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ISSCT XXVIth CONGRESS Durban, South Africa 29th July - 2nd August 2007 |
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CO-PRODUCTS
COMMISSION
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ISSCT XXVIth CONGRESS
Durban, South Africa
29th July - 2nd August 2007
CO-PRODUCTS COMMISSION
Papers & Posters Titles
CO1
Additional exportable energy from bagasse
A.F. Lau, K.T.K.F. Kong Win Chang and D. Gunness - Mauritius
CO2
A sugar mill cogeneration plant repowering alternatives: evaluation through the combination of thermodynamic and economic concepts
E.E.S. Lora, M. Zampieri, O.J. Venturini and J.J. Santos - Brasil
CO3
Life cycle analysis of different alternatives for the treatment and disposal of ethanol vinasse
M.H. Rocha, E.E.S. Lora and O.J. Venturini - Brasil
CO4
Conversion of cane-derived sugars into poly (3-hydroxyalkanoates)
R. Mungaroo, K.T.K.F. Kong Win Chang, A.S. Saumtally, J-F.Y. Moutia,M.H.R. Khoodoo and
G. Triton - Mauritius
CO6
Simulation and design of a bagasse gasifier
P.A. Hobson and J.A. Joyce - Australia
CO7
An overview of bagasse gasification R&D activities at the centre for Sugar Research and Innovation
P.A. Hobson - Australia
CO9
A techno-economical method to guide decision making over the energy-sugar-ethanol combined production under the changing world market conditions
A. Torres, G. Blanco, M. Herryman,O. Almazan and A. Cabello - Cuba
CO10
Benchmarks for a strategy in the energy generation of the sugarcane industry: a really clean source of energy
O.A. Almazán and M.A. Otero - Cuba
CO11
Fodder yeast production: a new approach for distillery vinasse treatment
M.A. Otero Rambla, G. Saura Laria,J.A. Martínez Valdivielso and O.A. Almazán Del Olmo - Cuba
CO12
The economical viability of animal production based on sugarcane co-products under the present prices of commodities
A. Cabello, A. Torres and O. Almazán - Cuba
CO14
Deterioration of molasses during storage: Possible cause and means to prevent it
V.M. Kulkarni - India
CO16
Co-generation thermodynamics revisited
M. Inkson and B. Misplon - USA
CO17
ISSCT Co-Products Workshop in Maceió, Brazil
M.R.L.V. Leal - Brasil
CO18
By-products from bagasse
D.F. Day, G. Dequeiroz, C-H. Chung and M. Kim - USA
CO19
New sugar cane varieties and year round sugar and ethanol production with bagasse based cogeneration in Barbados, Guyana and Belize
P.S. Rao, H. Davis and C. Simpson - West Indies
CO20
Formulation of a cattle feed from co-products of the sugarcane industry of Sri Lanka
G. Chandrasena, A.P. Keerthipala,V.P. Jayawardena, W.A.M.J.S.B. Abeysinghe and A. Nimal Perera - Sri Lanka
CO22
Preliminary assessment of the Zeachen technology for ethanol production from sugar process streams
B.P. Lavarack, T. Eggeman, L.A. Edye,P.A. Hobson, J.L. Blinco and G.E. Bullock - Australia
CO25
Carbonisation and gasification of bagasse for effective utilisation of sugarcane biomass
M. Ueno, Y. Kawamitsu, Y. Komiya and L. Sun - Japan
CO27
Applying consistent technology for fuel ethanol production
A.G. Moura and J.R. Medeiros - Brasil
CO29
Efficient cooling of fermentations vats in ethanol production - Part I
DM.O.S. Dias, R. Maciel Filho and C.E.V. Rossell - Brasil
CO30
Monte Carlo simulation as a tool for technical modelling and project analysis
J.A. Joyce and P.A. Hobson - AustraliaCO31 Integrated biodiesel production in sugar and alcohol mill
J.L. Oliverio, S.T. Barreira and S.C.P. RangelCO33 Cane energy for sustainable development and economic competitiveness in Southern Africa
F.X. Johnson, J. Woods, F. Rosillo-Calle,G. Brown, V. Seebaluck, H. Watson,F. Yamba, M. Mapako, L. Jolly, F. Farioli, M.R.L.V. Leal and P.R.K. Sobhanbabu
COP1
Sweet sorghum (Sorghum bicolor L.): a supple-mental sugar crop for ethanol production
G. Hunsigi, N.R. Yekkeli and B.Y. Kongwad - IndiaCO-PRODUCTS PAPERS
ABSTRACTCO1_abstract
ADDITIONAL EXPORTABLE ENERGY FROM BAGASSE
By
A.F. Lau, K.T.K.F. Kong WIN CHANG, d gunness
Mauritius Sugar Industry Research Institute (MSIRI)Keywords: bagasse, electricity, fuel.
