2.0 Literature survey
Food waste is the second largest category of municipal solid waste (MSW) sent to landfills. Over 30 million tons of food waste is sent to landfills each year and much of this goes into landfills where it produces methane, thus contributing to global warming. The most important reason that food waste should be recycled is for capturing the energy content. Food waste is highly biodegradable and has a much higher volatile solids destruction rate (86-90%) than bio solids. In fact, in a study done by East Bay Municipal Utility District it was revealed that food waste has up to three times as much energy potential as bio solids.
2.1 Types of Technology
1.0 Thermal Depolymerization
Thermal depolymerization is an industrial process of breaking down various waste materials into crude oil products. The materials are subjected to high temperatures and pressure in the presence of water, thereby initiating hydrous pyrolysis.
It is said to mimic the natural geological processes thought to be involved in fossil fuel production. Thermal depolymerization occurs in nature when an accumulated biomass is heated and pressurized in the earth's crust over millions of years. This biomass, also known as kerogen, is believed to react with clay mineral enzymes at temperatures below 200°C (392°F), which produces oil (Azocleantech.com).
Brune (2012) states that applying pressure and heat to the decaying remains of plants and animals transforms their long chains of hydrogen, oxygen and carbon into the short-chain hydrocarbons that make up oil. But while the earth takes millions of years, TDP takes a few hours.
Thermal depolymerization technology has a plethora of benefits that other technologies lacks. Thermal depolymerization is a useful process of recycling the energy content of organic products while retaining the water content. It avoid drying while producing liquid fuel that separates from water in thermal depolymerization. The vast bulk of waste content can be utilized to produce liquid crude oil products. This will not only make good use of all the non bio-degradable waste but also help in producing some crude oil. The light hydrocarbons that are produced by thermal depolymerization can be used fuel sources, filters and fertilizers (Community.Drprem.com).
Thermal depolymerisation is also highly sustainable economically, socially and environmentally. Thermal depolymerization breaks strong chemical bonds of organic poisons which is extremely beneficial to balance the ecosystem. It can be used a s a substitute for coal and also in quelling the alarming rise of carbon dioxide concentration in the air. CO2 is one of the chief greenhouse gases that is responsible for global warming.
Using water as medium, thermal depolymerization process not only helps in making good use of waste matter and by products, but it also produces fuel resources that can be a boon for the entire world. Invaluable fuel products can be produced in an environmentally friendly way from low quality feed stocks and organic waste. It also eliminates nitrogen and sulfur compounds and brings out clean and highly useful crude oil products (Community.Drprem.com).
The technology does not involve the usage of catalyst.
2.0 Anaerobic Digestion
Anaerobic Digestion uses microorganisms to break down food waste, animal manure, slurries and energy crops in the absence of oxygen, inside an enclosed system. As it breaks down it gives off methane, which is collected and converted into biogas and used to generate electricity, heat or transport fuels. It also creates a nutrient-rich digestive that can be used as a fertiliser for agriculture and in land regeneration
3.0 Hydrothermal Carbonization
Hydrothermal carbonization (HTC) is a technology (biomass conversion) of biofuel)that has recently been further developed. It involves moderate ranges of temperatures and pressures over an aqueous solution of biomass in a dilute acid for several hours. The resulting matter reportedly captures 100% of the carbon in a "bio coal" powder that could provide feed source for soil amendment (similar to bio char).
The reaction mainly involved is pyrolysis. In this reaction the feed is broken down to separate the liquid and solid composition separately. Then the remaining wet solid is dried at temperatures of 200-350 degree Celsius for around 8 hours.
The benefits of this process is that it’s economically efficient and less costly. The cons of it is that the process take very long.
2.3 Technology Used
Hydrothermal carbonization (HTC) is a chemical process which emulates the natural coalification of biomass (Blohse et.al). It involves a thermal conversion technique that converts food wastes and associated packaging materials to a valuable, energy-rich resource. The process uses a combination of heat and pressure to chemically transform bio-waste into a carbon dense material with similar or better properties as fossil coal.
This HTC technology was chosen because of the following factors:
1) The capability to process wet residues
2) Not an expensive pre-treatment process compared to other technology
3) Limited energy consumption for the process
4) Low emission process
HTC has been shown to have been a sustainable technology. On an economy aspect, HTC has gain and attracted many industries due to its low cost start up. Looking from an environment point of view, the HTC process has very little effect due to its emission (water and Carbon dioxide) have very minimal effect on the surrounding nature. Looking into all this aspect, HTC is the best process to treat all organic waste and has a positive impact.
