DESC:DESCRIPTION OF THE INVENTION: -
The invention is about an apparatus and method for conversion of pre-processed organic wastes into carbon rich product through thermal treatment in a specially designed apparatus which operates under controlled oxygen conditions at high temperature.
The invention has the capability to handle most of the organic waste materials Fig 1. (101) comprising of faecal sludge Fig 2 (208), sewage sludge Fig 2 (209), agricultural waste Fig 2 (210), and other organic wastes Fig 2 (211) further comprising of food waste, yard waste and organic fraction of municipal solid waste etc.,
Faecal sludge Fig 2 (208), broadly consists accumulation from onsite sanitation systems comprising of pit latrines, septic tanks, and container-based solutions which are not transported through a sewer and mainly comprises of human excreta along with onsite containment comprising flush water, cleansing materials and contraries.
Sewage sludge Fig 2 (209), comprise residual, semi-solid material which is produced as a by-product during sewage treatment of municipal wastewater.
Agricultural waste Fig 2 (210), contains residue waste of various agricultural operations which includes manure and other wastes from farms, poultry houses and slaughterhouses; harvest waste including stalks, stems and roots.
Other organic wastes Fig 2 (211), include food waste, yard waste and organic fraction of municipal solid waste.
Figure 1 illustrates the process of making carbon rich product from organic waste matters Fig 1 (100) comprising of faecal sludge, sewage sludge, agricultural field residue and other organic material and forms the raw material Fig 1 (101) of the process. The input feed is subjected to pre-processing steps The pre-processing Fig 1 (102) includes dewatering, size reduction and drying.
The pre-processing steps are different for different input materials, faecal sludge Fig 2 (208) require mechanical dewatering of sludge Fig 2 (212) followed by drying Fig 2 (213). Dewatering is carried out to ensure that the moisture content is not more than 80%. In the case of sewage sludge Fig 2 (209), it requires to be fully dried Fig 2 (212 & 213) before being processed. Agricultural waste Fig 2 (210) undergoes mechanical shredding Fig2 (214) and drying Fig 2 (213), mechanical shredding is carried out to ensure that the particles are within the size of 50mm and for any other organic materials Fig 2 (211) such as food waste, yard waste and organic fraction of municipal solid waste etc., they will have to undergo mechanical dewatering Fig 2 (212) , mechanical shredding Fig 2 (214) and drying Fig 2 (213) depending on the material.
Once the sludge is dried to less than 35% moisture, these materials are used as the input feed to the Carbonizing reactor Fig (3A & 3B) and the thermochemical conversion Fig 2 (218) of the dried input feed is carried out in the following steps: -
1. Further drying of sludge Fig 2 (216);
2. Thermal chemical conversion process Fig 2 (218);
3. Carbon rich product collection, cooling, and storage Fig2 (219 & 220);
4. Secondary burning Fig 2 (223) of the syngas Fig 2 (223) being the by product is passed through separator Fig 2 (224) for emission control Fig 2 (226);
5. Transfer of heat energy Fig 2 (227) from Flue gas Fig 2 (223) to auxiliary systems Fig 2 (228) through heat exchanger Fig 2 (225) .
The dried organic matter Fig 2 (213) is fed into the feed hopper Fig 2 (215) & Fig- 3A&3B (300) which is conveyed Fig- 3A&3B (312) to the drying zone of grate Fig 2 (216) & Fig 3A (314) where the material is further dried and subjected to primary thermochemical conversion process Fig 2 (218). The material is subjected to thermal treatment at a temperature between 500-750°C in controlled air condition. The thermochemical treatment zone consists of a controlled primary air inlet Fig 2 (217) to facilitate thermal conversion Fig 2 (218) and the organic material gets converted to carbon rich product Fig 2 (219). The output of the primary process Fig 2 (202) which is a carbon rich product from the reactor zone is then transferred to the storage container Fig 3A & 3B (304). To eliminate chances of accidental combustion of the carbon rich product the storage container Fig 2 (220) and 3A & 3B (304) is kept absolutely free from air. The bio rich product is cooled and transferred to an external storage unit Fig 2 (221).