Abstract
Since 1999, Mauritius has embarked on a strategy to install bagasse cum coal co-generation plants using high-pressure boilers and the conventional steam cycle. Electricity production had reached 200 kWh/t cane but, after satisfying its own heat and power use, the net exportable energy is 130 kWh/t cane. It is expected that electricity produced from bagasse will attain 700 GWh in 2012 from 5.5 million tonnes cane. Since massive investment has already been made, it is unlikely that, in the short-term, surplus energy for export would be produced, using a different co-generation set-up than the conventional steam cycle.
The aim of our study is to ascertain whether increasing the amount of exportable electricity, gas or liquid fuel from bagasse would be possible without affecting the set-up of existing co-generation plants. The study reviews and evaluates the surplus exportable energy potential, based on current research in Mauritius and from international literature, on concepts, not yet adopted or widespread in the cane sugar industry. Higher fibre or high quality cane, trash recovery, bagasse drying, condensing boiler, bagasse gasification gas turbine technologies, liquid fuel from bagasse, hydrogen from bagasse for fuel cells and cellulosic ethanol are among them.
CO2_abstract
A SUGAR MILL COGENERATION PLANT REPOWERING ALTERNATIVES EVALUATION THROUGH THE COMBINATION OF THERMODYNAMIC AND ECONOMIC CONCEPTS
By
Electo Eduardo Silva Lora, Marcelo Zampieri, Osvaldo José Venturini, Jose Joaquim Santos
Excellence Group in Thermal Power and Distributed Generation, Federal University of Itajubá.
electo@unifei.edu.brKEYWORDS: cogeneration, sugar and alcohol industry, thermoeconomics.
Abstract
This paper shows the advantages of using thermodynamic and economic concepts, the so called “thermo-economics”, to carry out the assessment of repowering alternatives in sugar and alcohol mills’ cogeneration plants, which allows the determination of the cost of each product separately. The present scheme of an existing sugar and alcohol mill (1000 tonnes of crushed cane per hour) and four repowering alternatives are modelled using the Gate-Cycle Enter software. Different steam parameters (63 bars/480oC and 82 bars/520oC) are considered. The cogeneration plant thermal efficiency is calculated according to four different criteria and conclusions are made according to the way each of these criteria considers real processes. Exergetic and monetary cost for steam, mechanical power and electricity are presented for all the evaluated scenarios.
CO3_abstract
LIFE CYCLE ANALYSIS OF DIFFERENT ALTERNATIVES FOR THE TREATMENT AND
DISPOSAL OF ETHANOL VINASSE
Mateus Henrique Rocha, Electo Eduardo Silva Lora, Osvaldo José Venturini,
Excellence Group in Thermal Power and Distributed Generation, Federal University of Itajubá.
electo@unifei.edu.brKEYWORDS: cogeneration, sugar and alcohol industry, thermo-economics, vinasse, stillage
Abstract
Ethanol production through sugar juice fermentation has a serious problem related to the quantities and high organic content of its main residue called vinasse or stillage. The awareness of the impact of the vinasse disposal by fertigation caused the environmental agencies to implement more rigorous conditions regarding this practice. Alternative disposal options are being analysed such as: anaerobic digestion, combustion, vinasse recirculation during fermentation, and dewatering. A discussion is presented about the main advantages and disadvantages of different vinasse treatment and disposal options and about the feasibility of Life Cycle Analysis for its evaluation. This paper aims at evaluating the energy balance and environmental impacts of the whole vinasse treatment and disposal life cycle. As possible alternatives for this study, the following were defined:
- Conventional fertigation (base reference case).
- Vinasse biodigestion and biogas use as fuel in mill boilers.
- Vinasse dewatering up to 40-50% and its direct combustion in boilers.
- Vinasse dewatering up-to 60% before fertigation in order to reduce transport costs.
The methodology applied is the ECO-95 Indicators that uses the software SimaPro 7 (PRé Consultants). At the same time, results about the mass and energy balance of the vinasse life cycle are presented. The conclusions present the advantages and disadvantages of each alternative. Graphics of normalized environmental effects for the evaluated alternatives are also presented.
CO4_abstract
Conversion of cane-derived sugars into poly(3-hydroxyalkanoates) (bioplastics)
R. Mungaroo, K.T.K.F. Kong Win Chang, A.S. Saumtally, J-F.Y. Moutia, M.H.R. Khoodoo and G.Triton
Mauritius Sugar Industry Research Institute, Reduit, Mauritius
rmungaroo@msiri.intnet.muKEYWORDS: Sugar-cane biomass, Hydrolysis, Ralstonia eutropha H16 G+, Azospirillum spp., Poly(3-hydroxyalkanoates)
Abstract
For the sustainability of the Mauritian sugar industry, more co-products need to be produced from sugarcane biomass. One of the co-products that is currently being investigated at the Mauritius Sugar Industry Research Institute (MSIRI) is poly(3-hydroxyalkanoates), more commonly known as PHAs or bioplastics.
