美国生物燃料乙醇生产近况

生物燃料乙醇生产原料可以是玉米、高梁、小麦、大麦、甘蔗、甜菜和土豆等,另外纤维质原料如城市垃圾、甘蔗渣、小树干、木片等都可用来生产生物燃料乙醇,但这些应用还没有商业化.美国生产生物燃料乙醇基本上采用玉米,也利用一部分高梁,美国生物燃料乙醇工业正在以前所未有的速度发展.     

纤维素乙醇生产原料的综合评定

木质纤维素是地球上最丰富而且被利用率最低的可再生资源,可用作生产洁净能源——燃料乙醇。自然界蕴含着的丰富的天然木质纤维质原料,例如:玉米秸秆、玉米芯、甘蔗渣、红麻等均可作为燃料乙醇的生产原料,具有极为广阔的前景。通过实验对比详细阐述这四种纤维素质原料生产纤维素乙醇的技术过程及原料利用价值分析。     

甘蔗渣生产燃料乙醇技术研究现状与展望

甘蔗渣是制糖工业的主要副产物,将其生产成燃料乙醇具有广阔的应用前景。本文重点介绍了近年来国内外有关甘蔗渣燃料乙醇过程中的预处理、纤维素水解、净化、发酵等工艺的最新研究进展。希望能为甘蔗渣燃料乙醇产业的发展提供一些帮助。     

云南省甘蔗渣资源及综合利用现状

估算云南省甘蔗渣资源量,综述了云南甘蔗渣废弃物资源综合利用现状：直接燃烧、造纸及生产燃料乙醇等,同时提出了甘蔗渣资源利用的建议。     

行业动态

从废物中“酿酒”农林废弃物制取燃料乙醇技术近日在上海取得明显成果,开始进入工业性试验阶段。目前,在我国燃料乙醇的生产均以糖类或粮食为原料,难以长期满足能源需求。含木质纤维素的生物质废弃物是生产燃料乙醇的另一原料来源,包括农作物秸秆、林业加工废料、甘蔗渣及城市垃圾中所含的废弃生物质等。据介绍,我国的生物质资源相当丰富,每年产生的秸秆就有7.2亿吨。生物质作为惟一可转化液体燃料的可再生资源,正日益受到重视。美国每年用于汽油添加剂的乙醇消耗约12亿加仑。巴西汽车普遍使用酒精和汽油的混合燃料或100%的燃料乙醇,泰国和…     

浅谈甘蔗汁的产品开发及应用

当前,甘蔗的主要工业产品是蔗汁制糖、甘蔗渣造纸及糖蜜发酵生产酒精,产品较为单一,而且能耗较大。为了增加蔗糖企业的产品种类,提高市场竞争力和经济效益,简要论述以甘蔗汁为原料,在饮料、发酵、生产燃料乙醇及提取生物活性物质等方面的产品开发及应用。     

同步糖化技术在燃料乙醇生产中的工程应用

国内燃料乙醇市场需求增长迅猛,用粮食作为主要发酵原料生产的燃料乙醇比例将逐年降低,木薯燃料乙醇生产技术逐步得到推广.通过介绍木薯燃料乙醇传统糖化工艺与同步糖化生产技术,为下一步能量综合利用的研究做铺垫.     

甘蔗渣资源利用现状与高值化利用途径

甘蔗渣是制糖工业副产物,也是一种产量丰富、可再生的生物质资源。我国绝大多数甘蔗渣被直接用作生物质燃料或生产纸浆的原料,产生的经济效益比较有限。本文就甘蔗渣在制备纸浆和生物质燃料等传统领域的利用现状进行了分析与讨论,提出了存在的主要问题。在此基础上,归纳了近年来以甘蔗渣为原料,在制备低聚糖、纳米纤维素、碳量子点以及活性炭新型高值化产品等领域的研究进展,并提出了甘蔗渣资源梯度、多值化、高值化综合利用策略,为甘蔗渣高值化产品的产业化提供一定参考。     

燃料乙醇生产原料筒仓储存的运用研究

燃料乙醇生产通常使用薯类和谷类为原料.为了实现大规模生产,节约原料及其占地面积,提高机械化和自动化程度,引进了谷类原料的筒仓储存系统.筒仓储存系统的运用改变了原来原料进入生产线时人工袋装上垛、人工倒料的生产模式,给燃料乙醇生产带来了诸多好处.在燃料乙醇生产中随着其他生物质原料(如秸秆和薯类原料等)的采用,筒仓储存系统的应用范围进一步拓宽.     

