LCI data for the calculation tool Feedprint for greenhouse gas emissions of feed production and utilization

Transcription

1 LCI data for the calculation tool Feedprint for greenhouse gas emissions of feed production and utilization Wet Milling Industry W.J. van Zeist 1 M. Marinussen 1 R. Broekema 1 E. Groen 1 A. Kool 1 M. Dolman 2 Subtitle H. Blonk 1 1 Blonk Consultants 2 Wageningen University and Research Centre November, 2012

2 Blonk Consultants Gravin Beatrixstraat PJ Gouda the Netherlands Telephone: 0031 (0) Internet: Blonk Consultants helps companies, governments and civil society organisations put sustainability into practice. Our team of dedicated consultants works closely with our clients to deliver clear and practical advice based on sound, independent research. To ensure optimal outcomes we take an integrated approach that encompasses the whole production chain.

3 LCI data for the calculation tool Feedprint for greenhouse gas emissions of feed production and utilization Wet Milling Industry W.J. van Zeist 1 M. Marinussen 1 R. Broekema 1 E. Groen 1 A. Kool 1 M. Dolman 2 H. Blonk 1 1 Blonk Consultants 2 Wageningen University and Research Centre November, 2012

4 Table of contents 2.1 Introduction Context of this document & reading guide Overview of products and allocation principles Structure of data Glossary of terms References By-products from the wet milling of maize By-products from wet milling of maize Note on allocation Sourcing Flowcharts Inputs Production of maize germ oil Maize germ oil: Mass balance Maize germ oil: Inputs Maize germ oil: Allocation References Wet milling of sorghum Introduction References Wet milling of starch potatoes Note on allocation By-products from potato starch production Sourcing Flowcharts Mass balance Inputs Allocation Energy use and allocation for heat treated and dried products References Wet milling of wheat By-products from wet milling of wheat Note on allocation Sourcing 19

5 2.5.4 Flowcharts Mass balance Inputs Allocation References 23

6 2.1 Introduction Context of this document & reading guide This document is part of the background documentation for the FeedPrint program and database. Background information of this project, underlying methodology and justification thereof, can be found in the FeedPrint methodology document. These chapters focus only on the processing step of crops into the feed materials. Information on origin of crops is given, but details on cultivation and transportation (to and from the processing facility) are described in separate documents: the cultivation of each crop is described in the cultivation background reports similar to this one (Marinussen et al, 201, whereas transportation is described in the Feedprint methodology report (Vellinga et al, 201. Each chapter can be read and interpreted as a standalone set of LCI data, which covers the country of crop cultivation, the country of processing, mass balances, energy inputs (and outputs, if applicable), as well as data needed for the allocation of the by-products. In some cases, multiple processes can follow one another with multiple allocation steps. In these cases, the data is entered into the database by following these specific processing steps consecutively. Usually (but not restrictively) the data entered are relative to an input of 1000 kg of crop product Overview of products and allocation principles Each chapter in this document describes a different animal feed material production process within the wet milling industry. Unless noted otherwise, the processes described in this document are treated as a single unit process with multiple valuable output products, where allocation approach 1 is applied (see 5.3, Vellinga et al, 201 in which all products are treated as valuable by-products to which upstream emissions will be allocated according to economic, energy, or mass allocation Structure of data This document contains tables that reflect those data applied in the FeedPrint program. Additionally, tables with background data are supplied, which are often inventories of encountered literature. Only the tables that are used as data for the FeedPrint database and calculations are given a table number (see for an example Table 2.1.1). Other tables that are not used in the FeedPrint database are not numbered and have a simpler layout, see the example below. Table Example default inputs table for FeedPrint database. Output Values Unit Best estimate Error ( g Electricity MJ/ton Natural gas MJ/ton Example of background data not directly used in FeedPrint database Source Data found Remarks Reference 1 80 MJ/ton Older data from 1 processing facility. Reference 2 90 MJ/ton Newer data from multiple facilities. There are a number of recurring types of tables, usually in the following order: 1) Definition of feed materials related to the process; Estimation of countries of origin of the crop and countries of processing; 3) Mass balances for the process; 4) Energy or material inputs needed for the process; 1

7 5) Allocation factors for the outputs from the process. Unless explained otherwise in a specific chapter, these five tables are present for each process. Additional sections or figures can give information on, for example, the definition of the process represented with a flowchart. Each section also contains the references for cited sources. The usual structure of a section is that first the default inputs for the FeedPrint database are presented, with the rest of the section explaining in detail which data sources were used and why. There are a number of different types of error ranges that can be given for each data point, and these are applied for the energy and auxiliary inputs. More background information can be found in the overall methodology document (Vellinga et al. 201, which also explains the decision process followed to arrive at the error ranges Glossary of terms Below is a list of terms with definitions as applied in this document. DMC GE Dry matter content in g/kg. Gross Energy content in MJ/kg References CVB-table: see appendix 1 in Vellinga et al. (201 European Commission. (2011). COMMISSION REGULATION ( EU ) No 575 / 2011 of 16 June 2011 on the Catalogue of feed materials. Official Journal of the European Union, (L 159), Marinussen et al (201 Background data documents on cultivation. Blonk Consultants. Gouda, the Netherlands Vellinga, T.V., Blonk, H., Marinussen, M., van Zeist, W.J., de Boer, I.J.M. (201 Methodology used in feedprint: a tool quantifying greenhouse gas emissions of feed production and utilization Wageningen UR Livestock Research and Blonk Consultants. Lelystad/Gouda, the Netherlands. 2