Cane juice, molasses and bagasse were chosen as raw materials for this study. The sucrose present in cane juice and molasses was quantitatively converted into simple sugars by dilute acids. Pretreated bagasse was converted into simple sugars by either acid or enzymatic hydrolysis, with emphasis being laid on the latter. Enzymes have been produced in situ by Trichoderma viride and T. harzianum. Media were prepared with the simple sugars obtained from the hydrolysis of sucrose and bagasse, and were inoculated with Ralstonia eutropha H16 G+ and Azospirillum spp. The bacterial cells were harvested, washed, freeze-dried and subjected to solvent extraction. Upon the removal of the solvents, biopolymers were obtained.
Once the yields for the production of simple sugars and PHAs have been optimized, the production of these biopolymers will be scaled up. Upon the successful completion of this study, the expertise will be shared with the sugar/plastic industry with the aim of making the commercial production of PHAs a reality in Mauritius. This could not only make the local sugar-cane industry more sustainable, but it could also enable the country to be less dependent on traditional petroleum-derived non-biodegradable (polluting) plastics.
CO6_abstract
SIMULATION AND DESIGN OF A BAGASSE GASIFIER
By
P.A. HOBSON1 AND J.A. JOYCE2
1Queensland University of Technology, Brisbane, Australia
2Formerly Sugar Research Institute,
currently James Joyce and Associates, Mackay, Australia
Contact p.hobson@qut.edu.auKEYWORDS: Gasifier, bagasse, optimisation, cold gas efficiency, pinch analysis
Abstract
An evaluation of options for the practical implementation of a novel biomass reforming concept has been carried out. This concept utilises the potassium that occurs naturally in biomass as a catalyst in cracking high molecular weight tars produced during gasification to deliver a high quality syngas. One of the primary objectives was to develop a process which yielded a gas with the highest possible fuel heating value, relative to that of the original bagasse fuel. This ratio is termed cold gas efficiency (CGE).
Initially, a first law of thermodynamics analysis (simple mass/atomic species and energy balances) was carried out in which the preferred operating regimes were identified in terms of basic process parameters. Both deterministic and Monte Carlo analyses were performed using the first law models. Key findings from this preliminary analysis included:
· Beyond the minimum steam requirement, maximum cold gas efficiency (CGE) is achieved by avoiding any further increase in the ratio of steam to dry ash free (d.a.f.) bagasse.
· The theoretical minimum steam requirement to fully convert all of the carbon in the bagasse to a gas of maximum heating value is approximately 13.5 wt% of the fuel (d.a.f. basis).
· Without chemical recuperation, char/coke yields in excess of 12 wt% on a d.a.f. basis (characteristic of the process in question) will lead to suppression of the CGE.
· The Monte Carlo sensitivity analysis indicated a 90% probability of achieving a CGE of between 62% and 85% given the range of process parameters considered.
Five basic concepts were evaluated for thermodynamic performance and engineering feasibility. A preferred hybrid of these concepts was selected and a process model developed. A second law approach (so-called “Pinch Analysis”) was then applied to elucidate the best heat recovery strategies.
The optimised model was used to establish key specifications in terms of bagasse and steam flows, heat transfer areas, pump capacities and parasitic power requirements for a notional 5 MWth pilot plant. The predicted performance figures of greater than 80% CGE and 12 MJ/m3 product gas Lower Heating Value compare favourably with the values targeted at the onset of the project and represent a major improvement on the performance expected from the commonly proposed gasification designs.
CO7_abstract
AN OVERVIEW OF BAGASSE GASIFICATION R&D ACTIVITIES AT SUGAR RESEARCH AND INNOVATION
By
P.A. HOBSON
Sugar Research and Innovation, Queensland University of Technology, Brisbane, Australia
Contact p.hobson@qut.edu.auKEYWORDS: Bagasse, gasification, catalyst, ash, kinematics, co-generation
Abstract
Sugar Research and Innovation (SRI) has been involved for some years in developing aspects of bagasse gasification technology. This has been undertaken with the long-term aim of implementing advanced cycle, high efficiency power generation in the sugar industry or the production of a gaseous feedstock for alcohols and other industrial commodities.
