Activated alumina

About: Activated alumina is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 31090 citations.

Agent for detoxifying halogen-based gas and acidic gas

Abstract: PROBLEM TO BE SOLVED: To provide an agent for detoxifying halogen-based gas and acidic gas, by which waste gas such as halogen-based gas and acidic gas is fixed efficiently so that the fixed waste gas is not separated again from the agent and does not pollute the environment. SOLUTION: This agent for detoxifying halogen-based gas and acidic gas contains slaked lime having ≥0.1 cc/g pore volume as a principal component and has a granulated shape. This agent can furthermore contain a hydroxide of an alkali metal or an alkaline-earth metal other than calcium and/or at least one of activated carbon, activated alumina, sepiolite, zeolite, silica gel and activated clay, as an adsorbent. COPYRIGHT: (C)2005,JPO&NCIPI

Ammonia synthetsis iron-alkali metal-carrier- - catalyst

Abstract: The catalyst contains 5-25 wt.% of reduced Fe, deposited on an activated alumina or silica carrier containing 3-30 atoms of alkali metal promotor (spec. Cs or K) per 100 molecules of carrier. These catalysts have very even activity, even with varying particle size or temp. they are very suitable for the first bed where high temp. rises can occur.

Thiobacillus denitrificans immobilized biotrickling filter for NO2 removal

Abstract: Nitrogen dioxide (NO2) removal efficiency of a biotrikling filter was evaluated under different operating conditions. Activated alumina (AA) was used as the immobilization matrix for Thiobacillus denitrificans (T. denitrificans) in the biotrickling filter. Batch studies were conducted to find out the degradation kinetics of nitrate and nitrite for a concentration range of 600–10,000 mg/L expressed as nitrogen. Nitrite exhibited maximum degradation rate followed by nitrate. Electron acceptor in the form of NO2 gas showed least removal efficiency. Bio-kinetic parameters for T. denitrificans, by utilizing nitrate and nitrite as electron acceptors, were also evaluated. The μmax (Maximum specific growth rate) and YT (Yield coefficient) values for T. denitrificans in the presence of nitrate and nitrite were 1.03 h−1, 0.275 and 0.63 h−1, 0.1316 respectively. Column study was conducted to find the adsorption and desorption potential of activated alumina. The adsorbed NO2 from AA could easily be desorbed using distilled water with an efficiency of 76±0.8%. Once fed batch studies were conducted to evaluate the NO2 removal efficiency by a biotrickling filter. With an influent NO2 gas concentration of 2,735 ppm, the reactor could achieve a removal efficiency of 99% within 2 min from gas phase and within 96 h from the liquid phase, with an average biomass concentration of 200 mg/g of AA. The mechanism of NO2 gas removal in the biotrickling filter seems to be the dissolution of NO2 in water to form NO 3 − , conversion of NO 3 − to NO2 −, and finally to N2 gas.

Preparation of high temperature-resistant active aluminum oxide

Abstract: The invention relates to a method for preparing fireresistant activated alumina. A liquid phase counter-titration precipitation method is adopted; a sodium aluminate solution and a nitric acid solution are used as raw material; organisms are used as a pore expanding agent; a rare earth oxide is used as a stabilizing agent; the alumina with large specific surface area and good fireresistant performance is prepared by adopting the liquid phase counter-titration precipitation method. The rare earth oxide content in the alumina is between 0.1 and 10 wt percent; an alumina solid is treated for 5 hours in the atmosphere of 700 DEG C; the specific surface area of the alumina solid is more than 350m /g; the average pore volume is 0.3122 mL/g; the average aperture is 5.23 nm; and the aperture distribution range is between 3 and 12 nm. The alumina solid is treated for 5 hours in the atmosphere of 1100 DEG C; and the specific surface area of the alumina solid is more than 150 m /g. The method has the characteristics of low production cost, simple process, large specific surface area, even aperture distribution and good high-temperature thermal stability.