Days 1-3, May 19, 20, 21 – Ashley


Day 1 – Saturday May 19th

                On the first day, most of the group arrived early in the morning at Frankfurt airport, and only had to wait a few hours for everyone else to arrive.  We met up with Arno Tschunke, who not only showed us were to find lunch, but later gave us tours of two Anaerobic Digesters sites.

Anaerobic Digesters are a process in which material, such as waste or crops, are broken down by bacteria and create gases which are used to power CHP (or Combined Heat and Power) generators.  The particular Anaerobic Digesters which we looked at today are powered by energy crops, such as corn or sugar beets, though the Anaerobic Digesters we looked at used only corn as an energy crop.

Storage Tank of Anaerobic Digester

The first site we visited had an Anaerobic Digester that was not quite finished. We were allowed to scale the side of the walls and look into the storage tank to see how it looked from the inside before the double layered ceiling was put on it. The inside contained two small mixers at different levels the material doesn’t become still.  Walls were made with multiple layers, before shipped to the site and put together. On the right you can see a picture of the under construction storage tank and parts of the ladder that we used to climb the wall.

The inside of the mixer for an Anaerobic Digester

We were also able to look into what would be the Anaerobic Digester mixer, which there is a picture of on the left. One can see one of the mixers which are used to slowly turn the mixture of silage and manure, which will soon be home to tons of gas making bacteria. We also got to glimpse the CHP unit, which will be sending it heating to a nearby greenhouse along with making electricity.

An Anaerobic Digester at the second site

The next site we visited had two Anaerobic Digesters on site. The first on was older and had a horizontal plug flow with mixes thirty percent manure, which is the minimum required by state law, and seventy percent silage which is made from chopped up corn. The plug flow turns this mixture and it slowly becomes more of a liquid due to agitation, before being piped into the Anaerobic Digester where it sits for days and allows bacteria to grow. The heat from the CHP off this Anaerobic Digester is used to dry chopped wood, which is then sold on the market.

The seconded Anaerobic Digester on site was new and can be seen in the picture on the right. Unlike the first one it had a vertical feed into the Anaerobic Digester, however the feed it made with the same amount of manure and silage.

Anaerobic Digesters are common in places like Germany and hold advantages such as constantly all year round as oppose to other green energy such as wind or solar which only respectively work with the wind is blowing or the sun is shining. Anaerobic Digesters are less common in the United States however there are a few around. Michigan State University will creating an Anaerobic Digester, however this Anaerobic Digester will run off waste from the cafeteria as oppose to the energy crop in the Anaerobic Digester seen today.

After visiting both sites we traveled back to Frankfurt were after a long walk we found our hotel before winding down for the day.

Picture Citation:

  1. Berryman, Maureen. Storage Tank of Anaerobic Digester. 2012. Photograph. Bauer Farm, Germany.
  2. Berryman, Maureen. Mixer of Anaerobic Digester. 2012. Photograph. Bauer Farm, Germany.
  3. Downey, Kelsey. Anaerobic Digester. 2012. Photograph. Bauer Farm, Germany.


Day 2 – Sunday May 20th

                The second day of our trip was a free day where we were allowed to explore the city and visit a few of the culture sites.

There was the Palmengarten, or the Botanical Garden, which is home to many different types of plants and animals.  Below  is a picture of one of the many greenhouses in the garden, this one holding more tropical plants. The next picture below is a picture of the floral garden area. The Botanical Garden had many different areas and a lot to see, including areas for desert and tropical plants as well as a small pond which one could walk around and a rose garden.

Green House in the Palmengarten

Floral Display in the Palmengarten

Romer in Frankfurt Germany

There was also Romer which is a small area of a couple blocks with cobblestone roads, older looking buildings, and a market square along with street entertainment such as a floating man and a person painted to look like a statue.  On the right is a picture of the older looking buildings, as well as an outside area where you could drink and eat.

Locks on the Love Bridge in Frankfurt Germany

Another place to go is the riverside of Frankfurt.  Along the river there are many places to eat and drink, where one could sit out and watch people pass in boats on the river. There were also a couple of small fairs going on, where they advertised drink, food, football.  Interesting on one of the bridges crossing the river there were a bunk of locks with names and dates on them. There is a picture on the right of this. Turns out that the Bridge is called The Frankfurt Love Bridge, and the reason for the locks are a tradition where couple write their names and dates on the locks before locking them to the bridge and throwing the keys into the river to symbolize their everlasting love(1).  It was a pretty interesting find.

