Prospects for the development of sugarcane biorefineries

Sugarcane biorefineries co-producing fuels, green chemicals and bio-products offer great potential for improving the profitability and sustainability of sugarcane industries around the world. Sugarcane bagasse is widely regarded as one of the best biomass feedstocks for early adoption and commercialisation of biorefining technologies because of the large scale of the resource and its availability at sugar factories. Biomass biorefineries aim to convert bagasse through biochemical and thermochemical processes to produce low cost fermentable sugars which are a platform for value-adding. Through subsequent fermentation technologies or chemical synthesis, the sugars can be converted to fuels including ethanol and butanol, oils, organic acids such as succinic and levulinic and polymer precursors. Other biorefinery products can include food and animal feeds, plastics, fibre products and resins. Recent advances in biorefinery production technologies are being demonstrated in a unique research facility at the Queensland University of Technology’s Mackay Renewable Biocommodities Pilot Plant in Mackay, Australia. This pilot scale production facility located at Mackay Sugar Ltd’s Racecourse Mill is demonstrating the production of a range of fuels and other products from sugarcane bagasse. This paper will address the opportunities available for sugarcane biorefineries to contribute to future profitability and sustainability of the sugarcane industry.

Revenue diversification opportunities from sugarcane

Sugarcane is a major global agricultural crop that produces significant quantities of sugar and biomass in tropical and sub-tropical regions. Over many centuries, the crop has been grown primarily for its high sugar content which traditionally contributes over 95% of the revenue derived from the crop. While the production of renewable electricity from bagasse and rum from molasses has a long history, in more recent decades significant advances have been made in the production of cogeneration products and fuel ethanol at large scale. Sugarcane biorefineries producing fuels, green chemicals, biopolymers and bio-products offer great potential for improving the profitability of sugarcane production. This paper will address the opportunities available for sugarcane biorefineries to contribute to future profitability and sustainability of the sugarcane industry.

Biorefineries – creating economic opportunities from biofuels and bio-products

Biorefineries, producing fuels, green chemicals and bio-products, offer great potential for improving the profitability and sustainability of tropical agricultural industries. Biomass from tropical crops like sugarcane, sweet sorghum, palm and cassava offer great potential because of the high biomass growth potential under favourable climatic conditions. Biorefineries aim to convert waste residues through biochemical and enzymatic processes to low cost fermentable sugars which are a platform for value-adding. Through subsequent fermentation utilising microbial biotechnologies or chemical synthesis, the sugars can be converted to fuels including ethanol and butanol, oils, organic acids such as lactic and levulinic acid and polymer precursors. Other biorefinery products can include food and animal feeds, plastics, fibre products and resins. Pretreatment technologies are a key to unlocking this potential and new technologies are emerging. This paper will address the opportunities available for tropical biorefineries to contribute to the future profitability of tropical agricultural industries. The importance of pretreatment technologies will be discussed.

The economic value of new tropical biorefinery industries in Australia

Biorefineries, co-producing fuels, green chemicals and bio-products, offer great potential for enhancing agricultural value, and developing new industries in the bioeconomy. Biomass biorefineries aim to convert agricultural crops and wastes through biochemical and enzymatic processes to low cost fermentable sugars and other products which are platforms for value-adding. Through subsequent fermentation or chemical synthesis, the bio-based platforms can be converted to fuels including ethanol and butanol, oils, organic acids such as lactic and levulinic acid and polymer precursors. Other biorefinery products can include food and animal feeds, plastics, fibre products and resins. In 2014, QUT commissioned a study from Deloitte Access Economics and Correlli Consulting to assess the potential future economic value of tropical biorefineries to Queensland. This paper will report on the outcomes of this study and address the opportunities available for tropical biorefineries to contribute to the future profitability and sustainability of tropical agricultural industries in Queensland and more broadly across northern Australia.

Gas Hydrate Inhibition: A Review of the Role of Ionic Liquids

Ionic liquids (ILs) are popular designer green chemicals with great potential for use in diverse energy-related applications. Apart from the well-known low vapor pressure, the physical properties of ILs, such as hydrogen-bond-forming capacity, physical state, shape, and size, can be fine-tuned for specific applications. Natural gas hydrates are easily formed in gas pipelines and pose potential problems to the oil and natural gas industry, particularly during deep-sea exploration and production. This review summarizes the recent advances in IL research as dual-function gas hydrate inhibitors. Almost all of the available thermodynamic and kinetic inhibition data in the presence of ILs have been systematically reviewed to evaluate the efficiency of ILs in gas hydrate inhibition, compared to other conventional thermodynamic and kinetic gas hydrate inhibitors. The principles of natural gas hydrate formation, types of gas hydrates and their inhibitors, apparatuses and methods used, reported experimental data, and theoretical methods are thoroughly and critically discussed. The studies in this field will facilitate the design of advanced ILs for energy savings through the development of efficient low-dosage gas hydrate inhibitors.

Upgrading biomass fast pyrolysis liquids

A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. This considers all aspects of the special characteristics of bio-oil – how they are created and the solutions available to help meet requirements for utilisation. Particular attention is paid to chemical and catalytic upgrading including synthesis gas and hydrogen production which has seen a wide range of new research activities and also more limited attention to chemicals recovery. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material.

Upgrading biomass fast pyrolysis liquids

A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe, and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material. © 2012 American Institute of Chemical Engineers (AIChE).