Many of the R&D outcomes achieved at SRI in the area of gasification can be traced back to the formation in 1998 of the Queensland Biomass Integrated Gasification (QBIG) program. This program was set up to develop gasification for boosting power generation in the sugar industry. Under the QBIG program, major research projects were undertaken in the areas of bagasse and cane trash gasification kinetics, ash characteristics in bagasse gasifiers, the development of a continuous pressurised bagasse feeder, cane harvest residue recovery systems to improve gasifier utilisation and economies of scale as well as a financial appraisal of gasification for power generation. It became evident from this latter study that there was significant scope for reducing costs via a staged and highly factory integrated introduction of this technology, and a study was initiated to determine optimum strategies for the large scale adoption of gasification technology across the industry.
On a more fundamental level, SRI has been collaborating with Hokkaido and Monash universities in a project aimed at utilising the potassium that occurs naturally in biomass as a catalyst in cracking high molecular weight tars produced during gasification. This catalysed reforming process occurs at relatively low temperatures (500°C to 700°C) and has the potential to deliver significant gasifier cost and efficiency advantages. The role of SRI in this project has been to develop computational fluid dynamics (CFD) and process models with which to implement laboratory data in a thermodynamically optimised gasification cycle.
This paper draws together the R&D activities undertaken at SRI to provide a positive picture with respect to the technical feasibility of implementing gasification technology for power generation and highlights some of the financial barriers to the large scale adoption of the technology in Australia.
CO9_abstract
A TECHNO-ECONOMICAL METHOD TO GUIDE DECISION MAKING OVER THE ENERGY-SUGAR-ETHANOL COMBINED PRODUCTION UNDER THE CHANGING WORLD MARKET CONDITIONS
By
TORRES, A.; BLANCO, G.; HERRYMAN, M.; ALMAZAN, O.; CABELLO, A.
Cuban Research Institute on Sugar Cane by Products.
Vía Blanca 804, Ciudad de La Habana, Cuba.
Email: oscar.almazan@icidca.edu.cuKEYWORDS: model, decision making, linear programming, commodity prices, management.
Abstract
The ways and means of linear programming models for the analysis of different combined electricity-sugar-ethanol production schemes were designed and tested to guide the process of profitable decision making under different national sugar policies, production costs, world market conditions, etc. The models provide a simple and comprehensive tool to work with under the complex and unstable behaviour of commodity prices.
CO10_abstract
BENCHMARKS FOR A STRATEGY IN THE ENERGY GENERATION OF THE SUGARCANE INDUSTRY:
A REALLY CLEAN source OF ENERGY
By
OSCAR A. ALMAZÁN AND MIGUEL A. OTERO
Cuban Institute for Research on Sugarcane By-Products (ICIDCA)
Via Blanca 804 P.O. Box 4026 10400 Havana Cuba
Email: oscar.almazan@icidca.edu.cuKEYWORDS: Renewable energy, sugarcane industry, cogeneration, clean development mechanism.
Abstract
An historical analysis of the development of the energy use in the sugarcane industry is presented. The study shows how the search for less energy consumption was the driving force that led the sugar industry through its qualitative technological development up to date. In addition, the main goal to achieve as much energy as bagasse and cane residues, which are renewable resources, can assist the environment, opening new ways and means to succeed in the effort for less steam consumed per tonne of sugar, higher combustion efficiency, less equipment and investment. In addition, more surplus bagasse and electricity produced from it leads to an important reduction of fossil fuel usage, in the sugar industry and in the electricity grid. The results obtained in different countries are reported in detail giving the improvements in “green” electricity generated per tonne of milled cane, and its potential effect on climatic change.
CO11_abstract
Fodder yeast production: A new approach for distillery vinasse treatment
By
M. A. Otero Rambla, G. Saura Laria, J. A. Martínez Valdivielso, O. A. Almazán del Olmo
Biotechnology Division Cuban Institute for Research on Sugar Cane By-Products (ICIDCA)
Vía Blanca 804 & Carretera Central, Havana 11000, Cuba
Email: miguel.otero@icidca.edu.cuKeywords : yeast, distillery vinasse, wastewaters treatment, microbial protein, bioprocess
Abstract
Distillery vinasse is one of the most contaminating industrial wastes and, for a full development of an ethanol industry, this problem has to be solved. The study was conducted at lab scale in a yeast factory using raw materials from industry.
Through this technology, the organic load of vinasse was reduced by 75% when the process was carried out batch wise or slightly over 60% in continuous mode. Important amounts of high quality proteins with relatively high yields (about 60 cubic metres of vinasse per tonne of yeast on a dry matter basis) can be obtained in parallel with wastewater treatment. Distillery vinasse can be utilized as the sole source of carbon in fodder yeast production. Addition of growth enhancer QZ-350 at a ratio of 1 to 3 kg/t of yeast, substitutes 1.1 tonnes of molasses.
If protein production is the main target, continuous culture is the indicated choice. However, if environmental issues prevail, batch mode is preferred since it leads to a higher depletion of organic matter (potential pollution) in the propagation medium.