8 2.2 By-products from the wet milling of maize By-products from wet milling of maize Maize, also named corn, is a cereal grain 1 and is known for being a high-yielding variety of cereal grains. There are multiple types of maize which are used for various purposes like grain, cattle, seed, or cobs for consumption. In this section, only the wet milling of the industrially processed dent corn is described. Dent corn, getting its name from the dent in the crown of the seed, is grown more than any other type of corn. Millions of tons of grain are produced from dent corn, and is used for human and industrial use, and for livestock feed. The starch reaches the summit of the seed, and the sides are also starchy. The denting is caused by the drying and shrinking of the starch. The dent corn grown in the Corn Belt came from a mix of New England flints and gourseed (an old variety of corn grown by the Indians in southeaster North America). By-products from the wet milling process can come from North America as well as Europe, but since there is no specific regional data the choice has been made to focus on reporting one general mass balance. Feed materials derived from wet milling of maize are described below. The products from the oil production process originate from oil extraction from dried maize germ, a by-product of wet milling. Table By-products from maize wet milling in the CVB list are: name CVB Process DMC Starch (g/kg) (g/kg) Maize germ meal extruded Oil production Maize germ meal feed expeller Oil production Maize germ meal feed extruded Oil production Maize gluten meal Wet milling Maize glutenfeed Crude Protein Wet milling Maize glutenfeed Crude Protein<200 Wet milling Maize glutenfeed Crude Protein>230 Wet milling Maize glutenfeed fresh+sillage Wet milling Maize solubles Wet milling Maize starch Wet milling Maize bran Wet milling Note on allocation For the wet milling of maize it was decided to apply detailed sub-process allocation (approach 2 for allocation, see 5.3, Vellinga et al, 201. The specific energy use for by-products is fully allocated to those products (e.g. drying). The prices and composition data of intermediate products are derived form end products on the basis of a deduced dry matter value of the different end-products Sourcing An inventory of the origin of feed materials for the Dutch feed industry indicated that four countries supply the major part of this material. We assumed a division amongst these countries according to the shares listed in Table This means for example that 25% of the maize wet milling feed material is sourced from Dutch wet milling factories which sources the maize for 34% of the USA, 33% of Germany and 33% of France. Both the origin of wet milling feed materials form industry and the input of maize in that industry fluctuates over the years. 1 Maize is known as corn in countries such as the United States, the English-speaking provinces of Canada, Australia and New Zealand. 3

9 Table Estimated countries of origins of the feed materials. Processing in: the Netherlands USA Germany France percentage 25% 35% 20% 20% Crop-country the Netherlands USA 34% 100% 25% Germany 33% 50% France 33% 25% 100% Flowcharts Corn 1 kg 1.Receving and Steeping Dewatering Steepwater/ steep liquor 2. Degermination Dry germ Corn Oil Production Germ meal Corn oil 5. Mixing and drying Gluten feed meal 3. Grinding and Screening Fiber/Bran Dewatering Fiber/Bran 4. Starch-Gluten Separation Gluten Drying Gluten meal Starch Drying Starch Input product Process Main products Figure Flowchart of wet milling of maize. For each main product, a drying or dewatering step is included. The main feed products of the wet milling of maize are corn oil, fiber, gluten, and starch. Depending on the prices of these products though, the manufacturer can decide to alter processing routes, resulting in a different mix of alternative products such as corn steep liquor, dry germ and ethanol (not shown in the figure). Yields of the different by-products vary through the years so yields from processing found in literature should be qualified as typical yields. Gluten feed is composed by mixing bran/fiber and steep liquor. Depending on many factors steep liquor, germ and bran/fiber can also be final products, but typically they are processed as described above Corn oil is often included as a main product in maize wet milling studies. However, it is usually not processed on the same site, and additional animal feed by-products (maize germ meal and expeller) arise 4

