the raw material of the sawmill and the pulp mill production lines of the complex and in the case of the plywood mill, the biomass residue is determined quantifiying the production losses and an expansion factor is applied to consider the pilling effect at the storage area. The determination of the biomass residues that come from each production line and the information sources were verified on site and found correct/ Annex 2/
It was verified that the project deviates from the methodological requirement because the total Quantity of biomass (volume) combusted in the project plant (BFi,y) during the third monitoring period (from October 01st, 2007 to September 30th, 2008) was determined through a monthly stock balance according to the following formulas:
Volume inlet – Volume outlet = Volume final-stock (1)
Volume Inlet: Volume entering the storage area (S) plus the initial volume of the stock at the beginning of the measurement period (Vi)
Volume Outlet: The volume sent outsite the complex (I) plus the volume consumed in the power plant (C)
Volume Final-Stock: Volume of the stock on site at the end of the measurement period (Vf).
Volume inlet = S + Vi
Volume outlet = I + C
Volume final –stock = Vf
C: Biomass Power Plant Consumption: Calculated using equation (2) of this request (please see below)
I: Biomass sent to the external plant Measurement
Vi: Initial Volume Stock: Monthly topographic measurement of the storage sites
Vf: Final Volume Stock: Monthly topographic measurement of the storage sites
S: Entrance Volume to the storage site: Calculated using equation (3) of this request (please see below)
The aforementioned parameters are entered in the SCR Control system of reception where the data is protected against edition.
The Quantity of biomass combusted in the project plant (BFi,y) is calculated using equation 2:
C = S + Vi – I – Vf (2)
Where S correspond to biomass residues provided by the different production lines of the complex (pulp mill, sawmill and plywood plant) plus the biomass residues, transported by trucks, obtained from other parties like sawmills and forestry operation activities located outside the complex and the by-product of the waste water treatment of the complex, which is a biomass residue consisting of cellulose fiber, sawdust and bark with a high moisture content.
S = Rpulp mill + R sawmill + Rplywood + Rthird parties (3)
Calculations/Annex 2/, data sources and factors/Annex 3/used to determine the quantity of biomass from each source inside the complex were verified against data sources and found correct.
The calculated data is based in operational information collected and recorded by the project participant in the production lines as part of the production efficiency control. The biomass determination method /Annex 2 and 3/ is conservative compared with the energy balance results obtained/Annex 4/.
The determination of the biomass residues that come from outside the complex were verified against the information sources and found correct/Annex 2/
There is no change from the project activity since it continues to be a renewable energy project activity that involves the installation of a new cogeneration plant that uses a mix of forest plantation and forest industry residues at a site where no power generation would have occurred which is in accordance to the PDD and validation report.
A revision of the monitoring plan is not needed because the project participant already installed meters to measure directly the biomass that the power plant consumes. The meters were physically installed on December 15th 2009 and then time was needed to install the monitoring automatic system until December 31st.The request for deviation seeks the approval from the EB to be applied for the third monitoring period before requesting the issuance but also seeks approval of this deviation to be applied to the part of the next fourth monitoring period until December 31st 2009 i.e. after the biomass meters installation date.
This request for deviation does not increase or overestimate the total amount of credits claimed by the project activity. The estimated credits from the PDD for the same monitoring period were 108,943 tCO2 e(PDD page 13), the verified value for the same period was 161,802 tCO2e. The difference is mainly explained because the verified grid emission factor were 660.5 and 665 tCO2e/GWh for 2007 and 2008 respectively which are higher values than the estimated value (470 tCO2e/GWh PDD page 71), the verified value is higher because the natural gas supply from Argentina was cut. The verified total energy displaced from the grid 197.3 GWh is similar to the estimated value 192.7 GWh (PDD page 71) being this consistent with the quantity of additional biomass, 126,923 BDt and 116,008 BDt verified and estimated.
This deviation is being presented because the project participant did not directly measure all the biomass combusted in the power plant which is needed in equation 24 to determine the baseline emissions due to natural decay of biomass, as it is stated in the monitoring plan and applied methodology. This situation happened because the project was validated, on 31 March 2006, deviating the methodology ACM0006 Version 01 page 32, the baseline emissions due to natural decay or burning of additional biomass amount related to power generation in scenario 3 should have been calculated using equation No.24 of the methodology ACM0006 version 01 but the project was not validated in that way.
In the case with the Nueva Aldea Phase 1 project; to determine the baseline emissions due to natural decay of the biomass, the additional biomass amount related to the project activity was calculated using a “biomass power generation factor” equal to 0.283 MWh/m3stereo) applied to the measurement of electricity generated. This factor was calculated from the energy / mass balances of the project Nueva Aldea phase 1 power plant as it is described and validated in pages 41 and 81 of the registered PDD and in validation report page 8 and A-22.
