Abstract: A system for pre-treating biomass for the production of ethanol is provided. The system supplies biomass to a steaming bin, wherein the biomass is mixed with water, and inputting the steamed biomass to a first pretreatment reactor, wherein the steamed biomass comprises liquids and solids. The system removes a bulk of liquids from the solids and feeding the solids into a second pretreatment reactor. The system applies a pressure drop to the solids in the second pretreatment reactor, wherein the pressure drop opens up a structure of the solids, and sending the solids to a fermentation process for ethanol processing.

Abstract: The present invention is a catalyst comprising one or more kinds of catalyst metal, a promoter metal composed of at least one element selected from alkaline earth metals, transition metals, rare earth metals, aluminum and gallium, and a support, wherein the catalyst metal and the promoter metal are supported on the support through allowing a multi-element metal colloid solution to be attached to the support, and the multi-element metal colloid solution comprises a solvent comprising water or a mixture of water and an organic solvent, metal cluster particles which are dispersed and suspended in the solvent and composed of one or more kinds of catalyst metal, a protective agent for protecting the metal cluster particles, and one or more kinds of metal ions bonded to the protective agent, the ions selected from alkaline earth metal ions, transition metal ions, rare earth metal ions, aluminum ions and gallium ions.