10 from this next step. It is therefore treated here as a separate industry, with the maize germ as described in the first part as an input 2. Since the data from Galatisky is detailed enough to perform a step-by-step allocation at each sub-process, it was opted to apply the mass balance from this source. The elaboration of this is found in the next section, while below a number of the mass balances are presented, in order to show that the mass balance by Galitsky is reasonable in general 3. Table Mass balance maize wet milling (excluding corn oil production) Input DMC (g/kg) Mass, as is Mass, dm Corn output Maize germ Maize gluten feed bran/fibre steep liquor Maize gluten meal Maize starch The mass balances are expressed on a dry matter basis, since often an undisclosed amount of water is used at a number of different points during the process. The mass balance described by Kim and Dale (200 (see table A) was difficult to interpret. Adding up and comparing the dry matter going in and dry matter coming out of the process described by Kim and Dale leads to the observation that the mass balance is not complete, because more dry matter goes into the process than seems to come out.ethanol is produced by fermentation of starch. The chemical equation of this fermentation process is: 2 C 6H 10O H 2O 4 C 2H 5OH + 4 CO 2 Table :Mass balance according to Kim and Dale (200 (A = original, B = deduced to input of starch used for ethanol) A B IN kg dry matter corn 0,85 OUT ethanol 0,295 corn oil 0,038 corn gluten meal 0,047 corn gluten feed 0,201 IN kg dry matter corn 0,794 OUT starch 0,508 corn oil 0,038 corn gluten meal 0,047 corn gluten feed 0,201 The amount of dry matter of starch corresponding with 0,295 kg of ethanol is 0,508 kg (see equation of fermentation process). Replacing ethanol by starch in the mass balance of table B above almost completes the dry matter coming out of the process. The minor difference might be explained by rounding errors. 2 Other sources (e.g, also describe germ meal as a separate product from the feed by-products directly from wet milling. 3 Galitsky (2003) presents typical yields of corn components. The mass balance is on a dry matter basis, but no information is given on exact dry matter contents and these have been deduced from other sources. 5

11 Ramirez (2009) has also published a mass balance for the wet milling of maize. The two values are derived from conventional and enzymatic wet milling. Ramirez has quite detailed information on the processes involved and the evolution of dry matter contents of the intermediate products. Although unfortunately no direct information on energy usage during the process steps is presented. The data were used in constructing the intermediate mass balances (especially dry matter contents) for the process allocation steps. Mass balance according to Ramirez (2009), from 1 tonne corn, dry matter basis Product DM% Value (mass, dm) Unit Min Max Maize germ Kg Maize gluten feed Kg Maize gluten meal Kg Maize starch Kg Balance arises after taking into account loses of 2.4% in the prehandling of corn Inputs Galitsky (2003) reports a rather detailed table on energy consumption of the wet milling of maize. Here, we will follow the allocation of subprocess and intermediate product prices. The energy data by Galtisky gives us enough information to do this. What follows will be a step-by-step breakdown of the production, including allocation steps. Additional energy usage such as drying steps will be included as well, but not treated as an allocation step. In this final breakdown, the mass balance from Galitsky is used, which seems prudent as energy usage originates from the same source. The dry mater contents of (intermediate) products have been taken from Galitsky, Ramirez and the CVB list. According to Ramirez, corn enters at 85% dry matter. Protein contents and GE (all on dry matter basis) have been calculated from the CVB list. Prices for allocation are derived from Faostat and Eurostat prices on bran/fiber, germ, starch and gluten feed/meal. These were recalculated based on dry matter content and applied in the intermediate process steps. Often the intermediate product can be directly related to a final product (such as wet germ resulting in the final dried germ) and the price of the final product is applied (on a dry matter basis). Some intermediate corn products arise and the price components are derived from the final product. For example, in processing step 4, the intermediate corn product from step 3 named intermediate wet corn (step 3) enters and the process produces starch and gluten. From the mass balance we know that 680 kg starch (at 0.39/kg) and 56 kg gluten (at 0.18/kg) is produced from this intermediate product. From these proportions the price of the intermediate product is calculated at 0.37/kg (resulting from 56* *0.39)/740). The prices (and composition data) are all derived in this way. Table Product category Price (euro/kg) DMC (g/kg) Price on DM basis Bran or fiber Germ Starch Gluten feed/meal The tables below show all the steps involved in corn wet milling, including energy usage. As the moisture content of intermediate products vary significantly during processing and is highly uncertain, the mass balance is based on the dry matter content. 6

12 Step 1: Corn receiving, steeping and steepwater evaporation Step 1a: Corn receiving and steeping Parameter Value Unit Inputs Mass (dm) DMC Price GE (MJ/kg) (g/kg) ( /kg) Corn Energy inputs Error ( g natural gas MJ/tonne corn electricity from the grid Mj/tonne corn Outputs Mass (dm) DMC (g/kg) Price ( /kg) GE (MJ/kg) Steepwater (wet) 65 10% Intermediate wet corn (step 1) % Step 1b: Steepwater dewatering Parameter Value Unit Inputs Mass (dm) DMC (g/kg) Steepwater (wet) Energy inputs Error ( g natural gas MJ/tonne corn electricity from the grid MJ/tonne corn Outputs (CVB Name) Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Maize Solubles 65 10% * 14.1 * [Editor s note: This price should be double-checked; specific price for maize solubles).] Step 2: Degermination (Germ recovery) and germ drying Step 2a: Degermination Parameter Value Unit Inputs Mass (dm) DM (g/kg) Price ( /kg) GE (MJ/kg) Intermediate wet corn (step 1) Energy inputs Error ( g electricity from the grid MJ/tonne corn Outputs Mass (dm) DMC Price ( /kg) GE (MJ/kg) (g/kg) Germ (wet) 75 10% Intermediate wet corn (step % Step 2b: Germ drying Parameter Value Unit Inputs Mass (dm) DMC (g/kg) Germ (wet) Energy inputs Error ( g natural gas MJ/tonne corn Diesel MJ/tonne corn electricity from the grid MJ/tonne corn 7