Hydrothermal technologies for the production of fuels and chemicals from biomass

Biomass and non-food crop residues are seen as relatively low cost and abundant renewable sources capable of making a large contribution to the world’s future energy and chemicals supply. Signifi cant quantities of ethanol are currently produced from biomass via biochemical processes, but thermochemical conversion processes offer greater potential to utilize the entire biomass source to produce a range of products. This chapter will review thermochemical gasifi cation and pyrolysis methods with a focus on hydrothermal liquefaction processes. Hydrothermal liquefaction is the most energetically advantageous thermochemical biomass conversion process. If the target is to produce sustainable liquid fuels and chemicals and reduce the impact of global warming as a result of carbon dioxide, nitrous oxide, and methane emissions (i.e., protect the natural environment), the use of “green” solvents, biocatalysts and heterogeneous catalysts must be the main R&D initiatives. As the biocrude produced from hydrothermal liquefaction is a complex mixture which is relatively viscous, corrosive, and unstable to oxidation (due to the presence of water and oxygenated compounds), additional upgrading processes are required to produce suitable biofuels and chemicals.

Visible light photocatalysts for synthesis of fine organic chemicals on supported nanostructures

This thesis is focus on developing new photocatalysts for synthesis of fine organic chemicals on supported nanostructures. These photocatalysts can facilitate reactions by using visible light, moderate temperature and atmospheric pressure which is suitable for a sustainable, green and eco-friendly modern chemical industry. Both Semiconductor Photocatalyst and Noble Metal Photocatalysts are designed to facilitate the homocouplings reaction of imine generation by amines.

Impact of agricultural chemicals on the environment and human health in Asia: Are there solutions?

Modern commercial agricultural practices in Asia during the last three to four decades involving chemicals (fertilisers and pesticides) have been associated with large increases in food production never witnessed before, especially under the Green Revolution technology in South Asia. This also involves large-scale increases in commercial vegetable crops. However, the high reliance on chemical inputs to bring about these increases in food production is not without problems. A visible, parallel correlation between higher productivity, high artificial input use and environmental degradation and human ill-health is evident in many countries where commercial agriculture is widespread. In this chapter, we focus on the impact of chemical inputs, in particular the impact of pesticides on the environment and on human health in South Asia with special reference to Sri Lanka...

Visible light photocatalytic synthesis of fine organic chemicals with new photocatalysts

This project was a step forward in developing new recyclable photocatalysts for chemical reactions. These new photocatalysts can facilitate reactions by using visible light under moderate reaction conditions which is suitable for a sustainable, green and eco-friendly modern chemical industry. The outcome of the study greatly extended our understanding in metal nanoparticle photocatalysis, which reveals new photocatalytic mechanisms for the controlled transformation of chemical reactions. The prospect of sunlight irradiation driving chemical reactions may provide opportunity for the organic synthesis via a more controlled, simplified, and greener process in the future.

Low carbon fuels and commodity chemicals from waste gases – systematic approach to understand energy metabolism in a model acetogen

Gas fermentation using acetogenic bacteria offers a promising route for the sustainable production of low carbon fuels and commodity chemicals from abundant, inexpensive C1 feedstocks including industrial waste gases, syngas, reformed methane or methanol. Clostridium autoethanogenum is a model gas fermenting acetogen that produces fuel ethanol and 2,3-butanediol, a precursor for nylon and rubber. Acetogens have already been used in large scale industrial fermentations, they are ubiquitous and known to play a prominent role in the global carbon cycle. Still, they are considered to live on the thermodynamic edge of life and potential energy constraints when growing on C1 gases pose a major challange for the commercial production of fuels and chemicals. We have developed a systematic platform to investigate acetogenic energy metabolism, exemplified here by experiments contrasting heterotrophic and autotrophic metabolism. The platform is built from complete omics technologies, augmented with genetic tools and complemented by a manually curated genome-scale mathematical model. Together the tools enable the design and development of new, energy efficient pathways and strains for the production of chemicals and advanced fuels via C1 gas fermentation. As a proof-of-platform, we investigated heterotrophic growth on fructose versus autotrophic growth on gas that demonstrate the role of the Rnf complex and Nfn complex in maintaining growth using the Wood–Ljungdahl pathway. Pyruvate carboxykinase was found to control the rate-limiting step of gluconeogenesis and a new specialized glyceraldehyde-3-phosphate dehydrogenase was identified that potentially enhances anabolic capacity by reducing the amount of ATP consumed by gluconeogenesis. The results have been confirmed by the construction of mutant strains.

Organic reactions in supercritical fluids: Continuous, selective and green

Supercritical fluids (SCFs) offer a wide range of opportunities as media for chemical reactions and supercritical CO2, ScCO2, is becoming increasingly important as a benign replacement for more toxic solvents.1 High pressure reactions, however, are more capital intensive than conventional low pressure processes. Therefore, supercritical fluids will only gain widespread acceptance in those areas where the fluids give real chemical advantages as well as environmental benefits. This lecture gives a brief account of the use of flow reactors for continuous reactions in supercritical fluids, particularly those of interest for the manufacture of fine chemicals.

Distribution patterns of PCDD/Fs in chlorinated chemicals

The purpose of this research was to determine polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in five chlorinated chemicals (phthalocyanine copper, phthalocyanine green, chloranil-1 and 2, and triclosan), and to compare their 2,3,7,8-tetrachlordibenzo-IpI-dioxin equivalents (TEQ). The distribution patterns of total PCDD/Fs and 2,3,7,8-substituted PCDD/Fs were elucidated in detail. The TEQ values of toxic PCDD/Fs in all chemicals were in the range of 5.03-1379.55 ng I-TEQ/kg. The contribution of OCDD and OCDF in phthalocyanine green was 75% of the total TEQ. For chloranils, the maximum contribution of toxic PCDD/Fs was from 2,3,7,8-substituted HxCDF and 2,3,7,8-substituted HpCDF. The TEQ of HxCDF and HpCDF in chloranil-1 was 90% and in chloranil-2 was 71%. And the toxic contribution increased with the degree of chlorination for PCDFs. (C) 2005 Elsevier Ltd. All rights reserved.