不同淀粉质原料发酵生产燃料乙醇

自2017年,十五部委联合印发《关于扩大生物燃料乙醇生产和推广使用车用乙醇汽油的实施方案》推广使用车用燃料乙醇方案以来,我国燃料乙醇行业进入了快速发展的阶段。为减少以玉米为原料生产燃料乙醇而产生的"与人争粮"情况,开发不同淀粉质原料生产燃料乙醇具有重要意义。同时,为响应国家粮食"去库存"政策,将陈化水稻作为燃料乙醇生产的原料,开发其生产工艺具有重要意义。本文探讨了除玉米以外的其他多种淀粉质作物作为原料生产燃料乙醇的可行性,包括陈化水稻、脱壳大米及木薯等,并进行不同原料的复配,对原料使用及发酵结果进行分析讨论,以期为燃料乙醇生产工艺提供一定借鉴。     

甘蔗渣的糖化及转化为酒精的研究概况

生物质转化为能源的重点和难点，集中于纤维类物质的转化利用，蔗渣用于生产酒精具较好的发展前途，本文从蔗渣的化学结构出发，阐述了蔗渣分解，糖化及转化为酒精的机理及研究概况，具有重要的现实意义。     

Comparative Production of Sugarcane Vinegar by Different Immobilization Techniques

Sugarcane juice was converted to ethanol by Saccharomyces cerevisiae producing 8% (v/v) ethanol. This ethanol was used for vinegar production using adsorbed (bagasse, corn cobs and wood shavings) and entrapped (calcium alginate) cells of Acetobacter aceti NRRL 746. All three adsorbed carrier materials were statistically similar for acetic acid production and produced acidity from 5.9 to 6.7% after 28 days of submerged fermentation. By recycling bagasse adsorbed cells, the time of acetic acid fermentation was reduced to 13 days. Semi‐continuous fermentation of bagasse adsorbed cells using a packed bed column further reduced the fermentation time to 80 h.     

利用甘蔗渣制备羟甲基纤维素的工艺研究

本文采用甘蔗渣为原料，经单一态氧漂白，在乙醇溶剂中与氢氧化钠、氯乙酸反应，制备了羟甲基纤维素。讨论了反应温度、时间及物料配比对产品性能的影响。确定了最佳反应条件。     

Bioethanol production from ball milled bagasse using an on-site produced fungal enzyme cocktail and xylose-fermenting Pichia stipitis

Sugarcane bagasse is one of the most promising agricultural by-products for conversion to biofuels. Here, ethanol fermentation from bagasse has been achieved using an integrated process combining mechanical pretreatment by ball milling, with enzymatic hydrolysis and fermentation. Ball milling for 2 h was sufficient for nearly complete cellulose structural transformation to an accessible amorphous form. The pretreated cellulosic residues were hydrolyzed by a crude enzyme preparation from Penicillium chrysogenum BCC4504 containing cellulase activity combined with Aspergillus flavus BCC7179 preparation containing complementary β-glucosidase activity. Saccharification yields of 84.0% and 70.4% for glucose and xylose, respectively, were obtained after hydrolysis at 45 °C, pH 5 for 72 h, which were slightly higher than those obtained with a commercial enzyme mixture containing Acremonium cellulase and Optimash BG. A high conversion yield of undetoxified pretreated bagasse (5%, w/v) hydrolysate to ethanol was attained by separate hydrolysis and fermentation processes using Pichia stipitis BCC15191, at pH 5.5, 30 °C for 24 h resulting in an ethanol concentration of 8.4 g/l, corresponding to a conversion yield of 0.29 g ethanol/g available fermentable sugars. Comparable ethanol conversion efficiency was obtained by a simultaneous saccharification and fermentation process which led to production of 8.0 g/l ethanol after 72 h fermentation under the same conditions. This study thus demonstrated the potential use of a simple integrated process with minimal environmental impact with the use of promising alternative on-site enzymes and yeast for the production of ethanol from this potent lignocellulosic biomass.     

