Satish Joshi

Product Environmental Life‐Cycle Assessment Using Input‐Output Techniques

Summary Life-cycle assessment (LCA) facilitates a systems view in environmental evaluation of products, materials, and processes. Life-cycle assessment attempts to quantify environmental burdens over the entire life-cycle of a product from raw material extraction, manufacturing, and use to ultimate disposal. However, current methods for LCA suffer from problems of subjective boundary definition, inflexibility, high cost, data confidentiality, and aggregation. This paper proposes alternative models to conduct quick, cost effective, and yet comprehensive life-cycle assessments. The core of the analytical model consists of the 498 sector economic input-output tables for the U.S. economy augmented with various sector-level environmental impact vectors. The environmental impacts covered include global warming, acidification, energy use, non-renewable ores consumption, eutrophication, conventional pollutant emissions and toxic releases to the environment. Alternative models are proposed for environmental assessment of individual products, processes, and life-cycle stages by selective disaggregation of aggregate input-output data or by creation of hypothetical new commodity sectors. To demonstrate the method, a case study comparing the life-cycle environmental performance of steel and plastic automobile fuel tank systems is presented.

Technical and financial feasibility analysis of distributed bioprocessing using regional biomass pre-processing centers.

Research indicates that large biorefineries capable of handling 5000-10000MT of biomass per day are necessary to achieve process economies. However, such large biorefineries also entail increased costs of biomass transportation and storage, high transaction costs of contracting with a large number of farmers for biomass supply, potential market power issues, and local environmental impacts. We propose a network of regional biomass preprocessing centers (RBPC) that form an extended biomass supply chain feeding into a biorefinery, as a way to address these issues. The RBPC, in its mature form, is conceptualized as a flexible processing facility capable of pre-treating and converting biomass into appropriate feedstocks for a variety of final products such as fuels, chemicals, electricity, and animal feeds. We evaluate the technical and financial feasibility of a simple RBPC that uses ammonia fiber expansion pretreatment process and produces animal feed along with biorefinery feedstock.

A Life-Cycle Comparison of Alternative Automobile Fuels

ABSTRACT We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (C2H5OH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as C2H5OH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and reduce the demand for imported fuels. Fuels from food sources, such as biodiesel from soybeans and C2H5OH from corn, can be attractive only if the co-products are in high demand and if the fuel production does not diminish the food supply. C2H5OH from herbaceous or woody biomass could replace the gasoline burned in the light-duty fleet while supplying electricity as a co-product. While it costs more than gasoline, bioethanol would be attractive if the price of gasoline doubled, if significant reductions in GHG emissions were required, or if fuel economy regulations for gasoline vehicles were tightened.

Can ethanol alone meet California's low carbon fuel standard? An evaluation of feedstock and conversion alternatives

The feasibility of meeting California’s low carbon fuel standard (LCFS) using ethanol from various feedstocks is assessed. Lifecycle greenhouse gas (GHG) emissions, direct agricultural land use, petroleum displacement directly due to ethanol blending, and production costs for a number of conventional and lignocellulosic ethanol pathways are estimated under various supply scenarios. The results indicate that after considering indirect land use effects, all sources of ethanol examined, except Midwest corn ethanol, are viable options to meet the LCFS. However, the required ethanol quantity depends on the GHG emissions performance and ethanol availability. The quantity of ethanol that can be produced from lignocellulosic biomass resources within California is insufficient to meet the year 2020 LCFS target. Utilizing lignocellulosic ethanol to meet the LCFS is more attractive than utilizing Brazilian sugarcane ethanol due to projected lower direct agricultural land use, dependence on imported energy, ethanol cost, required refueling infrastructure modifications and penetration of flexible fuel E85 vehicles. However, advances in cellulosic ethanol technology and commercial production capacity are required to support moderate- to large-scale introduction of low carbon intensity cellulosic ethanol. Current cellulosic ethanol production cost estimates suffer from relatively high uncertainty and need to be refined based on commercial scale production data when available.

