Martin Kumar Patel

Plastics Derived from Biological Sources: Present and Future: A Technical and Environmental Review

In the time period 2010 2015, the worldwide annual production of plastics is very likely to surpass 300 million tons,1,2 requiring multiple amounts of petroleum and leading to hundreds of millions of tons ofCO2 in addition to health risks for the public due to the release of other types of emissions.1,3 A large amount of plastics (at least 40% of the total consumption) is used in short-term applications, and the resulting waste can quickly lead to additional environmental damage unless adequate waste management systems are in place. For example, conventional petrochemical plastics are harmful for terrestrial and sea animals as well as birds that tend to eat plastic residues;4 these impacts could be reduced by plastics that are biodegradable by microorganisms. In short, petrochemical plastics are not sustainable and bio-based sustainable plastics should be developed to avoid problems caused by the petrochemical plastics.

Replacing fossil based PET with biobased PEF; process analysis, energy and GHG balance

An energy and greenhouse gas (GHG) balance study was performed on the production of the bioplastic polyethylene furandicarboxylate (PEF) starting from corn based fructose. The goal of the study was to analyze and to translate experimental data on the catalytic dehydration of fructose to a simulation model, using the ASPEN Plus modeling software. The mass and energy balances of the simulation model results were then used as inputs for a process chain analysis (by application of the life cycle assessment methodology, LCA) and compared to its petrochemical counterpart polyethylene terephthalate (PET). The production of PEF can be divided into three main units: the production of fructose from corn starch; the conversion of fructose into Furanics and subsequent recovery and upgrading; and the oxidation to the monomer 2,5-furandicarboxylic acid (FDCA) and polymerization with ethylene glycol (EG) into PEF. The ASPEN Plus simulation model describes the conversion of fructose into Furanics, subsequent recovery and upgrading and a CHP unit. The production of fructose from corn starch and the oxidation and polymerization into PEF were based on the literature. In total, six model cases were analyzed, using different sets of underlying experimental data; four cases based on crystalline fructose and two cases on high fructose corn syrup (HFCS). Fructose can be converted into Furanics at efficiencies between 38% and 47%. The production of PEF can reduce the NREU approximately 40% to 50% while GHG emissions can be reduced approximately 45% to 55%, compared to PET for the system cradle to grave. These reductions are higher than for other biobased plastics, such as polylactic acid (PLA) or polyethylene (PE). With an annual market size of approximately 15 million metric tonnes (Mt) of PET bottles produced worldwide, the complete bottle substitution of PEF for PET would allow us to save between 440 and 520 PJ of non-renewable energy use (NREU) and to reduce GHG emissions by 20 to 35 Mt of CO2 equivalents. If also substantial substitution takes place in the PET fibres and film industry, the savings increase accordingly. The GHG emissions could be further reduced by a switch to lignocellulosic feedstocks, such as straw, but this requires additional research.

Comparing the land requirements, energy savings, and greenhouse gas emissions reduction of biobased polymers and bioenergy: an analysis and system extension of life-cycle assessment studies.

This study compares energy savings and greenhouse gas (GHG) emission reductions of biobased polymers with those of bioenergy on a per unit of agricultural land-use basis by extending existing life-cycle assessment (LCA) studies. In view of policy goals to increase the energy supply from biomass and current efforts to produce biobased polymers in bulk, the amount of available land for the production of nonfood crops could become a limitation. Hence, given the prominence of energy and greenhouse issues in current environmental policy, it is desirable to include land demand in the comparison of different biomass options. Over the past few years, numerous LCA studies have been prepared for different types of biobased polymers, but only a few of these studies address the aspect of land use. This comparison shows that referring energy savings and GHG emission reduction of biobased polymers to a unit of agricultural land, instead of to a unit of polymer produced, leads to a different ranking of options. If land use is chosen as the basis of comparison, natural fiber composites and thermoplastic starch score better than bioenergy production from energy crops, whereas polylactides score comparably well and polyhydroxyalkaonates score worse. Additionally, including the use of agricultural residues for energy purposes improves the environmental performance of biobased polymers significantly. Moreover, it is very likely that higher production efficiencies will be achieved for biobased polymers in the medium term. Biobased polymers thus offer interesting opportunities to reduce the utilization of nonrenewable energy and to contribute to GHG mitigation in view of potentially scarce land resources.