Sequential high pressure extractions applied to recover piceatannol and scirpusin B from passion fruit bagasse

Passion fruit seeds are currently discarded on the pulp processing but are known for their high piceatannol and scirpusin B contents. Using pressurized liquid extraction (PLE), these highly valuable phenolic compounds were efficiently extracted from defatted passion fruit bagasse (DPFB). PLE was performed using mixtures of ethanol and water (50 to 100% ethanol, w/w) as solvent, temperatures from 50 to 70 °C and pressure at 10 MPa. The extraction methods were compared in terms of the global yield, total phenolic content (TPC), piceatannol content and the antioxidant capacity of the extracts. The DPFB extracts were also compared with those from non-defatted passion fruit bagasse (nDPFB). Identification and quantification of piceatannol were performed using UHPLC–MS/MS. The results showed that high TPC and piceatannol content were achieved for the extracts obtained from DPFB through PLE at 70 °C and using 50 and 75% ethanol as the solvent. The best PLE conditions for TPC (70 °C, 75% ethanol) resulted in 55.237 mg GAE/g dried and defatted bagasse, whereas PLE at 70 °C and 50% ethanol achieved 18.590 mg of piceatannol/g dried and defatted bagasse, and such yields were significantly higher than those obtained using conventional extraction techniques. The antioxidant capacity assays showed high correlation with the TPC (r > 0.886) and piceatannol (r > 0.772). The passion fruit bagasse has therefore proved to be a rich source of piceatannol and PLE showed high efficiency to recover phenolic compounds from defatted passion fruit bagasse.     

Production of coumaric acid from sugarcane bagasse

Phenolic acids were released from sugarcane bagasse by alkaline hydrolysis at 30 °C for 4 h; The alkaline hydrolysates were ultrafiltrated, the permeates purified with anion exchange resin. The phenolic acids bound by the resin were desorbed by a mixture of water–ethanol–HCl solution (36: 60: 4) after washing the resin with water, ethanol and dilute HCl respectively. The combined eluents were concentrated for crystalization, and the crystals filtered and washed using 1% (v/v) HCl. After this purification process, the purity of products reached 89.7% based on coumaric acid. Results of HPLC/MS, HPLC using standard coumaric acid and ferulic acid showed that the main component of the purified bagasse hydrolysate was p-coumaric acid rather than ferulic acid. The purified products showed the same antioxidant activity, reducing power and free radical scavenging capacity as the standard p-coumaric acid.The technology could be applied on industrial scale.Industrial relevanceThis research presents a technology to produce coumaric acids from sugarcane bagasse. The first step is to release coumaric acid by alkaline hydrolysis. The second step is to remove the viscous polysaccharides and protein by ultrafiltration. The third step is to purify coumaric acid from the permeate of ultrafiltration by anion chromatography, and the alkaline could be reused to hydrolyze the bagasse. The technology showed potential application on industrial scale.     

甘蔗渣纤维表面Zeta电位变化特性及其对酶水解效果的影响

将纤维素原料降解为可发酵糖是木质纤维素生物质生物转化乙醇过程中的重要环节,通过对原料的预处理可以提高纤维素酶的催化效率.本文通过改变甘蔗渣纤维的尺寸、添加多聚磷酸盐等方法,发现均能改变蔗渣纤维的表面Zeta电位.初步研究了其Zeta电位变化规律及Zeta电位的变化对纤维素酶水解效果的影响,并对Zeta电位的变化影响纤维...     

同时酶解发酵(SSF)转化造纸厂废细小纤维为酒精

<正> 发酵法生产酒精主要以糖蜜和淀粉质谷物为原料。从开辟新能源和解决环境污染考虑,以废纤维为原料生产酒精的研究近年来日益受到重视。主要有两种方法,一是用两类厌氧纤维素细菌直接发酵纤维废物为酒精;另为用纤维素酶酶解纤维素废物为葡萄糖后再经酵母发酵为酒精。前者方法较简单,但终产物中酒精所占的比例较低,后者遇到的困难主要是纤维素分解微生物和酵母菌发酵之间,所需条件不一。两类方法都是只适用于已经化学预处理脱去木质素的纤维材料,预处理费用高和同时伴有环境污染使此项技术至今还未能     

Evaluation of Ammonia Pretreatment for Enzymatic Hydrolysis of Sugarcane Bagasse to Recover Xylooligosaccharides

Sugarcane bagasse is a useful biomass resource. In the present study, we examined the efficacy of ammonia pretreatment for selective release of hemicellulose from bagasse. Pretreatment of bagasse with aqueous ammonia resulted in significant loss of xylan. In contrast, pretreatment of bagasse with anhydrous ammonia resulted in almost no xylan loss. Aqueous ammonia or anhydrous ammonia-pretreated bagasse was then subjected to enzymatic digestion with a xylanase from the glycoside hydrolase (GH) family 10 or a xylanase from the GH family 11. The hydrolysis rate of xylan in bagasse pretreated with aqueous ammonia was approximately 50 %. In contrast, in the anhydrous ammonia-treated bagasse, xylan hydrolysis was > 80 %. These results suggested that anhydrous ammonia pretreatment would be an effective method for preparation of sugarcane bagasse for enzymatic hydrolysis to recover xylooligosaccharides.