Cellulose conversion in dry grind ethanol plants

The expansion of the dry grind ethanol industry provides a unique opportunity to introduce cellulose conversion technology to existing grain to ethanol plants, while enhancing ethanol yields by up to 14%, and decreasing the volume while increasing protein content of distiller’s grains. The technologies required are cellulose pretreatment, enzyme hydrolysis, fermentation, and drying. Laboratory data combined with compositional analysis and process simulations are used to present a comparative analysis of a dry grind process to a process with pretreatment and hydrolysis of cellulose in distiller’s grains. The additional processing steps are projected to give a 32% increase in net present value if process modifications are made to a 100 million gallon/year plant

Use of General Equilibrium Models in Evaluating Biofuels Policies

This paper reviews the use of computable general equilibrium (CGE) models, especially GTAP based models, in the evaluation of biofuels policies. In this particular area of research, CGE models have been used in several different ways – estimating the induced land use change (ILUC) and associated greenhouse gas (GHG) emissions caused by increases in biofuels production; estimating the impacts of biofuels production on crop and food production and prices; estimating the economic or welfare impacts of policies aimed at stimulating biofuel production; and evaluating the interactions between biofuels and livestock production. Clearly the area that has gotten the most attention is the ILUC area. The California Air Resources Board (CARB) used GTAP to estimate the carbon scores in used in its Low Carbon Fuel Standard (LCFS). The European Commission reported estimates for ILUC provided by IFPRI and the MIRAGE model. The second major area to be covered concerns the evaluation of food-fuel tradeoffs. Biofuels have been criticized for causing food price increases. Here we will explore the literature in this area, which sometimes is quite contradictory. The third area to be covered is economic and welfare impacts of biofuels. In general, the studies conclude that mandating or subsidizing biofuels is welfare reducing because they are more expensive than fossil fuels. Most of the analyses do not estimate the societal benefits of GHG reduction due to biofuels, so there is no balancing of the pure economic losses with the environmental gains. The fourth grouping concerns the impacts of biofuel programs on the global livestock sector. Since ethanol has an animal feed co-product, and oilseed biodiesel involves production of oilseed meals used as animal feed, there is a close linkage between biofuels and the livestock sector. We conclude with a discussion of possible future directions for research on this topic

Renewable Fuel Standard: Implications for Land Use Changes in Malaysia and Indonesia

plantations in Malaysia and Indonesia (M&I). The main focus of this literature was the environmental damage done when peat land is converted to palm plantation. The existing literature also has examined land use implications of biofuel production and policy in considerable detail. However, no major attempt has been made to highlight interactions between US biofuel policy and land use changes in M&I. This paper offers the first comprehensive analysis on the extent to which production of biofuels in US affects markets for vegetable oils, in particular for palm oil, and examines their land use implications. To achieve the goal of this paper, we modified and used the most recent version of the GTAP-BIO model that has been frequently used in analyzing the environmental, energy, biofuel, agricultural, and trade issues and policies. Unlike the earlier version of this model, the new model takes into account land intensification in the livestock industry due to expansion in supplies of oilseed meals. An expansion in the US soy biodiesel by 0.5 billion gallons increases the US imports of palm oil by 0.4% and that generates an expansion in palm plantation in M&I by 0.48% with only 6500 hectares expansion in cropland due to deforestation when all vegetable oils are included in the model, and the rate of substitution among vegetable oils in US is about 0.5. In this case, the induced land use change (ILUC) emissions for soy biodiesel produced in US is about 17.5 g CO2e MJ-1. With a substitution elasticity of 2 among vegetable oils, the same expansion in biodiesel increases US imports of palm oil by 2.2% but that does not lead to more production of palm oil in M&I, as there is greater global trade of and substitution between other vegetable oils. Even some countries extend palm plantation on lands with lower carbon content compared to M&I. With a substitution elasticity of 2, ILUC emissions for soy biodiesel drops to 16.6 g CO2e MJ-1

Renewable Fuel Standard: Implications for Land Use Changes in Malaysia and Indonesia

plantations in Malaysia and Indonesia (M&I). The main focus of this literature was the environmental damage done when peat land is converted to palm plantation. The existing literature also has examined land use implications of biofuel production and policy in considerable detail. However, no major attempt has been made to highlight interactions between US biofuel policy and land use changes in M&I. This paper offers the first comprehensive analysis on the extent to which production of biofuels in US affects markets for vegetable oils, in particular for palm oil, and examines their land use implications. To achieve the goal of this paper, we modified and used the most recent version of the GTAP-BIO model that has been frequently used in analyzing the environmental, energy, biofuel, agricultural, and trade issues and policies. Unlike the earlier version of this model, the new model takes into account land intensification in the livestock industry due to expansion in supplies of oilseed meals. An expansion in the US soy biodiesel by 0.5 billion gallons increases the US imports of palm oil by 0.4% and that generates an expansion in palm plantation in M&I by 0.48% with only 6500 hectares expansion in cropland due to deforestation when all vegetable oils are included in the model, and the rate of substitution among vegetable oils in US is about 0.5. In this case, the induced land use change (ILUC) emissions for soy biodiesel produced in US is about 17.5 g CO2e MJ-1. With a substitution elasticity of 2 among vegetable oils, the same expansion in biodiesel increases US imports of palm oil by 2.2% but that does not lead to more production of palm oil in M&I, as there is greater global trade of and substitution between other vegetable oils. Even some countries extend palm plantation on lands with lower carbon content compared to M&I. With a substitution elasticity of 2, ILUC emissions for soy biodiesel drops to 16.6 g CO2e MJ-1