CO12_abstract
THE ECONOMICAL VIABILITY OF ANIMAL PRODUCTION BASED ON SUGARCANE COPRODUCTS UNDER THE PRESENT PRICES OF COMMODITIES
By
A. Cabello, A. Torres, O. Almazán
Cuban Research Institute for Sugarcane Derivatives (ICIDCA)
agustin.cabello@icidca.edu.cuKEYWORDS: animal production, bagasse, molasses, “B” molasses
Abstract
Animal production from sugarcane co-products is an alternative to diminish hunger and malnutrition in many sugar producing countries and to overcome low sugar prices. Due to the big differences of local market prices and cost considerations of feed, animal products and energy, average international market prices forecast by OECD-FAO have been used. The aim was to evaluate the comparative economical efficiency of milk, beef cattle and swine meat based on bagasse, blackstrap molasses and “B” molasses respectively according to reported results and compared with their alternative uses. The net value of bagasse for producing milk has been estimated in the range of 20-30$/tonne, and depends heavily on the price of non sugarcane ration components and transportation costs, and is lower than its use for electricity generation at the sugar mill. Blackstrap molasses gives negative revenue when used for fattening cattle as compared with its export price or ethanol production. Swine fattening based on “B” molasses shows a better revenue than converting it to sugar and blackstrap molasses for export. The obtained values do not take into account important factors affecting the economical revenue of each alternative, but may serve as a primary reference for the use of the sugarcane co-products for different purposes.
C0 14_abstract
Deterioration of molasses during storage: Possible cause and means to prevent it
V.M. Kulkarni
V.M. Biotech, 1004, Siddharth Towers (2), 12 / 3 B Kothrud, Pune 411029, INDIA.
vmbio@vsnl.comKEY WORDS: Molasses deterioration, microbial consortium, Pseudomonas, Lactobacillus, anaerobic degradation, biocide treatment
Abstract
Molasses has sugar content around 50% and, with a Brix above 85, it should not deteriorate during storage. However, it is not uncommon to observe reduction in sugars during storage. Sometimes, this deterioration is accelerated and instances of foaming with or without a rise in temperature are observed, which changes the colour and smell of molasses. There is a rapid reduction in sugars and a rise in acidity. Microscopic observation revealed that the microbial population is very high, and further microbial evaluation confirmed the growth of two bacteria growing in consortium as single bacteria which required a minimum sucrose content of 30% when grown under anaerobic conditions. When this consortium, was broken in aerobic conditions, none of the isolates could tolerate more than 5% sucrose. Their growth and thus molasses deterioration was controlled only with the use of Polmax ESR, a special biocide formulation used with continuous circulation of molasses with cooling. The possible reasons for such infection and efforts to control or avoid such deterioration in some factories will be presented.
CO16_abstract
CO-GENERATION THERMODYNAMICS REVISITED
by
MIKE INKSON and BEN MISPLON
Thermal Energy Systems
mbi@sucrose.comKEYWORDS: co-generation, thermodynamics, optimisation
Abstract
Whilst most engineers understand that higher HP steam conditions result in a more efficient power station, a wide range of different HP and exhaust steam conditions have been selected around the sugar industry’s export co-generation stations. This paper examines the thermodynamics of such a station and then sets out a method to optimise it.
Nature is, of course, never that simple. There also needs to be a discussion on how to optimise the thermodynamics when, as is often the case with our export stations, there are two entirely different sets of conditions: in-crop export cogeneration and out of crop generation. The paper also offers some practical advice for the conceptual design of new stations.
CO17_abstract
ISSCT CO-PRODUCTS WORKSHOP IN MACEIÓ, BRAZIL
M.R.L.V. LEAL
CENEA - Centro de Energias Alternativas, Fortaleza, Ceará, Brazil
E-mail: regis@cenea.org.brKEY WORDS: co-products, sugarcane, cogeneration, ethanol, vinasse
Abstract
The ISSCT Co-Products Workshop took place on November 12-16, 2006 in Maceió, Alagoas-Brazil, hosted by STAB Leste (The Eastern Division of the Sociedade de Técnicos Açucareiros e Alcooleiros do Brasil – STAB) with the main theme as “Co-products as renewable feedstock for energy, fuels, plastics and other applications”. A total of 38 delegates from eight countries participated at the workshop that was organized in one opening session, two days of plenary sessions and two days of site visits. In the plenary session, 25 presentations were made, 30 minutes each, covering five themes: sugarcane for energy, ethanol production process, other co-products, ethanol programs and policies, environmental impacts of ethanol production; most presentations were concentrated on cogeneration and ethanol production. Two mills, Caeté and Coruripe, were visited as part of the program as well as the Sugar Terminal at the port of Maceió, a major outlet for the region’s sugar exports. The discussions during the sessions and visits indicated the increasing interest of technicians of the sector in the diversification of the industry, mainly in the energy potential of sugarcane.
