Ferroalloy methane emissions

[edit / update model]
The category business/processes/production/ferroalloy/ch4 is aimed towards industry professionals to enable them to prepare inventories of greenhouse gas emissions from ferroalloy production. This category is designed for use alongside the ferroallloy tier 1 or tier 2 categories. The methodology provided in this category represents the Tier 1 (default) and Tier 2 (user-supplied) approach for CH4 emissions calculation described by the IPCC Guidelines for National Greenhouse Gas Inventories (NGGIP).

The heating of carbon materials in the furnace releases volatiles including methane. With open or semi-covered furnaces – predominantly used for FeSi and Si ferroalloy production - most of the volatiles will burn to CO2 above the charge, in the hood and off-gas channels, but some will remain un-reacted as CH4 and NMVOC. The amounts depend on the operation of the furnace. Sprinkle-charging will reduce the amounts of CH4 compared to batch-wise charging. Increased temperature in the hood (less false air) will reduce the content of CH4 further. The errors associated with estimates or measurements of N2O emissions from the ferroalloys industry are very large and thus, a methodology is not provided.


How to use this category

Selecting an emissions scenario

To use this category use the typeOfAlloy drill-down to select the alloy type being used from the following options:

  1. si-metal
  2. fesi 90
  3. fesi 75
  4. fesi 65
A second drill-down must then be specified using the operationOfFurnace drill-down to select the operation type of the furnace used, from the following options:

  1. unknown
  2. batch-charging
  3. sprinkle-charging
  4. sprinkle-charging and over 750 degrees C
If unknown is selected, the default values used are those for sprinkle-charging operation.

Specifying activity data

The only required profile item value is productQuantity. The emission factor has a default value provided by the Discover engine, but this can be over-ridden, using the massCO2PerMassProduct profile item value, by the user if more precise site or country-specific values are known. If using a site-specific emissions factor, the calculation represents the tier 2 IPCC NGGIP methodology.

Results and calculation

The returned amounts represent the CH4 emissions associated with the quantity specified. Two quantities are returned, as follows:

  • CH4: CH4 (methane) emissions
  • CO2e: CO2e emissions (CH4 converted using these global warming potential)
The individual quantity for CH4 represents an absolute quantity rather than a CO2e quantity.

UIDLabel
R22K7J5JHD3T fesi 65, batch-charging
IIZPT9V0YDYG fesi 65, sprinkle-charging
VV97UNM5H0HR fesi 65, sprinkle-charging and over 750 degrees C
B77UYSE9R57C fesi 65, unknown
KXJRGOJV2Z6G fesi 75, batch-charging
0F19I6XZTSYV fesi 75, sprinkle-charging
10VRNC8KLK1F fesi 75, sprinkle-charging and over 750 degrees C
6YIMNJCL92ZQ fesi 75, unknown
9AAS5G2HFYDJ fesi 90, batch-charging
V8QIDXT30X7H fesi 90, sprinkle-charging
CP3D6D3PPVOL fesi 90, sprinkle-charging and over 750 degrees C
40995KNGIRCM fesi 90, unknown
U9PG32KY22C3 si-metal, batch-charging
66O59HF7WCKV si-metal, sprinkle-charging
ADF65OQT2HYY si-metal, sprinkle-charging and over 750 degrees C
F1XSAD7E9Q7P si-metal, unknown
user-supplied value for quantity of product produced