Analysis of Energy Contained in Domestic Solid Waste

Transcription

1 Analysis of Energy Contained in Domestic Solid Waste Co-Author Harsh Gupta Assistant Professor Department of Mechanical Engineering I.T.S Engineering College, Greater Noida Puneet Saini Assistant Professor Department of Mechanical Engineering I.T.S Engineering College, Greater Noida Abstract- The increasing problem of continuous population growth in the metro cities and subsequent increase in solid waste generation has created a severe problem of its disposal as well as its hazardous effects may not be overlooked. The major utilization of this solid waste in India is limited to composting only. The amount of solid waste in Delhi alone is nearly 9000 MT / day. The quality of compost is not appropriate because of mixed solid waste. In domestic solid waste if the organic content is collected separately the food stuff waste content can be utilized for compost which shall be of good quality. Again the content in the form of Plastic and paper is suitable for the purpose of energy extraction as these contents have high value of energy. The organic domestic solid waste samples from the residents of two different societies were collected and estimation was carried out for the energy content per capita domestic solid waste. I. INTRODUCTION In urban areas a lot of solid waste being dumped everyday, the amount is very high on account of life style as well as the increasing population density. In Delhi it is nearly 9,000MT per day. So it is important to manage it properly in order to avoid its impact on environment and to save the creatures from various hazardous effects of it. The continuous problem of shortage of electricity in big cities as well as the paucity of land has diverted the attention of engineers and local governing bodies for energy production out of the solid waste. Urban solid waste includes household garbage and rubbish, street sweeping, construction and demolition debris, sanitation residues, trade and industrial refuse and bio-medical solid waste (CPCB, 2000). Solid waste management (SWM) has three basic components, namely, collection, transportation and disposal. The efforts are being made to utilize the solid waste by composting it as well as establishing the project for producing energy out of the land fills. Still it is not being done at its full potential. The economic viability of these projects is questionable, but with the help of financial institutions, participation of NGOs and the subsidiary given by the State and Central Government can overcome the hurdle. The potential of energy extraction per kg of plastics, wood, paper, cardboard and food waste are nearly kj, 18300kJ, 16750kJ, 16300kJ and 4600kJ respectively. We all know that electricity is the most convenient form of energy. As per an estimate for Delhi alone the electricity generation potential from solid waste is 140MW approximately. For NCR it is nearly 180MW. So we should make a use of solid waste, which is only possible through an appropriate and effective solid waste management system. This paper is an attempt to bring the facts in front of the general public as well as to the bodies involved in managing the solid waste of our country for its utilization for energy generation. In order to estimate the content of energy in the domestic solid waste, I had the option to adopt a macro or minor approach. It has been not feasible to go for collecting the samples on macro level, so the micro approach was adopted for. II.. METHODOLOGY ADOPTED The micro approach was adopted for the estimation of energy content per capita of domestic solid waste. The societies at Rajinder Nagar Sahibabad were requested for providing the solid waste, the individuals were approached for. At Sahara II, all the 5 occupants agreed for where has at Rajmahal II, 10 out of 11 occupants agreed for. The samples were collected the details are as given in the tables ahead.

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3 5. MATHEMATICAL FORMULATION Estimation of Per Capita Energy Content The samples collected at two residential building comprising of food, fruit, vegetable and plastics (polythene only being organic compound) & paper products waste was found to have Paper to Plastic ratio as 7:1. The energy potential / kg of different ingredients are normally as mentioned below. 1 Plastics kj/kg 2 Paper Products kj/kg 3 Food Waste 3500 kj/kg For collected sample energy potential/kg content shall be as calculated ahead:- Avg. Energy/kg from plastic & paper waste = (27900* *7)/8 = kj Which can be taken as kj/kg. 5. MATHEMATICAL FORMULATION

