Methanol Reforming in Supercritical Water

Abstract

The production of hydrogen by the reforming of methanol was studied in a continuously operated tubular reactor made of the nickel-based alloy Inconel 625. Experiments were performed at pressures from 25 to 45 MPa and temperatures in the range of 400−600 °C. The concentration of the aqueous feed varied from 5 to 64 wt % methanol. Residence times under reaction temperature conditions varied in the range from 3 to 100 s. The main component of the product gas is hydrogen, with smaller amounts of carbon dioxide, carbon monoxide, and methane. Methanol conversion is up to 99.9% without addition of a catalyst. Obviously, the heavy metals on the inner surface of the reactor influence the composition of the product gas and the conversion rate. Oxidation of the reactor inner surface before gasification turned out to enhance the reaction rate and to decrease the carbon monoxide concentration.

Gasification of corn and clover grass in supercritical water

“…Yu et al [18] found that the wall of a reactor made of Inconel catalyzed the water-gas shift reaction. Boukis et al [19] studied the catalytic role of the heavy metals of the reactor material in methanol reforming in supercritical water. The inner surface of the reactor was mainly covered with NiO after a reaction with 3% H 2 O 2 solution at 873 K. Chromium and molybdenum were dissolved selectively and removed from the surface.…”

Supercritical Water Gasification of Biomass: A Literature and Technology Overview

“…Boukis et al [81] studied the methanol reforming in a nickel-based alloy Inconel 625. They concluded that the conversion rate as well as the product gas composition is influenced by the presence of heavy metals on the inner surface of the reactor and the catalytic effect remained high even after more than a thousand operation hours.…”

Hydrogen production by supercritical water gasification of fruit pulp in the presence of Ru/C

“…Pressure, which is known to have a negligible effect on hydrogen yield above the critical pressure of water, is kept i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y x x x ( 2 0 1 5 ) 1 e1 1 constant (25 MPa) during the runs [15]. To ascertain the influence of the reaction temperature on gas product composition and gasification efficiency of catalytic SCWG of fruit pulp, a series of gasification experiments was conducted at 673, 773 and 873 for a constant reaction time of 30 min with a biomass ratio of 2.5% and the results are given in Fig.…”