13 Outputs Mass (dm) DMC (g/kg) Price ( /kg) GE (MJ/kg) Germ (dried)* * Dried germ are used as input for the oil crushing process described later in this document. Step 3: Grinding and screening (Fibre recovery) and fibre dewatering Step 3a: Grinding and screening Parameter Value Unit Inputs Mass DMC Price GE (dm) (g/kg) ( /kg) (MJ/kg) Intermediate wet corn (step Energy inputs Error ( g electricity from the grid Mj/tonne corn Outputs Mass DMC Price GE (dm) (g/kg) ( /kg) (MJ/kg) Fibre/Bran (wet) Intermediate wet corn (step 3) Step 3b: Fibre dewatering Parameter Value Unit Inputs Mass (dm) DM (g/kg) Fibre/Bran (wet) Energy inputs Error ( g electricity from the grid MJ/tonne corn Outputs Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Fibre/Bran (dewatered) Step 4: Starch gluten separation (Gluten recovery), gluten drying and starch drying Step 4a: Gluten recovery Parameter Value Unit Inputs Mass (dm) DM Price (g/kg) ( /kg) Intermediate wet corn (step 3) Energy inputs Error ( g electricity from the grid MJ/tonne corn GE (MJ/kg) Outputs Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Gluten (wet) Starch (wet) Loss 4 Loss in overall process. Step 4b: Gluten drying Parameter Value Unit Inputs Mass (dm) DM (g/kg) Gluten (wet) Energy inputs Error ( g Diesel MJ/tonne corn electricity from the grid MJ/tonne corn 8

14 Outputs (CVB Name) Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Maize gluten meal Step 4c: Starch drying Parameter Value Unit Inputs Mass (dm) DM (g/kg) Starch (wet) Energy inputs Error ( g Diesel MJ/tonne corn electricity from the grid MJ/tonne corn Outputs (CVB Name) Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Maize Starch Step 5. Mixing fiber with steep liquor for gluten feed. Step 5a: Maize glutenfeed production (no drying) Parameter Value Unit Inputs Mass (dm) DMC (g/kg) Fibre/bran (dewatered) Steep liquor (concentrated, Maize Solubles) Output (CVB Names) DMC Price GE (g/kg) ( /kg) (MJ/kg) Maize glutenfeed fresh+sillage Step 5b: Maize glutenfeed production (with drying) Parameter Value Unit Inputs Mass (dm) DMC (g/kg) Fibre/bran (dewatered) Steep liquor (concentrated, Maize Solubles) Energy inputs for drying step Error ( g Diesel MJ/tonne corn electricity from the grid MJ/tonne corn Outputs (CVB Names) Mass (dm) DMC Price GE (g/kg) ( /kg) (MJ/kg) Maize glutenfeed crude protein <200 Maize glutenfeed crude protein Maize glutenfeed crude protein > Step 5c: Maize dried bran production (with drying) Parameter Value Unit Inputs Mass (dm) DMC (g/kg) Fibre/bran (dewatered) Energy inputs for drying step Energy Error ( g input Diesel MJ/tonne corn electricity from the grid MJ/tonne corn Outputs (CVB Names) Mass (dm) DMC (g/kg) Price ( /kg) GE (MJ/kg) Maize bran

15 Maize bran is the dried gluten feed without steep liquor (maize solubles) added. It is listed here as comparable as maize glutenfeed as the same drying step applies, but with reduced energy usage as the total amount dried has changed. Detailed input and output data for end products. Data below on composition is used in the detailed breakdown of the process in the section above. Also included are the overall energy usage without the process breakdown. The European Commission (EC) has published a reference document on best available techniques in the Food, Drink and Milk Industries (2006) which indicates an energy use for the wet milling of maize comparable to the energy use reported by Galitsky. The EC reports a variation in energy use between a minimum and a maximum. These values have also been used to get an insight on the error margin of the values by Galitsky, which we have chosen to be 30%. Table Input data inventory Product Parameter Value Unit Data quality Ref Mean Min Max Rel Com TRC GSp TeC Energy use: fuels diesel 33,2 kg/kg a natural gas MJ/kg 1 4 Energy use: electricity electricity from the grid 113, kwh/kg a (mean) b (min-max) a (mean) b (min-max) a) Galistky C., Worrel E., Ruth M., 2003, Energy Efficiency Improvement and Cost Saving Opportunities for the Corn Wet Milling Industry, University of California, USA. b) European Commission, 2006, Reference document on best available techniques in the food, drink and milk industries Production of maize germ oil The germ that originates (in dried form) from the wet milling process, is further processed to extract the oil content, which is particularly high in this part of maize. This produces, as a by-product, germ meal or expeller. The processing of germ to germ (corn) oil and germ meal is a fairly straightforward process where the oil is extracted via a solvent extraction process with hexane (usually preceded by a light mechanical pressing step), or via a mechanical pressing method. 10

