Loading

Alison's New App is now available on iOS and Android! Download Now

Study Reminders
Support
Text Version

Set your study reminders

We will email you at these times to remind you to study.
  • Monday

    -

    7am

    +

    Tuesday

    -

    7am

    +

    Wednesday

    -

    7am

    +

    Thursday

    -

    7am

    +

    Friday

    -

    7am

    +

    Saturday

    -

    7am

    +

    Sunday

    -

    7am

    +

So, I mean to the extent that you can handle it this itself is not a major issue, but you can think about at least you need to apply thought in the process right. So, so that we know that we are not pushing the society into a corner, where suddenly you may have a shortage which you may not be able to control in the short term and food is something that we need on a daily basis. So, even if you have a sudden shortage of food for let’s say 2 months or 3 months, that’s not something that you can easily handle for a large population right. So, that is something that is significant. So, it is in direct competition with food resources that’s the point we have to remember right. So, its in direct competition with food resources especially when you do farming of this nature, exclusively for the sake of the energy industry. So, there is a competition with food resources. So, we have to be aware of it aware of the say the extent of it the magnitude of it so, that we can keep it manageable and still be say secure both from the energy perspective as well as from the food perspective. There is also some biomass agriculture is one aspect of it, the other issue is also that you can use bio wastes. So, as part of normal agriculture, so if you were to use bio waste then you are not really impacting the normal agriculture; normal agriculture in the sense agriculture for the perspective of food right. So, agriculture for food this is a waste product, from this is waste product from agriculture for food. So, to the extent that it is only a waste product from the agricultural process it does not affect the food supply chain okay. So, it does not affect. So, it does not affect food supply because you have grown some crop and you have harvested that crop. So, that crop has already been harvested and sent you to the food cycle for people to buy, it is going to you know wherever the wholesale distributors are etcetera it goes that way. So, that is not being affected, but after the cross main part of the crop is gone, do you have a lot of waste associated with just regular agricultural process. So, that waste you can actually use as a bio fuel, in that case the first issue that we were discussing off which is competition with food resources is not an issue ok. So, that is something that we can look at. (Refer Slide Time: 20:50) So, for example, straw that would be an excellent example of this bio based. So, to speak. So,. So, as I said you know biomass is often a byproduct of or waste product from agriculture. So, straw is a major by product straw is a major by product from grain production ok. So, any grain you produce you have plenty of straw that comes along with it. So in fact, if you look at the weight percentage, that is very significant you look at this weight percent almost 40 percent of the weight of the overall product is the straw. So, if you have a 1 ton total product that you make right. So, 1000 kilograms you make total product. So, of which 600 kilograms would be the grain, 400 kilograms will be straw. So, for every you know ton of the total product 600 kilograms is the grain which we will take for eating purposes 400 kilograms of straw is just going to be sitting around right. So, if you can use that 400 kilograms that’s a great thing to do so. In fact, if you look at it globally if you look at it globally billions of tons are being produced every year of straw billions of tons of straw is being produced every year globally. However, only 100 million tones or so, roughly about 100 million tones is seems to be getting used in the form of biofuel or in the form of a biomass that is this you know 100 million tones of straw or any other ways that is being generated is getting converted into a fuel that is then being put into the energy sector. The rest very unfortunately the rest of it is being burnt in the open or allowed to rot ok. So, this is a huge waste I mean we just burn it or you allow it rot. So, when you burn it you actually do damage in two way two different ways, first thing is you are releasing you are burning it and you are releasing carbon dioxide into the atmosphere right in carbon dioxide many particulate matter a lot of stuff is being released into the atmosphere, when you burn the you know straw. Most importantly and very unfortunately in this case, you are not even using that energy you are just burning it in open that’s it you are just burning it, destroying it, throwing the energy throwing the waste, throwing you know particulate matter everything into the atmosphere and nothing you are gaining from it only all the negatives you put together and handoff to society that’s basically all happens when you just burn it out in the open without any other purpose being served. So, this is what is happening unfortunately internationally. Only about 100 million tons is being used properly to generate energy and you know billions of tons out of the billions of tons that is available all the rest of it is just being destroyed in a manner that is a highly self destructive for us right. So, that’s something we have to really look at. So, for example, in India one of the things that keeps coming to our news very regularly, every year we have this thing coming to our news that if you look around October November you will see that pollution in Delhi shoots up right pollution in our capital shoots up in a very significant way. Pollution in Delhi goes up in a very significant way typically you will hear this news around October November. Now and there will be a major spike and the pollution is really bad we are not just talking off slight increase in pollution, we are looking at situations where the amount of particulate matter in the air is 16 times ok. So, 15 to 20 times the upper permissible limit ok. Is the upper permissible limit itself is a high limit, but they say you know up if you cross this limit it is no it is fairly dangerous to the health. Now you are not crossing you are not just. So, most of the time you want to be well below that limit, you don’t want to cross say 10 percent of the limit or some such thing you want to stay well below that limit. Now