Green Concrete LCA Web Tool

Structure of the GreenConcrete LCA Web Tool

The Web version consists of two major sections: “User Input” and “Results” that are visible to the user and each of these two sections are connected to one another through “Reference Data Pool” and “Processes and Calculations” that provide the necessary data and calculations at the background and these two sections are not visible in the Web tool but in the Excel version (See Figure 1). In addition to the “Reference Data Pool” pages in Excel version, each “Process and Calculation” section accommodates smaller databases from exhaustive literature including ([EPA] 1994; CEMBUREAU 1999a; CEMBUREAU 1999b; Worrell, Martin et al. 2000; Worrell, Price et al. 2001; [USDOE] 2003; Bhatty, Miller et al. 2004; [CSI] 2005; [EFCA] 2006; Marceau, Nisbet et al. 2006; Alsop 2007; Facanha and Horvath 2007; Marceau, Nisbet et al. 2007; [APP] 2008; [LBNL] 2008; Worrell and Galitsky 2008; [IPPC] 2009; Boesch, Koehler et al. 2009; Boesch and Hellweg 2010; [NREL] 2011; [EIA] 2011a; [EIA] 2011b; [EPA] 2012; [NREL] 2012).

The “Reference Data Pool” worksheets consist of life-cycle inventories of electricity generation grid mix, freight transportation, and fuel pre-combustion and combustion based on the database from current studies. Life-cycle inventories of electricity, fuel, and materials are organized for each materials production phase in “Process and Calculation” worksheets within the Excel tool. Emission factors from the “Reference Data Pool” worksheets are multiplied by the phase inventories to calculate the total phase impacts. These emission inventories are summed and collected in the “Results” page together. Figure 3 illustrates the GreenConcrete LCA tool structure briefly.

Figure 3 GreenConcrete LCA tool structure

Description of the User-Input Page

The user-input page provides necessary information to the remaining worksheets of the tool it consists of color-shaded and drop-down cells with input data entered or selected by the user.

There are seven sections on this page:

1. Modeling parameters used throughout the tool such as; functional unit of concrete mix (cubic meter), unit type (volume), and quantity of concrete produced (user-defined).


2. Concrete mix proportions input; users are asked to provide information about the concrete mix proportions per unit volume (cubic meters) of concrete mix, which in turn requires input for quantities and types of materials (type of cement and chemical admixtures) used in the mix.


3. Quarry/plant location requires information about the quarry/plant location for quantifying the energy use and emissions associated with electricity use for quarrying, producing, and processing of cement raw materials (limestone, gypsum, etc.), different types of ASTM-defined cements (Type I-V Portland cements and blended cements), fine and coarse aggregates, and supplementary cementitious materials (SCMs) that include limestone, natural pozzolan, fly ash, and granulated blast furnace slag (GBFS). Only admixtures production worksheet does not require electricity input from the user since the database ([EFCA] 2006) that provides the admixture inventory lacks the production-related electricity factors. For each of the quarry/plant location, the corresponding electricity grid mix drop-down list consists of the States (50 states plus D.C.), the U.S. average, and one user-defined grid mix option.


4. Operation (electricity grid mix) input section allows users to create three customizable grid mixes by entering the percentages of the fuels that contribute to the mix (by percent energy). The Table 1 below tabulates the most common types of energy sources used in the U.S. electricity generation and default fuel usage percentages are calculated based on U.S. Energy Information Agency’s annual energy reviews ([EIA] 2011a).



Table 1 User Input Page – Electricity grid mix input (by % energy) for user defined options (US average % values are demonstrated for comparison purposes)




Type of Electricity Source	User-defined grid mix (%)	US average (default) (%)
Bituminous Coal	User Input	44.4%
Natural Gas	User Input	23.3%
Residual(Heavy) Oil	User Input	0.5%
Distillate (Diesel/Light) Fuel Oil	User Input	0.2%
Petroleum Coke	User Input	0.4%
Nuclear (Uranium)	User Input	20.2%
Hydro	User Input	6.9%
Biomass	User Input	1.4%
Geothermal	User Input	0.4%
Solar	User Input	0.0%
Wind	User Input	1.9%
Lignite Coal	User Input	0.0%



5. Transportation input; distance and mode data are required for calculating impacts associated with the delivery of materials to cement plant and concrete batching plant. The user is asked to enter one-way distance (in km) traveled to the destinations listed below:



User Input Page – Destinations for Transportation Input

Cement Raw Materials (limestone, clay, etc.) to Cement Plant Gypsum to Cement Plant Fly Ash to Cement Plant (if Blended cement) Granulated Blast Furnace Slag to Cement Plant (if Blended cement) Cement to Concrete Plant Fine Aggregates to Concrete Plant Coarse Aggregates to Concrete Plant Admixture to Concrete Plant (assume all types are from one plant) Fly Ash to Concrete Plant Granulated Blast Furnace Slag to Concrete Plant Natural Pozzolan to Concrete Plant Limestone to Concrete Plant



