Commercial Distribution of Energy from Manure
By: Muhtasim Mushfiq, Syed Ali, Yosef Zidell, Sohyanni Luke, Ralph Godfrey
Summary
Nonrenewable energy resources such as coal, fossil fuels, and gas are being depleted at an extensive rate because we depend on them for most of our energy needs. Finding a solution such as another renewable energy source would help solve this major crisis the world has been facing. Manure is a source that can be converted into energy that companies have been using to power their facilities. Manure is turned to energy through a digester. The digestor takes manure and converts it into energy by having the bacteria break down, and turn into methane gas, which is then burned for fuel and electricity. There are many dairy farms in the United States that are wasting their manure because they don’t have enough cows to generate a suitable amount of manure to power their own digester. For that reason, these farms neglect to build and operate a digester, leaving manure to release methane gas that can be converted. Our proposal is to collect this unused manure from these farms, place it into our own digester, and canister the methane produced and sell it to Energy Plants as usable methane gas. To go about this, we plan to build digesters within a certain radius of these farms. Once, the digester converts the manure into methane gas we will can it into high pressurized storage tanks, then sell and transport it to our local Energy Plant, Xcel Energy Plant. We are asking for an investment of 6.8 million dollars for a startup in our company with a 10% equity. We would be selling and transporting about $12,000 of methane gas a day, however, our daily expenses are $3,690. With that, we will have nearly $8,310 in net profit each day.
Table of Contents Page #
Summary …………………………………………………………………………… Pg. 1
- Muhtasim Mushfiq
Introduction……………………………………………………………………………. Pg. 3 – 4
- Ralph Godfrey, Muhtasim Mushfiq, Yozef Zidell
Proposed Program ……………………………………………………………………. Pg. 5 – 14
- Syed Ali and Sohyanni Luke
Innovation Process ………………………………………………………………… Pg. 15 – 20
- Yosef Zidell
Appendices …………………………………………………………………………. Pg. 21 – 22
- Muhtasim Mushfiq
Introduction
Methane is a well known environmentally harming greenhouse gas. Although by volume it is not extremely overwhelming in the environment, it affects climate change even in small quantities, as it is twenty-one times more potent than carbon dioxide, another greenhouse gas. Methane is a byproduct of the decomposition of waste and trash and shows its dramatic effect and harm coming primarily from landfills. Many government projects have made strides in not only removing this toxic methane gas but utilizing it to produce energy through Waste to Energy (WTE) plants. Meanwhile, there is a common source of methane which is not utilized to its full extent, which is the methane produced from manure on dairy farms. There are 40,000 dairy farms in America, each on average hosting 235 dairy cows. Each cow produces close to 130 pounds of manure per day, leaving each dairy farm on average with over 30,000 pounds, or 15 tons of manure daily. Conceptually, each gallon of liquid manure can produce 2.5 cubic feet of methane gas, which means that each dairy farm on average can produce 13.4 billion Kilojoules of energy from its manure alone. Given the average home usage of energy, the manure produced in one day on a dairy farm can fuel more than 24 homes for a week. This potential energy is wasted currently, and the methane is harming the environment rather than being used resourcefully as fuel. However, there is a possible solution to this dilemma. Of all the dairy farms in America, only 250 have a system of generating their own manure to use for fueling their farms and all the operations that come with it. This process is completed by using a Digester, a massive tank which extracts the methane from manure and generates it into energy. Only large dairy farms can financially benefit from personal digesters, as they produce enough manure daily. But for most dairy farms, it isn’t viable to make their own digestor, leaving valuable manure untouched. Our proposal is to create a digester not for private farm usage but for commercial use. The digestor will run on the unused manure of these smaller dairy farms, as it will be strategically located within a given radius of dairy farms (realistically, no more than 100 miles). The manure from these farms will be collected and transported using trucks, and then will be fed into the digester to produce methane. Since this digester cannot supply energy directly to any source, we will compress the methane into cylinders and transport them for public use. It is important to note that the use of a digester to produce methane gas in order to compress it into cylinders is innovative, as digesters are currently only used for private use rather than commercial distribution. From 20 dairy farms, our digester can theoretically yield enough energy from one day’s worth of manure to provide energy to 365 homes for a week
This innovation is not primarily solving the problem of over-usage of fossil fuels, although it contributes to helping the cause by providing more availability for renewable energy in the form of methane. The main purpose of this innovation is to maximize the use of manure to make energy and get rid of the toxic nature of methane gas on the environment in the process.
