Simone Kraatz

Life Cycle Impact Assessment and Allocation Methods Development for Cheese and Whey Processing

In this study, life cycle assessment (LCA) methods are used to develop life cycle inventory (LCI) and life cycle impact assessment (LCIA) data to estimate the global warming potential (GWP) and energy intensity (EI) of cheese and dry whey manufacturing in Wisconsin using a farm gate to plant gate approach. All of the environmental burdens and benefits are assigned to the product (cheese) and none are assigned to the land-spread waste stream (whey) for a single-output system typical of small cheese plants in Wisconsin. For a multifunction system, in which both cheese and food-grade whey are produced, the following methods are applied to handle co-product multifunctionality: subdivision, allocation ratios, and a method that combines both subdivision and allocation ratios. Total solids, nutritional content, and economic value are considered as the allocation ratios. Each of these fixed allocation ratios is applied to the entire process and to individual processes unique to each product. The differences in the GWP and EI for cheese and dry whey are highly influenced by the choice of method. The EI of cheese ranges from 7.1 to 19 MJ kg-1 cheese, and the GWP of cheese ranges from 0.46 to 1.3 kg CO2-eq kg-1 cheese. The main source of these differences is the shift of environmental burdens from cheese to the dry whey co-product resulting from different allocation strategies. The method that combines subdivision and allocation is presented as the preferred and most accurate method to deal with the multifunctionality of cheese and whey manufacturing. Sensitivity analysis shows that GWP and EI are most affected by variations in milk pasteurization, whey evaporation, whey drying, and whey pasteurization. This study demonstrates the importance of the allocation method on LCA analysis and suggests methods to more accurately assess the environmental burdens when more than one product is produced at a dairy plant.

Energy Inputs for Corn Production in Wisconsin and Germany

Corn is one of the most important agricultural commodities in U.S. agriculture not least because of the expansion of ethanol production. The main purpose of this analysis is to quantify the total energy input used to produce corn in Wisconsin and to improve the quality of data and the methodology in the estimation. Therefore a comprehensive literature review was done. The calculation of the energy demand includes direct energy (for example fuel, electricity) and indirect energy (for example fertilizer, seed and machines). Data from the United States Department of Agriculture (USDA) are used to assess the development of the cultivation of corn over the last 30 years; especially the yields and the input of fertilizer in corn production are regarded.

Relationship between irrigation water demand and yield of selected crops in Germany between 1902 and 2010: a modeling study

The demand for irrigation water is increasing worldwide, including regions in Germany with low precipitation and water-demanding crops. In this study, history of irrigation water demand (IWD) in the German nation states in relation to the yield of four crops (1) potato, (2) spring barley, (3) oat, and (4) winter wheat, during droughts between 1902 and 2010 was analyzed. The difficulties caused by the shifting borders of the German nation state over the past century were dealt with by dividing the data for the region into four time periods for the analysis. Low precipitation during droughts influenced crop yield in the German nation states. Analyses of droughts resulted in no clear conclusions; however, it appeared that after 1950, German nation states droughts had a negative influence on the yield of the four crops despite the important role irrigation played in German agriculture since 1960 in the German nation state. Lower yield because of weather conditions since 1950 was primarily attributable to the high-yield potential of improved crop varieties, for which yield potential is only reached under optimal growing conditions. In this study, the analysis of the modeled historical IWD in agriculture revealed the urgency with which the German crop production systems must adapt to extremes in a changing climate not only by improving irrigation systems via irrigation scheduling but also by greater higher diversification of crops.

Methods for Solving the Multifunctionality Problem in the Life Cycle Assessment of Ethanol Production from Corn Grain

Decreasing fossil resource availability and increasing climate change concern drives the demand for renewable alternatives, such as ethanol, to fossil fuels. Life Cycle Assessment (LCA) is the tool used to evaluate environmental impacts, such as Energy Intensity (EI) and Global Warming Potential (GWP), from ethanol production, but the application of this tool varies greatly. The goals of this study are to evaluate the various solutions to the multifunctionality problem which arises in LCA, explore ethanol production scenarios which differ at the treatment of the Whole Stillage (WS) co-product and, enumerate the life cycle EI, Net Energy Value (NEV) and GWP of corn grain ethanol production in Wisconsin. In Scenario 1, all suggested solutions to the multifunctionality problem are considered by transforming WS into the animal feed Dried Distillers Grains with Soluables (DDGS). Scenario 2 avoids allocation by using an integrated system which recycles the WS with an anaerobic biodigester and a Combined Heat and Power (CHP) plant to provide electricity and steam to the ethanol refinery and returns the residue to the land as fertilizer. We recommend the sub-division (SD) solution to the multifunctionality problem because it enables clear comparisons between different ethanol production systems, it distinguishes between the environmental impacts from ethanol production and co-product processing and it reduces the number of assumptions in the LCA calculations. We also recommend recycling the WS into electricity, heat and fertilizer because it results in a 40% lower EI and a 57% lower GWP than the processing of WS into DDGS.

Energy Efficiency in Raising Livestock at the Example of Dairy Farming

In consideration of climate change, the reduction of resources and the growing population the efficient use of energy becomes one of the key indicators for the development of sustainable agricultural practices.

Global Warming Potential and Energy Intensity of Cheese Manufacturing in Wisconsin

Life Cycle Assessment (LCA) methods were used to quantify the Global Warming Potential (GWP) and Energy Intensity (EI) of cheese and dried whey manufacture in Wisconsin. Several allocation methods to assign environmental impacts to cheese and dried whey were compared: Economic, total solids, and nutritional value were each applied to the entire process and to individual processes unique to each product. The differences in the GWP and EI for cheese and dried whey were highly influenced by the choice of allocation method. The EI of cheese ranged from 5.08 MJ kg-1 to 15.01 MJ kg-1 and the GWP of cheese ranged from 0.31 kg CO2-eq kg-1 to 0.99 kg CO2-eq kg-1. This study demonstrates the importance of the allocation method on LCA analysis and suggests methods to more accurately assess the environmental burdens when more than one product is produced at a dairy plant.

Input of resources in dairy farming – energy, arable land and reduction of greenhouse gas emissions

The sustainable use of natural resources and the impacts of greenhouse gas (GHG) emissions on the global climate have become important concerns world-wide.

Emission Reduction by Brown Coal Powder

There is still a need for measures to reduce gaseous emissions from animal manure effectively. Malodor shall be reduced as well as the emission of ammonia, methane and nitrous oxide. Powder is a by-product during coal processing. The effect of powder from brown coal processing on these emissions was studied. Investigations were done with liquid swine manure with a dry matter content of 2.5% in a laboratory at 20 C temperature. The manure was stored in open vessels with 70 liters content over a period of 238 days. The amount of brown coal powder (BCP) mixed into the manure was 3% by mass forming a floating layer of about 3 cm. The samples were analyzed for pH, total solids, volatile solids, total Kjeldahl nitrogen, total ammoniacal nitrogen and organic acids. The vessels were closed and ventilated only during measurement (dynamic chamber method). Ventilation rates were measured by flow meters, concentrations of ammonia, nitrous oxide and methane by a photo acoustic IR spectrometer and odor concentration by an olfactometer. Laboratory investigations were attended by measurements at a storage facility on a farm at 16 m³ scale using the same methods.