Hydrolysis of sugar cane bagasse with hydrochloric acid,promoted by metallic cations

Lithium chloride, in combination with commercial grade hydrochloric acid, is very effective in the hydrolysis of prehydrolysed sugar cane bagasse. After 10 min at 50°C the holocellulosic portion is completely dissolved and after 20 min most of the sugar oligomers are hydrolysed to monomers, making the time-and energy-consuming post-hydrolysis unnecessary. With longer reaction times the sugars start to reoligomerise and decompose. Zinc chloride is a milder promoter, requiring post-hydrolysis even after reaction for 30 min at 50°C. On the other hand, it does not decompose the sugars giving the highest sugar yields after prolonged reaction time and post-hydrolysis. Ferric chloride is mostly ineffective in the hydrolysis of cellulose but is a good promoter of the hydrolysis of the sugar oligomers, under the reaction conditions.     

Ultrafine grinding of sugar cane bagasse ash for application as pozzolanic admixture in concrete

Sugar cane bagasse ash, a byproduct of sugar and alcohol production, is a potential pozzolanic material. However, its effective application in mortar and concrete requires first the controlled use of grinding and classification processes to allow it to achieve the fineness and homogeneity that are required to meet industry standards. The present paper investigates the role of mill type and grinding circuit configuration in grinding in laboratory- and pilot plant-scale on the particle size, specific surface area and pozzolanic activity of the produced ashes. It was observed that, although different size distributions were produced by the different mills and milling configurations, the pozzolanic activity of the ground ash was directly correlated to its fineness, characterized by its 80% passing size or Blaine specific surface area. From a low pozzolanic activity of less than 50% of the as-received ash, values above 100% could be reached after prolonged grinding times. Electric power requirements to reach the minimum pozzolanic activity were estimated to be in the order of 42 kWh/t in an industrial ball mill. Incorporation of an ultrafinely-ground ash in a high-performance concrete in partial replacement of Portland cement (10, 15 and 20% by mass) resulted in no measurable change in mechanical behavior, but improved rheology and resistance to penetration of chloride ions.     

Hydrolysis of sugar cane bagasse with hydrochloric acid: Separation of the acid by pervaporation. Evaluation of the bergius process

Polyester reinforced PTFE membranes with a nominal pore size of 0.02 μm are very effective in pervaporating HCl gas from hydrochloric acid solutions and cellulose hydrolysates. The efficiency of such membranes, which may be as high as 1.8x10^?2 mmol HCl min^?1 cm^?2 at 40°C, is almost independent of the flow rate and the static pressure of the acidic solution but depends strongly on the acid concentration. At an acid concentration of 26% (w/v) the pervaporation of HCl is negligible at 40°C, but can be accelerated by increasing the temperature. A slow increase of temperature during the pervaporation process is proposed, as this promotes post-hydrolysis of the sugars. Lithium chloride induces structural changes in the membrane which increase efficiency without compromising performance. The use of this new technology in conjunction with the original Bergius process could improve the performance of the latter and reduce its overall costs. The use of the improved process for the hydrolysis of sugar cane bagasse could double the yields of sugar or alcohol per hectare of planted sugar cane.     

Liquefaction of sugar cane bagasse with formate and water

Sugar cane bagasse is available in large quantities in Brazil. Its liquefaction with $\text{formate}\text{inert}$ gas and $\text{base}\text{CO}$ in water is studied. The $\text{formate}\text{inert}$ gas system is the most effective under certain conditions, resulting in higher conversion and better yields of heavy oils. However, the heavy oils are highly oxygenated and solidify on standing in air. As a byproduct, considerable amounts of water-soluble, unextractable carboxylic acids are formed. Systematic studies are carried out with the $\text{formate}\text{inert}$ gas system to determine the reaction conditions appropriate for a future semi-continuous bench-scale reactor. A possible mechanism for the conversion reaction with formate is discussed.     

乳酸菌发酵甘蔗糖蜜产乳酸的培养条件优化

乳酸是有广泛应用的有机酸,廉价原料是降低乳酸生产成本的重要因素。以实验室前期筛选的植物乳杆菌sy4为出发菌株研究了利用甘蔗糖蜜生产乳酸的培养条件。在确定发酵温度和初始pH后,通过Plackett-Burman实验和中心复合实验优化乳酸发酵条件。结果表明：植物乳杆菌sy4乳酸发酵的最适条件为温度32℃、60h、初始pH 6.5;Plackett-Burman实验表明酵母提取物、糖蜜和碳酸钙是影响乳酸产量的主要因素;中心复合实验得到三因素的最优组合为：酵母提取物13.19g/L、糖蜜476.63g/L和碳酸钙134.82g/L,确定了最适发酵培养基。在此条件下乳酸产量为（145.53±1.24） g/L,与模型预测值147.23g/L接近。本研究为以甘蔗糖蜜为原料生产乳酸提供了技术支持。     

Application of15N-labelled urea to sugar cane through a drip-irrigation system in Mauritius

Nitrogen (N) fertilizer use efficiency by sugar cane in Mauritius rarely exceeds 40%. Since drip-irrigation delivers water uniformly and directly to the root zone with little run-off, application of N via the drip-irrigation system could therefore provide a means of enhancing fertilizer N use by sugar cane.A study was initiated in Mauritius to determine what benefits would accrue from applying urea (120 kg N per ha) to sugar cane through the drip-irrigation network. The data obtained showed that the efficiency of fertilizer N when measured at harvest was nearly doubled by supplying the N daily over 10 to 20 weeks by fertigation. Increased yields of sugar or cane did not, however, accompany the improved N use efficiency. Furthermore, when N was applied through the drip-irrigation network, recovery of N at harvest did not accurately reflect N use efficiency.     