The estimated quantity of biomass related to the baseline emissions due to natural decay was calculated using a “biomass power generation factor” equal to 0.283 MWh/m3stereo which was based on feasibility studies and the verified value was calculated based on measured data and it was checked against the energy balance done using the nominal efficiency of the boiler and the efficiency measured on site as it is explained below.
According to the information presented by the project participant and verified by SGS, the biomass calculation was done in a conservative way according to the energy balance presented below the reported Quantity of biomass combusted in the project plant during the third monitoring period is lower than the Quantity of biomass combusted in the project plant determined through the energy balance using the nominal power plant efficiency or less when using a lower boiler efficiency measured.
ACM0006 version 1 page 39 requires that if the amount of biomass combusted is estimated from the amount of biomass delivered to the project site, a procedure should be established to undertake an energy balance for the verification period, considering the stocks of biomass at the beginning and at the end of each verification period. A monthly energy balance/ Annex 4/ was carried out, calculating the quantity of biomass combusted in the project plant (BFi,y) considering the nominal efficiency of the power plant and the verified values of steam enthalpy, BDt Factor (page 12), NCV of biomass (page 13), fossil fuel consumption (page 12) and NCV of the fossil fuel (page 13) (http://cdm.unfccc.int/UserManagement/FileStorage/XUAIHY9TBG6JFKCL4Z1N5MDW2VPR78;) using the following formula:
BFi,y = ((ΔH / ξpower boiler) – ((FFproject plant,i,y* ρ*NCVff)/1000)) * (1/(NCVbm* BDt factor))
BFi,y: Quantity of biomass combusted in the project plant
ΔH: Entalphy (GJ/month)
ξpower boiler: Power boiler nominal efficiency 86.7% defined in the registered PDD, lay out page 10
FFproject plant,i,y: Fossil fuel consumed in the power boiler (lt/month)
ρ: Density of the fossil fuel (kg/lt)
NCVff: Fossil fuel net calorific value (GJ/ton)
NCVbm: Net calorific value of biomass combusted (GJ/BDt)
BDt factor: (BDt/m3st)
Only diesel consumption was used in the energy balance because LPG consumption is 0.012% of total fuel consumption (e.g. used for start-up operations) and therefore was considered to be negligible.
The value of boiler efficiency used 86.7% was deemed reasonable when compared with the value informed in the Power plant manual (Kvaerner Pulping Power division BFB Boiler Itata item 4.2 mass, heat and energy balances page 4) (86.8% and 89.1% for different operational temperatures) and the efficiency of 89.7% obtained in an actual boiler efficiency test hired by the project participant (Proterm report issued on November 25th, 2005 page 2).
The deviation does not increase the emission reductions of the project activity. The reported Quantity of biomass combusted in the project plant during the third monitoring period (2,157,645 m³st) is conservative, according to equation 24 of the applicable methodology, because it is 6.8% (in terms of BDt Bone Dried ton (BDT): one ton (1,000kg) (0% moisture content)), and 8.4% (m3st) less than the Quantity of biomass combusted in the project plant determined through the energy balance (2,429,580 m³st) using the nominal power plant efficiency equal to 90% or a 11% (BDt) and 12.6%(m3st) less when using a boiler efficiency equal to 86.7%/Annex 4/. In other words if the biomass determined by the energy balance were used in the CER determination, the CER would increase by 2.8 % with respect to the amount of CERs calculated using the estimated biomass consumption data.
The main reason of the difference between the biomass determined through the proposed method and through the energy balance corresponds to the insufficient biomass residue sampling for determining the BDt conversion factor (the factor used to convert volumetric biomass (m3st) unit to dry mass biomass unit (BDt) as it can be seen in the row 49 of the Annex 4. A theoretical BDt factor is determined in energy balance spreadsheet (please see row 47)/Annex 4/.
It was subsequently verified that the method of sampling for the BDt determination had been improved in the corresponding procedure in order to avoid or minimize this error in the future. The improvement basically consisted in increasing the number of biomass samples, from two to five per month and checking the resulting BDt conversion factor with historic data. This was duly verified on-site by means of checking the new procedure to determine the BDt (TA05- PTE-PO-025 approved on 11/09/2009).
|Annexes||Annex 1 biomass sources diagram (17 KB)|
|Annex 2 Biomass residues calculation (2007 KB)|
|Annex 3 determination of biomass (43 KB)|
|Annex 3 determination of biomass track changes (113 KB)|
|Annex 4 Energy balance (37 KB)|
|Link to the documentation made available at validation stage or monitoring report||Link to relevant documentation|
|Signed form||Signed form (344 KB)|
This request for deviation has not been accepted.
The Chairs have decided to not to approve this Request for Deviation.
|Current status||16 Aug 2010 - Deviation not accepted|
08 Jun 2010 -
06 Jul 2010 - Successfully passed the Completeness Check
30 Jul 2010 - Awaiting EB decision