16 Dried maize germ Solvent extraction Mechanical pressing Crude oil Meal Crude oil Expeller Figure Flowchart of germ processing Maize germ oil: Mass balance Typical oil contents for maize germ (dried) is up to 50% ( while typical values lie around 45% ( If the dry matter and oil contents of the oilseed are known, the mass balances can be deduced for both the mechanical cold pressing (which leaves more oil in the residue, typically 75% of the oil is extracted) and oil extraction with an organic solvent (which leaves very little oil, typically 98% of the oil is extracted). The numbers in Table and Table are based on these extraction rates (while also taking into account de deshelling), while allowing for a loss of around 1.5% (see Schmidt (2007)). Oil content data is found in a range from around 40 (Johston, 2005) to 48 (Ramirez, 2009) procent. A 44% oil content is used as a basis for the mass balance below. The dry matter contents of dried germ are calculated backwards based on the germ meal and expeller production and moister content from the CVB. The moisture content is within the expected range for dried germ (see for example Table Default mass balance of germ processing (cold pressing, from 1 tonne of germ). Input DMC (g/kg) Mass (kg) Germ (dried) Output Germ expeller Germ oil Loss (mostly water) 0 15 *Germ originating from corn wet milling process as described in Table Default mass balance of germ processing (solvent extraction, from 1 tonne of germ). Input DMC (g/kg) Mass (kg) Germ

17 Output Germ meal Germ oil Loss (mostly water) 0 15 *Error margin determined by pedigree matrix, see generic oilseed processing Maize germ oil: Inputs Rapeseed processing is used as a basis of comparison to obtain general oilseed figures on energy requirements for processing of germ. Thus, values obtained for the CFPAN project for rape seeds are used (see chapter Generic oilseed production in the background data report on the crushing industry (Part 1/7). These can then be recalculated based on the energy required for the extraction of a unit of oil. Table and Table show the inputs needed for processing 1 tonne of germ, calculated in this manner. Table Default inputs for oilseed processing (pressing, for 1 tonne of germ, based on rapeseed) for the production germ expeller. Input Values Unit Best estimate Error ( g Electricity (pressing) MJ/ton Based on values from Croezen (2005) and Hamelinck (2008), recalculated relative to oil production. * Error margin to be calculated based on pedigree matrix. Table Default inputs for oilseed processing (solvent extraction, for 1 tonne of germ, based on rapeseed) for the production germ meal. Input Values Unit Ref Best estimate Error ( g Electricity (extraction) MJ/ton b Natural gas (extraction) MJ/ton b Hexane kg/ton c b: Based on values from Croezen (2005), Schmidt (2007), and Hamelinck (2008), recalculated relative to oil production.; c: Schmidt (2007) Maize germ oil: Allocation All items on the CVB list, except for the unprocessed germ, are represented in the mass balances and allocation data tables below. Maize germ meal prices derived from Faostat (Cake of Maize) average prices from (prices not available for 2007 and 2008). Germ oil prices are from Eurostat (Corn oil). Table DMC (g/kg) Price GE Pressing Name CVB Mass (euro/ton) (MJ/kg) Germ expeller Maize germ meal feed expeller (13600) Germ oil NA Extraction Germ meal Maize germ meal extruded (13500) Maize germ meal feed extruded (13700) Germ oil NA

18 References Croezen, H. en B. Kampman Op (de) weg met pure plantenolie? De technische, milieuhygiënische en kostengerelateerde aspecten van plantenolie als voertuigbrandstof. Report 2GAVE CE Delft. CVB-table: see appendix 1 in Vellinga et al. (201 European Commission, 2006, Reference document on best available techniques in the food, drink and milk industries. Galistky C., Worrel E., Ruth M., 2003, Energy Efficiency Improvement and Cost Saving Opportunities for the Corn Wet Milling Industry, University of California, USA. Hamelinck, C., K. Koop, H. Croezen, M. Koper, B. Kampman, G. Bergsma Technical specification: Greenhouse gas calculator for biofuels. Version 2.1b. Ecofys CE Delft. Johnston, David B, Mcaloon, Andrew J, Moreau, Robert A, Hicks, Kevin B. Composition and Economic Comparison of Germ Fractions from Modified Corn Processing Technologies. JAOCS, Vol. 82, no. 8 (2005). Kim S., Dale B.E., 2002, Allocation Procedure in Ethanol Production System from Corn Grain, Michigan State University, USA. National Academy of Sciences,1971, Atlas of nutritional data of United States and Canadian feeds Ramirez (2009), Enzymatic corn wet milling: engineering process and cost model, Biotechnology for biofuels, january Singh, VijaySchmidt, J. H Life cycle assessment of rapeseed oil and Ph.D. thesis, Part 3: Life cycle inventory of rapeseed oil and palm oil. Department of Development and Planning, Aalborg University, Aalborg. University of Missouri Exntention, april 2011, Feed prices of by-products sorted by product: USDA: Vellinga, T.V., Blonk, H., Marinussen, M., van Zeist, W.J., de Boer, I.J.M. (201 Methodology used in feedprint: a tool quantifying greenhouse gas emissions of feed production and utilization Wageningen UR Livestock Research and Blonk Consultants. Lelystad/Gouda, the Netherlands. 13