not only you are not staying below the limit you are crossing the limit you are crossing it by an order of magnitude more than an order of magnitude. So, you are crossing it by a factor of 15 or 20 that’s a huge you know you have you have suddenly change the scenario of a place from being you know livable city to something that you know is extremely toxic, you cannot be there extremely dangerous. So, many times in October November last few years we have the situation that you have major shutdown in Delhi okay. So, schools are all shut down many things are shut down, people are asked to stay indoors a people are asked to use some kind of mask to cover their noses and so on and even staying indoors, I don’t know to what degree it helps because ultimately the ashes comes in. So, that tissue is there, but you have a lot of particulate matter at least if you put something or around your nose to that extent you can avoid the particulate matter, but this is happening, why is this happening? A very significant reason this is happening is that there are a lot of agricultural activities that go on in areas that are neighboring Delhi ok. So, in states our neighboring Delhi, you have various places where there are lot of agricultural farms and it is this season when they change from one crop to another crop and when they have harvested a crop, there’s a lot of the waste of the crop that is sitting there in that form, and they need to clear that waste and then start the next crop. So, it turns out that for many of them it economically and time wise it works out very conveniently if they just like the fire, and then they just burn that burned the place down burn the farm all the waste in the farm is just burnt. So, unfortunately the economic reality and the you know convenience of quick disposal creates this situation, where the large number of farms that is burning their waste and this seems to be fairly well documented. They seem to be lot of reports saying that at that point huge number of farms were burning, and its a strictly there are rules which prohibit this kind of an activity, but unfortunately the ground reality is that you know due to economic reasons you know pressures various pressures etcetera this seems to be the ground reality that many people are burning their the waste in the farm. And as a result huge amount of pollution comes up and this is dangerous even for those people, because whatever you may say even though may be the wind eventually takes the pollution into Delhi, wherever those farms are wherever that burning is happening with all these farms neighboring farms burning, people who live in those places their families they are all breathing that highly toxic air I mean highly injurious here they are breathing for several days. So, there can be nothing good about it and maybe it is a you know a lack of understanding of the situation that and also the circumstances their circumstances that even if they understand it is not good for the health, they are in a corner where they need to really do something and they end up doing this and this is a pretty bad situation and lot of efforts have to be made to know educate them to stop this kind of burning and give them not just educate them, to give you an avenue give them an avenue. So, for example, the straw that is the waste material that is generated there, all the you know by product of this the farming process that is lying there. So, most mostly mostly in the form of straw for example, that can easily be bundled and sent off to a plant where it can be burnt in a controlled manner and you can generate huge amount of electricity right. So, this can be done, but for that to happen this has to be economical. So, many times the report suggests that you know if they have to actually bundled this up and take it and go and give it to a plant which will accept it, that process of bundling it the process of transporting it and going and selling it will cost them a lot more than what the companies are willing to pay them for right for that. So, you take one kilogram of the straw and go and go and hand it off, if they are only going to give you a 100 rupees for it, but it is going to take you 500 rupees to know make that bundle put it on a truck take the truck to that place and hand it off. So, you are going to spend 500 rupees delivering it and they are going to give you 100 rupees for it. If nobody who is you know running any kind of business we will see this as economically viable and so on. So, clearly governments need to assist them in some process to you know take care of this kind of waste disposal and and then try to do something more you know effective with respect to this. But the point being this is a reality not just in some remote international location this is a reality in our country in our nations capital ok. So, it affects our nations capital every year and in a manner that is very dramatic very visible and affects a lot of people every year you are going to see I mean you see a you end up seeing this just you will see newspaper reports that you know it is just full of smog full of smoke particulate partner matter. You take a photograph you can barely see you know 100 meters ahead of you. It is so, heavily ridden with we smoke that has come into the city. So, this is clearly something that needs are just argent addressing, and it has got to do exactly with this idea of biomass right. So, this biomass in this case being destroyed recklessly being destroyed we just because the circumstances are like that and so, something needs to really be done about it. And so so in terms of bio waste straw is there, unfortunately it is not being used. So, if you choose to use bio waste and you can find a way to do it economically, at least you won’t affect the food supply you can actually stick to waste. I mean in a more comprehensive way you can use the entire cycle of the agricultural process from you know end to end. So, this is something that we need to keep in mind ok. (Refer Slide Time: 29:50) So, what kind of substitutions are people talking about when we talk of biomass in what ways is biomass being used. So, that’s something that we will briefly look at. So, we do know that coal is being used extensively in thermal power plants. So, many times biomass is used as a substitute for coal and in fact, this is a major activity, because as I said the power industry is where the pressure is to say that you know we have shifted to renewable because then that can be something that is reported. See the general public if you have somebody who is I mean