Technical Description: Turning Manure into Energy
By Syed Ali, Yosef Zidell, Sohyanni Luke, Muhtasim Mushfiq, Ralph Godfrey
Table of Contents
Part 1: Introduction
- 1.1 The Why …………………………………………………………………….. Page 7
- 1.2 The Basic Process ………………………………………………………… Page 7 – 8
- 1.3 Its Intended Effect …………………………………………………………… Page 9
Part 2: The Anaerobic Digester
- 2.1 The Digester …………………………………………………………… Page 10 – 11
Part 3: Compressing the Methane
- 3.1 The Compressor …………………………………………………………. Page 11 – 12
- 3.2 The Fitting, Pipelines, and Valves ……………………………………….. Page 12
- 3.3 The Cryogenic Tank ………………………………………………………… Page 13
- Conclusion …………………………………………………………………….. Page 14
Part 1: The Introduction
1.1 The Why
Farms and agriculture have been economic cornerstones since the establishment of the United States. To this day a substantial portion of the United States is farmland; 44.37 percent to be exact. In the United States, nearly every farm relies on manure to provide nutrients for their produce and vegetation. Manure is a mixture consisting of organic waste, mainly animal waste. Besides its use in agriculture, it has nutrients that can be converted to biogas through a process called anaerobic digestion. Biogas consists of multiple gases, the most important one being methane. Methane can be manipulated and used to produce clean energy. When done right anaerobic digestion can produce biogas used to make energy and fertilizer at the same time. The process pulls usable nutrients out of the manure leaving fresh fertilizer that can be used in farmlands.
Because the United States is nearly 50 percent farmland with about 2 million farms, if this process is introduced, it can provide a safe way to produce sustainable energy while promoting the growth of farm produce. With the number of farms available, this can potentially be a primary source of energy in the United States.
1.2 The Basic Process
The entire process of turning manure into consumable energy involves five main parts. These parts consist of feeding, digesting, filtration, compression, and packaging. In the feeding process, manure is fed to the anaerobic digester mixer (Figure 1 Step 1) which mixes all the waste and smooths it out to be fed to the digester. Next, the anaerobic digester (Figure 1 Step 2) stirs the mixture while microorganisms break down the mixture, this keeps the mixture from solidifying while it is being heated. Heating the mixture creates biogas which escapes through pipes at the top of the digester to be filtered later. This process is done over 15-20 days to ensure that all biogas is extracted from the waste. Any manure that goes through this process becomes nutrient-rich digestate and is then fed into a final storage tank (Figure 1 Step 3) where it can be stored before distribution. Once the biogas reaches the Filtration, Compression, and Distribution Center (Figure 1 Step 4), water vapor and hydrogen sulfide are filtered out by passing through a filtration tank (Figure 1 Step 5) with two chambers, one chamber utilizes air to catch the hydrogen sulfide and the next chamber with a condensation tank to catch water vapor.
After filtration, methane gas is compressed for it to be distributed. In this process, the methane is compressed then fed into a liquid nitrogen cryogenic tank (Figure 1 Step 6) for 48 hours so it can reach negative one hundred and fifty degrees Celsius, then it is extracted with a vacuum (Figure 1 Step 7) then pressurized (Figure 1 Step 8) with 46 bars of pressure so the gas can be condensed into a liquid. Once in liquid form, the methane is ready for distribution alongside the digestate, the digestate is distributed to farms that utilize the digestates fertile capability. Methane, on the other hand, is distributed countrywide for commercial and personal use.
Figure 1: Digester to Compressing Process (Steps 1-8)
1.3 Its Intended Effect
Using manure to harvest energy has numerous effects that benefit the earth and our population. The biggest effect that comes from this process is that renewable energy is being made. Another effect is that the plant can run itself, which makes it energy efficient. By using some of the methane and biogas that is harvested, the plant can supply its own electricity and heating by making it itself. The plant also doesn’t eat away at the manure supply as well as it only pulls methane out of the manure leaving usable biomass.
