18 2.00-4.50 - 1.10-1.50 - - 0.7-1.0 - 1.10-2.50 p 19 Notes: a Data sources are 1 (Tibrewal et al., 2023); 2 (Abbas et al., 2023); 3 (Eil et al., 2020); 4 (Valdes et al., 2020); 5 (Nepal et al., 2019); 6 (Deore et al., 2019); 7 (TERI, 2017); 8 (FNCCI, 2017); 9 (Kumar and Maithel, 2016); 10 (Weyant et al., 2016); 11 (MinErgy and FNBI, 2015); 12 (Kamyotra, 2015); 13 (Maithel et al., 2014); 14 (Manandhar and Dangol, 2013); 15 (Maithel, 2013); 16. (Maithel et al., 2012); 17 (Premchander et al., 2011); 18 (Heierli and Maithel, 2008); and 19 Rapid Survey study.

b P is the primary source; S is the secondary source; V is the various sources; and U is the source unknown. The number in the parenthesis is a reference number from a data source.

c Fuel types and their share by kiln technology and by data source are as follows: For BTK: 0.19 MJ/kg (100% coal), 1.26 MJ/kg (coal dominated), 1.33 MJ/kg (biomass dominated), and 1.43 MJ/kg (100% biomass); For ZZK: 1.02 MJ/kg (100% coal), 1.24 MJ/kg (coal dominated), and MJ/kg 1.32 (100% biomass); CK: 1.64 MJ/kg (low capacity), 1.51 MJ/kg (medium capacity), and 1.07 MJ/kg (high capacity). The SEC for average internal fuels (boiler ash and agriculture waste) is 0.48 MJ/kg. d Nepal-specific data sources.

e For BTK: 1.17 MJ/kg (90% coal and 10% rice husk), 1.04 MJ/kg (70% coal and sawdust, and 30% rice husk), 1.19 MJ/kg (100% bagasse briquette), and 0.99 MJ/kg (40% coal and 60% bagasse briquette.; For ZZK: 0.60 MJ/kg (100% coal), 0.91 MJ/kg (100% coal), and 1.06 MJ/kg (43% coal, 32% coal and rice husk and 25% rice husk as internal fuel).

f For ID ZZK, the value is for 25% perforation brick; and for TK, the value is for 60% perforation hollow brick. g All values are 100% coal-based. Electric SEC is excluded. BTK with perforated brick production is 1.06-1.16 MJ/kg. h Based on the combination of coal, sawdust, and bagasse. Values reported are in MJ/brick.

i Values for CK (100% fuelwood); BTK (100% coal), VSBK (100% coal as external fuel; boiler ash/wheat straw as internal fuels) j Based on a combination of coal and fuelwood. k (MinErgy and FNBI, 2015). 100% coal.

l All is 100% coal-based. Also reported is 100% biomass-based for BTK as 1.33-1.95 MJ/kg of fired brick. m For BTK: 1.46 MJ/kg (coal, wood and tire), 1.12 MJ/kg (100% coal), and 1.1 MJ/kg (coal and coal slurry); For ZZK: 1.21 MJ/kg (coal and sawdust), and 1.03 MJ/kg (100% coal); For VSBK it is coal and coal slurry; for CK it is fuelwood; and for TK, it is coal ash and coal slurry. For TK, an additional 0.26 MJ/kg of brick (total 1.72 MJ/kg) of electric energy is used.

# A2.3 Calorific Value of Fuels-Related Data Compilation

Coal is mainly used for firing commercial clay bricks in Nepal. Many classifications are used around the world with the main parameter being the coal rank. The ranks of coal, based on the carbon content (in decreasing order) are anthracite (86% - 97% carbon), bituminous (45% - 86% carbon), subbituminous (35% - 45% carbon), lignite (25% - 35% carbon) and peat (< 25% carbon) (IEA, 2022; EIA, 2022). The first three coal types are also known as hard coal. Coal is also classified by its intended use, e.g., thermal (or steam) and metallurgical applications. Thermal coal refers to hard coal used for purposes other than metallurgy. Metallurgical coal refers to coking coal, semi-soft coal, and pulverized injection coal, and they are high-quality coal mainly used to produce coke or to reduce coke consumption used in blast furnaces to make pig iron. Note that depending on its intended use, anthracite can be classified either as thermal coal (used for heat and electricity generation) or metallurgical coal (used for making coke). More than 80% of all coal produced today is steam coal, which is mainly used for heat and electricity generation (IEA, 2023b). Nearly 5% is lignite, which is also generally used for power generation. Coking coal makes up around 15% of global production and is mainly used in steelmaking.

The calorific value and impurity content are the main parameters defining the quality of thermal (steam) coal, whereas caking properties, resistance, and impurity content are the distinguishing characteristics of coking coal (IEA, 2022). The quality (calorific value) of thermal coal mainly depends on its moisture content, ash content, volatile matter, and fixed carbon content. In general, 47