Bio-oil production from pyrolysis of oil palm biomass and the upgrading technologies:A review

Oil palm biomass(OPB)represents major portion of the lignocellulosic waste in Malaysia that can be converted into bio-oil.This review aims to provide important insights in OPB-derived bio-oil production by first discussing the chemical compositions of different OPB and their effects to the bio-oil yield and quality obtained from pyrolysis process,followed by discussing the addition of plastics and catalysts into the pyrolysis for bio-oil upgrading,and lastly summarizing the existing technoeconomic and environmental studies and the potential use of process integration and intensification in this topic.Polypropene(PP),low density polyethylene(LDPE),and high density polyethylene(HDPE)have been commonly used in co-pyrolysis of OPB,which can effectively increase the heating value of bio-oil up to 80%that of diesel.Likewise,acidic,basic,and neutral catalysts have been applied to increase the amount of hydrocarbon and phenol in the bio-oil,further improving the heating value to be comparable to diesel.The bio-oil production from OPB is currently still limited to demonstration scale despite the favorable environmental compatibility and technoeconomic feasibility shown by studies focused on empty fruit bunch(EFB).Several promising advanced pyrolysis processes that integrate other processes such as anaerobic digestion,hydrogen production process,and heat and power generation units as well as the advanced reactor designs are also overviewed here as future innovation of the bio-oil production from OPB,which may play more significant role as the technology matures.

Evaluation of Weed Incidence and Biomass in Coffee Intercropped with Oil Palm in Avenue and Hollow Square Arrangement in Nigeria

Weed incidence and biomass in tree crop plantations are mainly influenced by environmental, farm management practices and cropping systems. Manipulation of intercropping systems to improve weed management in coffee intercropped with oil palm requires a better understanding of spatial and temporal dynamics of weeds. To evaluate the effect of weed incidence and biomass in coffee intercropped with oil palm in avenue and hollow square arrangement, a study was carried out in Cocoa Research Institute of Nigeria (CRIN) in two locations. The locations are Idi-Ayunre (7°25'N, 3°24'E) (an alfisol) and Uhonmora (6°5'N, 5°50'E) (ultisol) in rainforest and derived savannah parts of Nigeria respectively. The experiment had three treatments comprising coffee sole (control), coffee with oil palm (Hollow square) arrangement and coffee with oil palm (Avenue) planting. Coffee was planted 3.0 m apart while oil palm was planted 9 m apart. Equal size of land area was used for coffee in each treatment. The experimental design was Randomized Complete Block (RCBD) with three replicates. Data on vegetative growth of coffee, weed incidence and biomass were taken at three-monthly intervals. The result showed that coffee/oil palm (Hollow Square) had the least weed incidence and biomass closely followed by coffee/oil palm (Avenue) planting. The control had the highest weed biomass which was significantly different from Hollow square and Avenue planting at P ≤ 0.05. The morphological parameters on coffee followed the same pattern but Hollow square arrangement was significantly higher than Avenue and control at P ≤ 0.05.

Photocatalytic degradation of organic pollutants using green oil palm frond-derived carbon quantum dots/titanium dioxide as multifunctional photocatalysts under visible light radiation

The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogendoped carbon quantum dots(NCQDs)and proposed a straightforward in-situ hydrothermal method for the preparation of NCQDs/TiO_(2)nanocomposites.The elemental composition,morphological,structural and optical characteristics of NCQDs/TiO_(2)nanocomposites have been comprehensively investigated.The successful grafting of NCQDs on TiO_(2)matrix was confirmed by the formation of Ti AOAC bond and the electronic coupling between theπ-states of NCQDs and the conduction band of TiO_(2).For the first time,the oil palm frond-derived NCQDs/TiO_(2)was adopted in the photodegradation of methylene blue(MB)under visible-light irradiation.As a result,the photocatalytic efficiency of NCQDs/TiO_(2)nanocomposites(86.16%)was 2.85 times higher than its counterpart TiO_(2)(30.18%).The enhanced performance of nanocomposites was attributed to the pivotal roles of NCQDs serving as electron mediator and visiblelight harvester.Besides,the optimal NCQDs loading was determined at 4 ml while the removal efficiency of NCQDs/TiO_(2)-4 was the highest at a catalyst dosage of 1 g.L^(-1)under alkaline condition.This research work is important as it proposed a new insight to the preparation of biomass-based NCQDs/TiO_(2)using a facile synthetic method,which offers a green and sustainable water remediation technology.