Part 2: The Anaerobic Digester
2.1 Digester
To retrieve the valuable methane gas from the manure requires the use of an anaerobic digester. A digester breaks down the nutrients in the manure through a mixing process, which in turn releases methane gas. The digester structure will consist of a high-pressure holding tank for the manure and a dome roof which will be used to house the exposed methane gas(Figure 2). For our intended magnitude of production, the holding tank will be 1.3 million gallons large. This size was determined using our average manure intake (250,000 pounds) and spread across 21 days in order to fully extract the methane gas. This number comes out to about 620,000 gallons of manure over the span of 21 days, so we need to make our tank at least double that necessary size to allow room for the gas to extract and store in the top of the tank. This 1.3-million-gallon size is very realistic according to the Company HRS, and the cost for constructing such a digester will be close to 2 million dollars.
Figure 2: The Anaerobic Digestion Process
As shown in the image above, the digester consists of an inflow pipe in which the manure is transferred into the tank. Excess manure (manure which has been sitting in the tank past the time needed to remove their methane) will be rid of using an exit pipe on the bottom of the tank. Once the manure is in the tank, it is mixed consistently using a steel rod controlled from the outside of the tank. This mixing breaks down the manure over the span of three weeks and releases the methane gas into the dome ceiling. For our project, the gas is then vacuumed into a storage chamber where it is then compressed into tanks. According to the HRS company, six people will be required to work the digester of our caliber.
Part 3: The Methane Compressor
3.1 The Compressor
Methane is particularly difficult to transport because of its molecular size, which is why the only realistic form of transportation besides transporting the gas through pipelines is to compress it. The main process of compressing any gas requires a mechanical device known as an air compressor. A gas compressor increases the pressure of a gas by reducing its volume. When the pressure of the gas decreases the temperature increases proportional to the pressure. For the sake of easier maintenance and lower costs, we have opted for the gas compressor made by Corken which goes for about $22,000 dollars. The Compressor is displayed above in figure 3.
Figure 3: The Compressor
The Corken gas compressor is a reciprocating compressor that consists of pistons driven by a crankshaft. Both the pistons and crankshafts are made of iron because of its temperature resistant and is durable. The crankshaft is powered by an external motor that drives the pistons that are held within cylinders. The motor can be an electric engine or a combustion engine. The size of the engine determines the horsepower of the entire mechanism. As the pistons retract, gas is inserted from an intake valve into the cylinders. The pistons then reciprocate their motion and compress the gas and push it into the compression tanks. The cylinders consist of steel for the least amount of gas leakage and gas to metal erosion.
3.2 The Fitting, Pipelines, and Intake Valves
The fitting is a cylindrical iron attachment that is screwed into the tank that is connected to the intake valve. It aids in changing the speed at which air flows into the compressor. The pipelines consist of chain mixed in with a sturdy but flexible rubber compound and are connected to the nitrogen tanks that cool the gas. The length of the pipes varies based on desired setup. The intake valve is a steel apparatus filters and allows for the passage of the gas through either the cryogenic nitrogen tank or the gas compressor. The intake valve allows all gas passage within the compression process. The fitting, pipelines, and intake valves are displayed below in figure 4 respective to the order in which they were discussed.
4a: The Fitting 4b: Pipelines 4c: Intake Valve
Figure 4: The Fitting, Pipelines, and Intake Valve
3.3 The Cryogenic Tank
The cryogenic nitrogen tank is what will house the methane and cool it to a temperature where it can be compressed. Cryogenic tanks contain gases that are meant to be kept cold. In this case the cryogenic tank will contain liquid nitrogen which will cool the methane gas. The tanks are composed of steel and have their own external valves that allow for changes in pressure to maintain the temperature within the tank.