poor and is using some twigs to do some cooking, it is difficult to document to what degree they are using what and then see if to what degree it has affected our power sources so, to speak whereas, the major part of our power comes from power plants. So, if you impact the way in which the power plant generates the power, that is how you report that you know you have made a change to the energy sector and you have made a change to make it cleaner or whatever it is that you are trying to project. So, the governments put pressure on power plants and power plants find this is a nice way to proceed. So, they use coal instead of coal where they had been using previously coal, they can now additionally add wood and add. So, you have some percentage of coal some percentage of wood. So, to the extent that they add wood they have now added say 20 you put 20 percent of by mass of wood then 20 percent substitution you have done with a renewable source. So, we will we will talk about this idea of renewable shortly, but you would treat it for the moment that it is renewable. So, we put it in as 20 percent substitution. And again as a substitute for coal instead of directly using the wood instead of directly using the wood, you can convert wood to charcoal which is basically wood heated in the absence of air. So, you first heat would in the absence of air, it will remove lot of volatile materials from it various other unnecessary things should be removed from it, what will remain would be primarily carbon and it is twice the energy content per unit mass ok. So, you can get much higher you know energy in unit mass and therefore, that is much more useful for us when we try to get you know some useful power out of it. So, therefore, you can convert. So, you can either use the wood directly as a substitute for coal or you can take the wood convert it to charcoal and then use that as the substitute. So, this is this is way in which we are dealing with solid, solid fuel coal either as char coal or wood is the substitute. Then we have liquid form which is petrol or diesel. So, for petrol typically ethanol is used as a substitute and this is largely obtained by fermentation of corn and sugarcane anaerobic fermentation. So, again absence of air. So, fermentation of corn and sugar is done and from that we get ethanol, and that ethanol can be used as a substitute for petrol and people have demonstrated and in fact, many patrol mixes that are out there usually have some maybe 10 percent of ethanol already mixed in it. So, each government has you know put in some rule from how much of this kind of ethanol should be there already added to the fuel, and to that degree reduces dependence on incoming supply of petrol right. So, so far petrol the substitute is the you know biomass substitute is ethanol. Similarly, for diesel there is something called biodiesel, which is which can be derived from vegetable oils such as soybean oil. So, large amount of it is coming from vegetable oils, soybean oils, some animal fats etcetera you can all be used to create the biodiesel and this can be used directly in you know as a substitute for diesel. So, with varying levels of percentages, you can use you know this ethanol for petrol biodiesel for diesel etcetera and therefore, to that degree you change the mix of the fuel. So, this is. So, petrol and diesel in this case our biomass being used in I mean biomass substitutes are being used for petrol and diesel. So, that is biomass substitutes in the form of liquids and then finally, you get you have natural gas which is being used by many of us. So, that can be substituted by biogas. So, biogas can be used to substitute natural gas, and this is also derived from organic wastes. So, we have many biogas plants, many you know farms will have biogas plants many places you can have biogas plants it generates biogas and that can be directly used for cooking in various ways. So, as I said you know solid liquid and gas in all these three you know common states of matter you can get your biomass supply you with some fuel and then you can use that. So, these are the kinds of major substitutions that are being done with respect to biomass. (Refer Slide Time: 34:28) So, if you look at the top 10 nations in terms of biomass electricity in gigawatt hours. So, the usual suspects are here, United States is here, you have China then you have Germany, Brazil United Kingdom, India is also there Italy, Sweden, Finland and Austria. So, you can see a large number of nations are trying to introduce biomass and this is in you know capacity in gigawatt hours. So, of course, you have to see this as a fraction of that energy that they use. So, that we are not really looking at this point, but this is significant amount of energy that is being generated and potential is there for this to increase dramatically because many countries can get into using this not right now not every country is actively pushing it. So, they may actually end up pushing it further and so, potential for this to grow is quite significant. Within India so, this is the overall global perspective. So, we are you know sort of sixth. So, to speak in this list of currently you know the users of biomass as part of the renewable energy mix. (Refer Slide Time: 35:36) Within India if you see if you look at the top 10 states in biomass capacity in megawatts. So, we have Maharashtra second highest is Uttar Pradesh then we have Karnataka and Tamilnadu. So, Maharashtra, Uttar Pradesh, Karnataka and Tamilnadu have are 4 states that have significantly pushed in the direction of usage of biomass, we have a lot of other states also who have done some activities in this context. Andhra Pradesh and Telangana together have done you know essentially after that, Chhattisgarh, Punjab, Rajasthan, Gujarat, Haryana. So, these are all the states that are the top 10 of you know energy usage. So, again there’s a lot of variety here just the way we saw across nations, wide range of different nations contributing significantly or less significantly to the use of biomass similarly amongst the states also there’s lot of variety. So, clearly here also there is room for you know significant changes or in terms of demand for biomass based on how the other states also you know look into this idea see some benefits in the idea and build on it. So, for example, Punjab and Haryana have lot of fields where they have a lot of hay so, if they want to look at it and then that is something that they can consider. So, this is what it looks like across the nation. (Refer Slide Time: 36:52)
 