This process does not require a catalyst to increase the rate of reaction.
Reference list:
1. Azocleantech.com, 'Applications Of Thermal Depolymerization'. N.p., 2015. Web. 27 July 2015.
2. Burne, Jerome. 'Alistair Mcconnachie Sovereignty Website. Article On WASTE INTO OIL THERMAL DEPOLYMERIZATION PROCESS'. Sovereignty.org.uk. N.p., 2015. Web. 27 July 2015.
3. Community.Drprem.com, Community. 'Everything I Need To Know About Thermal Depolymerization - Green Diary - Green Revolution Guide By Dr Prem'. Green Diary - Green Revolution Guide by Dr Prem. N.p., 2011. Web. 27 July 2015.
4. Discover Magazine,. 'Anything Into Oil | Discovermagazine.Com'. N.p., 2015. Web. 27 July 2015.
5. M Helal, Hydrothermal Carbonziations, Reactions and water productions, Retrieved from http://www.aiche.org/academy/videos/conference-presentations/hydrothermal-carbonization-reactions-and-water-production
6. Parmar A., Nema P., Agarwal T. ‘Biochar production from agro-food industry residues: a sustainable approach for soil and environmental management’ 15 October 2014
7. Özçimen, D. and Karaosmanoğlu, F., Production and characterization of bio-oil and biochar from rapeseed cake. Renew. Energy,2004, 29, 779–787.
8. Titirici MM, Antonietti A, Baccile N.Hydrothermal carbon from biomass: a comparison of the local structure from poly- to monosaccharides and pentoses/ hexoses. Green Chem. 10, 1204 1212 (2008).
9. Cantrell, K. B., Hunt, P. G., Uchimiya, M., Novak, J. M. and Ro, K. S., Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar. Bioresour. Technol., 2012, 107, 419–428.
10. Román, S., Nabais, J. M. V., Laginhas, C., Ledesma, B. and González, J. F., Hydrothermal carbonization as an effective way of densifying the energy content of biomass. Fuel Process. Technol., 2012, 103, 78–83.
Food waste is the second largest category of municipal solid waste (MSW) sent to landfills. Over 30 million tons of food waste is sent to landfills each year and much of this goes into landfills where it produces methane, thus contributing to global warming. The most important reason that food waste should be recycled is for capturing the energy content. Food waste is highly biodegradable and has a much higher volatile solids destruction rate (86-90%) than bio solids. In fact, in a study done by East Bay Municipal Utility District it was revealed that food waste has up to three times as much energy potential as bio solids.
2.1 Types of Technology
1.0 Thermal Depolymerization
Thermal depolymerization is an industrial process of breaking down various waste materials into crude oil products. The materials are subjected to high temperatures and pressure in the presence of water, thereby initiating hydrous pyrolysis.
It is said to mimic the natural geological processes thought to be involved in fossil fuel production. Thermal depolymerization occurs in nature when an accumulated biomass is heated and pressurized in the earth's crust over millions of years. This biomass, also known as kerogen, is believed to react with clay mineral enzymes at temperatures below 200°C (392°F), which produces oil (Azocleantech.com).
Brune (2012) states that applying pressure and heat to the decaying remains of plants and animals transforms their long chains of hydrogen, oxygen and carbon into the short-chain hydrocarbons that make up oil. But while the earth takes millions of years, TDP takes a few hours.
Thermal depolymerization technology has a plethora of benefits that other technologies lacks. Thermal depolymerization is a useful process of recycling the energy content of organic products while retaining the water content. It avoid drying while producing liquid fuel that separates from water in thermal depolymerization. The vast bulk of waste content can be utilized to produce liquid crude oil products. This will not only make good use of all the non bio-degradable waste but also help in producing some crude oil. The light hydrocarbons that are produced by thermal depolymerization can be used fuel sources, filters and fertilizers (Community.Drprem.com).
Thermal depolymerisation is also highly sustainable economically, socially and environmentally. Thermal depolymerization breaks strong chemical bonds of organic poisons which is extremely beneficial to balance the ecosystem. It can be used a s a substitute for coal and also in quelling the alarming rise of carbon dioxide concentration in the air. CO2 is one of the chief greenhouse gases that is responsible for global warming.