Figure 5: Cryogenic Tank
Conclusion
The processes discussed take a mass-produced agricultural product and extract necessary chemical elements to produce clean energy that is reliable and can replace a substantial portion of the polluting energy in the national grid. Combining the popular use of an anaerobic digester for manure with the commercialized distribution to energy plants of the valuable methane gas is innovative on a large scale. Although our sample innovation takes place in upper colorado, it very well can be applied to other areas of the united states which experience the same problem: having small farms without the means to produce their own methane gas from their rich manure.
Innovation Process
The primary point of our innovation process is accentuated through the costs of the proposal process. This includes transportation costs, digester costs, compressing gas costs, and permit/ land fees.
Transportation
We plan on developing our facility in Upper Colorado, near the town Wendona, where twenty dairy farms are located. On average, the farms will each be twenty miles from our facility. There will be three hundred and fifty thousand pounds of manure needed to be delivered to our facilities, per day. To transport all of that requires manure tankers. A ten-thousand-gallon manure tanker costs roughly $75,000, making four trucks cost a total of $300,000. Based on the amount of manure we need to handle daily, four trucks will be sufficient, both in size and time efficiency, to transport the manure from all twenty farms to the facility. Once the trucks are funded, the recurring costs are gas and labor. The trucks will take diesel gas, which costs roughly 2.75$/gallon in Upper Colorado. Assuming a similar MPG to a conventional semi-truck (5.6 miles per gallon), the gas cost per day will be around $39.30 per truck ($157 total), assuming they are each driven 80 miles a day (the necessary average distance needed for the trucks to reach all twenty farms). For labor costs, we need to consider the drivers and manure loaders. The drivers will be paid per hour at a standard rate of $14/ hour (average truck driver salary), and assuming 10 hour days (hours needed to reach the farms, load the manure, and deliver to the facility), that will cost $560 a day for all four driver’s fees. Once the manure is completely processed in the digester, additional tankers will be needed to redistribute the liquid effluent back to the farms for storage and land application, such as use for fertilizer. Storage facilities for this manure are already in place at these farms, so there is no cost for that. The only obvious addition to costs would be in the gas and wages of the drivers, which is directly proportional to that of the costs for delivering the manure to the facilities: $560 in driver’s fees and $157 in gas costs. However, due to the limited hours in the day, and the need to be as efficient with our manure supply as possible, we physically cannot use the same trucks to complete both the delivery and redistributing tasks. Therefore we will need four more tankers to do this task, costing an additional $300,000 in initial expenses.
Transportation for the methane gas, once already in the tanks, is a different cost to consider. The driver’s fees are negligible, as the electrical utility plants are within 20 miles of our facility. After production, we can potentially yield 400,000 pounds of methane per day, which would require four Semi-trucks to deliver to the energy complex. Each truck will cost around $100,000. Totaling up to $400,000 for the initial costs of the trucks. Based on similar calculations with the tankers, Truck driver wages will come out to $28 a day per truck (or $112 a day for all four drivers), while gas will cost $19.60 per truck a day, or $78.6 for all four. On top of this, each farm will require a Loader in order to scrape the manure from the farm into the transportation trucks. It is important to note that generally a Scraper is used to collect dirt and manure, it is not necessary for our project as we need a lot of smaller units as opposed to a few larger ones (since we are working with twenty small farms as opposed to a few large farms). Loaders, which can hold up to 10,000 pounds of manure, cost a minimum of $40,000 to purchase, so twenty loaders can cost as low as $800,000 as an initial investment. The cost of operating the Loader will be dependent on wages and diesel costs. Proper training for operating the loaders can be done through schooling and a six-week learning program. This is rather excessive and unnecessary as most farmers are familiar with operating this machinery and we can pay them directly to haul the manure with this machinery. Considering a loader can hold up to 8,700 pounds of manure per lift, an entire day’s worth of manure collection can be done within 2 hours per farm. According to an online salary site, the average loader operator gets paid $16.47 per hour. For two hours usage of the machinery, it will cost about $33 in daily loader wages per farm, tallying $658 per day for all the farms involved in the operation. The cost of diesel fuel in Upper Colorado, near our designated region of interested, is $2.75 per gallon. A medium-sized loader, which are the ones we are working with, can use as little as 1 gallon per hour and up to 12 gallons per hour, depending on the demand of the operation at hand. As a rough estimate, we can assume the loader uses 6 gallons per hour. Therefore, each loader will use 12 gallons of fuel per day, totaling up to 240 gallons of fuel. This will calculate to $660 per day in gas costs for the loaders. So, as a rough estimate, we will require close to $1.8 million for the initial costs of transportation equipment. Recurring costs will come out to $2,942 per day.