4 III. MATHEMATICAL FORMULATION Estimation of Per Capita Energy Content The samples collected at two residential building comprising of food, fruit, vegetable and plastics (polythene only being organic compound) & paper products waste was found to have Paper to Plastic ratio as 7:1. The energy potential / kg of different ingredients are normally as mentioned below. 1 Plastics kj/kg 2 Paper Products kj/kg 3 Food Waste 3500 kj/kg For collected sample energy potential/kg content shall be as calculated ahead:- Avg. Energy/kg from plastic & paper waste = (27900* *7)/8 = kj Which can be taken as kj/kg. Energy content of the solid waste sample containing plastic, paper and vegetable waste : e = (47* *3500)/1000 = kj/capita, take it as 1000 kj per capita. The present population of Delhi is 1,50,00,000. IV. RESULT AND DISCUSSION Energy Potential of Waste At Delhi E = P*e/1000 Where E is the estimated potential of total energy /day in MJ P is the population of Delhi e is the energy potential per capita in kj With the samples collected it would be as: E = 1,50,00,000*1000/1000 =1,50,00,000 MJ/day Three samples were taken as we see from these samples that the collection of different components of the waste varies on daily basis from same apartment as well as from different apartments. We can say that the waste content is neither fixed for individual house nor for entire collection of society on per day basis, so by taking three samples each from two different societies gives us a more uniform estimation of collected ingredients on /capita/day basis. V. CONCLUSIONS This much potential of energy contained in the biodegradable content of waste of Delhi can be utilized for heat energy recovery or for power generation purpose by utilizing different method of WTE application. Out of various methods, incineration and biomethanization are found to be more suitable. Although the pollution problems are associated with incineration but it can be made viable for handling small amount of waste. If due care is given to the treatment of flue gases. Similarly biomethanization is also recommended for small quantities to deal. The gas obtained from biomethanization can be used for power generation purpose as a fuel in power plant. As the amount of entire waste generation for Delhi is as high as 9000 MT per day it can alone not be dealt by using any one method only. But incineration and biomethanization are method which reduces the load on SLF. The proper segregation of solid waste at the source itself will enable us to extract higher amount of energy at a considerable low cost as well as it helps us in producing a high quality compost. The need is to make the public aware of the fact and to operate on an efficient waste collection and utilization mechanism. In order to exploit the solid waste as a source of energy the steps are to be taken by ULBs and the participation of private sector as well as that of the RWAs and NGOs is must for the success of WTE application. If we do not take the necessary steps on time we shall be facing the problem of public hygiene as well as the deterioration of environment. VI. SUGGESTIONS The complete elimination of SW is not possible at all, so the emphasis should be on its proper management. Certain suggestions to improve the situation are as mentioned below: Commercial establishments and road side vendors are to be monitored for safe disposal of their waste generation. Participation of NGOs and RWAs is to be encouraged. Government should have a strict supervision on recycling plants. Public Awareness through hygiene camps. Encouraging separate use of separate containers for biodegradable and non biodegradable waste segregation at source. Transportation of garbage to be carried out in covered vehicles.

5 Disposal of waste on road sides is to be banned. Ensuring the segregation at the source. Banning the recycling plants operating illegally. Introduction of sanitation course at school level. Developing nodal energy centers for institutional MSW to handle and WTE generation. Funding and subsidizing the loans to technical institutions for implementation of such projects. ACKNOWLEDGEMENT I acknowledge my sincere thanks to the residents of SAHARA II, and RAJMAHAL -- II, for their support in conducting the experiment and providing me their domestic solid waste on regular basis. References [1] Renewable Energy Akshay Urja Journel from Ministryof Non-conventional Energy Sources [2] Bio Energy News from Ministry of Non- Conventional Energy Sources [3] C. Chiemchairi. W. Chiemchairi, Sunil Kumar. J.P.A. Hettiaratchi, Solid Waste Characteristics and their relationship to gas production in tropical landfill [4] C. Chiemchairi., J.P.Juanga., C. Viswanathan, Municipal Solid Waste management in Thailand and disposal emission Inventory. [5] Times of India, Mumbai, March 7, 2002 [6] Times of India, TIMES CITY (Delhi) May 20, 2008 [7] Desh Deepak Johri and Dr. Emran Khan Potential of Energy Generation from Solid Waste. [8] Desh Deepak Johri, M.K. Lohumi and Deepak Bhalla Solid Waste Disposal in Metro Cities - A threat to Environment.