Valorization of Camellia oleifera oil processing byproducts to value-added chemicals and biobased materials: A critical review

The C.oleifera oil processing industry generates large amounts of solid wastes,including C.oleifera shell(COS)and C.oleifera cake(COC).Distinct from generally acknowledged lignocellulosic biomass(corn stover,bamboo,birch,etc.),Camellia wastes contain diverse bioactive substances in addition to the abundant lignocellulosic components,and thus,the biorefinery utilization of C.oleifera processing byproducts involves complicated processing technologies.This reviewfirst summarizes various technologies for extracting and converting the main components in C.oleifera oil processing byproducts into value-added chemicals and biobased materials,as well as their potential applications.Microwave,ultrasound,and Soxhlet extractions are compared for the extraction of functional bioactive components(tannin,flavonoid,saponin,etc.),while solvothermal conversion and pyrolysis are discussed for the conversion of lignocellulosic components into value-added chemicals.The application areas of these chemicals according to their properties are introduced in detail,including utilizing antioxidant and anti-in-flammatory properties of the bioactive substances for the specific application,as well as drop-in chemicals for the substitution of unrenewable fossil fuel-derived products.In addition to chemical production,biochar fabricated from COS and its applications in thefields of adsorption,supercapacitor,soil remediation and wood composites are comprehensively reviewed and discussed.Finally,based on the compositions and structural characteristics of C.oleifera byproducts,the development of full-component valorization strategies and the expansion of the appli-cationfields are proposed.

Effects of the <i>Camellia oleifera </i>Shell Substrate on the Yield and Nutritional Composition of <i>Pleurotus geesteranus</i>

Pleurotus geesteranus was cultivated on the substrates blended with different ratios of treated and untreated Camellia oleifera shells using cottonseed hull as the control substrate. The mycelial growth rate, yield, nutritional composition, ash and heavy metals of the Pleurotus geesteranus cultivated on these substrates were compared. The results suggest that the Camellia oleifera shell in substrate can accelerate the mycelial growth and increase the yield, nutrients and the contents of protein, ash, crude fiber and amino acid of Pleurotus geesteranus. It was found that the contents of tannin and saponin in Camellia oleifera shell affected the mycelial growth rate. The optimal C/N of the substrate for the growth of Pleurotus geesteranus was determined to be 27 ± 0.7. The C/N ratios higher than 30 reduced the protein, fat and soluble sugar contents of the cultivated Pleurotus geesteranus. The contents of heavy metals including Hg, As, Cd and Pb were found in Pleurotus geesteranus cultivated on the substrates containing Camellia oleifera shell complex.

Infrared-Spectral Characteristics of <i>Camellia oleifera</i>Shell/Meal during Composting

The compost products of Camellia oleifera shell/meal mixed at different mass ratios were characterized by Fourier-transform infrared spectroscopy (FTIR) at different composting stages to monitor the structural changes of their components. The results showed that the amount of Camellia oleifera meal significantly affected the composting rate of the shell, but did not change the degradation order and decomposition of the related compounds. During the composting process, microorganisms used the highly decomposable carbon source materials, such as proteins and sugars, first to grow and multiply, and then decomposed hemicellulose, cellulose and lignin by oxidative cleavage after these nutrients were consumed to a certain extent. The decomposition products were then condensed into more stable humic acids. The degradation rates of the compounds were directly proportional to the amount of Camellia oleifera?meal. The compounds in Camellia oleifera shell were composted faster with higher amounts of Camellia oleifera meals, resulting in less lignocellulose in the final products.

Coating of Mineral Acids with Niobic Solid Acid for Preparing Furfural from Nut Shell of Camellia oleifera Abel

Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of which is as much as 16% (based the dried nut shell). In early time, mineral acids were employed as typically catalyst for preparing of furfural from the nut shells. These mineral acids could pollute water and corrode equipment. In this paper we used various mineral acids coating with niobic acid as catalysts to investigate reactions for preparation of furfural. Among these catalysts, the catalyst of sulfuric acid coating with niobic acid was found to be very effective, which had higher hammett acidity and better effect of hydrolysis of the nut shells;The catalysts of sulfuric acid coating with niobic acid was characterized, and the conditions of preparation of the catalyst were investigated. The optimum conditions were: sulfuric acid as coating acid, the concentration of sulfuric 1.1 mol/L, impregnation time 8 h, calcination time 8 h and calcination temperature 450°C. Then hydrolysis of the nut shells was explored, the optimum conditions were as follows: dose of catalyst 20%, ratio of solid to liquid 1:15, reaction temperature 100°C, reaction time 4 h;Under this condition, the yield of furfural was 8.7%.