The primary process Fig 2 (202) also produces syngas Fig 2 (222) as a byproduct, which is further directed towards a secondary combustion area Fig 2 (224) within the carbonizing reactor. In this area excess secondary air Fig 2 (223) is provided to ensure complete combustion of the syngas Fig 2 (222), by subjecting it to high temperature conditions up to 950 °C. The flue gas Fig 2 (225) thus produced is then directed towards the gas cleaning system Fig 2 (226) to remove any residual toxic components and for dust removal. The flue gas Fig 2 (225) is passed through a heat exchanger Fig 2 (227) to extract the heat for heating air or water Fig 2 (229) of the auxiliary system Fig 2 (230) before finally being released to atmosphere through a chimney Fig 2 (228).
The Carbonizing reactor comprises of the following parts:-
a. Outer body Fig 3A & 3B (317) made of metal shell with internal and external insulation Fig 3A & 3B (315 & 316) and an external skin for aesthetic appeal;
b. A grate Fig 3A & 3B (314) is designed and placed at an angle for further drying of the raw material in the carbonizing rector. Based on the raw material type, volume and size of the plant, the design of the grate is varied. In one of the embodiments the grate could be static Fig 3A & 3B (314), in another embodiment it could be pusher plate model and yet another embodiment it could be of moving type based on the raw material and size of the unit;
c. Air blowers to provide controlled primary Fig 3A & 3B (302) and secondary air Fig 3A & 3B (307) with provision for ducting to cool the bio rich product and external skin of the carbonizing reactor.
d. Material feed system Fig 3A & 3B (300), consisting of either a pusher plate or screw mechanism Fig 3A & 3B (312) based on the raw material and size of the unit
e. Screw conveyor systems Fig 3A & 3B (318) is utilized for bio rich product movement from the internal storage Fig 3A & 3B (304) to the external storage.
f. An induced draft fan Fig 3A & 3B (307) to aid as a catalyst for secondary combustion and for safe extraction of flue gases
Additional Features of the Carbonizing reactor
I. Carbonizing reactor can be adopted for different feed stock by controlling the feed rate, primary and secondary air and the carbon rich product extraction rate
II. The scaling of the unit can be done by increasing the length, width and type of the grate unit and the carbon rich material storage capacity.
III. Temperature Sensors are provided in the Carbonizing reactor at suitable locations for monitoring the temperature and flue gas characteristics and is being used to monitor and control the unit operations.
IV. Level sensors are installed to monitor the level of raw material and finished products to send alerts to the respective motor controls for stop and start operations on achieving low and high levels respectively.
V. The control of the motors can be done using a manual control panel or through an automated control panel with IOT for remote monitoring and control.
VI. The hot water/hot air can be used for drying of the input material or for the other requirements.
VII. The carbon rich material is used as a soil enhancer in agriculture fields.
TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE OF THE INVENTION
The invention has ample utility value and is capable of providing smart solutions to variety of service applications such as:
Uses of Biochar
Biochar has multiple uses in soil and could help in tackling the problem of soil infertility due to climate change.
1. Enhances Soil Nutrients: Biochar is a natural fertilizer that enhances soil nutrients and prevents them from leaching.
2. Promotes Soil Health: Biochar is used to promote soil health by retaining soluble nutrients in the soil.
3. Remediation of Soil: Biochar is often used for the remediation of soil suffering from heavy metal pollution.
4. Increases Activity of Soil Biota: During unfavorable weather conditions, biochar retains water due to its porous nature and provides nutrients to microbial communities living in the soil.
Advantages of Biochar
Biochar has many advantages due to its properties. Because it is a natural product that has fewer negative impacts on the environment.
