A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide(H2S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as H2S oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of H2S inlet concentration and EBCT(Empty Bed Contact Time) on H2S elimination. The pressure drop for particles of size range from 5.6 to 10 ㎜ was 14 ㎜H2O/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under H2S inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of 15.2 ℓ/min. H2S removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of H2S inlet concentration. When EBCT was reduced to 5.5 sec, H2S removal efficiency decreased by about 12 percent. The maximum H2S elimination capacity was determined to be 269g-H2S/㎥·hr.

Sorbents of calcined limestone and oyster particles having a diameter of about 0.63㎜ were exposed to simulated fuel gases containing 5000ppm H2S for temperatures ranging from 600 to 800℃ in a TGA (Thermalgravimetric analyzer). The reaction between CaO and H2S proceeds via an unreacted shrinking core mechanism. The sulfidation rate is likely to be controlled primarily by countercurrent diffusion through the product layer of calcium sulfde(CaS) formed. The kinetics of the sorption of H2S by CaO is sensitive to the reaction temperature and particle size, and the reaction rate of oyster was faster than the calcined limestone.

A porous α-alumina tube of 2.5 ㎜ O.D. and 1.9 ㎜ I.D. was used as the support of an inorganic membrane. Macropores of the tube, about 150 nm in size, were plugged with silica formed by thermal decomposition of tetraethylorthosillcate at 600℃. The forced cross-flow CVD method that reactant was evacuated through the porous wall of the support was very effective in plugging macropores. The H_2 permeance of the prepared membrane was of the order of 10^-8 mol s^-1 m^-2 . Pa^-1, while the N_2 permeance was below 10^-11 mol. s^-1 . m^-2 . Pa^-1 at 600℃. This was comparable to that of silica-modified Vycor glass whose size was 4 nm.

The pure compound chloromethanes; methyl chloride, methylene chloride, chloroform and carbon tetrachloride were used as a model of chlorocarbon system with Cl/H ratio to investigate thermal stability and hydrodechlorination process of carbon tetrachloride under excess hydrogen atmosphere. The parent thermal stability on basis of temperature required for 99% destruction at 1 second reaction time was evaluated as 875℃ for CH3Cl, 780℃ for CH2Cl2, 675℃ for CHCl3, and 635℃ for CCl4. Chloroform was thermally less stable than CCl4, at fairly low temperatures (<570℃). The decomposition of CCl4, became more sensitive to increasing temperature, and CCl4 was degraded easier than CHCl3 at above 570℃. The number and quantity of chlorinated products decreases with increasing temperature for the product distribution of CCl4 decomposition reaction system. Formation of non-chlorinated hydrocarbons such as CH4, C2H4 and C2H6 increased as the temperature rise and particularly small amount of methyl chloride was observed above 850℃ in CCl4/H2 reaction system. The less chlorinated products are more stable, with methyl chloride the most stable chlorocarbon in this reaction system.

Granular sludge formation and it`s activity change are the most important factors in achieving successful start-up and operation of UASB reactor. Nevertheless, the detailed mechanism is still unknown. On the basic of the experiments in laboratory-scale UASB reactor, the effect of hydrogen partial pressure on sludge granulation was evaluated. Size distribution method and specific metabolic activity of the sludge with the operation time were used as a means for estimating the degree of the sludge granulation. At the constant hydrogen loading, the granulation increased as starvation periods in hydrogen supply increased, resulting in high organic removal efficiency. It was evidient that hydrogen play very important role in granulation and sludge granulation was achieved through mutual symbiosis between hydrogen utilizing bacteria and hydrogen producing bacteria under the hydrogen deficient conditions.