γ射线辐照协同水热处理制备油茶壳低聚木糖的工艺研究

为采用低成本、可再生的农林生物质制备高价值低聚木糖以提升木质纤维素生物炼制经济效益,本研究以茶油加工副产物油茶壳为原料,选择吸收剂量(A)、水热处理温度(B)、水热处理时间(C)和固液比(D)4个因素,以低聚木糖转化率为评价指标,通过单因素和正交试验优化γ射线辐照协同水热处理油茶壳制备低聚木糖的工艺条件。单因素试验结果表明,油茶壳低聚木糖转化率随吸收剂量、固液比的增加而逐渐升高,随着水热处理温度的升高、反应时间的延长呈先升高后降低趋势。正交试验优化得出,各因素对油茶壳低聚木糖转化率影响的主次顺序为A>B>D>C,综合考虑确定最优工艺条件为A_(2)B_(3)C_(1)D_(2),即吸收剂量400 kGy、水热处理温度200℃、水热处理时间20 min、固液比1∶10 g·mL^(-1),此条件下的油茶壳制备低聚木糖转化率为74.33%,比对照提高22.61个百分点。本研究为油茶壳资源高值化制备低聚木糖提供了技术参考。

油茶蒲黄酮的制备及组分鉴定

为促进油茶蒲的高值化开发利用,推动油茶产业高质量发展,以油茶蒲为原料,采用超声辅助醇提法制备油茶蒲粗黄酮,并采用AB-8大孔树脂吸附法纯化。另外,对纯化的油茶蒲黄酮的结构进行了紫外光谱和红外光谱表征,利用UPLC-Q-TOF-MS对其组分进行了鉴定。结果表明:采用超声辅助醇提法制备的油茶蒲粗黄酮中黄酮含量为32.41%,采用AB-8大孔树脂纯化后的黄酮含量为70.14%,黄酮总回收率为60.12%;紫外光谱与红外光谱分析表明,纯化物具有明显的黄酮类紫外、红外特征光谱,证明该纯化物主要成分为黄酮类化合物;UPLC-Q-TOF-MS从该纯化物中共鉴定出44种多酚类和黄酮类化合物,其中14种黄酮类化合物、30种多酚类化合物,油茶蒲黄酮多以黄酮苷类化合物形式存在,且多为山奈酚的糖苷类化合物,油茶蒲黄酮中含有原花青素、儿茶素、表儿茶素及没食子酸等抗氧化活性成分。根据油茶蒲黄酮的组成成分,推测其具有开发成为抗糖尿病食品以及与抗癌药物联用治疗疾病的潜力。

油茶壳堆肥用量对土壤肥力及苦麦菜生长与品质的影响

【目的】探明腐熟油菜壳有机肥不同施用量对土壤理化性质及苦麦菜生长与品质的影响,为油茶壳资源化利用及有机肥的合理施用提供依据。【方法】以苦麦菜为试验材料,设置不同油茶壳有机肥用量水平,采用田间小区试验(CK1:不施底肥;T1:常规施肥,复合肥450 kg/hm^(2);T2:油茶壳有机肥7500 kg/hm^(2);T3:油茶壳有机肥15000 kg/hm^(2);T4:油茶壳有机肥22500 kg/hm^(2);T5:复合肥360 kg/hm^(2)+油茶壳有机肥15000 kg/hm^(2))和盆栽试验(CK2:不施肥;P1:常规施肥,复合肥225 kg/hm^(2);P2:油茶壳有机肥3750 kg/hm^(2);P3:油茶壳有机肥7500 kg/hm^(2);P4:油茶壳有机肥11250 kg/hm^(2);P5:复合肥180 kg/hm^(2)+油茶壳有机肥7500 kg/hm^(2)),共12个处理,研究腐熟油茶壳有机肥不同施用量对土壤理化性质及苦麦菜生长与品质的影响。【结果】田间和盆栽试验下,施用油茶壳有机肥总体上能提升土壤养分。各处理土壤pH为5.92~6.89,施用油茶壳有机肥和复合肥减量配施处理的土壤有机质、有效磷、速效钾含量较未施肥处理总体增加,水解性氮含量与常规施肥处理间无显著差异,其中,田间试验有机质、有效磷和速效钾含量分别为33.13~43.94 g/kg、43.39~162.61 mg/kg和247.00~667.69 mg/kg,盆栽试验分别为12.44~38.32 g/kg、1.17~344.79 mg/kg和41.79~1889.03 mg/kg。田间试验施用油茶壳有机肥22500 kg/hm^(2)和盆栽试验施用油茶壳有机肥7500 kg/hm^(2)时,苦麦菜株高和地上部鲜重分别为43.42 cm、116.25 g和40.25 cm、73.76 g,显著高于未施肥和常规施肥处理。田间试验苦麦菜可溶性糖、维生素C、叶绿素和蛋白质含量分别为0.34~0.67 g/100g、13.52~19.23 mg/100g、1.06~1.52 mg/g和0.91~1.29 g/100g,盆栽试验分别为0.65~1.64 g/100g、13.75~29.44 mg/100g、0.99~1.36 mg/g和1.25~2.51 g/100g。施用适量油茶壳有机肥或复合肥减量配施的苦麦菜可溶性糖、维生素C和叶片叶绿素含量高于常规施肥处理,未施肥处理苦麦菜的蛋白质含量显著高于其余处理。【结论】综合苦麦菜的生长和品质性状,油茶壳有机肥以田间施肥量22500 kg/hm^(2)和盆施肥量7500 kg/hm^(2)为宜。