Energy requirements for single cell protein production

The direct and indirect energy inputs to SCP production by microbial fermentations from six different substrates are assessed, together with labour and land area requirements. Future energy savings envisaged with improving technology are described, and found to be of minor significance. From an energy point of view SCP production from hydrocarbon substrates compares most unfavourably with that from carbohydrates, particularly carbohydrate wastes, although the former is less land intensive. Large-scale units give greater protein yields per unit of labour than do small-scale plants. The applicability of SCP to Third World food problems seems limited due to its high energy production requirements.     

利用甘蔗糖蜜半连续发酵生产琥珀酸

为获得较高的琥珀酸发酵产量和生产强度,对Actinobacillus succinogenes CGMCC1593两级双流半连续发酵甘蔗糖蜜生产琥珀酸的工艺过程进行了研究。通过对一级罐初始总糖浓度、补加培养基体积分数和批次发酵时间等发酵条件的优化,琥珀酸产量较分批发酵36 h提高12.9％,与补料分批发酵结果接近;生产强度较分批发酵和补料分批发酵分别提高111％和114%。     

Thermomechanical behavior of poly(vinyl alcohol) and sugar cane bagasse composites

Fibers from renewable resources are gaining interest for use as fillers in hybrid composite materials. Particularly waste material such as sugar cane bagasse offer large availability, biodegradability, and low cost. Influence of single components on composite material properties is an important parameter to be evaluated. Composites of poly(vinyl alcohol) (PVA) at 88 and 98% saponification degrees and sugar cane bagasse (B) were prepared by casting water suspensions of the components and characterized for their dynamic mechanical behavior. The storage modulus below and above the glass transition and the shape of the relaxation process are strongly influenced by the amount of B. Good adhesion was observed at the lignocellulosic fiber–synthetic polymer interface. Urea and glycerol are able to plastify the PVA/B composites thus giving rise to a decrease of the glass transition temperature and to a widening of the glass transition temperature gap. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 426–432, 2004     

Flocculation and sedimentation of cane sugar juice particles with cationic homo‐ and copolymers

Rapid flocculation and sedimentation of suspended particles in primary cane sugar juice is achieved using a high molecular weight anionic polymer flocculant. This work reports on efforts to enhance the performance of an anionic flocculant by the addition of cationic polymers. Homopolymers of poly(trimethylammonium ethyl methacrylate chloride) (TMAEMAC) and cationic copolymers of poly(trimethylammonium ethyl acrylate chloride) (TMAEAC) and acrylamide were synthesized and their performance, to enhance the flocculation and sedimentation of cane sugar juice particles, was evaluated by turbidity and settling rate measurements. The charge–patch mechanism best explains the performance of the homopolymers, whereas the action of the copolymers is attributed to the bridging mechanism. The results of this work indicate that the copolymers are more effective than the homopolymers to aid flocculation and sedimentation of the cane sugar juice particles, and that the best‐performing polymers are those that act by the bridging mechanism. Addition of increased amounts of anionic flocculant did not confer an improvement, suggesting that the cationic bridging flocculant targets a different population of particles that is largely responsible for the residual turbidity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 316–325, 2003     

Continuous process for yeast biomass production from sugar beet stillage by a novel strain of Candida rugosa and protein profile of the yeast

Thermotolerant yeast Candida rugosa isolated from East Africa was used for the continuous production of yeast protein from sugar beet stillages at 40°C. At a dilution rate of 0·15 h⁻¹, biomass productivity was at a maximum (0·85 dm⁻³ h⁻¹) and the Chemical Oxygen Demand reduction rate of the stillage was 30·4%. This yeast contained 45·1% crude protein, 36·5% actual protein and 5·6% RNA. The yeast protein had adequate essential amino acids, except for sulphur-containing types.     

Activated carbon from sugar cane bagasse by carbonization in the presence of inorganic acids

Dried ground bagasse, impregnated with 50% inorganic acids and carbonized at 500°C, showed the sequence H₃PO₄ > H₂SO₄ > HCl > HNO₃, with respect to the efficiency of activation. Treatment with phosphoric acid of various concentrations (30–50 wt%) was followed by carbonization at 300–500°C for 3 h. Pore structure parameters were determined from the low-temperature adsorption of nitrogen, by applying the BET and α_s methods. Activated carbons obtained at low temperatures are essentially microporous with a low degree of mesoporosity. At higher temperatures products of higher surface area and total pore volume with developed mesoporosity and low microporosity are formed. An increase in the period of carbonization leads to a small decrease in both surface area and pore volume. Activated carbons with surface areas > 1000 m² g^?1 and mean pore dimensions around 2·0 nm, suitable for various purposes, are thus obtained.     

