Energy use and economical analysis of sugar beet production in Tokat province of Turkey

The purposes of this study were to determine energy consumption of input and output used in sugar beet production, and to make a cost analysis in Tokat, Turkey. Data were collected from 146 sugar beet farms in Tokat, Turkey by using a face-to-face questionnaire performed in January and February 2005. Farms were selected based on random sampling method. The results revealed that total energy consumption in sugar beet production was 39 685.51 MJ ha⁻¹, and accounted for 49.33% of fertilizer energy, and 24.16% of diesel energy. The output/input energy ratio was 25.75 and energy productivity was 1.53 kg MJ ha⁻¹. Results further indicated that 82.43% of total energy input was in non-renewable energy form, and only 12.82% was in renewable form. Economic analyses showed that profit–cost ratio of farms was 1.17. The highest energy cost items were labor, land renting, depreciation and fertilizers. Although intensive energy consumption in sugar beet production increased the yield, it also resulted in problems such as global warming, land degradation, nutrient loading and pesticide pollution. Therefore, there is a need to pursue a new policy to force producers to undertake energy-efficient practices to establish sustainable production systems without disrupting the natural resources. In addition, extension activities are needed to improve the efficiency of energy consumption and to sustain the natural resources.     

Optimization of very high gravity fermentation process for ethanol production from industrial sugar beet syrup

In order to reduce production costs and environmental impact of bioethanol from sugar beet low purity syrup 2, an intensification of the industrial alcoholic fermentation carried out by Saccharomyces cerevisiae is necessary. Two fermentation processes were tested: multi-stage batch and fed-batch fermentations with different operating conditions. It was established that the fed-batch process was the most efficient to reach the highest ethanol concentration. This process allowed to minimize both growth and ethanol production inhibitions by high sugar concentrations or ethanol. Thus, a good management of the operating conditions (initial volume and feeding rate) could produce 15.2% (v/v) ethanol in 53 h without residual sucrose and with an ethanol productivity of 2.3 g L h⁻¹.     

Biohydrogen production by extracted fermentation from sugar beet

In the study, the production of biohydrogen by extracted fermentation from sugar beet was evaluated. Effects of initial amount of sugar beet, biomass and particle size of sugar beet on biohydrogen formation were investigated. The hydrogen (H₂) gas was predicted to be 78.6 mL at initial dry weight of sugar beet 24.6 g L^?1 and H₂ yield was calculated as 81.9 mLH₂ g^?1TOC while biomass concentration (1 g L^?1) and particle size (0.3 cm) were constant. The peak H₂ gas volume was predicted to be 139.9 mL at the low particle size of 0.1 cm. Hydrogen gas production potential was predicted as 143.6 mL h^?1. The peak value of 197.9 mLH₂ g^?1TOC was obtained with particle size of 0.1 cm when dry weight of sugar beet and initial amount of biomass was kept constant at 24.6 g L^?1 and 1 g L^?1, respectively.     

甜菜乙醇发酵条件的研究

以甜菜为原料,利用酿酒酵母对经过预处理后得到的汁液进行酒精发酵试验。通过单因子试验和正交试验,探讨最优发酵条件。试验结果显示的最佳发酵条件:初始糖浓度为10.4%,营养盐添加量分别为K2HPO40.2%,NH4Cl0.2%,MgSO40.01%,种龄24h,接种量15%,初始pH值为5,温度为32℃,摇床转速为175r/min。     

The impact of sugar beet varieties and cultivation conditions on ethanol productivity

The 49 hybrids of sugar beet and semi-forage beet used in this research were characterized by a variable concentration of saccharose (14.58% ± 1.28), Na (5.51 ± 3.07 mmol kg⁻¹), K (57.44 ± 9.71 mmol kg⁻¹), N (21.68 ± 4.75 mmol kg⁻¹), yield (68.36 ± 10.29 t ha⁻¹) and differentiated fermentation efficiency (5.14 ± 1.22 m³ ha⁻¹).It was found that the effectiveness of fermentation depends not only on the saccharose content in the sugar beet, but also its relationships with other components of the dry matter. High sugar beet yield have significant effect on ethanol yield. The impurities such as K, N and Na have a negative effect on efficiency of the fermentation process. It also specifies varietal differences on ethanol yield. It has been found that high ethanol yield is correlated with diploid hybrids which are sugar hybrids.     