Using water as medium, thermal depolymerization process not only helps in making good use of waste matter and by products, but it also produces fuel resources that can be a boon for the entire world. Invaluable fuel products can be produced in an environmentally friendly way from low quality feed stocks and organic waste. It also eliminates nitrogen and sulfur compounds and brings out clean and highly useful crude oil products (Community.Drprem.com).
The technology does not involve the usage of catalyst.
2.0 Anaerobic Digestion
Anaerobic Digestion uses microorganisms to break down food waste, animal manure, slurries and energy crops in the absence of oxygen, inside an enclosed system. As it breaks down it gives off methane, which is collected and converted into biogas and used to generate electricity, heat or transport fuels. It also creates a nutrient-rich digestive that can be used as a fertiliser for agriculture and in land regeneration
3.0 Hydrothermal Carbonization
Hydrothermal carbonization (HTC) is a technology (biomass conversion) of biofuel)that has recently been further developed. It involves moderate ranges of temperatures and pressures over an aqueous solution of biomass in a dilute acid for several hours. The resulting matter reportedly captures 100% of the carbon in a "bio coal" powder that could provide feed source for soil amendment (similar to bio char).
The reaction mainly involved is pyrolysis. In this reaction the feed is broken down to separate the liquid and solid composition separately. Then the remaining wet solid is dried at temperatures of 200-350 degree Celsius for around 8 hours.
The benefits of this process is that it’s economically efficient and less costly. The cons of it is that the process take very long.
2.3 Technology Used
Hydrothermal carbonization (HTC) is a chemical process which emulates the natural coalification of biomass (Blohse et.al). It involves a thermal conversion technique that converts food wastes and associated packaging materials to a valuable, energy-rich resource. The process uses a combination of heat and pressure to chemically transform bio-waste into a carbon dense material with similar or better properties as fossil coal.
This HTC technology was chosen because of the following factors:
1) The capability to process wet residues
2) Not an expensive pre-treatment process compared to other technology
3) Limited energy consumption for the process
4) Low emission process
HTC has been shown to have been a sustainable technology. On an economy aspect, HTC has gain and attracted many industries due to its low cost start up. Looking from an environment point of view, the HTC process has very little effect due to its emission (water and Carbon dioxide) have very minimal effect on the surrounding nature. Looking into all this aspect, HTC is the best process to treat all organic waste and has a positive impact.
This process does not require a catalyst to increase the rate of reaction.
Reference list:
1. Azocleantech.com, 'Applications Of Thermal Depolymerization'. N.p., 2015. Web. 27 July 2015.
2. Burne, Jerome. 'Alistair Mcconnachie Sovereignty Website. Article On WASTE INTO OIL THERMAL DEPOLYMERIZATION PROCESS'. Sovereignty.org.uk. N.p., 2015. Web. 27 July 2015.
3. Community.Drprem.com, Community. 'Everything I Need To Know About Thermal Depolymerization - Green Diary - Green Revolution Guide By Dr Prem'. Green Diary - Green Revolution Guide by Dr Prem. N.p., 2011. Web. 27 July 2015.
4. Discover Magazine,. 'Anything Into Oil | Discovermagazine.Com'. N.p., 2015. Web. 27 July 2015.
5. M Helal, Hydrothermal Carbonziations, Reactions and water productions, Retrieved from http://www.aiche.org/academy/videos/conference-presentations/hydrothermal-carbonization-reactions-and-water-production
6. Parmar A., Nema P., Agarwal T. ‘Biochar production from agro-food industry residues: a sustainable approach for soil and environmental management’ 15 October 2014
7. Özçimen, D. and Karaosmanoğlu, F., Production and characterization of bio-oil and biochar from rapeseed cake. Renew. Energy,2004, 29, 779–787.
8. Titirici MM, Antonietti A, Baccile N.Hydrothermal carbon from biomass: a comparison of the local structure from poly- to monosaccharides and pentoses/ hexoses. Green Chem. 10, 1204 1212 (2008).
9. Cantrell, K. B., Hunt, P. G., Uchimiya, M., Novak, J. M. and Ro, K. S., Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar. Bioresour. Technol., 2012, 107, 419–428.
10. Román, S., Nabais, J. M. V., Laginhas, C., Ledesma, B. and González, J. F., Hydrothermal carbonization as an effective way of densifying the energy content of biomass. Fuel Process. Technol., 2012, 103, 78–83.