6. Technology options (for cement plant and concrete batching plant); discrete technology options are provided for cement production processes (see Table 2 ) for major cement production phases from raw materials preparation to finish milling/grinding to produce Portland cement and/or mixing the Portland cement (clinker + gypsum) with SCMs to produce blended cements that are ready to exit the cement plant for further use in concrete plant. User is asked to select among the production technology options listed in the Table 2 :



Table 2 User Input Page - Technology Drop-down Options by Cement Production Phases




Cement Production Phases	Product of Each Phase	Technology Options
Raw Materials Prehomogenization	Raw Meal	Dry process Raw storing, non-preblending Dry process Raw storing, preblending Wet process Raw storing
Raw Materials Grinding	Ground Meal	Dry raw grinding ball mill Dry raw grinding tube mill Dry raw grinding vertical roller mill Wet raw grinding tube mill Wet raw grinding wash mill
Raw Meal Blending/ Homogenization	Blended Meal	Raw meal homogenization, blending, and storage Slurry blending homogenization and storage
Pyroprocessing	Clinker	Wet kiln Long dry kiln Preheater kiln Preheater/Precalciner kiln U.S. Average kiln
Clinker Cooling	Cooled Clinker	Rotary (Tube) Cooler Planetary (Satellite) Cooler Reciprocating Grate Cooler (Conventional) Reciprocating Grate Cooler (Modern) Vertical Gravity Cooler with Planetary Cooler Grate Cooler (Recirculating Excess Air) PM Control Technology Options: Fabric Filter (FF) Electrostatic Precipitators (ESP)
Finish Milling, Grinding, and Blending with Portland Cement	Blended Cement or Traditional Portland Cement	Tube Mill Vertical Roller Mill Ball Mill Roller Press Horizontal Roller Mill (Horomill)

In addition to the production process technology inputs, pyroprocessing phase requires user input of major kiln fuels (by percent kiln energy requirement). In case the user does not know the kiln fuel percentages, he/she can still perform the calculations by selecting the default U.S. average values provided by Portland Cement Association ([PCA] 2006). Data from this section feeds into “Pyroprocessing” tab to estimate energy use and emissions for the preparation of six types of traditional fuels and nine types of waste fuels for kiln use. Additionally, input from this section is used to calculate pyroprocessing-related pre-combustion and combustion impacts for four different kiln technology options and one U.S. average kiln option. Below, Table 3 tabulates kiln fuel options and default energy percentages (corresponding to the fuel options) for US average case.




Table 3 User Input Page - Cement Pyroprocessing Fuel Use Options

Fuel Options	Percent by Energy	US Average Fuel Percent (based on Economic Research Survey by [PCA] 2006)
Bituminous Coal	User Input	64.1%
Lignite Coal	User Input	0.0%
Distillate (Diesel/Light) Fuel Oil	User Input	0.8%
Residual(Heavy) Oil	User Input	0.2%
Petroleum Coke	User Input	21.2%
Natural Gas	User Input	3.7%
Waste Oil	User Input	0.3%
Waste Solvent	User Input	4.0%
Waste Tire (whole)	User Input	1.8%
Waste Tire (shredded)	User Input	1.8%
Waste (Other) (non-hazardous)	User Input	2.3%
Waste Paper, cardboard	User Input	0.0%
Waste Plastics	User Input	0.0%
Waste Sewage sludge (dry)	User Input	0.0%
Waste (Other) (hazardous)	User Input	0.0%




During the production of cement, process input and output materials (e.g. raw meal, ground meal, clinker, etc.) are transferred from one process station (e.g. pyroprocessing) to the next one (e.g. finish milling) and this can be accomplished by various conveying technologies. In addition to the conveyance distance input, the user is asked to select among four different conveying technology options that are commonly used in cement plants.

User Input Page – Options for Conveyance Technology within Cement Production Plant
Cement Conveying Technology Options Screw Pump Airlift Dense Phase Pump Bucket Elevator

Major technological variations in concrete batching plant are captured by two technology variables, namely, PM control technology options (same as cement plant dust control options which are fabric filter and ESP) and loading/mixing technology options (either mixer loading or truck loading). User can select the concrete batching technology option from the drop-down lists provided.

7. “Run Analysis” which calculates “Results”

In case of lack of input data, the user has option to proceed with the default values defined in the tool and can still run the analysis successfully.

_____________________________________________________________________________________________________________________________________

For further information contact Petek Gursel at pgursel[at]berkeley.edu
HTML and Javascript Coding by Claudine Custodio