Sludge Carbonization Turns into Biochar Fertilizer and Soil Remediation Agent

Every day, the Chengbei Sewage Treatment Plant generates more than 45 tons of sludge with a moisture content of about 80%, which requires specialized transport vehicles to deliver to brick factories as raw material for brick making. In the workshop, the reporter saw that after high-temperature carbonization, the sludge has turned from yellow to black, becoming reusable biomass charcoal. The site manager introduced that by lifting the sludge from the sludge storage tank into the sewage pipes inside the plant, the dewatered sludge becomes biomass charcoal.

It is reported that ten tons of sludge with 80% moisture content can be carbonized into one ton of biomass charcoal with moisture content less than 1%. During the carbonization process, the odor factors and heavy metals inherent in the sludge are deodorized and solidified by high temperature. The pyrolysis gas generated during carbonization is cracked at high temperature and then introduced through pipes into a burner where it serves as fuel to provide energy for the carbonization furnace. The entire process produces no residue and generates no new pollution.

The deeply processed product, biomass charcoal, is rich in nitrogen, phosphorus, and potassium, and is loose and porous. It can serve as a soil remediation agent, soil conditioner, and purification adsorbent for sewage treatment, among other raw materials. It can also be used as biochar-based fertilizer to improve soil fertility and combat soil compaction, fully achieving waste treatment with waste, energy conservation and emission reduction, and recycling of materials. After joint commissioning of previous processes, more than 100 tons of biomass charcoal have been produced. Currently, the equipment in this workshop has been operating continuously 24 hours a day, and will be able to accommodate the remaining sludge from the entire Chengbei Sewage Treatment Plant.

Editor: Liu Zishan

Reviewer: Huang Jingyu

Changsha County Radio and Television Station report link: http://csxxsj.cn/xingsha-news/info-video-news.html?infoId=9685&token=c206395a8a8141949f8758f655861ee41527564451364&token=c206395a8a8141949f8758f655861ee41527564451364​