Introducing First and Second Generation Biofuels into GTAP Data Base version 7*

The first version of GTAP-BIO Data Base was built based on the GTAP standard data base version 6 which represents the world economy in 2001 (Taheripour et al., 2007). That data base covers global production, consumption, and trade of the first generation of biofuels including ethanol from grains (eth1), ethanol from sugarcane (eth2), and biodiesel (biod) from oilseeds in 2001. Version 7 of GTAP Data Base, which depicts the world economy in 2004, is now published (Narayanan, B.G. and T.L. Walmsley, 2008). However, this standard data base does not include biofuel industries explicitly. The first objective of this research memorandum is to introduce the first generation of biofuels into this new data base. To accomplish this task we will follow Taheripour et al. (2007). The rapid expansion of the first generation of biofuels in the past decades has raised important concerns related to food-fuel competition, land use change, and other economic and environmental issues. These issues have increased interest in the second generation of biofuels which can be produced from cellulosic materials such as dedicated crops, agricultural and forest residues, and waste materials. To examine the economic and environmental consequences of the second generation of biofuels, a CGE model is an appropriate and essential instrument. A data base which presents the first and second generation of biofuels will facilitate research in this field. Hence the second objective of this research memorandum is to expand the space of biofuel alternatives to the second generation. Given that advanced cellulosic biofuels are not yet commercially viable, we used the most up to date information in this area to define the production technologies for these industries.

Modeling Land Intensification Response in GTAP: Implications for Biofuels Induced Land Use Change

Proper modeling of land intensification response is critical since it affects, for example, in response to a rise in crop prices driven by biofuels expansion, how land use change in a region may be biased towards the intensive margin as opposed to the extensive margin, and consequently how much greenhouse gas would be emitted. In this paper, we model land intensification characterized by the cropping intensity response to price changes and estimate the response parameter at the global level. We run a modified GTAP-BIO to demonstrate that introduction of this response mechanism would significantly revise the projections of induced land use change. Sensitivity analyses are also conducted for the estimated response parameter to examine the ballpark of relevant land use change variables

Modeling land use in large scale global computable general equilibrium models: Preserving physical area of land

Modeling land use in a large-scale global CGE model is a challenging and important task. While several approaches were developed to accomplish this task, some GTAP based applications used Constant Elasticity of Transformation (CET) functions to allocate land across its alternative uses (Some applications are: Golub and Hertel (2012); Hertel et al. (2010); Taheripour et al (2010); Golub et al. (2017); and Taheripour et al. (2018)). This traditional approach provides a relatively simple method to move land from one application to another application, while it implicitly takes into account the opportunity costs of land transformation (van Tongeren et al. (2017). However, it is frequently argued that this approach fails to maintain the physical accounting of land area in balance. The GTAP based applications have used some yield adjustment factors to fix this problem and maintain the physical area of land in balance. Fujimori et al. (2014) used a logit function to preserve physical area of land. More recently, van der Mensbrugghe and Peters (2016)) introduced a new approach, named Additive CET (ACET), to keep physical area of land in balance. Zhao et al. (2017) argued that “there is a direct mapping between ACET and the logit approach” developed by Fujimori et al. (2014)

Modeling land use in large scale global computable general equilibrium models: Preserving physical area of land

Modeling land use in a large-scale global CGE model is a challenging and important task. While several approaches were developed to accomplish this task, some GTAP based applications used Constant Elasticity of Transformation (CET) functions to allocate land across its alternative uses (Some applications are: Golub and Hertel (2012); Hertel et al. (2010); Taheripour et al (2010); Golub et al. (2017); and Taheripour et al. (2018)). This traditional approach provides a relatively simple method to move land from one application to another application, while it implicitly takes into account the opportunity costs of land transformation (van Tongeren et al. (2017). However, it is frequently argued that this approach fails to maintain the physical accounting of land area in balance. The GTAP based applications have used some yield adjustment factors to fix this problem and maintain the physical area of land in balance. Fujimori et al. (2014) used a logit function to preserve physical area of land. More recently, van der Mensbrugghe and Peters (2016)) introduced a new approach, named Additive CET (ACET), to keep physical area of land in balance. Zhao et al. (2017) argued that “there is a direct mapping between ACET and the logit approach” developed by Fujimori et al. (2014)