K_(2)CO_(3)活化法油茶果壳活性炭的制备及表征

以油茶果壳(COS)为原料,K_(2)CO_(3)为活化剂,分别在空气和氮气中活化制备COS活性炭,探讨了活化温度、活化时间和K_(2)CO_(3)溶液浸渍COS的比例(浸渍比,mL∶g)对活性炭制备的影响,利用元素分析、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)等手段对活性炭进行了表征。研究结果表明:在空气中活化,浸渍比值为1.5,温度为800℃,炭化活化时间为1 h的条件下,制得的活性炭得率为12.48%,BET比表面积为1080.94 m^(2)/g,亚甲基蓝(MB)吸附值为441.62 mg/g;在氮气中活化,浸渍比值为2.5,温度为800℃,炭化活化时间为1 h时,制得的活性炭得率为18.00%,BET比表面积为942.42 m^(2)/g,MB吸附值为428.77 mg/g。元素分析结果表明氮气气氛下制备的活性炭H/C元素比低,芳香性提高;FT-IR和SEM分析表明活化促进了活性炭—CH、—COOH热解和孔隙生长;相比N_(2)气氛下的样品,空气作热解气制备的活性炭孔隙更发达,吸附性能更好。

10t/d双螺杆榨油机压榨油茶籽的工艺研究

为提高油茶籽油的品质,减少传统油茶籽制油工艺对油茶籽油的营养成分损失,对日处理10t双螺杆榨油机压榨油茶籽的工艺进行了研究。结果表明,最佳工艺条件为:油茶籽经过分级处理后入榨油茶仁水分控制在9%、油茶仁中含壳控制在8%时,压榨饼中残油率为2.49%,且产品符合一级油的国家标准。与市场上销售的油茶籽油相比,通过本工艺获得的油茶籽油中α-生育酚的保留率更高,从而进一步提高油茶籽油的营养价值,可为我国油茶籽油的高值化加工提供了技术参考。

高填充油茶果壳基木塑复合材料的制备及力学性能

以油茶果壳和不同塑料即聚丙烯、高密度聚乙烯(PE-HD)、低密度聚乙烯、线性低密度聚乙烯为原料,采用模压成型的方法制备了高填充油茶果壳基木塑复合材料,利用电子万能试验机和悬臂梁冲击试验机测试其力学性能。通过单因素试验分析塑料种类对复合材料力学性能的影响,确定较优塑料种类后进一步优化制备参数。以壳粉含量、增容剂马来酸酐接枝聚乙烯(MAPE)含量、热压温度、热压时间为设计因素,以弯曲强度、弯曲弹性模量、拉伸强度、冲击强度为力学性能优化目标,设计L_(9)(3^(4))正交试验,研究了高填充油茶果壳基木塑复合材料的制备工艺,利用极差分析和方差分析得到了较优配方和工艺参数组合。研究表明:当添加塑料为PE-HD时,复合材料的弯曲强度最大为34.40 MPa,拉伸强度最大为18.20 MPa,力学性能较优;壳粉含量为65%时,添加7%MAPE的复合材料强度较好,弯曲强度最大为33.66 MPa;优化制备参数组合为壳粉含量55%,MAPE含量5%,热压温度160℃,热压时间10 min。