CO18_abstract
By-products from Bagasse
By
D.F Day, G. Dequeiroz, C-H. Chung and M. Kim
Audubon Sugar Institute, LSU Agricultural Center, Baton Rouge, La., USA
dday@agctr.lsu.eduKEYWORDS: biorefinery, by-products; mono-phenols, lignin
Abstract
A biorefinery will have to produce a range of products, including ethanol, for economic viability. Any process for manufacturing ethanol from bagasse will also yield lignin fragments which contain aromatic compounds, and some cellobiose due to incomplete cellulose conversion. The pretreatment and hydrolysis methods dictate the actual compositions of these streams. An ethanol, organo-solv process, a singlet oxygen pretreatment and an ammonia explosion process were tested, not only for their ability to increase sugar availability for fermentation, but also for the “by-products” produced.
A range of monophenolic compounds derived from the lignin were detected, ranging from 30 mg to 100 mg of vanillin equivalent per gram of dry bagasse. The mono phenols produced by the various treatments were characterized using GC/MS. The compound with commercial value that turned up in all treatments was vanillin.
Typically, enzyme hydrolysis of ligno-cellulose produces primarily glucose and a small amount of cellobiose. Cellobiose in its own right is a potentially valuable product as a non-nutritive sugar. Co-production of a b-glucosidase inhibitor, gluconic acid, during enzymatic hydrolysis of cellulose altered the amounts of glucose and cellobiose produced. Addition of a b-glucosidase inhibitor, gluconolactone or gluconic acid, significantly increased the amount of cellobiose with a corresponding decrease in amount of glucose produced. In situ production of cellobiose during enzymatic conversion, using the enzyme glucose oxidase, yielded the same effect. With a suitable concentration of glucose oxidase it was possible to convert over 19.3% of the cellulose to cellobiose.
CO19_abstract
NEW SUGARCANE VARIETIES AND YEAR ROUND SUGAR AND ETHANOL
PRODUCTION WITH BAGASSE-BASED COGENERATION IN BARBADOS AND GUYANA
By
P. Seshagiri Rao1, HAROLD Davis2, CARL Simpson3
1 West Indies Central Sugar Cane Breeding Station, St George, Barbados,
2 Guyana Sugar Corporation Inc, LBI, Guyana,
3 Barbados Agricultural Management Co. Ltd, Warrens, Barbados
psrao@caribsurf.comAbstract
The sugar industries of Barbados and Guyana have been looking for ways to secure their industries in view of the increasingly uncertain sugar markets and a likely price reduction for export sugar. These industries have therefore been exploring opportunities to generate additional income from energy through the production of ethanol and electricity. New multipurpose cane (MPC) varieties with very high fibre content developed at the West Indies Central Sugar Cane Breeding Station (WICSCBS) in Barbados have been found to produce more biomass per hectare and a wider range of brix values when compared to the traditional sugar cane varieties. The MPC varieties are being tested and would be likely to complement older commercial varieties in the traditional crop period as well as during the out-of-crop season to supplement bagasse production for co-generation projects. These varieties are also being considered for the production of ethanol. In Barbados, the feasibility of a 12 month operation to produce electrical power as the principal product, with direct consumption raw sugar, molasses and fuel as co-products has been evaluated. Conventional sugarcane varieties would be grown on 40% of the present cane lands and MPC varieties on the rest of the estates. This project is anticipated to commence with the completion of a new multi-purpose production facility in 2009. In Guyana, the construction of a 8400 tonne cane per day (TCD) mill has commenced. This mill will supply 10 megawatts (MW) of power to the grid by co-generated electricity. A 12 million litres fuel alcohol distillery is likely to be attached to this factory. High fibre MPC varieties with acceptable levels of fermentable sugars are under evaluation for extending the supply of bagasse and contributing to fuel ethanol production in an extended crop season.
CO20_abstractFORMULATION OF A CATTLE FEED FROM CO-PRODUCTS OF THE SUGARCANE INDUSTRY OF SRI LANKA
By
G. CHANDRASENA1, A. P. KEERTHIPALA1, V.P. JAYAWARDENA2, W. A. M. J. S. B. ABEYSINGHE2 AND A. NIMAL PERERA2
1 Sugarcane Research Institute, Uda Walawe, Sri Lanka.
2 Department of Animal Science, Faculty of Agriculture, University of Peradeniya, Sri Lanka.
1 sri@bellmail.lkKEYWORDS: Cattle feed, Sugarcane tops, Molasses, Diversification
Abstract
The co-products of the Sri Lankan sugar industry have not been fully utilised. The depressed price of sugar has adversely affected the viability of the sugar industry. There exists a severe shortage of animal feed in the dry zone of Sri Lanka, particularly during the dry period from May to September, and this has badly affected the milk production in the country. This study aimed at investigating the possibility of production of a cattle feed from sugar industry co-products such as cane tops and molasses to gain additional income to sugar companies and to cater to the feed demand for increasing milk yield and production.