There was also and Occupy Frankfurt going on during the time we were there. It however looked rather small and seemed to be confined to a block near the bank; however there were a couple of sleeping bags and tents lying around different parts of the city.

All in all, Frankfurt Germany was a pretty interesting city and had many different sites to go see and to enjoy.


  1. Demotix. “The Frankfurt Love Bridge.” Web. May 21 2012.

Picture Citation:

  1. Green House in Palmengarten, Frankfurt, Germany. Personal photograph by author. 2012.
  2. Floral Display in Palmengarten, Frankfurt, Germany. Personal photograph by author. 2012.
  3. Romer, Frankfurt, Germany. Personal photograph by author. 2012.
  4. Locks on the Bridge, Frankfurt, Germany. Personal photograph by author. 2012.


Day 3 – Monday May 21st

                On Monday we woke up early to head to Montabaur AD Plant, which is a waste management site in Montabaur, Germany. Our tour guide for this plant was Frank Riedel, who gave a very informative lecture on how they separate the waste and work the Anaerobic Digester at the plant.

The Beginning of the Flow Chart

This particular Anaerobic Digester ran off of the organic waste from the nearby city, however most of the waste was mixed with inorganic material and needed to be separated from the organic material. Once the organic material is separated it is mixed with manure so the material is thirty percent manure and the rest organic material before it goes into the Anaerobic Digester where it is mixed by the gases the material produces.   The gas created from the Anaerobic Digester is used to run the CHP, (Combined Heat and Power), where they use the electricity to run the building and selling the rest, and the heat to keep the mixture for the Anaerobic Digester at the correct temperature. After sitting in the Anaerobic Digester for days, the mixture leaves and is the water is separated from the solids to create compost which can later be sold. The first part of process is shown on the diagram to the right.

The ‘Light’ Separator

As mention before, the waste needs to be separated between inorganic and organic materials before the organic materials are sent to the Anaerobic Digester and the inorganic materials go through Gasification. The waste goes past a giant magnet which helps picks up large metals, before being liquefied and sent through two types of separators. The first separate is a heavy separator, is spins the material around very fast and the heavy material such as stones are sent to the bottom being thrown out of the waste.  The waste then goes through a light separator, with takes the small inorganic waste such as plastic out of the waste. The machine that does this process is shown on the left. This machine takes most of the plastic out however small bits of plastic gets by its filter goes into the Anaerobic Digester and even end up in the final product.

The heating system

The Anaerobic Digester makes gas which powers the CHP generator. The CHP generator will generator both heat and electricity, and part of the heat will go back into the plant to warm the mixture to the correct temperature. A picture of the heating system is shown the right.

The open separator

The final product – Compost

After mixture of organic was and manure leaves the Anaerobic Digester, it goes into another separator to take out the water. The separator works by spinning at high speed and forcing the water and the solids to separator. The water is then taken to be treated and the solid is dropped out of the machine to be used and sold as compost.  A picture of one of the separator can be seen on the right. This machine has been taken apart so one can see the inside. On the right is a picture of the compost. Oddly enough the compost has no or little smell to it. While the waste originally comes in with a bad smell, the plant is under negative pressure to keep the smell inside. After the waste goes through this Anaerobic Digester and multiple separations it seems to have lost its smell.

After the tour was over we all stopped to take a picture which can be seen below with a storage tank in the back ground. Frank Riedel did a wonderful job with the tour and answering all of our questions. This site showed a very efficient way to handle waste, and was very informative considering we will be building and Anaerobic Digester to handle the cafeteria waste at Michigan State.  Unlike the Anaerobic Digesters that use energy crops, this Anaerobic Digester needs to take the time to separator waste, however unlike it uses a material that would otherwise be incinerated as Germany has a law against landfills. With Anaerobic Digesters that use energy crops one was to consider the food vs. fuel debate, while Anaerobic Digester which uses waste isn’t using material that is needed elsewhere.