19 2.3 Wet milling of sorghum Introduction Sorghum gluten meal is included as a number of sources indicate that the wet milling of sorghum is quite comparable to that of maize. This is valid for the processes involved as well as the resulting products. Since only one, relatively unimportant, feed ingredient is derived from sorghum, it is included here as a similar product to those arising from corn wet milling. See: - C. Wayne Smith,Richard A. Frederiksen Sorghum: origin, history, technology, and production. - Ping Yang and Paula Seib. 1995, Low-Input Wet-Milling of Grain Sorghum for Readily Accessible Starch and Animal Feed. Cereal Chem. 72(5): Therefore, sorghum gluten meal can be considered a substitute of maize gluten meal, which is discussed in the chapter on maize wet milling. Obviously upstream emissions from sorghum cultivation can be applied instead of maize cultivation. Table By-products from sorghum wet milling in the CVB list are: name CVB Process DMC (g/kg) Starch (g/kg) Sorghum gluten meal Wet milling Thus, for the process description, inputs and outputs, and allocation, the chapter on maize wet milling applies, specifically the by-product Maize gluten meal which is the maize version of Sorghum gluten meal References C. Wayne Smith,Richard A. Frederiksen Sorghum: origin, history, technology, and production. Ping Yang and Paula Seib. 1995, Low-Input Wet-Milling of Grain Sorghum for Readily Accessible Starch and Animal Feed. Cereal Chem. 72(5): Vellinga, T.V., Blonk, H., Marinussen, M., van Zeist, W.J., de Boer, I.J.M. (201 Methodology used in feedprint: a tool quantifying greenhouse gas emissions of feed production and utilization Wageningen UR Livestock Research and Blonk Consultants. Lelystad/Gouda, the Netherlands. 14

20 2.4 Wet milling of starch potatoes Note on allocation Unlike for the wet milling of maize, not enough detailed information was uncovered to allocate according to subprocesses in the wet milling of potatoes. 4 Thus, the wet milling is described as a single unit process. It should be noted that the European starch industry has informed us that, in the beginning of 2012, a detailed report on energy usage in the industry will be publicly released. It is our intention to update the default values in this document when this report becomes available By-products from potato starch production Feed materials derived from the potato starch production are: name CVB DMC Starch (g/kg) (g/kg) Potato protein Crude ASH < Potato protein Crude ASH > Potato starch dried Potato pulp pressed Potato juice concentrated Potato pulp Crude Protein< Potato pulp Crude Protein> Potato starch heat treated and dried According to Roelof de Weerd potato pulp crude protein, which is mentioned in the CVB-table, is hardly produced any more by this industry. Roquette in France is to his knowledge the only producer of potato pulp crude protein in Europe. Potato starch heat treated is produced in another process than is being done in this industry. For sake of completeness, however, these products will be included, with an estimate on the amount of energy needed for drying the products to the listed moisture content Sourcing It is assumed that the Dutch feed industry sources the feed materials in the countries that are listed in Table Table Estimated countries of origins of the feed materials Processing in: the Netherlands percentage 100% Crop-country Germany 30% the Netherlands 70% 4 Although and older source (Blonk, 1997), does mention an estimation of energy use in a number of processes. However, as the source is somewhat outdated, it was decided not to incorporate these data 15

21 2.4.4 Flowcharts Starch potatoes 1 kg Cleaning of potatoes Grinding of potatoes Tare Input product Process Additional products Main products Fibers 0,140 kg Extraction of fibers Starch Starch refinery Starch 0,238 kg Fruit juice Protein 0,016 kg Separation process Protamylase 0,054 kg Figure Flowchart of potato starch production (as is). The first stage in potato processing is a cleaning stage in which the tare is removed from the potatoes. Then the potatoes are grinded and the fibers are extracted. From the remaining substance the starch and fruit juice are separated. The fruit juice can be a final product from processing but can also be further processed producing a protein meal and protamylase (also called concentrated fruit juice). Protamylase is a thick fluid substance, which can be used as a fertilizer Mass balance Various mass balances have been found in literature, providing information on varying output products (Blonk 1997, Rosenau 1979, Karup Kartoffelmehl Fabrik ( )). However, most literature was found to be outdated, and superior information was retrieved from an industry expert of AVEBE, which represents a large part of the feed rawe materials being consumed in the Dutch sector. The figures endorsed by the industry expert are generally in agreement with average figures from the older sources and are considered broadly applicable. They are presented below in the default mass balance. This mass balance will be applied to the Netherlands with an error of 10%, and for Germany and Belgium with an error of 20%. Table Default mass balance per tonne of potatoes. Input DMC (g/kg) (kg/tonne) Potatoes Output DMC (g/kg) Best estimate (kg/tonne) 16

