Question

Consider the following statements with respect to hydrothermal carbonisation:

1. It is a thermo-chemical process that converts wet biomass into a carbon-enriched solid.
2. Biochar generated from the reaction can be used in soil improvement in contaminated land sites.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2​

Answer 1

Option C - Both 1 and 2

■ Explanation :-

• A research team from IIT Kharagpur has adapted a process called Hydro Thermal Carbonization (HTC) for the Indian conditions which can effectively manage mixed Municipal Solid Waste (MSW) with high moisture content. Through the process most of the mixed MSW can be converted into biofuel, soil amendment and absorbents.

• Hydrothermal Carbonization (HTC) is a chemical process for the conversion of organic compounds to structured carbons. It can be used to make a wide variety of nanostructured carbons, simple production of brown coal substitute, synthesis gas, liquid petroleum precursors and humus from biomass with release of energy. Hence statement 1 is correct.

• The current waste burning processes adopted from the developed nations are primarily focused on treating drier waste content. These processes require high energy input to combust municipal solid waste generated in India which has high moisture content due to tropical weather, open collection systems and mixed waste.

• The Hydrothermal Carbonization (HTC) process allows the treatment of wet biomass without the need for a drying pretreatment, which is necessary for traditional thermochemical processes (combustion, air gasification, pyrolysis). The process novelty lies in the use of water for the reaction thus the moisture in the MSW gets used during the recycling process without requiring any removal of moisture from segregated wet waste or high energy intake.

• Once the organic waste is entered into the process, the output generated are all usable including the water which can either be reused in the process or can be converted to biogas or methane through anaerobic digestion.

• The biofuel (biochar) generated as the recovered output is comparable to lignite coal thus significantly addressing the fossil fuel depletion issue and helping curb air pollution issues. The product can further be used as an absorbent to manage soil contamination. This could significantly help brownfield sites or contaminated industrial sites or landfills. Hence statement 2 is correct.

Hope It helps you.