System and method for treating sludge and organic wastes

Abstract

The invention relates to a system and a method for treating sludge and organic wastes. The invention relates to the system and the method for treating various organic wastes such as sludge, kitchen waste, kitchen garbage, biomass, excrement (including livestock excrement), straw and the like. A pyrohydrolysis device is used for pretreating the sludge, so the dewatering performance and the digestion performance of the sludge are improved, and the sludge is inactivated at high temperature; combined treatment is conducted on various mixed organic wastes by adopting combined anaerobic digestion to generate biogas and biogas residues; the biogas is used as fuel or used for power generation or natural gas purification, the biogas residues are dried by various waste heat of a cement kiln and then are pyrolyzed and gasified, and finally, pyrolysis residues and pyrolysis gas are generated; and the pyrolysis residues are used as a cement kiln raw material, and the pyrolysis gas is used as cement kiln fuel and plays a role in flue gas denitration. By means of the system and the method, harmless, stable, reduction and recycling treatment of various mixed organic wastes such as sludge, kitchen waste, kitchen garbage, biomass, excrement (including livestock excrement) and straw is achieved.

Description

technical field [0001] The invention relates to the technical field of sludge and organic waste treatment, in particular to a system and method for thermal hydrolysis combined with anaerobic digestion, pyrolysis gasification and cement kiln waste heat treatment of sludge and organic waste. Background technique [0002] With the acceleration of my country's urbanization process and the rapid development of social economy, the output of various organic wastes such as sludge, kitchen waste, kitchen waste, biomass, manure (including livestock), and straw has increased year by year, which has a great impact on the ecological environment. The pressure is increasing. [0003] For example, sludge is a by-product of the sewage treatment process, mainly from the primary sedimentation tank and secondary sedimentation tank of the sewage treatment plant. Sludge not only contains a large amount of organic matter and plant nutrients such as nitrogen and phosphorus, but also a certain amoun...

AI Technical Summary

Problems solved by technology

Such as the existing technology 1: the sludge is dehydrated after adding chemicals to achieve initial reduction, and then it is directly pulled to make bricks, and then sent to a power plant or cement plant for incineration; such as the existing technology 2: the dehydrated municipal sludge continues to be dried with an external heating source Further dehydration is achieved, and the dried sludge is then sent to brick making, power plants or cement plants for incineration to achieve final reduction and harmlessness; however, the sludge in the prior art 1 is directly dehydrated and reduced without pretreatment. Quantitative treatment, the dehydration effect is average; and some have added a large amount of chemicals for the dehydration effect, which greatly reduces the reduction effect; the final sludge is incinerated, and the more water contained in it will affect the stability of the incineration process

In prior art 2, the sludge is dried after dehydration to minimize the moisture content in the sludge. This method avoids the impact on the incineration process, but the drying process requires an external heat source, which increases energy consumption. ; In addition, the organic matter in the sludge is a precious resource, and this technology only "burns" the sludge, and the resource utilization method is not high

Images