Twelve rations were formulated at different levels of cane tops, molasses, coconut poonac, rice polish, urea, dicalcium phosphate and sodium chloride, considering the nutrition requirements of the cattle and tested for their in-vitro organic matter digestibility (IVOMD), metabolisable energy (ME), and digestible crude protein (DCP) contents. The ration with the highest ME and DCP contents was used to test its effect on milk yield.
The results showed that the ration with 55% cane tops, 15% molasses, 2% urea, 15% coconut poonac, 10% rice polish, 2% dicalcium phosphate and 1% sodium chloride gave the highest ME and DCP. It increased milk yield by 49%, length of lactation period by 17%, total milk production 56%, and fat content by 21%. Financial analysis indicated that cattle feed production from sugarcane co-products was viable at the prevailing prices. Thus, utilisation of cane tops and molasses for cattle feed helps both the sugar industry and dairy farmers to raise their income by product diversification and by increasing milk production respectively.
CO22_abstract
Preliminary assessment of the Zeachen technology
for ethanol production from sugar process streams
By
B.P. LAVARACK1, T. EGGEMAN2, L.A. EDYE3, P.A. HOBSON3, J.L. BLINCO4 and G.E. BULLOCK3
1MSCA, 2ZeaChem, 3SRI at QUT, 4formerly of SRI at QUT.
b.lavarack@mkysugar.com.auKEYWORDS: Ethanol, fermentation, esterification, hydrogenolysis, economics
Abstract
The technical and economic investigation of the ZeaChem process for increased production of ethanol from sugar process streams has been completed at SRI and this paper reports on these investigations. The main benefit of the process is the theoretical increase in ethanol production by up to 50% per unit dextrose sugar feed.
The ZeaChem process utilises bacteria to convert fermentable sugars to acetic acid either in a one step direct fermentation process or in a two step fermentation process via lactic acid. The production of lactic acid can provide an additional revenue source from the sale of single cell protein produced in the two step process. After fermentation, the acetic acid is extracted from the fermentation broth in an acid recovery stage, esterified in a reactive distillation process and converted to ethanol by hydrogenolysis. The ZeaChem process has four main production stages. In order to achieve high yields of ethanol, high yields are required for each stage of the process. High yields are obtained for each stage of the process. Several sugar process streams were considered for the process and these included clarified juice, syrup, A molasses, B molasses and C molasses. However, the fermentation process is inhibited if C molasses only is used as feed. Large dilutions of C molasses are required to obtain high yields during the fermentation stage. The reasons for the inhibition of the fermentation of C molasses are not understood and should be targeted in further laboratory scale testing, while the project is progressed to pilot plant trials.
The evaluation of the ZeaChem ethanol process has confirmed the potential of the process to achieve significantly higher yields than the conventional yeast fermentation process.
CO25_Abstract
CARBONIZATION AND GASIFICATION OF BAGASSE FOR EFFECTIVE UTILIZATION
OF SUGARCANE BIOMASS
By
MASAMI UENO, YOSHINOBU KAWAMITSU, YASUAKI KOMIYA AND LIYA SUN
University of the Ryukyus
ruenom@agr.u-ryukyu.ac.jpKEYWORDS: carbonization, gasification, charcoal, global warming, biomass.
Abstract
Two types of carbonization plant and one gasification plant have been developed and tested for effective utilization of the products. The importance of by-products is increasing, as global warming is now a significant problem, and biomass resources can be used to alleviate the energy shortage and minimise the emission of greenhouse gases. Carbonization of bagasse can add new value for production of energy and other materials, so continuous type carbonizers were developed. The bagasse becomes charcoal by heating in the absence of oxygen for about 30 minutes at 400 to 900 degrees Celsius temperature. Bagasse charcoal was used as a soil improvement material, absorbent, deodorant and so on. A large volume of burnable gas was obtained from bagasse or its charcoal by the developed gasifier. The plant turns to a carbonizer by exclusion of air. Therefore, bagasse can be used as a value-added resource for energy and other materials by carbonization and gasification.