 
 
 
 
 
 
 
 
 
So, for example, in India In fact, 32 per cent of the energy in the country is already coming from biomass or something like that some reasonable 30 per cent of less is coming from biomass and it impacts 70 per cent of the population both in terms of you know people being involved in the process people utilizing the energy etcetera. 70 per cent of the people are directly or indirectly connected to this biomass usage. And we have various now kinds of plants which are either connected to the grid or you know off-grid kind of plants this being the total being generated from the plants. And in all of this Bagasse is a major part of this supply. So, what is Bagasse? Bagasse is simply fibrous remains after juice has been extracted from sugarcane. So, this is very interesting if you speak to several of the people who are involved in the sugarcane industry, who make you know who extract juice out of sugarcane and you know supply sugarcane and we use that for generating sugar or supplying it as juice etcetera. The interesting thing you will learn is that for many of them. The sugar that they get out of the sugarcane is a by-product. So from an economic perspective sugar from sugar cane comes across to them more as a byproduct whereas, the waste that comes after you have extracted this you know juice out of the sugar cane that wastes which then they supply to the energy industry give them more money from the for the overall product. So, for saying whatever you know 100 kilograms of sugar cane plants that they create, the money they will get for the sugar that they will extract out of these 100 kilograms of the plant is less than the money they will get from the waste being of those same 100 kgs of sugarcane plants being supplied to the energy industry. So, this is a very nice win situation for the sugarcane industry, because it means more parts of the plant are being effectively utilized from an economic perspective. So, they grow a sugar cane nothing is being wasted, they get the juice out of it the juice can be sold as juice the juice can be used to create sugar and what whatever waste remains it doesn’t just sit there in the field, they are very happy to gather up this waste and then send it off to power plants and they get paid for that also. So, that is and they get paid more for that. So, they are very happy to do that and so, this is what is happening in our country. So, this is the source for this are MNRE. So, this data is available on the MNRE website. (Refer Slide Time: 39:20) So, now let’s look at this question is biomass clean ok. So, the reason people think biomass is clean its because the carbon that is released see you are burning something right you are burning wood if you burn wood that has carbon it burns and it becomes carbon dioxide. So, in that sense from a fundamental perspective, you are just putting CO2 into the atmosphere and therefore, from that perspective alone you cannot think of it as clean you are just burning wood and putting it out in the atmosphere you have putting carbon dioxide into the atmosphere. So, when you supply wood to a thermal power plant, and they substitute some of the coal using wood they have not changed the release of CO2 into the atmosphere CO2 is still being released into the atmosphere. They may be releasing even more CO2 into the atmosphere we will think to talk about that in just a moment. So, in terms of CO2 release you are not making any difference, I mean you are still releasing, but the big difference is the carbon that is released the thinking is that the carbon that is released is what was captured by the plant originally. So, this is thinking slightly in the reverse cycle so, to speak. So, we are normally saying that there is carbon dioxide in the atmosphere, we should grow plants to capture the carbon dioxide and that way we will clean up the atmosphere. So, here the thinking is reversed; that the thinking is that you take a plant that plant already captured a lot of carbon dioxide right. So, in the process of it growing into being a plant into a tree, it already captured a lot of carbon dioxide. So, when you now burn the plant and release the carbon dioxide you are not releasing any new carbon dioxide into the atmosphere you are only releasing the carbon dioxide that the plant originally captured from the atmosphere. So, in terms of a cycle. So, you have a plant and you have an atmosphere. So, you can think of it this way. So, we are saying that this is a cycle, you take plant you burn it you get CO2 into the atmosphere than CO2. So, it depends on where you are starting your cycle you can say that CO2 was already in the atmosphere the plant captured it. Now, you burnt it and released it back into the atmosphere. So, you have done no damage ok. So, CO2 was already in the atmosphere this plant was grown it captured all the CO2 and so, now, when you burn this plant you are not releasing any new CO2. So, you are not damaging the