Terraviva Domestic Composter

In recent years, with the rapid development of society and economy, the phenomenon of garbage surrounding cities has attracted much attention. It is expected that by 2020, the annual discharge of urban household waste in China will reach 755 million tons. The rapidly increasing discharge of urban garbage has become an important factor restricting economic development and posing a threat to the human living environment. How to economically and effectively manage this garbage and prevent pollution has become an urgent hot issue that needs to be addressed by the whole society.

Cities are large resource consuming areas, and if not handled properly, they can also be significant sources of pollution. The expansion of urban scale not only promotes economic development and social prosperity, but also puts enormous pressure on the earth. Whether the problem of energy recycling within cities can be solved directly affects the implementation of sustainable development concepts and whether economic development can truly meet the needs of contemporary people without harming the ability of future generations to meet their needs.

Guided by this concept, our company has accumulated rich experience in various types of waste disposal through years of practice and exploration. The household waste treatment line designed and produced by our company is also developing towards modularization, modularity, and integration. In recent years, professional and personalized process solutions have been developed that can be tailored to the characteristics of waste in different regions and customer requirements, and have received high praise from a large number of customers.

Household waste belongs to biomass waste, and the volatile matter in household waste is particularly high, accounting for about 70% of the calorific value, while coal is relatively low, with anthracite accounting for less than 10%. Volatile matter is mainly composed of high calorific value hydrogen, oxygen, methane, and hydrocarbons. Coal mainly generates heat during combustion, while household waste releases a large amount of volatile matter at 225-500 ℃ during combustion. It is difficult to completely burn it with a single gas supply, so household waste is not suitable for direct combustion. The way to burn household waste is to use medium temperature and oxygen deficient pyrolysis to extract the volatile components from the waste and convert them into biomass combustible gas, which can be burned like natural gas. That is to say, household waste is a good raw material for producing combustible gases.

Compared with traditional pyrolysis of household waste, thermal cracking with low temperature and oxygen in household waste can produce combustible gases, but there is a qualitative difference.

Traditional household waste pyrolysis

Traditional household waste pyrolysis is high-temperature pyrolysis, which produces combustible gases and ash from waste under thermal conditions of partial carbon combustion and partial carbon reduction.

The traditional pyrolysis of household waste produces combustible gases mainly through the oxidation-reduction and cracking reactions of the waste raw materials. Oxidation reaction: It is a combustion reaction between a portion of carbon in garbage and air, generating a large amount of carbon dioxide and releasing heat at a temperature of up to 1000-1300 ℃. This heat provides a heat source for reduction and cracking reactions.

Reduction reaction: Carbon dioxide and residual carbon generated in the oxide layer undergo a reduction reaction with water vapor, producing carbon monoxide and hydrogen gas.

Cracking reaction: At a temperature of 225-500 ℃, combustible gases, carbon, tar, and water vapor are released.

The combustible gases produced by traditional household waste pyrolysis are carbon monoxide (15-20%), nitrogen (about 50%), and volatile gases (only 30-35%), so their calorific value is relatively low. The calorific value of combustible gas per cubic meter of waste is about 1000 kcal, and about 3 cubic meters of gas can be generated per kilogram of waste; Due to the complete consumption of charcoal, only residual ash remains (some municipal solid waste pyrolysis furnaces advertise that they also produce charcoal, but this is also because the slag discharge is too fast, and the charcoal is not completely burned out. If there is charcoal, it is not good charcoal). At present, the thermal decomposition performance of small traditional household waste in China is extremely unstable and cannot be widely applied, while the thermal decomposition of large traditional household waste has extremely unsafe factors and is trapped by ash, floating ash, and tar.