Zero emissions in Birkenfeld.

A new circular economy in Rhineland-Palatinate

Manuel Marin, 2013

The concept of « zero emissions » introduced by industrial ecology in the late 1990s, described by the United Nations University (UNU) as the next step towards sustainable and environmentally friendly industrial production, is gaining ground in a world facing resource depletion and sustained growth. In this context, the state of Rhineland-Palatinate in Germany has implemented an interesting initiative : to establish a circular economy (a key concept of industrial ecology) in which the waste from one industry is the raw material for another industry in a chain that runs through the territory. This includes CO2-free energy production. This approach protects the environment and at the same time increases the autonomy of the region concerned, which becomes its own source of resources for a number of applications. The role of municipalities and local governments is essential in this scheme as they have the opportunity to establish modern sustainable production channels within cities and neighborhoods. Any structure can become « zero-emission » and it depends on the opportunities and the dynamism of the authorities and the population. The Birkenfeld Environmental Campus at the Trier University of Applied Sciences, built according to the principles of passive architecture and, at the same time, energy producer, is an example.

Efforts to reduce the impact of industrial activity on the environment began in the 1970s with « end-of-pipe » techniques. This was a first approach to the ecological problem, seeking to eliminate the waste produced by industrial activity by touching the production process as little as possible. This approach proved to be largely insufficient. In the following decade it gave way to the « precautionary » approach, which incorporated measures to reduce harmful emissions within the chain and constituted what has been called « cleaner production », regulated by management instruments such as ISO14001 and EMAS (Eco-Management and Audit Scheme), among others. The concept of « zero emissions » came later, only in the late 1990s, driven by an emerging discipline known as industrial ecology. By observing the cycles of nature, where resources are entirely used by one process, then entirely restored by another, in a continuous flow, this discipline proposed the organization of an industrial activity governed by these same regulations. Several actors have tried to set up systems with such characteristics and the results, although far from reaching the efficiency of nature, have validated the viability of the so-called « circular » economies in certain regions of the world. This is the case in the state of Rhineland-Palatinate.

Circular economies, by incorporating systematic reuse techniques, represent an innovation compared to linear economies that deplete resources and constantly produce waste. It is not only recycling, a technique already practiced by linear economies, which seeks to reduce the final waste as much as possible. The circular economy, seeks to reuse waste by transforming it into a material or energy resource for the next cycles of the system. The focus is on the flow of material and energy within the system and their optimization in order to minimize the dependence on external resources and flows. This strategy allows the development of new practices that produce improved performance.

One example is the use of organic waste for biomass production. Biomass is a way to store energy in the form of waste without removing it from the system. Subsequently, this waste is transformed into bioenergy and returned to the loop. The savings are twofold : on the one hand, the need for a drain is eliminated by keeping the waste inside ; on the other hand, the in situ production of bioenergy reduces the use of external sources. This tenfold saving is pursued on several levels.

The Birkenfeld Environmental Campus began its activities in October 1996. Intended to host training in environmental matters, it was called upon to materialize the principles of industrial ecology : global vision, process sequencing, use of renewable sources, energy efficiency and decentralization of energy supply sources. In particular, the « zero-emission » approach adopted as the main guideline of the project has made it possible to develop several instruments of action, which can be grouped into four main areas : ecological construction ; rainwater harvesting and treatment ; CO2-free energy supply ; ecological air conditioning. The boundaries between the fields are not rigid, they can be juxtaposed and complement each other. The research work is supported and disseminated to industry by the service company OPËM, which is integrated into the Birkenfeld Environmental Campus.

The space between the buildings is as relevant as the space built for each building. At the Birkenfeld Environmental Campus, the unbuilt space is planted with vegetation and allows the filtering and recovery of rainwater through the soil. This also contributes to soil conservation. Materials are chosen with an eye to their manufacture - the energy consumed and emissions generated - as well as their availability in the region and their recyclability. A hallmark of the Campus’ building style is its economy of space.

Rainwater flows through about 2000 square meters of partially vegetated roof and is collected in two storage tanks. The excess water, directed to a retention area between the buildings, is filtered into the network. After a purification process, the recovered water is used for rinsing and cleaning tasks. It is also used as a coolant for the ventilation system, resulting in significant savings in supply. Projects are underway, supervised by the same Trier University, to set up a system to separate the water according to its color (gray, brown or yellow, depending on its level of nutrients).

The CO2-free energy supply is provided by the Neubrük biogas plant, located in the neighboring district. This facility uses renewable fuels such as waste wood, forest waste and agricultural slash to power two biogas plants that produce electricity and heat. The biogas is obtained from the fermentation of organic waste produced by local households. The electricity generated is fed directly into the grid and far exceeds the needs of the campus. Photovoltaic panels (370 m2) are distributed on the façade of one of the buildings for additional electricity production. They also help reduce excess light and heat in the summer. The energy efficiency of the buildings is increased by structures that channel natural light.

Fresh air is integrated into the buildings through three underground channels, allowing it to be pre-heated or pre-cooled to a constant temperature of 12 degrees. The air coming out of these channels can be preheated again if necessary by an absorber which recovers the heat from the used air. After these processes the desired temperature in each room can be reached with very little energy consumption. Thermal solar panels (260 m2) are used for the heating system, in winter, and for the ventilation system that uses rainwater as a coolant, in summer.

The circular economy can be applied at multiple scales and is an alternative to continuous, unsustainable growth. The concept of growth needs to be rethought to consider the interaction between different industrial activities and processes. This is a fundamental issue. The implementation of cyclical supply circuits as described above, where possible, would help to make the natural resources present in the environment more sustainable. The conversion of linear systems to circular is being addressed as a priority topic of interest by Trier University of Applied Sciences.