Assessment of the properties of poly(L-lactic acid) sheets produced with differing amounts of postconsumer recycled poly(L-lactic acid)

The properties of sheet containing mechanically recycled postconsumer poly(L-lactic acid) bottle flakes blended with virgin poly(L-lactic acid) resin were assessed. Poly(L-lactic acid) bottles were flaked, cleaned, blended with virgin resin and then extruded and thermoformed into trays. The molecular weight, physical, optical, thermal and mechanical properties of the sheet containing 0, 20, 40, 60, 80 and 100 wt.% poly(L-lactic acid) recycled content were evaluated. The best cleaning conditions were found by using a mixed-level fractional factorial design. Cleaning conditions of 15 min, at 85°C, 1 wt.% NaOH and 0.3 wt.% surfactant were adopted for cleaning the poly(L-lactic acid) flakes. Cast-extruded virgin poly(L-lactic acid) sheet had superior mechanical and optical properties than recycled poly(L-lactic acid) sheet. Recycled poly(L-lactic acid) sheets were darker and absorbed more ultraviolet light in the 260 to 285 nm range when 20% or more recycled content was added. At 40% poly(L-lactic acid) recycled content, the sheet had increased blue and red tones and the mechanical properties in the cross-machine direction decreased. At 60% poly(L-lactic acid) recycled content or above, reduction of weight average molecular weight, tensile strength and tensile strength at yield in the machine direction were found. At 80% poly(L-lactic acid) recycled content, the melting temperature and modulus of elasticity in the machine direction decreased. All sheet samples were successfully thermoformed into trays showing the potential to use post-consumer poly(L-lactic acid) flakes in the production of poly(L-lactic acid) containers.

Sustainability of EU Food Safety Certification: A survival analysis of firm decisions

This study aims to understand the implications of stricter food safety regulations and certification systems to the food industry and to find ways to manage risks and costs associated with these regulations and systems. This paper empirically examines the timing of initial decisions to adopt food safety systems and subsequent decisions to maintain the certification. Survival models are used to evaluate firm-level decisions among seafood processors in the Philippines. Whereas initial certification decisions were influenced mainly by easily obtainable a priori indicators such as output price, scale of production, and association membership, decisions to continue certification were influenced by a larger number of less visible factors including price differentials across markets and cost structures. Managerial hubris may have played a role in initial certification decisions, but decertification decisions were more informed by realized cost-benefit comparisons.

Prospects for Ethanol and Biodiesel, 2008 to 2017 and Impacts on Agriculture and Food

The impacts of increased biofuels production on key agricultural variables and consumer prices are analyzed using a multisector econometric model AGMOD. A “baseline” scenario and three alternative crude oil price scenarios are presented. Results indicate that conventional biofuels mandates of the Energy Independence and Security Act of 2007 can be met with moderate increases in crop area and consumer prices. Biodiesel production will increasingly need to draw on non-soybean oil sources. However, except under the “high crude oil price” scenario, ethanol and biodiesel will require a premium over their energy equivalent prices. Production of cellulosic ethanol is likely to be minor through 2017.

Estimating the demand for drop-off recycling sites: A random utility travel cost approach

Drop-off recycling is one of the most widely adopted recycling programs in the United States. Despite its wide implementation, relatively little literature addresses the demand for drop-off recycling. This study examines the demand for drop-off recycling sites as a function of travel costs and various site characteristics using the random utility model (RUM). The findings of this study indicate that increased travel costs significantly reduce the frequency of visits to drop-off sites implying that the usage pattern of a site is influenced by its location relative to where people live. This study also demonstrates that site specific characteristics such as hours of operation, the number of recyclables accepted, acceptance of commingled recyclables, and acceptance of yard-waste affect the frequency of visits to drop-off sites.

Economic Models of Hospital Behavior

This article is an updated version of the previous edition article by Xingzhu Liu, Anne Mills, volume 2, pp. 276–281,

General Purpose Computer-Aided Engineering Tools for Environmental Software Systems

Software systems to support environmental research and management can often be developed and applied within the context of general purpose computer-aided engineering tools such as spreadsheets and databases. Reliance on general purpose CAE tools reduces development time, is usually less expensive and yields software that is often more capable for a specific task than custom-designed systems with a broader range of functionality. We outline several examples of such applications in this paper, including a spreadsheet for toxic emissions weighting, database and matrix manipulation software for life cycle assessment using economic input-output models, a database system to support environmental reporting, and a Java-enabled browser for visualizing a TRI database.