Hydrogen peroxide is a chemical used in oxidation reactions, treatment of various inorganic and organic pollutants, bleaching processes in pulp, paper and textile industries and for various disinfection applications. It is a monopropellant, which, when purified, is self-decomposing at high temperatures or when a catalyst is present. Decomposing to yield only oxygen and water(disproportionation), hydrogen peroxide is one of the cleanest, most versatile chemicals available. The catalytic decomposition of hydrogen peroxide allows the use of various catalysts that will increase the rate of decomposition. Comparison and description of the most commonly used catalysts were presented in this review.

/pdf/decomposition-of-hydrogen-peroxide-kinetics-and-review-of-2ze93wq2vm.pdf

Decomposition of hydrogen peroxide - kinetics and review of chosen catalysts

In staged-bipropellant rocket combustors that use decomposed hydrogen peroxide as the oxidizer, a liquid fuel is injected into the hot decomposition products comprising oxygen and water vapor. For a well-designed combustor, the oxidizer is at a sufficiently high temperature to vaporize and to autoignite the liquid fuel; however, experimental autoignition data in key chamber contraction ratio and propellant equivalence ratio ranges are missing. In this study a transverse injector was used in a dump-combustor configuration to investigate the autoignition characteristics of JP-8 in decomposed hydrogen peroxide, specifically fuel-rich autoignition limits at contraction ratios less than 6 and with high hydrogen peroxide concentrations. The chamber contraction ratio was varied between 3 and 5 to evaluate the effects of chamber gas Mach number (0.45 and 0.27), and the hydrogen peroxide concentration was varied from 85 to 98% by weight to evaluate the effects of oxidizer temperature. Three regimes were noted: strong, weak, and no autoignition. Chamber pressure oscillations with a dominant frequency between 27 and 47 Hz occurred in the weak-autoignition regime. Results showed that as hydrogen peroxide concentration and/or contraction ratio was increased the equivalence ratio that defined the autoignition boundary increased as well. At a contraction ratio of 3.0, no autoignition was achieved at equivalence ratios of 1.37 and above using 85% hydrogen peroxide, but with 98% hydrogen peroxide autoignition occurred at an equivalence ratio as high as 2.06. When the contraction ratio was increased to 5.0, autoignition was achieved at an equivalence ratio of 1.38 using 85% hydrogen peroxide. These data provide a starting point for the development of an accurate autoignition model and an empirical basis for the design of efficient combustors.

Autoignition of kerosene by decomposed hydrogen peroxide in a dump-combustor configuration

This paper presents three-dimensional numerical simulations of the hybrid rocket motor with hydrogen peroxide (HP) and hydroxyl terminated polybutadiene (HTPB) propellant combination and investigates the fuel regression rate distribution characteristics of different fuel types. The numerical models are established to couple the Navier-Stokes equations with turbulence, chemical reactions, solid fuel pyrolysis and solid-gas interfacial boundary conditions. Simulation results including the temperature contours and fuel regression rate distributions are presented for the tube, star and wagon wheel grains. The results demonstrate that the changing trends of the regression rate along the axis are similar for all kinds of fuel types, which decrease sharply near the leading edges of the fuels and then gradually increase with increasing axial locations. The regression rates of the star and wagon wheel grains show apparent three-dimensional characteristics, and they are higher in the regions of fuel surfaces near the central core oxidizer flow. The average regression rates increase as the oxidizer mass fluxes rise for all of the fuel types. However, under same oxidizer mass flux, the average regression rates of the star and wagon wheel grains are much larger than that of the tube grain due to their lower hydraulic diameters.

Numerical analysis of fuel regression rate distribution characteristics in hybrid rocket motors with different fuel types

Performance characteristics of silver catalyst bed for hydrogen peroxide

Numerical and experimental studies of the hybrid rocket motor with multi-port fuel grain $

Thermal decomposition is an important process in propulsion systems that use hydrogen peroxide (HP). Neither a combined vaporization-decomposition model nor a fundamental understanding of the way liquid HP vaporizes and decomposes in these rocket applications exist. Results are presented from an experimental study of the combined thermal decomposition of HP at rocket-type conditions. A liquid spray of HP is injected into a cross stream of HP decomposition products at chamber pressures ranging from 2.0 to over 5.5 MPa. Two injectors with different orifice diameters are used. Experimental parameters include flow rates of the decomposition products and liquid injectant, HP concentration, chamber geometry, and momentum ratio between the liquid injectant and the decomposition stream. A decomposition efficiency of the liquid HP is determined based on the ratio between measured chamber pressure and chamber pressure calculated by equilibrium chemistry. An analysis of the crossflow injection is used to assess the effects of spray trajectory. Decomposition efficiencies ranging between 10 and 90% were measured. The results show that decomposition efficiency is inversely proportional to the fractional amount of liquid injectant flow rate, linearly proportional to residence time, and that higher concentration HP decomposes at a faster rate.

Thermal Decomposition of Hydrogen Peroxide, Part I: Experimental Results

Thermal decomposition is an important process in propulsion systems that use hydrogen peroxide. It occurs in the aft end of conventional catalyst beds, in thermal decomposition chambers, during bipropellant reaction in combustion chambers, in liquid film cooling layers, and to some degree in flow channels in regeneratively cooled combustion chambers. Neither a combined vaporization-decomposition model nor a fundamental understanding of the way liquid peroxide vaporizes and decomposes in these high pressure rocket applications exist. This paper provides results from an ongoing experimental study of the combined decomposition-vaporization process of hydrogen peroxide at realistic conditions. In the present work, a liquid spray of high concentration peroxide is injected into a chamber containing a stream of peroxide decomposition products at pressures ranging from 300 to over 800 psia. A decomposition efficiency is determined based on the ratio between measured chamber pressure and chamber pressure calculated by equilibrium chemistry. Experimental parameters include concentration of the liquid peroxide, residence time, mass and momentum ratio between the decomposition stream and the injected liquid, and injection area. Decomposition efficiencies ranging between 10 and 90% were measured. A limited number of highly accurate differential pressure measurements were made to determine local axial pressure gradients. The results indicate that liquid mass fraction is inversely proportional to decomposition efficiency, while residence time and hydrogen peroxide concentration are directly proportional. More testing is required to determine the exact correlations between these and other parameters, primarily momentum ratio.

W. J. Helms

Papers

Thermal Decomposition of Hydrogen Peroxide, Part I: Experimental Results

Decomposition and Vaporization Studies of Hydrogen Peroxide