The Importance of Emission Allocation in Determining Emission Impacts from Including Corn Oil

Transcription

1 The Importance of Emission Allocation in Determining Emission Impacts from Including Corn Oil Farzad Taheripour Wallace E. Tyner Purdue University October 26, 2015

2 Introduction This presentation is based on research published in Biofuels: Taheripour, F., Tyner, W.E., Corn oil biofuel land use change emission impacts: Sharing emission savings between ethanol and biodiesel Biofuels. Biofuels 5, Corn oil reduces the induced land use emissions due to total biofuel production Allocation rules determine how the emission savings is allocated.

3 Corn Oil Extraction Corn oil extraction has moved from near zero in 2001 to 78% in 2012 and now higher. The DDGS that is produced is lower in fat and higher in protein. Markets suggest that its value is about the same as traditional DDGS.

4 DDGS to Corn Price Ratio (prices in $/ton)

5 GTAP Model and Data Specifications (I) Data base represents world economy in Crops are divided into paddy rice, wheat, sorghum, other coarse grains, soybeans, palm, rapeseed, other oilseeds, sugar crops, other crops. Cropland pasture is used by the livestock industry, and can be switched to traditional crops. Projected productivity of new cropland has been estimated with a Terrestrial Ecosystems Model and varies by Agro-ecological zone and region.

6 GTAP Model and Data Specifications (II) The corn ethanol industry produces three commodities: ethanol, reduced fat DDGS, and corn oil. Biofuels included in the model are: corn ethanol, ethanol from sorghum, ethanol from sugar crops, soybean biodiesel, rapeseed biodiesel, palm oil biodiesel, and other biodiesel (including corn oil). By-products included in the model are: reduced fat DDGS, DDGS produced with sorghum ethanol, soybean meal, rapeseed meal, palm meal, other meals, and corn oil produced by the corn ethanol industry.

7 GTAP Model and Data Specifications (III) The model uses a multi-level nested demand structure which represents demands for alternative feed items for the livestock industry. The land cover component of the land supply tree uses a two-level nesting format. Regional land transformation elasticities (extensive margin) have been calibrated to the actual land cover changes The final consumers and also producers substitute one type of vegetable oil with another type in response to changes in the relative prices of vegetable oils in their demand systems.

8 This Research This research was done with GTAP-BIO 2004 data base and model with all the improvements that had been done over time. The model is essentially the version reported in Applied Sciences with two-level nesting structure: Taheripour, F., Tyner, W.E., Biofuels and Land Use Change: Applying Recent Evidence to Model Estimates. Applied Sciences 3,

9 Estimates for additional land requirement due to US ethanol production (demonstrating progress through time)

10 Modifications Made for Corn Oil We assume that all corn ethanol uses the corn oil extraction technology and that all corn oil is converted to biodiesel. Results would not be very different if we assumed part of the corn oil went to the veg oil sector. Each bushel of corn used for ethanol also produces 0.52 pounds of corn oil, and that reduces production of DDGS by the same amount.

11 Simulations Done Exp. I expansion of corn ethanol from 2004 level to 15 BGs (11.59 BG) with no corn oil. Exp. II same corn ethanol expansion with corn oil Exp. III expansion in soy biodiesel from 2004 (28MGs) to 1 BGs with no corn oil (972 MG expansion). Exp. IV starting from Exp. II (with 115 total biodiesel), expansion of soy biodiesel by 598 MG and corn oil biodiesel 287 BG to equal 1 BG. Exp. V expansion of both corn ethanol (15 BG) and biodiesel (1 BG), but no corn oil Exp. VI same as V, but with corn oil

12 Land Use Change Results There is little difference in induced land use change results between exp. I and II (ethanol). There is considerable difference in results for soy biodiesel (exp. III and IV). Results for V and VI are in between. Corn oil reduces the land requirement for biodiesel, and that helps achieve biofuel targets with lower land use emissions.

13 Table 2. Estimated induced land use changes (figures are in 1000 hectares) Description US EU Brazil Others Total Experiment I: Crop ,175 corn ethanol with no corn oil Cropland pasture to crops 1, ,943 Experiment II: Crop ,174 Corn ethanol with corn oil Cropland pasture 1, ,940 Experiment III: Crop Soy biodiesel with no corn oil Converted cropland pasture Experiment IV: Crop Soy biodiesel with corn oil Converted cropland pasture Experiment V: Crop ,336 Simultaneous corn ethanol & soy biodiesel Converted cropland pasture -2, ,298 with no corn oil Experiment VI: Crop ,260 Simultaneous corn ethanol, corn oil, and soy biodiesel Converted cropland pasture -1, ,122

14 Alternative Approaches to Estimating Land Use Emissions A - Assign energy credit to corn ethanol B - Assign credit to biodiesel industry C - Share corn oil credit based on energy shares of energy produced D - Assign credit to corn oil biodiesel effectively making its emissions zero (approach taken by CARB) E - Calculate emissions from simultaneous expansion (V) with no corn oil F - Calculate emissions from simultaneous expansion with corn oil (VI)

15 Regulatory cases Non regulatory cases Table 3. Induced land use emissions * for alternative cases of A to G (gco2/mj) Experiments Induced land use emissions for corn ethanol Induced land use emissions for soybean biodiesel Case A: No corn oil Case B: Credit ethanol for corn oil Case C: Credit biodiesel for corn oil Case D: Split credit Case E: Corn oil gets credit Case F: Joint expansion with no corn oil 14.1 ** Case G: Joint expansion with corn oil 13.5 ** * The induced land use emissions are calculated using the CARB emissions factors [16]. ** These figures represent emissions per unit of energy produced from produced ethanol and biodiesel

16 Similar Results for Corn Stover We compared corn ethanol, stover ethanol, corn ethanol plus stover animal feed, and corn plus stover ethanol: Mueller, S., Unnasch, S., Tyner, W.E., Pont, J., Johnson, J.M.-F., Handling of co-products in life cycle analysis in an evolving co-product market: A case study with corn stover removal. Advances in Applied Agricultural Science 3, We get total emissions for corn ethanol of 62.1, stover 8.7, corn ethanol plus stover feed 55.5, and corn plus stover ethanol 51.8 (g CO 2 e/mj). System boundaries and allocation method matter.

17 Conclusions The bottom line is that with corn oil in the system, fewer emissions are produced per unit of energy because less land is needed. In the regulatory environment, how the drop in emissions is credited matters.

18 The authors with to acknowledge the National Biodiesel Foundation for providing partial funding for this research. Questions and Comments