Looking for reference materials on the volatiles content of coking blend coal and gas production yield

General information on coal chemical processing is available; I can’t remember the specific formulas, haha

2.3 Yield of Chemical Products 2.3.1 Recovery Rates of Coal Tar and Crude Benzene The Donbas coal mines in the former Soviet Union proposed that when Vdaf·m = 18%～30%, the recovery rate for coal tar is given by Kd·g = [–18.35 + 1.53Vdaf·m – 0.026(Vdaf·m)²] × (100–Ad/100) (6), while the recovery rate for crude benzene is given by Kd·b = [–1.61 + 0.144Vdaf·m – 0.0016(Vdaf·m)²] × (100–Ad/100) (7). Anshan Iron and Steel Corporation’s Chemical Plant proposed that when Vdaf·m = 27.96%～30.37%, the recovery rate for coal tar is Kd·g = [–1.4 + 0.184Vdaf·m] × (100–Aa/100) (8), and the recovery rate for crude benzene is Kd·b = [–0.64 + 0.065Vdaf·m] × (100–Ad/100) (9). In these formulas, Kd·g and Kd·b represent the recovery rates of coal tar and crude benzene respectively, based on the dry basis of the coal used as feedstock; Vdaf·m refers to the volatile matter content on a combustible basis of the coal fed into the furnace. 2.3.2 Ammonia recovery rate ?Kd·A=(17/14)·bNd·m (10) ?Where Kd·A represents the recovery rate of ammonia from the coal based on its dry weight ； 17 is the molecular weight of ammonia ； 14 is the atomic weight of nitrogen ； Nd·m is the nitrogen content on a dry basis of the coal charged to the furnace (%) ； b is the conversion factor for the total nitrogen content in coal, generally taken as 0.12 to 0.16. The remaining nitrogen is transferred into coke and other nitrogen-containing compounds. 2.4 Yield of combined products: W = K·Od·m·(18/16)(100–Ad–St·d/100) (11) Where K = 0.437 ； W is the amount of combined water generated per unit of dry coal loaded ； Od·m is the oxygen content on a dry basis of the coal loaded ； 18 is the molecular weight of water ； 16 is the atomic weight of oxygen. ?Generally, the amount of water formed through combination is taken as 2% to 3% of the amount of coal loaded. ?The amount of bound water generated can also be calculated using the following formula: ?W=〔4.64-0.354Vd+0.0118Vd2〕 (12) Where Vd represents the dry-base volatiles of the coal loaded.

2.2 Net gas yield 2.2.1 Formula for calculating the net gas yield from dry-basis coal feed in the former Soviet Union: ? Kd·g=QVd·m (4) Where Q is a coefficient; for bituminous coal, Q=3, and for coking coal, Q=3.3； Vd·m represents the volatile matter on a dry basis of the coal loaded. 2.2.2 Formula for calculating the yield of net gas from thermal power plants in China relative to the dry-basis coal fed in: Kd·g = (1–β)AVd·m (5) Where β = 2%–4% (wall leakage rate) ； A=64～72 is a correction factor related to the type of coal ； Vd·m is the dry-base volatiles of the coal charged. ? The Ministry of Metallurgy recommends this formula as the basis for coking enterprises in China to calculate the quality of gas.

Question for Floor 4: Assuming the volatile matter on a dry basis of coal is 30%, the calculation according to 2.2.1 yields 3.3×30% = 0.99； While the calculation according to 2.2.2 yields (1-4%)×64×30% = 18.432. The two results differ greatly. What’s going on?

What are the units of the final results for these two formulas? Why is the difference so big?