Costs to Compress Gas into Tanks
Once the methane gas is produced, it must be transferred to an energy facility in order to be used. For our sample location, the targeted energy facility that will use our gas is the company Xcel Energy, which deals with renewable energy sources. In order to do this, the gas must be liquefied and then transferred into tanks. The cost involved in this process is comprised of the following: The cost of a nitrogen chamber, the cost of liquid nitrogen, and the cost of the equipment needed to hold the nitrogen and methane. The equipment needed for this will cost close to $22,000 per compression chamber, and in order to effectively run our operation, we need three of these compressors, totaling $66,000 in initial costs. For the cost of the cylinders which the gas will be compressed into, we will safely need 400 cylinders which can each hold 1000 pounds of methane gas. Because the energy facility we are working with will need at least a day to empty the tanks, either by using the gas or restoring it in their own storage area, we will need double the number of cylinders, totaling 800 cylinders. The store price of one of these cylinders is $635, which comes out to $508 when we consider the price difference of buying in bulk (20% cheaper on average). Taking this into account, it will cost roughly $406,000 for the initial costs of the cylinders.
Digester Costs
As mentioned in the technical description, the digester facility will cost close to 2 million dollars as an initial investment according to the Regenis Digester Company. This will include the tank, pre-digester pit for manure from the trucks, and post-digester separation equipment and infrastructure. Regenis can provide maintenance for our digester at $22,000 a month. This will include the costs of the worker’s wages and insurance to cover any maintenance issues that need to be fixed. This comes out to $733.33 a day in maintenance costs for the digester. Along with our digester, we will need a facility for storing the methane and trucks, as well as running our day to day operation. This facility, which is set up as a warehouse, will cost $2.5 million for construction.
Permit and Land fees
In order to build a digester in our intended area, we will need a certificate of designation and a review cap of the documentation, which costs $35,000 according to the Colorado permit standards for anaerobic digesters. The cost of land in upper Colorado, where we plan on constructing our digester, is around $150 a month per acre. Considering the size of our digester, we will need a minimum of 3 acres, which will cost $450 a month. For the sake of our total calculations, it will cost $15 a day.
Profitability
Understanding the costs related to the potential profit of this operation is the entire basis for our proposal’s validity. The total initial cost of this operation, according to our previous calculations, is $6,803,000 and our recurring daily cost is $3,690. Methane gas is sold at $.0735 per pound. Dealing with 385,000 pounds of manure per day produces close to 400,000 pounds of gas, which equates to 240,000 pounds of methane gas per day. This means we can theoretically yield $17,640 worth of methane gas at a price value. Taking into consideration the price decrease in selling in bulk (20% less), and methane used to run the digester (safely estimated to 10 percent), we are producing $12,700 worth of methane gas per day with this operation. If we subtract our daily costs of $3,690, we are left with a net profit of $9,010 per day. According to this calculation, it will take 26 months to start accumulating pay off the initial costs of the equipment needed for this operation. The long term plan is to grow this operation, which we are proposing as a 10-year plan. This proposal is situated in Upper Colorado, but we can implement this idea to many farms across the United States. In 26 months from the opening of our operation, we will have enough revenue to produce another digester in another location. Since a digester on average takes 8 months to construct, we can start doubling our production rate at month 34. This, in turn, will provide us enough revenue to afford to construct a third digester in a shorter amount of time. If this process holds true, realistically we can have 10 fully functional digesters across the United States in year 10, which will produce close to $32 million in revenue per year. From this, we can deduce that our business will be worth $220 million in year 10 of opening this operation. We are offering a 10% equity stake in our business for an initial investment of 6.8 million dollars, which will provide three times the return ($22 million) in ten years if we choose to sell the business.
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