Life cycle analysis for bioethanol production from sugar beet crops in Greece

The main aim of this study is to evaluate whether the potential transformation of the existing sugar plants of Northern Greece to modern bioethanol plants, using the existing cultivations of sugar beet, would be an environmentally sustainable decision. Using Life Cycle Inventory and Impact Assessment, all processes for bioethanol production from sugar beets were analyzed, quantitative data were collected and the environmental loads of the final product (bioethanol) and of each process were estimated. The final results of the environmental impact assessment are encouraging since bioethanol production gives better results than sugar production for the use of the same quantity of sugar beets. If the old sugar plants were transformed into modern bioethanol plants, the total reduction of the environmental load would be, at least, 32.6% and a reduction of more than 2 tons of CO₂e/sugar beet of ha cultivation could be reached. Moreover bioethanol production was compared to conventional fuel (gasoline), as well as to other types of biofuels (biodiesel from Greek cultivations).     

Reduction of irreversibility generation in sugar and ethanol production from sugarcane

Sugarcane is one of the most important industries of the Brazilian economy, and its main products are sugar and ethanol. Most of the industrial plants produce both products in an integrated process, in which the sugarcane bagasse is a by-product that can be used as a fuel in the cogeneration system. The bagasse is used as the only fuel of the plant, supplying all energy required for the process, and also producing electricity surplus that may be sold to the grid. In this paper, exergy analysis is used to assess an integrated sugar and ethanol plant with its cogeneration system. The plant was divided into eight sub-systems to evaluate the irreversibility generation in each separately. Data from typical sugarcane factories in Brazil, which produce sugar and ethanol, were used in the process simulation. The analysis has shown that the sub-systems with the highest contribution for the total irreversibility generation of the plant were co-generation, juice extraction and fermentation. Some improvements are proposed, including process thermal integration and the introduction of more efficient equipments for prime mover and steam and electricity generation. The analysis indicated that the total irreversibility could be reduced by 10% should those changes be implemented.     

Bioethanol production from grape and sugar beet pomaces by solid-state fermentation

A suitable alternative to replace fossil fuels is the production of bioethanol from agroindustrial waste. Grape pomace is the most abundant residue in San Juan and sugar beet pomace could be important in the region. Solid-State Fermentation (SSF) is a technology that allows transforming agroindustrial waste into many valuable bioproducts, like ethanol. This work reports a laboratory scale SSF to obtain alcohol from grape and sugar beet pomace by means of Saccharomyces cerevisiae yeasts. The initial conditions of the culture medium were: sugars 16.5% (p/p); pH 4.5; humidity 68% (p/p). Cultures were inoculated with 10⁸ cells/g of pomace, and incubated in anaerobic environment, at 28 °C, during 96 h. SSF showed ethanol maximum concentrations at 48 h and ethanol yield on sugars consumed was more than 82%. Yield attained creates expectation about the use of SSF to obtain fuel alcohol.     

Bioethanol production from thick juice as intermediate of sugar beet processing

The aims of this study were to investigate the bioethanol production of thick juice as intermediate from sugar beet processing in batch culture by free Saccharomyces cerevisiae cells and the effect of sugar concentration on ethanol yield and CO₂ weight loss rate. Thick juice and molasses of sugar beet from a domestic sugar factory were diluted with distilled water to give a total sugar concentration of 5, 10, 15, 20 and 25% (w w^?1). Initial concentration of fermentable sugars of 20% (w w^?1) in culture medium can be taken as optimal, enabling maximal ethanol yield (68%) and maximal CO₂ evolution rate was realized, amounting to more than 90 g L^?1 h^?1. The optimal concentration of fermentable sugar from thick juice for bioethanol production by free S. cerevisiae cells was 20% (w w^?1) at 30 °C, pH 5 and agitation rate 200 rpm gave maximum ethanol concentration of 12% (v v^?1).     

Optimization of ethanol production from hot-water extracts of sugar maple chips

Hot-water extracts from sugar maple chips prior to papermaking was employed in this study to produce ethanol by Pichia stipitis 58784. The effects of several factors, seed culture age, fermentation time, inoculum quantity, agitation rate, percent extract, concentration of inorganic nitrogen source (NH₄)₂SO₄ and pH value, on ethanol production were investigated by orthogonal experiments. Orthogonal analysis shows that the optimal fermentation was obtained in the condition of 48-h seed culture, 120-h fermentation, 16% inoculum, 180 rpm, containing 30% extracts, 8% ammonium sulphate supplement and pH 5. This optimal condition was verified at 800-mL level in a 1.3 L fermentor. The ethanol yield reached 82.27% of the theoretical (20.57 g/L) after 120 h.     

