Method for promoting rapid preparation of methane from organic waste by utilizing exogenous hydrogen

Abstract

The invention relates to a method for promoting the rapid preparation of methane from organic waste by utilizing exogenous hydrogen. The method comprises the following steps of: mixing sludge and domestic garbage in a weight ratio of 1:(2-4), wherein the content of volatile substances (VS) in the mixture is 20 to 65 percent, and the water content is 18 to 68 percent; and performing anaerobic fermentation reaction on the mixture for a period of 7 to 14 days at the temperature of between 35 and 37 DEG C and at the pH value of between 6.5 and 7.5, and introducing exogenous pure hydrogen under the pressure of between 1.1 and 5.5MPa from the bottom of the mixture in the second day of each period, wherein the maximum daily output of the methane can reach 3.65L / kg.d when the introducing amount is 50 to 150mL H2 / kg VS, and is 2.81 times the yield of the methane when the hydrogen is not added. The concentration of the methane can be improved from 33.2 percent to 75.5 percent. The cost is low, the method is easy to operate, the problem of environmental pollution of municipal refuse and greenhouse gas is solved, and the clean energy is also provided, so that the method has good social benefit and economic benefit. The method can be widely applied to the rapid preparation of the methane from the organic waste in middle and small-sized landfill sites.

Description

technical field [0001] The invention relates to a method for using exogenous hydrogen to promote rapid methane production of organic waste, and belongs to the technical field of solid waste recycling and pollution prevention and control. Background technique [0002] With the sustainable development of the economy and the steady improvement of residents' living standards, the annual output of municipal solid waste in my country has reached 150 million tons (per capita daily output is 0.9-1.2 kg), and it is increasing at a rate of 8-10% every year. Landfill is still the main way to deal with domestic waste in most cities in my country. During the landfill process, a large amount of methane greenhouse gas will be released, with a content as high as 50-60%. In large-scale landfills, landfill gas will be collected through pipelines and special gas-collecting devices, but for small and medium-sized landfills, due to unstable gas production, low total gas volume, and low comprehen...

AI Technical Summary

Problems solved by technology

[0005] Although there are many methods for increasing methane production reported at present, there are the following problems: 1. The promotion effect is not obvious, and some additives can only increase about 5-10% of methane due to loss or inability to distribute evenly; 2. The operation is complicated and difficult control

Although two-phase anaerobic fermentation can control the conditions of the methanogenic stage to the best, adjusting the parameters of the fermentation stage is a huge project for a device or site with a large daily processing capacity, and factors such as moisture content and temperature are affected. External weather conditions are greatly affected and are not easy to be controlled by humans; 3. The cost is high and it is not suitable for large-scale projects. For example, metal salt additives are not widely used due to the large amount required

4. Biogas backflow will also have disadvantages

Take the H formed in the previous stage 2 with CO 2 Introduced into the methanation stage, will cause H 2 Seriously insufficient

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