市政污泥与油茶壳混合燃烧特性研究

采用热重分析法研究掺混比和升温速率对市政污泥和油茶壳混燃特性的影响,使用FlynnWall-Ozawa(FWO)和Kissinger-Akahira-Sunose(KAS)2种方法对样品的燃烧动力学进行建模,计算了各类样品的稳燃性指数和综合燃烧特性指数,分析了燃烧过程中混合燃料成分间的交互作用。结果表明:污泥掺混油茶壳后,混合燃料的燃尽温度明显降低,燃烧稳定性能和综合燃烧特性有明显改善;随着油茶壳掺混质量比从20%升至80%,燃尽温度从590℃下降到532℃,燃尽程度也逐渐变大,失质量由63.13%增加到92.19%,稳燃性指数和综合燃烧特性指数分别增加1.66和2.32倍;随着升温速率的增加,混合样品的燃尽温度、稳燃性指数和综合燃烧特性指数均提高,而燃尽程度变小,且着火温度无明显变化;污泥与油茶壳混合燃烧各组分间发生了交互现象,在挥发分燃烧阶段表现为抑制作用,而固定碳燃烧阶段表现为促进作用;FWO法和KAS法计算污泥的平均表观活化能分别为122.32、118.08 k J/mol,油茶壳的平均表观活化能分别为166.46、164.94 k J/mol,混合样品的平均表观活化能随着油茶壳掺混质量比的增加而增大。

油茶果壳生物基材料研究进展及展望

油茶作为木本食用油料树种在南方各省被广泛种植,其加工剩余物油茶果壳若未合理有效利用,将对空气、水体等生态造成污染。油茶果壳富含中孔结构,用其制备活性炭,可用于吸附或电池、电极与电容器领域;油茶果壳去除木质素得到的综纤维素,可制备综纤维素膜材料或纳米纤维素膜材料,用于包装、纺织和医疗等领域;油茶果壳富含木质素及茶皂素等天然活性物质,可制备油茶果壳基树脂用作做胶合材料并具有耐恶劣气候及阻燃等特性;油茶果壳经热压工艺制备刨花板,可用于家具及建筑等领域;油茶果壳作为增强相与塑料复合制备木塑复合材料,可用于园林和室内装潢等领域。本文综述了油茶果壳在上述领域的研究进展,并对油茶果壳生物基材料提出了展望。

油茶壳基载镧磁性生物炭的制备及其吸附性能初探

针对油茶产业的副产物油茶壳随意丢弃造成环境污染和资源浪费的问题,本研究通过热解法和共沉淀法等物理化学过程,将油茶壳资源化利用制备成水处理吸附剂,并选用典型的有机染料甲基橙(MO)为吸附对象,对制备的油茶壳基载镧磁性生物炭吸附剂的吸附性能进行考察。结果表明,制备的载镧磁性生物炭磁化强度达到13.17 emu/g,具有良好的磁性分离效果,其对甲基橙的最大吸附容量可达2.62 mg/g,表明将油茶壳资源化制备为水处理吸附剂具有良好的前景。

FTIR and Thermogravimetric Analysis of Three Kinds of Nutshells

The main components and pyrolysis characteristics of Camellia oleifera Abel hells, Castanea mollissima Blume shells, and Castanea mollissima Blume shells were analyzed by using FTIR and thermogravimetric methods. The experimental results indicated that the main components of the three kinds of raw materials consisted of cellulose, hemicellulose, and lignin. The highest contents of hemicellulose, cellulose, and lignin were in Camellia oleiferaAbel shells (49.34% ± 0.07%), Castanea mollissima Blume shells (27.34% ± 0.01%), and Carya cathayensis Sarg shells (49.78% ± 0.01%), respectively. The pyrolysis processes of three kinds of shells generally included three stages, namely dehydration, pyrolysis, and carbonization. The peak values and the appearance times of their pyrolysis rates were closely related to their compositions.

Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural

In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.

油茶鲜果预处理方式对低温压榨油茶籽油品质的影响

为更多地保留活性成分,提高油茶籽油品质,研究了油茶鲜果6种不同预处理方式(剥壳-摊晒、直接摊晒、堆沤-摊晒、剥壳-烘干、直接烘干、堆沤-烘干)对油茶籽主要成分以及低温压榨油茶籽油中3种理化指标(酸值、过氧化值、多环芳烃)和4种微量活性成分(维生素E、维生素K_(1)、角鲨烯、多酚)的影响。结果表明:油茶鲜果预处理方式对油茶籽主要成分(脂肪、蛋白质、淀粉)影响不大;6种不同预处理方式对低温压榨油茶籽油的理化指标和微量活性成分均有一定的影响,其中剥壳-烘干处理油茶鲜果在油茶籽油的酸值、多环芳烃、维生素E、角鲨烯指标上较其他预处理方式存在一定优势。综上,采用剥壳-烘干对油茶鲜果进行预处理,可在一定程度上提高油茶籽油品质。

油茶果壳制备缓冲包装材料的动态力学性能研究

以油茶果壳为原料,选择不同质量分数的塑化剂、胶黏剂、发泡剂、填料等助剂,制备缓冲包装材料,采用正交试验的方法,利用动态热机械分析仪进行动态力学性能分析,确定最佳工艺条件.结果表明,助剂的质量分数对包装材料的性能影响较大,其最佳工艺条件为:塑化剂、胶黏剂、发泡剂、填料占油茶果壳的质量分数为12%、9%、8%、6%.在最佳工艺条件下,其密度、应变、可恢复形变、蠕变特性等性能均有所提高.