Production of ethanol from raw juice and thick juice of sugar beet by continuous ethanol fermentation with flocculating yeast strain KF-7

Sugar beet juice can serve as feedstock for ethanol product due to its high content of fermentable sugars and high energy output/input ratio. Batch ethanol fermentation of raw juice and thick juice proved that addition of mineral nutrients could not improve ethanol concentration, but could accelerate the fermentation rate. Fermentation of thick juice with an initial pH of 9.1 did not affect the fermentation process. The continuous ethanol fermentation of raw juice was performed at 35 °C with a dilution rate of 0.3 h⁻¹, resulting in ethanol concentration, ethanol yield and productivity of 70.7 g L⁻¹, 89.8% and 21.2 g L⁻¹ h⁻¹, respectively. A two-stage reactor was used in the continuous ethanol fermentation of thick juice by feeding fresh yeast cells into the second reactor. This process was stable at a total process dilution rate of 0.11 h⁻¹ with an overall sugar concentration of 190 g L⁻¹ in the influent. The ethanol concentration was kept at approximately 80 g L⁻¹, corresponding to ethanol yield of 82.5% and productivity of 8.8 g L⁻¹ h⁻¹.     

A model for industrial production of fuel grade ethanol from sugar beets

In this work we describe a model for industrial production of low cost ethanol from sugar beets. Care is taken to cover the energy needs of the factory in part by using dry pulp as fuel and in part by solar energy, using suitable solar collectors. Also, care is taken for recovery of rejected energy of vinasse, and we propose the use of one distillation column, instead of three column distillation plants which are used for the production of pure ethanol. A method of high fermentation rate, for reduction of cost, is proposed, and the rejected yeast per day from Laval separators. is processed as an animal protein food (8 kg pressed yeast per 1001 spirit). The mass and energy balance is given and a cost analysis of spirit production in current prices. This cost is 25.0 Dr or $0.50 per 1 (1$ - 50 Dr).     

The economic feasibility of sugar beet biofuel production in central North Dakota

This study examines the financial feasibility of producing ethanol biofuel from sugar beets in central North Dakota. Under the Energy Independence and Security Act (EISA) of 2007, biofuel from sugar beets uniquely qualifies as an “advanced biofuel”. EISA mandates production of 21 billion gallons of advanced biofuels annually by 2022. A stochastic simulation financial model was calibrated with irrigated sugar beet data from central North Dakota to determine economic feasibility and risks of production for 0.038 hm³y⁻¹ (or 10 MGY (Million Gallon per Year) and 0.076 hm³y⁻¹ (or 20 MGY) ethanol plants. Study results indicate that feedstock costs, which include sugar beets and beet molasses, account for more than 70 percent of total production expenses. The estimated breakeven ethanol price for the 0.076 hm³y⁻¹ plant is $400 m⁻³ ($1.52 per gallon) and $450 m⁻³ ($1.71 per gallon) for the 0.038 hm³y⁻¹ plant. Breakeven prices for feedstocks are also estimated and show that the 0.076 hm³y⁻¹ plant can tolerate greater ethanol and feedstock price risks than the 0.038 hm³y⁻¹ plant. Our results also show that one of the most important factors that affect investment success is the price of ethanol. At an ethanol price of $484.21 m⁻³ ($1.84 per gallon), and assuming other factors remain unchanged, the estimated net present value (NPV) for the 0.076 hm³y⁻¹ plant is $41.54 million. By comparison, the estimated NPV for the 0.038 hm³y⁻¹ plant is only $8.30 million. Other factors such as changes in prices of co-products and utilities have a relatively minor effect on investment viability.     

Modelling and prediction of bioethanol production from intermediates and byproduct of sugar beet processing using neural networks

The aim of this work was to model and predict the process of bioethanol production from intermediates and byproduct of sugar beet processing by applying artificial neural networks. Prediction of one substrate fermentation by neural networks had the same input variables (fermentation time and starting sugar content) and one output value (ethanol content, yeast cell number or sugar content). Results showed that a good prediction model could be obtained by networks with single hidden layer. The neural network configuration that gave the best prediction for raw or thin juice fermentation was one with 8 neurons in hidden layer for all observed outputs. On the other side, the optimal number of neurons in hidden layer was found to be 9 and 10 for thick juice and molasses, respectively. Further, all substrates data were merged, which led to introducing an additional input (substrate type) and defining all outputs optimal network architecture to 3-12-1. From the results the conclusion was that artificial neural networks are a good prediction tool for the selected network outputs. Also, these predictive capabilities allowed the application of the Garson's equation for estimating the contribution of selected process parameters on the defined outputs with satisfactory accuracy.     