Potential of bioethanol as a chemical building block for biorefineries: Preliminary sustainability assessment of 12 bioethanol-based products

The aim of this study is to present and apply a quick screening method and to identify the most promising bioethanol derivatives using an early-stage sustainability assessment method that compares a bioethanol-based conversion route to its respective petrochemical counterpart. The method combines, by means of a multi-criteria approach, quantitative and qualitative proxy indicators describing economic, environmental, health and safety and operational aspects. Of twelve derivatives considered, five were categorized as favorable (diethyl ether, 1,3-butadiene, ethyl acetate, propylene and ethylene), two as promising (acetaldehyde and ethylene oxide) and five as unfavorable derivatives (acetic acid, n-butanol, isobutylene, hydrogen and acetone) for an integrated biorefinery concept.

A Review of the Environmental Impacts of Biobased Materials

Concerns over climate change and the security of industrial feedstock supplies have been opening a growing market for biobased materials. This development, however, also presents a challenge to scientists, policy makers, and industry because the production of biobased materials requires land and is typically associated with adverse environmental effects. This article addresses the environmental impacts of biobased materials in a meta‐analysis of 44 life cycle assessment (LCA) studies. The reviewed literature suggests that one metric ton (t) of biobased materials saves, relative to conventional materials, 55 ± 34 gigajoules of primary energy and 3 ± 1 t carbon dioxide equivalents of greenhouse gases. However, biobased materials may increase eutrophication by 5 ± 7 kilograms (kg) phosphate equivalents/t and stratospheric ozone depletion by 1.9 ± 1.8 kg nitrous oxide equivalents/t. Our findings are inconclusive with regard to acidification (savings of 2 ± 20 kg sulfur dioxide equivalents/t) and photochemical ozone formation (savings of 0.3 ± 2.4 kg ethene equivalents/t). The variability in the results of life cycle assessment studies highlights the difficulties in drawing general conclusions. Still, common to most biobased materials are impacts caused by the application of fertilizers and pesticides during industrial biomass cultivation. Additional land use impacts, such as the potential loss of biodiversity, soil carbon depletion, soil erosion, deforestation, as well as greenhouse gas emissions from indirect land use change are not quantified in this review. Clearly these impacts should be considered when evaluating the environmental performance of biobased materials.

Sustainability assessment of novel chemical processes at early stage: application to biobased processes

Chemical conversions have been a cornerstone of industrial revolution and societal progress. Continuing this progress in a resource constrained world poses a critical challenge which demands the development of innovative chemical processes to meet our energy and material needs in a sustainable way. This challenge forms the basis for this article. We report a method for quick preliminary assessment of chemical processes at the laboratory stage. The proposed method enables a review of chemical processes within a broader sustainability context. It is inspired by green chemistry principles, techno-economic analysis and some elements of environmental life-cycle assessment (LCA). This method evaluates a proposed chemical process against comparable existing processes using a multi-criteria approach that integrates various economic and environmental indicators. An effort has been made to incorporate quantitative and qualitative information about the processes while making the method transparent and easy to implement based on information available at an early stage in process development. The idea is to provide a data-based assessment tool for chemists and engineers to develop sustainable chemistry. This paper describes the method in detail and examines plausibility of the results. A biobased process for the production of but-1,3-diene has been analyzed using this method. This biobased process is compared with a conventional process for the production of but-1,3-diene from petroleum sources. The effects of uncertainty in the underlying model parameters and assumptions are also analyzed, along with the effect of system boundary selection on the assessment outcome. Analysis and testing of the method shows that it can be used as a valuable tool for sustainable process development.

Plastics Streams in Germany: An Analysis of Production, Consumption and Waste Generation

This paper traces plastics streams through the German economy. A material flow simulation model is used to analyze the production of plastics products, their use and residence times in the economy and finally to calculate the present and future amounts of waste. We find that there is an indirect net export of plastics products incorporated in final products which amounts to 3–6% of domestic consumption. Residence times of plastics products range from a few months to 30 years and more, with the weighted average amounting to 14 years. In Germany, total post-consumer plastics waste will rise from 4.6 Mt in 1995 to 6.2–7.2 Mt in 2005 and could easily reach a value in the range of 12–14 Mt in 2025. At the same time, the accumulation of plastics in the economy will increase from about 72 Mt in 1995 to 180 Mt in 2025 in the business-as-usual scenario. The share of waste from long-lived products will continue to grow in the next decades. For polyolefins, PVC and polystyrene in plastics waste, we expect that the total amounts will more than double within the next 25 years. Analyses as presented in this paper can help to establish strategic waste management policies.