Group Picture

Once the tour we headed to Munich, which was a long four-hour car trip. We made it safely to a cozy Hotel a bus and a subway ride outside of Munich with a nice restaurant across the street.

Picture Citation:

  1. Flow Chart, Montabaur, Germany. Personal photograph by author. 2012.
  2. Light Separator, Montabaur, Germany. Personal photograph by author. 2012.
  3. Heating Unit, Montabaur, Germany. Personal photograph by author. 2012.
  4. Compost Separator, Montabaur, Germany. Personal photograph by author. 2012.
  5. Final Compost, Montabaur, Germany. Personal photograph by author. 2012.
  6. Picture of Everyone Together, Montabaur, Germany. Personal photograph by author. 2012.


The first days of this study abroad will take place in Frankfurt Germany. Frankfurt is considered one of the largest financial and business centers in all of Europe. The first two days here we will be staying at the family-run Hotel Monopol, which is located near the center of Frankfurt and a few blocks away from the river that flows through the city.

On the first day we will arrive early in the morning, before later heading to Bauer Farm. On the second day however we will be free to explore Frankfurt’s cultural sites such as the Frankfurt Zoological Garden and the Palmengarten. The Zoological Garden is a zoo famous for its open pens; tickets would cost around € 8.00. The Palmengarten is a botanical garden that is 22 hectares large and filled with plants from all over the world. It is open year round and tickets cost about € 5.00.

Other sights to see are along Rhine River, which flows through Frankfurt, as there are many Museums along both sides of the river and one may also take a boat tour along the river. Other parts of the town to see are Old Sachsenhausen which is a part of town with cobblestone lanes and pubs, often hosting to flea markets, or Römerberg with it medieval buildings.

On the third day we will visit Montabaur AD Plant plant in the morning. We will also travel to Munich where we will be staying at the Hotel Jagermo. During our stay the weather should be in the seventies and partly cloudy. Still it is early and the weather could be subject to change.



3 responses to “Days 1-3, May 19, 20, 21 – Ashley

  1. In my opinion, as far as the cultural experience went, it was very interesting to see the different architectural styles in comparison to the United States. Their precision to detail and keeping their historical background is just inspirational. Another thing that the group found interesting was their smaller streets and vehicle sizes. Only once did we see a large vehicle (besides transportation trucks and recreational vehicles), which was a Hummer located in the country side of Frankfurt. Kind of an eye-opener to see that difference as far as choice of transportation in this large city.

    On a side note, if anyone who ever visits Frankfurt for the first time like we did, definitely visit the Botanical Gardens and venture into Sachsenhausen, which is more of the residential area of Frankfurt that has quaint shops and a nice cozy atmosphere.

  2. It was great talking to Frank. He was always quick to crack a joke with a smile on his face and a twinkle in his eye. I could tell he enjoyed his work and truly believed he was doing good for the world, not to mention the monetary incentive gained from getting free municipal waste and selling it as fertile compost. This visit contrasted the previous day where we saw the digesters built by GreenCon primarily for energy crops. While Arno was a nice man he seemed more into the business side of things and the profits that he could make. I wonder if incentivizing energy crops more heavily than municipal and organic waste is such a good thing. UTS’s philosophy was that incentivizing energy crops would lead to efficient technology development and digester implementation that would ultimately handle all the organic and municipal waste. But wouldn’t incentivizing organic and municipal waste itself be the faster way to do that? In the end I think it comes down to money and the fact that we live in a profit driven world. Either way, all three of these companies we visited were doing their part to reduce their countries fossil dependence and make the world a greener place.

  3. It was interesting to see essentially the same technology put to use with two different feedstocks. While they were very similar, they also each had their own incentives and pre and post-processing procedures. It makes you really consider everything that goes into the process and why it is the way it is. Frank explained that municipal waste digesters get different incentives than the digesters using energy crops. It was also a completely different perspective from the way we see it in the U.S. Trash is a disgusting useless thing to Americans that ends up rotting in a landfill and rarely gets thought of again. Germany has the opposite perspective and they are greatly benefiting from it. When it comes to energy crops, Germany and the U.S. both have invested a lot in this area, but they still have differing uses for them. It seems to be that the government incentives really fuel the technology’s growth and have pushed Germany in the right direction.

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