CO27_abstract
APPLYING CONSISTENT TECHNOLOGY FOR FUEL ETHANOL PRODUCTION
By
A.G.MOURA and J.R.MEDEIROS
Dedini S.A. Ind. de Base
adler.moura@dedini.com.br; jose.medeiros@dedini.com.brKEYWORDS: Ethanol Process, Fermentation, Distillation, Dehydration
Abstract
Anhydrous fuel ethanol starting from molasses can be produced through several combined routes by application of different technologies for fermentation, distillation and dehydration processes. Indeed, they constitute chains of processes that must be driven by a specific objective, such as minimizing power consumption, steam consumption, losses, improving product quality or plant robustness, among others. The technology applied, however, has an initial investment, which can result in a less competitive plant, if that chain was not constructed under a strict sense of consistency and focused on real results. The present work shows a cross link among the main technologies pointing out their main features, and consistency in chains of production, in order to reach some specific purpose as described above, involving 1 - fermentation: continuous, batch, with or without yeast or vinasse recirculation, using centrifuges or floculant yeast; 2 - distillation: vacuum, pressurized, in cascade, with side streams or not; 3 – Dehydration: mol sieves, extractive and azeotropic distillation and vapour permeation through membranes, with liquid or vapour phase feed. The study concluded that each technology has its optimum in performance for each application in a different chain of technology for the whole process. For instance, some applications of vacuum distillation, fermentation under high yeast stress or with very special yeasts, dehydration under unsuitable route, etc. may be useless for some purposes and may have higher costs in maintenance, product quality control, high process sensitivity etc., despite their higher initial investments. On the other hand, neglecting these technologies may lead the project to a poor approach and consequently to a plant or process unbalanced and inefficient. It is very important to note that both pictures represent a business of lower competitiveness, especially in the case where the chosen technology chain is not robust enough.
CO29_abstract
EFFICIENT COOLING OF FERMENTATION VATS IN ETHANOL PRODUCTION – PART 1
By
M.O.S. DIAS a, R. MACIEL FILHO a, C.E.V. ROSSELL b
a Laboratory of Optimization, Design and Advanced Control, School of Chemical Engineering, State University of Campinas, Brazil
b Interdisciplinary Center for Energy Planning, State University of Campinas, Brazil
diasmos@feq.unicamp.brKEYWORDS: Bio-ethanol, fermentation cooling, energy consumption
Abstract
Fermentation done at 34ºC (sometimes at higher temperatures) limits the ethanol content of the final wine, increases energy consumption during the distillation step, increases stillage volume, promotes infection, flocculation and yeast inhibition, so the advantages of operating fermentation at temperatures of 28ºC (at least 32ºC) are evident.
A review on factors such as: wet and dry bulb temperature daily and monthly profiles, design of cooling towers and heat exchangers, the use of more efficient cooling tower internals, steam jet water cooling production system, and the use of cooled water accumulators were done. Kinetics of heat evolution during ethanol production was analysed, and a model considering these factors was developed.
This model helps to design the cooling system in order to attain the desired fermentation temperature, larger ethanol content on final wine and less stillage volume per volume of ethanol produced.
Three options are explored in this work, considering the use of a cooling tower to provide cooled water during the coolest hours of the day and the use of secondary equipment to provide cooled water during the warmest hours of the day. The equipment considered were a water accumulator, a steam jet ejector and an absorption machine.
In the case of a water accumulator, the cooling tower size would be greater, but for both steam jet and absorption machine, there would be an increase in consumption of utilities.
All options would cause an increase in initial cost, and an economic analysis is to be made in part 2 of this work in order to help in making a final decision.
CO30_abstract
Monte Carlo simulation as a tool for technical modelling and project analysis
by
J.A. JOYCE1 AND P.A. HOBSON2
1Consulting Engineer, 2Queensland University of Technology
Contact j.joyce@jamesjoyce.com.auKEYWORDS: project analysis, optimisation, cogeneration, by-products
Abstract
New sugar industry projects cost many millions of dollars to complete, so it is not surprising that project financiers want both the technical and financial risks to be properly examined. Conventional deterministic methods for “what-if” scenarios or sensitivity analyses can be not only tedious to undertake but presenting the results to decision makers can be challenging. Monte Carlo simulation provides a means to not only overcome the limitations of conventional methods but at the same time add levels of sophistication to the analysis that are not otherwise possible. One such advantage is the ability to use a variety of probability distributions to define each input variable. Monte Carlo simulation involves running thousands of scenarios with a dozen or more variables varying simultaneously, to yield the key outputs as probability plots for ready presentation and interpretation. Modern computers and software tools now make it possible to prepare such models and present the results without the need for PhDs in mathematics, computer science and graphic art. This paper presents the Monte Carlo simulation of a hypothetical sugar industry cogeneration case study. The simulation includes the mass and energy balance for a sugar factory cogeneration plant, to quantify the effects of changing cane quality on power production. The outputs from the technical model are then combined with a discounted cash flow analysis to quantify the financial aspects of the project. The outputs are described and the be