atmosphere that is the thought process that is involved, but there are some issues, first of all, what about other impurities ok. So, when you burn a plant you don’t just get CO2, you get other impurities also that are released we will see that in just a moment. So, you have more impact on the environment and just CO2 the second thing is a time scale ok. So, what kind of time scale are we talking about that we will see in just a moment and impact on wildlife? See when you destroy trees it's not just trees that you destroy there is a lot of wildlife that depends on the tree right. So, it could be anything it could be squirrels, it could be birds, it could be any number of creatures that live on these trees which have taken years to you know get used to that ecosystem and then you just go you cut those trees down and you make wood and you are only talking of the CO2 cycle, you are not talking of all the side impact that it causes. So, that’s another thing that you need to keep in mind when you look at the bigger picture of biomass because when you say biomass and you say this is going to help in nations energy supply, then you are talking of a large amount of biomass you are not talking of an assorted one twig being cut here or one small branch being cut there etcetera which itself may be an issue. But what I am saying is it is not small scale we are talking of entire forest being cut down for some activity and then maybe some new things being planted there etcetera. So, you talk of something massive. So, then you have to think to look at all the impact associated with it. So, if you are going to do a large scale disturbance to the wildlife in that area there is simply by cutting down trees in a massive way, planting them re-cutting them down and so on then that’s again something you cannot ignore it, you have to understand what you are trying to do on what you are doing. (Refer Slide Time: 43:05) So, that is something that we have to look at. So, time scale let’s look at the time scale, the lifespan of a tree is anywhere from 50 years to 3500 years is based on the type of tree that you are looking at, you will find the trees have a lifespan of 50 years to 3500 lives. So, when you say that the tree or you know we tree captured the carbon dioxide, it took 50 years to capture the carbon dioxide. Please do understand even at the lower end of the spectrum it took 50 years to capture the carbon dioxide. So, now, let’s look at it, you have the life cycle of a tree let’s say the circle represents 50 years of life ok. So, you start at some point and you go through this you know past the number of years, you come back it is 50 years you complete the circuit right how much time is required to burn a tree? You can burn a tree in like maybe I don’t know an hour you can burn a tree in an hour. So, you take a tree that took 50 years to grow and you burn it in one hour right and one hour is barely a dot on the circle right. So, whatever carbon dioxide is captured in 50 years you release back into the atmosphere in one in one other. So, you can argue that you know the argument that is made is that many things happen to the tree the natural process it dies it rots and. So, many things can happen. So, it may anyway release some carbon dioxide into the atmosphere, that that question is always being made. But the point is when a tree dries naturally in the environment, many things happened and many of you know constituents of the tree are consumed by other creatures and therefore, it’s not released into the atmosphere so, directly right. So, only a small fraction of that only a certain fraction of the carbon dioxide associated with that tree, carbon and carbon dioxide are associated with the tree gets released into the atmosphere as part of the natural you know the life cycle of the tree after it dies at least in the immediate context, whereas, here within one hour you release all the carbon dioxide possible from the tree into the atmosphere. So, we have to understand that time scale is a very important thing in the grand scheme of you know environmental protection, it doesn’t matter, if you look at the urgency of the situation when you say that you know carbon dioxide content is going up faster and faster and faster in the atmosphere, we need to control the carbon dioxide content now right. So, it doesn’t help if you say I will come to figure out a process that after 300 years, something will happen to the carbon dioxide which would be slightly better than what’s happening now that’s not how it works we would not do something now. So, if you were looking at it from that perspective, this is not helping you are putting an excessive amount of carbon dioxide back into the atmosphere now, you may attempt to clean it up later, but that is not now right. So, this is something that we have to keep in mind that the time scale is important to time scale is something that is not being acknowledged significantly in this process.