Si含量对油茶果壳基SiC陶瓷的结构及性能影响

以油茶果壳、硅粉和酚醛树脂为原料,经热压成型、高温原位反应烧结工艺制备油茶果壳基SiC陶瓷。采用热重-示差扫描量热(thermogravimetric-differential scanning calorimetry, TG-DSC)分析研究油茶果壳粉和酚醛树脂的裂解行为;通过X射线衍射仪、扫描电子显微镜、三点弯曲法和阿基米德排水法表征SiC陶瓷物相组成和微观组织,分析SiC陶瓷的抗压强度和孔隙率,基于表征分析结果探讨Si含量对油茶果壳基SiC陶瓷物相组成、微观结构、抗压强度和孔隙率的影响。结果表明:油茶果壳基SiC陶瓷由主晶相β-SiC和游离的Si组成,孔隙结构发达,孔洞呈蜂窝状,大小均匀,孔隙率高(>50%),抗压强度良好(12~18 MPa),随Si含量的增加,孔隙率与抗压强度先增大后减小。

油茶壳-鸡粪堆肥化发酵特性及其腐熟度评价

采用好氧堆肥方式,研究油茶壳-鸡粪堆肥过程中温度、pH值、CEC、C/N、NH_(4)^(+)-N、NO_(3)^(-)-N、GI等指标变化,并选取高温持续时间、C/N降幅、种子发芽指数为评价指标,运用灰色关联分析法对堆肥的腐熟度进行综合评价。结果显示:(1)添加鸡粪和有机物料腐熟剂能够加快油茶壳堆肥腐熟进程,其最高温度、高温持续时间、pH值、CEC均高于对照(纯油茶壳);(2)对照和油茶壳-鸡粪2个处理的C/N均随堆肥进程逐渐下降,试验结束时2个处理的C/N分别为75和12,降幅分别达到了37.0%和58.6%;(3)与对照处理的NH_(4)^(+)-N、NO_(3)^(-)-N和GI变化平缓不同,油茶壳-鸡粪处理NH_(4)^(+)-N在堆肥前期较高,中后期显著降低,N、NO_(3)^(-)-N则随发酵进程总体上呈上升趋势,且发酵后GI较高,对植物毒性较小;(4)灰色关联分析结果显示,油茶壳-鸡粪堆肥经过48d后达到完全腐熟,而对照未腐熟。综上所述,添加鸡粪和有机物料腐熟剂能有效提高堆体微生物活性,加速堆肥进程,使物料达到更好的腐熟效果。

基于油茶果壳的络合生物质对水中氨氮的吸附特性及机制

传统生物质去除废水中氨氮效果差,常需将其改性生成生物炭或活性炭等作为吸附剂来提高吸附性能。油茶果壳(Camellia oleifera shell,COS)是一种富含单宁酸的天然生物质,将其表面改性后可作为去除水中污染物的较好吸附材料。本研究以油茶果壳为生物质原料,制备络合生物质材料(Fe/COS),通过吸附实验,考察Fe/COS对氨氮的吸附特性,并采用SEM、XRD、FT-IR、BET分析Fe/COS的组成和结构,探讨材料对水中氨氮的吸附机制。研究结果表明,在pH=7~9时,材料表现出对水中氨氮的优异去除效果。吸附动力学结果表明:Fe/COS对氨氮的吸附符合拟二级动力学模型(R^(2)>0.99),即该过程以化学吸附为主。吸附等温线拟合结果符合Langmuir模型(R^(2)>0.99),即材料对氨氮吸附为单层吸附,且在290 K条件下,饱和吸附量可达19.18 mg•g^(−1)。水中常见的共存离子在较高浓度下对氨氮吸附无明显影响,表明Fe/COS对水中氨氮有较好的吸附选择性。Fe/COS吸附氨氮的机制主要为配位、静电引力和离子交换3种作用。综上,本文采用Fe^(3+)与油茶果壳表面的单宁酸进行络合制备生物质基吸附剂,此吸附剂对水中氨氮具有较好的吸附效果。本研究能够为油茶果壳废弃生物质应用于水中氨氮污染去除提供基础理论依据。