1. Less Emission of Greenhouse Gases in the Air: Biochar is a stable product that could stay in the soil for many years, ultimately reducing the emission of greenhouse gases from the burning of biomass.
2. Water Retention: Biochar has moderate porosity that increases the water retention of soil. In this way, it assists soil in growing plants and vegetables.
3. Carbon Sequestration: The conversion of biomass into biochar does emit carbon in the air but it is less as compared to the combustion of biomass. Hence biochar represents carbon sink in soil.
4. Agricultural Productivity: The application of biochar in the soil increases agricultural productivity and promotes agricultural resilience.
5. Reduction in Soil Acidity: One of the main advantages of biochar is it helps in decreasing soil acidity which hinders crop production.
,CLAIMS:We Claim,
1. A method for conversion of organic matter into heat energy and carbon rich soil fertility booster comprising:
= receiving and storing of plurality of organic materials comprising of faecal sludge, sewage sludge, agricultural waste, and other organic wastes at site after being segregated and moved Fig 2 (200) from source location;
= Carrying out pre-processing Fig 2 (201) operation at site, the process comprises of
i) treating faecal sludge Fig 2 (208) and sewage sludge Fig 2 (209) by mechanical dewatering Fig 2 (212) and drying Fig 2 (213) for moisture reduction and alternately;
ii) treating agricultural Fig 2 (210) and other organic waste Fig 2 (2011) by mechanical shredding Fig 2 (214) and drying Fig 2 (213) to achieve size reduction;
= primary carbonizing process Fig 2 (202) comprising of
i) material feeding through feed hopper Fig 2 (215);
ii) passing through slope grate for further drying Fig 2 (216) and thermo-chemical conversion Fig 2 (218) with the aid of primary air Fig 2 (217) to produce carbon rich product Fig 2 (219) and syngas Fig 2 (222) as by product along with heat energy;
iii) movement of carbon rich product to airtight storage Fig 2 (220) for cooling and further utilization for agricultural use for soil enrichment Fig 2 (221);
= secondary combustion process Fig 2 (224) for complete burning of syngas Fig 2 (222) with the aid of secondary air Fig 2 (223) to produce flue gas Fig 2 (225) and additional heat;
= heat exchanging process Fig 2 (227) for utilizing the heat energy for heating of air or water Fig 2 (229) of the auxiliary system Fig 2 (230) or for drying of the organic raw material of the main process.
2. An apparatus being carbonizing reactor Fig 3A & 3B for conversion of organic matter into heat energy and carbon rich soil fertility booster comprising:
= material feed system Fig 3 (300) for feeding the dry raw material into sloping grate Fig 3 (314)for further drying of the organic material and facilitate thermo-chemical conversion to carbon rich product and syngas as byproduct;
= Air blowers to provide controlled primary air Fig 3 (302) for thermo-chemical conversion and secondary air Fig 3 (307) for secondary combustion of syngas with provision for ducting to cool the carbon rich product and external skin of the carbonizing reactor
= Screw conveyor system Fig 3 (318) for carbon rich product movement from internal storage to external storage;
= An induced draft fan Fig 3 (313) to aid as a catalyst for secondary combustion and safe extraction of the flue gas;
= Gas cleaning and dust collection system for emission control;
= Heat exchange system for cooling of flue gas by utilizing the heat energy for heating of air or water of auxiliary system or for drying of raw material of the main process;
= Temperature and level sensors for monitoring and controlling the temperature and the level of the raw material and carbon rich product output respectively.

3. Carbonizing reactor as claimed in claim (2) is scalable for different feed stock by altering the size , the feed rate, primary and secondary air, and carbon rich product extraction rate.
4. Carbonizing reactor as claimed in claim (2) The control of the various motors can be done using a manual control panel or through an automated control panel with VFD and can also be supported with IOT for remote monitoring and control.

Dated this 30th August 2023
(Santhanam L)
Patent Agent, IN/PA -3125