C. Storm, H. Rudiger, H. Spliethoff, and K.R.G. Hein
C. Storm, H. Rudiger, H. Spliethoff, and K.R.G. Hein
"The ethanol would be sold as fuel, the companies said, but Dow’s long-term interest is in using it as an ingredient for plastics, replacing natural gas. The process also produces oxygen, which could be used to burn coal in a power plant cleanly, said Paul Woods, chief executive of Algenol, which is based in Bonita Springs, Fla. The exhaust from such a plant would be mostly carbon dioxide, which could be reused to make more algae...."
Rheinbraun concluded that co-gasification of sewage sludge or loaded coke with dried brown coal offered significant potential for disposing of these wastes without impairing plant efficiency and emissions. The commercial viability was demonstrated by an assessment study that included major aspects such as feed rate, total investment, and methanol price in order to establish the criteria for the use of sewage sludge in the high-temperature Winkler gasification process.
" Li Zhang, Shaoping Xu, Wei Zhao and Shuqin Liu
State Key Laboratory of Fine Chemicals, Department of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, PO Box 33, Dalian 116012, China
Abstract
An experimental study on co-pyrolysis of biomass and coal was performed in a free fall reactor under atmospheric pressure with nitrogen as balance gas. The coal sample selected was Dayan lignite, while the biomass used was legume straw. The operation temperature was over a range of 500–700 °C, and the blending ratio of biomass in mixtures was varied between 0 and 100 wt.%. The results indicated that there exist synergetic effects in the co-pyrolysis of biomass and coal. Under the higher blending ratio conditions, the char yields are lower than the theoretical values calculated on pyrolysis of each individual fuel, and consequently the liquid yields are higher. Moreover, the experimental results showed that the compositions of the gaseous products from blended samples are not all in accordance with those of their parent fuels. The CO2 reactivities of the chars obtained from the co-pyrolysis under the higher blending ratio (around 70 wt.%) conditions are about twice as high as those of coal char alone, even higher than those of biomass alone."
First, "straw" would suggest the dried stems of grasses or grains, consisting we would suppose, in large part, of cellulose - which we've previously documented to be compatible with coal as a co-feed for a suitably-designed gasification/liquefaction facility.
Second, the coal they are using is lignite, which will be lower in organic content and higher in ash than West Virginia bituminous, but which will be comparable in some ways to carbonaceous wastes found in some, especially older, WV coal mine spoil accumulations.
Third, the use of combining coal with cellulose appears to be synergistic: The "liquid yields are higher", with lower residual "char".
Finally, the combination is synergistic in another way, as well: The straw, as it grows, consumes the Carbon Dioxide that evolves when the fuel is combusted.