Water flux,DSC, and cytotoxicity characterization of membranes of cellulose acetate produced from sugar cane bagasse,using PEG 600

Summary In this article, cellulose acetate produced through the homogeneous acetylation of sugar cane bagasse cellulose was used to produce membranes, using poly(ethyleneglycol) 600 (PEG 600) as an admixture. The membranes were characterized using water flux measurements (Payne’s cup), differential scanning calorimetry (DSC) and neutral red uptake (cytotoxicity). The results showed that PEG 600 acts as a crystallinity inductor and/or pore former in the cellulose acetate matrix. The induction of crystallinity is important for this system since it had not been reported on the literature yet. The results also demonstrated that the studied membranes present a nontoxic behavior.     

甘蔗渣接枝技术研究进展

甘蔗渣（SCB）作为一种重要的植物纤维,是可再生资源,其接枝技术日益受到重视。本文先介绍了SCB的结构、物理化学性质以及接枝机理,再重点评述了预处理方式、不同的接枝单体和溶剂、引发方式对SCB接枝的影响。预处理破坏了SCB的超分子结构从而提高SCB的反应可及性;一般溶剂不能破坏SCB的多相结构,反应在SCB表面进行,纤维素溶剂和一些二元体系溶剂可溶解SCB而实现分子水平上的接枝;引发剂浓度对接枝率的提高有一个最佳范围;接枝单体用量直接影响接枝率。最后指出SCB接枝物在离子交换、重金属离子吸附、吸油和吸水保水等方面的应用前景,并建议SCB接枝技术应向着接枝效率高、接枝物性能稳定、工艺绿色环保和开发成本低等方向发展。     

Insect cell cultivation techniques for the production of high-valued products

The large scale cultivation of insect cells will likely play an increasingly important role for the commercial production of bioproducts. While much research work has been done on the engineering aspects of insect cell suspension culture, many questions remain unanswered (i.e. the nature of bubble damage in sparged reactors, shear sensitivity and adaptation of cells; the use of serum-free medium). In addition, insect cell immobilization may become a suitable technique for enhancing cell densities and product concentrations. This article presents a brief critical review of the development of insect cell suspension culture techniques for the production of insect pathogenic viruses and recombinant proteins.The problems of culturing microencapsulated insect cells, infected with a temperature sensitive baculovirus, also is discussed.     

酒糟沼气化利用的基础研发

酒糟是酒精工业和酿酒工业的废弃物,通过厌氧发酵不仅可以解决酒糟废弃物污染的问题,还可以提供能源,并且经厌氧发酵后的沼液、沼渣还可以用作生物肥。开展了中温（37℃）条件下的酒糟厌氧发酵产生沼气研究,并分析了厌氧发酵前后物料组成变化及酒糟沼液作为生物液态肥的可行性。结果表明：四种酒糟的沼气产量从高到低依次为玉米燃料乙醇酒糟、酱香型白酒酒糟、浓香型白酒酒糟、木薯燃料乙醇酒糟,对应的产气量分别为607.4、578.7、434.2、122.3 ml·g^-1（以VS计）;各酒糟厌氧发酵产沼气的甲烷体积分数均在60%～70%之间;酒糟的沼气产量与其VS降解率呈正比;酒糟发酵液各元素及离子含量符合生物液态肥标准,是一种很好的生物液态肥原料。     

Design and planning of infrastructures for bioethanol and sugar production under demand uncertainty

In this paper, we address the strategic planning of integrated bioethanol–sugar supply chains (SC) under uncertainty in the demand. The design task is formulated as a multi-scenario mixed-integer linear programming (MILP) problem that decides on the capacity expansions of the production and storage facilities of the network over time along with the associated planning decisions (i.e., production rates, sales, etc.). The MILP model seeks to optimize the expected performance of the SC under several financial risk mitigation options. This consideration gives a rise to a multi-objective formulation, whose solution is given by a set of network designs that respond in different ways to the actual realization of the demand (the uncertain parameter). The capabilities of our approach are demonstrated through a case study based on the Argentinean sugarcane industry. Results include the investment strategy for the optimal SC configuration along with an analysis of the effect of demand uncertainty on the economic performance of several biofuels SC structures.     

Thermochemical characteristics of sugar cane bagasse pellets

Pelletisation facilitates utilisation of sugar cane bagasse as a fuel and storage for year-round electricity generation. The present work determines thermochemical characteristics of bagasse pellets of different sizes and origins, using various temperatures (600, 750 and 900 °C) and gas flow rates (4, 7 and 10 L/min) with varying concentrations of oxygen (5, 10 and 15%) in mixtures with nitrogen. Of major interest are the effects of raw material, origin and size of pellets, and the treatment conditions on the rate of pyrolysis and the structure and reactivity of char in combustion. The char yield of the larger pellets of high-ash content bagasse was practically independent of treatment conditions. Smaller pellets gave better mechanical stability of the char but lower reactivity.