22 Potato Starch Potato fibers/ pulp Potato protein Protamylasse/ concentrated fruit juice Inputs Table gives the default values for energy usage in potato starch processing. These values will be underpinned in the remainder of the text. Table Default values for energy inputs unit process I Product Parameter Value Unit Best Min Max estimate Energy use: fuels natural gas 0.79* MJ/kg Energy use: electricity electricity from the grid 0.00* kwh/kg * Best estimate energy usage is Dutch industry data based on a facility with a CHP, hence no electricity is listed as input. This input translates to 0.08 kwh and 0.51 MJ natural gas per kg. The tables below give background information on composition and references for the energy usage included. For potato starch wet milling, reference values are found in the EC (2006) BREF document, which give a range of values for energy inputs. The best estimate is information for the Dutch industry obtained from AVEBE. Table Inventory data potato starch processeing Energy use: fuels diesel 0,0016 kg/kg a natural gas 0,079 0,32 1,27 MJ/kg 2 4 Energy use: electricity electricity 0,00 0,04 0,08 kwh/kg 2 4 C-contents are based on reference h. a) Blonk et al.., b) European Commission (2006) c) AVEBE (2011) Allocation c (mean) b (minmax) c (mean) b (minmax) Table Data for allocation By-product Name CVB Mass DMC Economic Fraction* GE (MJ/kg) (g/kg) Potato protein Potato protein Ruw ASH <10 (34910) Potato protein Ruw ASH >10 (34920) ,930 Potato starch Potato starch dried (34700) ,592 Potato fibers/ pulp Potato pulp pressed (53600) ,917 Protamylasse/ Potato juice concentrated (35000) ,989 concentrated fruit juice * Economic fraction are relative prices provided by AVEBE. 17

23 2.4.8 Energy use and allocation for heat treated and dried products The input table below concerns the potato starch production by-products that are not specifically listed but are dried varieties of potato pulp ( potato pulp crude protein and Potato starch heat treated ). There is no specific information available on how much of this is produced. It is, however, possible to estimate the energy needed to dry these products from approximately 20% dry matter content in the pulp or wet starch, which can be subsequently added separately as an input for this specific category. Based on (Roe, 2003) the energy use for drying ranges from 3 6 MJ per kg water evaporated. For drying potatoes from the 60% dry matter to 88% (up until 60% usually happens via significantly more efficient mechanical process), this amounts to 920 to 1920 MJ of heat (assumed to be produced with natural gas) per tonne potatoes. Table Default input/output of for drying by-product. Product Parameter Value Unit Input: Wet potato by-product Amount 1000 kg DMC 165 g/kg Natural gas for heat 0.92 (min) 1.92 (max) MJ/kg Output: DMC (g/kg) Amount (kg) Potato pulp Crude Protein<95 (34610) Potato pulp Crude Protein>95 (34820) Potato starch heat treated and dried (79800) A: (Nemecek & Kägi, 2007), As these products likely arise form wet low value by-products, we treat these within the scope of allocation approach 3 (see 5.3, Vellinga et al, 201 and no upstream allocation takes place towards these residual by-products prior to drying. Thus, only the energy use for drying and subsequent transportation will be taken to be taken into account. No further information on allocation is therefore required References AVEBE (2011), personal communication with Roelof de Weerd. Blonk H., Lafleur M., van Zuijts H., 1997, Screening LCA on potato starch, IVAM Environmental Research, Amsterdam. CVB-table: see appendix 1 in Vellinga et al. (201 European Commission, 2006, Reference document on best available techniques in the food, drink and milk industries. Eurostat: Karup Kartoffelmehl Fabrik ( ): Rosenau J.R., Whitney F., 1979, Low wastewater potato starch/protein production process, Industrial Environmental Research Laboratory, Cincinnati, Ohio. USDA: Vellinga, T.V., Blonk, H., Marinussen, M., van Zeist, W.J., de Boer, I.J.M. (201 Methodology used in feedprint: a tool quantifying greenhouse gas emissions of feed production and utilization Wageningen UR Livestock Research and Blonk Consultants. Lelystad/Gouda, the Netherlands. 18

24 2.5 Wet milling of wheat By-products from wet milling of wheat Feed materials derived from wet milling of wheat are: name CVB DMC Starch (g/kg) (g/kg) Wheat gluten meal Wheat gluten feed Wheat bran Wheat starch tot Wheat starch tot Wheat starch tot Note on allocation Unlike for the wet milling of maize, not enough detailed information was uncovered to allocate according to subprocesses in the wet milling of wheat. The manner of allocation is thus chosen to be approach 1 as described in the methodology document (see 5.3, Vellinga et al, 201. Thus, only input/output data covering the overall process is included. It should be noted that the European starch industry has informed us that, in the beginning of 2012, a detailed report on energy usage in the industry will be publicly released. It is our intention to update the default values in this document when this report becomes available Sourcing The Dutch feed industry source the feed materials in the countries that are listed in Table Table Estimated countries of origins of the feed materials. Processing in: the Netherlands Belgium Germany percentage 80% 10% 10% Crop-country France 25% Germany 35% 100% Denmark 10% UK 25% Belgium 100% 19

