Static Factorial Experiment And Initial Pilot-scale Test On Bio-desulfurization Of Biogas

Hydrogen sulfide in biogas is one of the most obstructive factors on utilization of biogas as fuel gas. At present, a domestic desulfurizing process of biogas in wide-spread use is the ferric oxide process, but the main disadvantages of that include: the high cost of desulfurizer, the difficult regeneration of it and the second pollution caused. Recently, the bio-desulfurization of biogas is focused, as a new technique. The previous researches are paid more attention to the operational analysis of an individual reactor, cultivation and domestication of the high efficiency sludge in desulfurization, physico-chemical characteristics of the desulfurizing microorganism, and so forth. However, it is absent to study the general effect factors in bio-desulfurizing process of biogas for engineering application, systematically.This dissertation, with the experience of an initial pilot-scale test, the conceptual design of static factorial experiments and the quantitative analysis of some effect factors, is expected to provide a clue or a reference for technique research and engineering application of latter day. The main conclusions are as follows:1. In the different media liquids, there are functional relations of quadratic polynomial with negative correlations between the proportion of anaerobic sludge and the removal efficiency of hydrogen sulfide; the functional variation rate presents a descending trend.2. There is a functional relation of power with positive correlation between the biogas retention time and the removal efficiency of hydrogen sulfide. The whole reaction rate of desulfurizing process presents a descending trend and becomes stable.3. There is a difference on functional relations between the reaction temperature and the removal efficiency of hydrogen sulfide in two stages, and these are a linear function and a quadratic function, with positive correlation, respectively. Therefore, while the reaction temperature rises in a certain range, the effect of desulfurization gets better. Temperature shocks have significant influences on desulfurization, the stable reaction temperature is a necessary condition of the stable removal efficiency of hydrogen sulfide, consequently.4. There is no relation between the air loads and the removal efficiency of hydrogen sulfide, however, the consumption of dissolved oxygen is measured before and after reaction in the experiment.5. There is a functional relation of exponent with negative correlation between the biogas loads and the removal efficiency of hydrogen sulfide; there is a functional relation of quadratic polynomial with positive correlation between the capability of desulfurizing liquid and the biogas loads; the functional variation rate presents a descending trend, either.6. The average removal efficiency of hydrogen sulfide in the groups with packing and without packing is 96.1% and 73.6%, respectively.7. It is an efficient scheme to remove hydrogen sulfide of high concentration in biogas by using the biological & chemical combined process on engineering. Removing some hydrogen sulfide in biogas by the bio-desulfurizing tower in the first stage, it is to make the concentration of hydrogen sulfide in biogas met the standard on utilization of fuel gas by the chem-desulfurizing tower in the second stage.