Hydrothermal gasification

Elliott, D.C., Hart, T.R., Neuenschwander, G.G., Chemical processing in high pressure aqueous environments 8. Improved catalysts for hydrothermal gasification, Ind. Eng. Chem. Res., 2006, 45, 3776. 

The observed results show that a nearly complete gasification of the used model compounds can be achieved at temperatures of 600 C. The screening experiments with the real feedstock confirm the experiments done at the University of Hawaii. Compared to the traditional gasification process the following advantages for the hydrothermal gasification of wet biomass / organic waste feedstock can be expected ... 

Supplying solid biomass into a hydrothermal gasification reactor at high pressure is a di icult problem. The pressure in the hydro ermal reactor is much higher than the screw feeder can withstand. Moreover, it is difficult to apply a fluidized bed at the high temperatures and pressures encountered in supercritical water reactions. 

With the intention of feeding wet biomass into a hydrothermal gasification reactor at... 

H. Schmieder, J. Abeln, N. Bpukis, E. Dinjus, A.Kruse, M. Kluth, G. Petrich, E. Sadri, M. Schacht. (2000), Hydrothermal gasification of biomass and organic wastes. Journal of Supercritical Fluids. 17,145-153. 

A very promising alternative to wet biomass is the less investigated hydrothermal gasification (expected thermal efficiency of 70 % at a water content of 90 % [128]). In principle there are three different ways to use biomass for energy production ... 

In comparison to the traditional gasification processes for hydrothermal gasification, the following advantages for a wet biomass/organic waste feedstock can be expected ... 

Vogel, F., Hildebrand, F. (2002) Catalytic hydrothermal gasification of woody biomass at high feed concentrations. Paper 123, 4th International Symposium On High Pressure Process Technology and Chemical Engineering, EFCE, Venice Italy. 

Another field of research at the moment is hydrothermal gasification. In this process biomass reacts with supercritical water and even wet biomass can be used and converted to a high degree [14]. 

Waldner MH, Vogel F. Renewable production of methane from woody biomass by catalytic hydrothermal gasification. Ind Eng Chem Res 2005 44 4543-51. 

Hydrothermal gasification. A potential route to synthesize gas under conditions in which water is in the liquid or fiuid at elevated temperature and hydrostatic pressure (supercritical conditions). 

The general steps anticipated in a modem hydrothermal gasification facility are summarized in Fig. 17.7. 

Several approaches have been used to tackle the problem of the wastewater byproduct. For example in the case of microalgae HTL, PNNL applied catalytic hydrothermal gasification (CHG) effectively for HTL process water clean-up and fuel gas production... 

There are only limited reports on hydrothermal gasification in larger than laboratory scale. At PNNL bench-scale systems were developed as early as 1989 (Elliott et al., 1989). This work was used to design a scaled-up mobile reactor system, designed for up to 0.5 t of wet feed per day (Elliott et al., 1994). PNNL demonstrated successfully the continuous gasification of biomass to methane-rich product gas. Initially problems occurred with plugging of the catalyst bed by biomass which was solved by a two-step process where biomass was liquefied in a CSTR before HTG. The design... 

A system analysis was carried out by Ro et al. using swine manure as a feedstock for subcritical gasification. The study suggests that catalytic hydrothermal gasification... 

Cherad, R., et al., 2015. Hydrogen production from the catalytic hydrothermal gasification of process water from microalgae hquefaction. Fuel 166, 24—28. 

Elliott, D.C., 2008. Catalytic hydrothermal gasification of biomass. Biofuels, Bioproducts, and Biorefining 2 (3), 254—265. 

Elliott, D.C., 2015. Catalytic hydrothermal gasification. In Biomass Power for the World. Pan Stanford, pp. 665—701. 

He, C., et al., 2014. Hydrothermal gasification of sewage sludge and model compounds for renewable hydrogen production a review. Renewable and Sustainable Energy Reviews 39 (0), 1127-1142. 

Luterhacher, J.S., et al., 2009. Hydrothermal gasification of waste biomass process design and life cycle asessment. Envirorunental Science Technology 43 (5), 1578—1583. 

Waldner, M.H., Krumeich, F., Vogel, F., 2007. Synthetic natural gas by hydrothermal gasification of biomass selection procedure towards a stable catalyst and its sodium sulfate tolerance. The Journal of Supercritical Fluids 43 (1), 91—105. 

Waldner, M.H., 2007. Catalytic Hydrothermal Gasification of Biomass for the Production of Synthetic Natural Gas (Ph.D. thesis). ETH/PSE Zurich. 

---