25 2.5.4 Flowcharts Wheat 1 kg Dry milling Bran 0,18 kg Dough Making Vital Gluten Separation Dewatering and Drying Vital Gluten 0,10 kg Bran Evaporation Starch Separation Drying Wheat Gluten Feed 0,08 kg Stripping Input product Starch slurry Starch 0,54 kg Process Main products Additional products Slurry 0,10 kg Figure Flowchart of wet milling of wheat The main products of the wet milling of wheat are bran, vital gluten, wheat gluten feed and starch slurry. Depending on the current prices of these products though, de manufacturer can make the decision to alter processing resulting in another variety of products. Altering processing can lead to other products like pure starch or to alterations in for instance protein, starch and dry matter contents of products Mass balance Below, the default mass balance for wet milling of wheat is shown. As explained below, it is difficult to construct one accurate mass balance due to large varieties of components and process outputs. The upper and lower boundaries are therefore quite uncertain. Table Default mass balance (in kg, from 1 tonne of wheat). Output DMC (g/kg) Mass Wheat bran

26 Wheat protein/ gluten Wheat gluten feed Wheat starch Wheat slurry Various mass balances have been found in literature, providing information on varying output products. One overall mass balance is elaborated for the five main products from the wet milling of wheat. Due to incomplete data or variations in processing and for instance dry matter content of process outputs it is unclear what the most likely mass balance is. By combining all mass balances, including protein and starch contents a mass balance has been constructed. Table Mass balance constructed based on Westfalia Seperator Industry and industry experts and based on protein and starch content. The following mass balance has been found in a presentation given by dr. W. Witt, M. Seiler and B. Schiemann by Westfalia Separator Industry. Table Mass balance according to Westfalia Separator Industry In the process described by Westfalia Separator Industry the first step is the dry milling of wheat in order to produce wheat flour. This step is not described in this presentation. A more detailed mass balance is given below. First the dough is prepared using wheat flower and water. The dough enters a 3 phase decanter/ 2 gear drive adding more water and separating b-starch, gluten, pentosanes and a rest product which is added to the starch slurry. The pentosanes are also added to the starch slurry. The b-starch and gluten are treated in the gluten screen system separating the gluten from the starch. The b-starch is combined with the rest of the starch slurry. The gluten is treated in a gluten finisher. A rest product from the gluten finisher is transported back to the gluten screen system. Table Detailed mass balance according to Westfalia Separator Industry 21

27 Personal communication with an industry expert in 2009 resulted in the following mass balance: Table Mass balance according to industry experts (2009) This process includes dry milling of wheat in which the bran is separated from the wheat flower (82%). The wheat flower enters the next process which results in a protein rich gluten fraction, a starch fraction and starch slurry. According to another industry expert (2004) the mass balance of the wet milling of wheat looks like this: 22

28 Table Mass balance according to industry experts Inputs Below the default energy inputs for the wet milling wheat are listed. The energy values are from European Commission (2006), which should give a reliable range of energy uses for the European industry. Table Eergy inputs for wet milling of wheat. Product Parameter Value Mean Min Max Energy use: fuels natural gas 3,78 2,88 4,68 MJ/kg Energy use: electricity electricity from the grid 1,26 0,72 1,80 MJ/kg Allocation It is likely that the in order to process various types of starch the process and the mass balance will also slightly vary. We expect that the allocation factor might be different for the three types of wheat starch. The price per type of wheat starch will probably also be different per type. For now there is not enough data available to make a well based differentiation between these products. Table Allocation data By-product CVB Name Mass (kg) DMC (g/kg) Price (euro/kg) a Wheat bran Wheat bran (20700) Wheat protein/gluten Wheat gluten meal (21100) Wheat gluten feed Wheat gluten feed (21200) Wheat starch NA Wheat starch tot 300 (80210) Wheat starch slurry Wheat starch tot 400 (80010) Wheat starch tot 600 (59500) a. Industry experts, 2004, personal communication, Blonk Milieu Advies database References CVB-table: see appendix 1 in Vellinga et al. ( GE (MJ/kg) European Commission, 2006, Reference document on best available techniques in the food, drink and milk industries. Industry experts, 2004, personal communication, Blonk Milieu Advies database. Industry experts, 2009 personal communication, Blonk Milieu Advies database. National Academy of Sciences,1971, Atlas of nutritional data of United States and Canadian feeds 23

29 Ponsioen T., van der Flier S., Blonk H., 2009, Broeikasgasemissies voedergrondstoffen Nutreco, Blonk Milieu Advies, Gouda. Punter G., et. al., 2004, Well to Wheel evaluation for production of ethanol from wheat, Low carbon vehicle partnership University of Missouri Exntention, april 2011, Feed prices of by-products sorted by product: USDA: Vellinga, T.V., Blonk, H., Marinussen, M., van Zeist, W.J., de Boer, I.J.M. (201 Methodology used in feedprint: a tool quantifying greenhouse gas emissions of feed production and utilization Wageningen UR Livestock Research and Blonk Consultants. Lelystad/Gouda, the Netherlands. Westfalia Separator Industry, Presentation: Comparison of wet milling and dry milling by Dr. E. Witt, M. Seiler and B. Schiemann. 24