Isolation of fermentative microbial isolates from sugar cane and beet molasses and evaluation for enhanced production of bioethanol

In an attempt to produce bioethanol as a renewable and natural energy resource and as a promising alternative/complement to conventional petrol (i.e., gasoline), 44 microbial isolates (12 yeast and 32 bacterial strains) were isolated from molasses samples obtained from some of the sugar factories in Egypt. Among the microbial isolates obtained, only two yeast isolates (HSC-22 and HSC-24) were selected from sugarcane molasses (SCM) for their high bioethanol fermentation capabilities, recording bioethanol production of ≈9.6 and 8.2 g/L with actual yield of 0.48 and 0.41 g ethanol/g SCM, respectively, within 48-h incubation period at 30°C. Phylogenetic identification of these isolates was performed based on the analysis of the nucleotide sequence of the 18S rDNA gene, which indicated that these isolates can be identified as Pichia veronae and Candida tropicalis, respectively, with similarity of 99%.     

Bioconversion of sugar industry by-products—molasses and sugar beet pulp for single cell protein production by yeasts

In the bioconversion studies of molasses and sugarbeet pulp to single cell protein by four Candida spp. (utilis, tropicalis, parapsilosis and solani) maximum protein content of 37.5 and 43.4% was achieved from the two substrates, respectively, in 48 h. Candida utilis and C. tropicalis performed better than the other yeasts. The maximum bioconversion efficiency for molasses (43%) was given by C. parapsilosis and for beet pulp (46%) by C. tropicalis in 48 h batch flask fermentations. The bioconversion of beet pulp under controlled conditions was studied using C. tropicalis in a 51 fermentor, which gave 29 and 48% product recovery with 39 and 25% protein level, in a two- and one-stage process, respectively. The one-stage process (simultaneous saccharification and fermentation) was also run in a larger volume and gave 50% product recovery with 29% protein content. The results are discussed in terms of biomass yield, protein content and bioconversion efficiency of yeasts under each condition.     

Alkali-aided enzymatic viscosity reduction of sugar beet mash for novel bioethanol production process

Ethanol fermentation of fresh sugar beet mash (SBM) could give a benefit on reducing energy input for sugar diffusion, juice separation, and water evaporation as used in conventional practices, thus offering promise as a low energy process. Actions of cell-wall degrading enzymes provide a mash with low viscosity, which can be easily fermented to ethanol. However, a several-fold higher enzyme loading was required for viscosity reduction of SBM compared with that of potato mash. In this study, the use of dilute alkali treatment (0.025–0.15 N NaOH, 25 °C, 1 h) in enhancing enzymatic viscosity reduction of SBM was evaluated. The results showed that higher NaOH concentration enhanced demethylation and deacetylation of SBM, resulting in greater performances of the enzymes on reducing viscosity. Efficient enzymatic viscosity reduction of SBM was observed with the 0.1 N NaOH treatment. On the other hand, untreated SBM was highly resistant to viscosity reduction, even though a 20-fold more enzyme loading was used. The resulting mash containing 12–13% (w/v) sucrose yielded 7–8% (v/v) ethanol after 24 h of fermentation (90% efficiency). Accordingly, alkali treatment can be applied for facilitating the use of fresh sugar beet for ethanol production.     

重组酿酒酵母发酵木糖产乙醇的研究进展

木糖发酵是利用木质纤维素原料制取乙醇商业化生产的基础和关键,但传统的乙醇生产菌株酿酒酵母(Saccharomyces cerevisiae)不能利用木糖,因而无法满足商业生产的需求.人们利用各种基因工程手段对S. cerevisiae实施基因改造,包括对木糖运输途径的改造,木糖代谢途径的引入,增强其对发酵抑制剂的耐受性等方面都得到广泛研究,各重组菌的木糖发酵能力有了不同程度的改善,但是仍然未能用于商业化生产.酿酒酵母的木糖代谢工程有待于进一步深入研究.