A Correction Is Made with Regard to the Ch4and CO2 Yields of the R0b Run. Original Paper

A correction is made with regard to the CH4and CO2 yields of the R0b run. Original paper shows values of 160 and 171 NL/dry kg, respectively for R0b. The correct values (i.e. 133 and 142) are shown in Table 1 in bold. These corrected values agree with Figure 1 of the original submission. Conclusions do not change. Table 1 includes the C closures that were calculated for each reactor. Closures were calculated according to the ash conservation principle based on equation: . An ideal closure would be 100%.These closures had not been included in the original submission in Waste Management and Research.

Table 1

Run / Duration of anaerobic run (d) / CH4 yield
(NL/dry kg) / CO2 yield
(NL/dry kg) / C closure (%)
R0a / 541 / 254 / 213 / 96%
R0b / 530 / 133 / 142 / 78%
R8 / 340 / 319 / 231 / 93%
R45 / 309 / 58 / 72 / 68%
R90 / 230 / 28 / 34 / 27%

The lowest C closure was measured in the R90 run, which had the lowest residual amounts of solids at the end of the experiment. Probably, some gases were not measured by the gas flowmeter. The TG05/5 gas-meters have a measuring error of ±0.32% (in theflowrate range from 1 L/h to 60 L/h), whilst at lower flowrates the measuring error increases to±1.0% to ±1.5%.

The ash conservation principle was used to calculate the amount of solid (dry mass) at the end of the experiment. A comparison was made between the amount calculated by the ash conservation principle and the direct weighing of the final dry mass.

Run / Solid C based on weighing
(g) / Solid C based on the ash conservation principle (g) / Deviation
R0a / 1413 / 2074 / 32%
R0b / 1828 / 2237 / 18%
R8 / 677 / 836 / 19%
R45 / 1639 / 1659 / 1%
R90 / 459 / 497 / 8%

The ash conservation principle is considered more accurate to calculate final dry mass contentsand is always used by our group instead of weighing.

D.Komilis (6/12/2013)