Cumulative energy demand (CED) and cumulative CO2 emissions for products of the organic chemical industry

This paper both presents and discusses the results of calculations on the Cumulative Energy Demand (CED) and the related Cumulative CO2 emissions (CCO2) for products of the organic chemical industry. The entire process chain is studied, starting with the extraction of resources and ending with the saleable material (cradle-to-factory gate). The materials studied are chemical intermediates and plastics as produced in Germany in the mid 1990s. The two bulk plastics, polyethylene and polyvinyl chloride, belong to the group of polymers that can be produced with a relatively low input of energy resources. By contrast, the CED and the CCO2 values for manufacturing engineering and special plastics can be more than twice as high. The CED and CCO2 data determined on the basis of our calculations is compared with data from other sources. The differences show that for a reliable study it is essential that use is made of only one set of data which has been determined in a consistent manner. In contrast, comparative assessments which use CED and CCO2 data originating from various sources, can easily result in distorted conclusions given the large data ranges. The data ranges found indicate that considerable uncertainties continue to exist, calling for further analysis in the area. Comparative calculations using CED and CCO2 data from independent, consistent sources are recommended for the time being.

Preliminary evaluation of risks related to waste incineration of polymer nanocomposites.

If nanotechnology proves to be successful for bulk applications, large quantities of nanocomposites are likely to end up in municipal solid waste incineration (MSWI) plants. Various studies indicate that nanoobjects might be harmful to human health and the environment. At this moment there is no evidence that all nanoobjects are safely removed from the off-gas when incinerating nanocomposites in MSWI plants. This paper presents a preliminary assessment of the fate of nanoobjects during waste incineration and the ability of MSWI plants to remove them. It appears that nanoobject emission levels will increase if bulk quantities of nanocomposites end up in municipal solid waste. Many primary and secondary nanoobjects arise from the incineration of nanocomposites and removal seems insufficient for objects that are smaller than 100nm. For the nanoobjects studied in this paper, risks occur for aluminum oxide, calcium carbonate, magnesium hydroxide, POSS, silica, titanium oxide, zinc oxide, zirconia, mica, montmorillonite, talc, cobalt, gold, silver, carbon black and fullerenes. Since this conclusion is based on a desktop study without accompanying experiments, further research is required to reveal which nanoobjects will actually be emitted to the environment and to determine their toxicity to human health.

Fuels and plastics from lignocellulosic biomass via the furan pathway; a technical analysis

Biorefineries convert biomass into bio-based products, which have the potential to replace typical products produced by petroleum refineries. They provide a technology platform to reduce anthropogenic greenhouse gas emissions, increase security of supply and reduce the dependency on crude oil. The biorefinery concept presented in this paper focuses on a combination of (1) organosolv fractionation to produce carbohydrates from lignocellulosic biomass and (2) the furan technology to convert carbohydrates into polyethylene furanoate (PEF), a bio-based alternative to polyethylene terephthalate (PET), and furfuryl ethyl ether (FEE), a bio-based transportation fuel component. The goal of this paper is to determine the mass and energy balances of the production of PEF and FEE from lignocellulosic biomass and indicate the benefits, as well as potential bottlenecks in the coupling of organosolv and furan chemistry as a biorefinery concept. Three cases are defined, modeled and analyzed, each focusing on a different approach to combine the organosolv and furan conversion technologies and determine the possibility and degree of integration. Modeling results based on experimental data and expert judgments show that wheat straw, as an example of lignocellulosic biomass, can be converted into PEF and FEE at yields between 20 and 40 w/w%, based on total input, while energetic efficiencies are between 30 and 40%. This is comparable or even better compared to other upcoming bio-based processes, e.g. 15–35% yield for second generation bio-ethanol production and 25–50% energy efficiency. The conclusion is that in each of the three cases presented bio-based fuels and plastics can be produced via the furan pathway at efficiencies that constitute a viable option from a technological point of view.