Insight on the Ultrastructure, Physicochemical, Thermal Characteristics and Applications of Palm Kernel Shells

The ultrastructure and physicochemical and thermal properties of Palm Kernel Shells (PKS) in comparison with Coconut Kernel Shells (CKS) were investigated herein. Powder samples were prepared and characterized using Surface Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Chemical and elemental constituents, as well as thermal performance were assessed by Van Soest Method, TEM/EDXA and SEM/EDS techniques. Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) were also performed for thermal characterization. SEM/EDS and TEM/EDXA revealed that most of the PKS and CKS materials are composed of particles with irregular morphology;these are mainly amorphous phases of carbon/oxygen with small amounts of K, Ca and Mg. The DSC data permitted to derive the materials’ thermal transition phases and the relevant characteristic temperatures and physical properties. Thermal Transition phases of PKS observed herein are consistent with the chemical composition obtained and are similar to those of CKS. Nonetheless, TGA/DTG showed that the combustion characteristics of PKS are higher than those of CKS. Taken together, our results reveal that PKS have nanopores and can be efficiently used for 3D printing and membrane filtration applications. Moreover, the chemical constituents found in PKS samples are in agreement with those reported in the literature for material structural applications and thus, present potential use of PKS in these applications.

Assessment of Growth, Carbon Stock and Sequestration Potential of Oil Palm Plantations in Mizoram, Northeast India

A study was conducted to assess growth, carbon stock and sequestration potential of oil palm plantations along a chronosequence in Mizoram, Northeast India for which a total of 148 oil palms drawn from different age group plantations (1 to 11 years) were sampled for their biometric parameters and assessment of carbon stock through partial non-destructive methods. All the growth parameters of oil palm (trunk height, crown depth, total height, trunk diameter) and biomass drew from different parts of the palm showed a significant (p belowground biomass (BGB) > standing litter biomass > deadwood biomass > understorey biomass. AGB, BGB and deadwood biomass followed an increasing trend while understorey biomass decreased with age. An 11-year oil palm plantation accumulated 111.96 Mg ha-1 biomass with a carbon density of 49.90 Mg C ha-1 and could sequester 3.70 Mg C ha-1 year-1 in 10 years after planting in Mizoram, Northeast India. The findings showed considerable carbon storage with comparative higher values in oil palm plantations than shifting cultivation fallows. This will enable policy and decision makers in framing climate change mitigation and adaptation policies regarding the extension of oil palm plantations in Mizoram.

Bio-Oil Production by Pyrolysis of Oil Palm Empty Fruit Bunch in Nitrogen and Steam Atmospheres

This work investigated the bio-oil production from oil palm empty fruit bunch (EFB) by continuous pyrolysis reactor under nitrogen and steam atmospheres as sweeping gas. The study parameters were particle size, biomass feeding rate, reactor temperature, and reactor sweeping gas. The EFB particle ranges were below 500 micrometers, between 500 - 1180 micrometers and 1180 - 2230 micrometers. Feeding rates were 150, 350, and 550 rpm. Both factors were analyzed by single factor ANOVA. Additionally, Box-Behnken design was used to investigate temperature (350oC - 600oC) under the following nitrogen and steam flow rates as sweeping gas: 0, 100, and 200 cm3/min of nitrogen and 0, 9, and 18 cm3/min of steam. The mathematical model from Box-Behnken design succeeded in predicting the optimal conditions for normal and nitrogen atmospheres. A particle size below 1180 μm was determined to be optimal for bio-oil production. In a normal atmosphere or no sweeping gas, the condition was 475oC and 450 rpm of feed rate. The optimal condition for nitrogen atmosphere was 530oC, 450 rpm of feed rate, and 200 cm3/min of nitrogen flow rate. However, steam as sweeping gas caused high uncertainty and the model was unable to predict the optimal conditions accurately. The biooils from normal, nitrogen, steam, and mixed atmospheres were analyzed for general characteristics. NMR and GC-MS were used to analyze chemical compositions in the bio-oils. Relationships between physical and chemical characteristics were determined and discussed.

温度对生物质固定床热解影响的研究

在固定床上研究不同温度下生物质的热解过程,采用微型气相色谱、傅立叶红外光谱仪、比表面积和孔径分析仪等研究了热解温度对棕榈壳热解气体产物的释放特性和固体残余物生物质炭的物化特性及生物质的热解机理。实验发现生物质的热解主要集中在400～700℃,高温有利于气体产物的析出,生物质炭的量及其所含的有机官能团(C=0,C-C,C-H,C-O和OH等)随热解温度的升高快速减少。在600℃时固体生物质炭有较高的比表面积和小的孔径,表面孔结构较均匀。

生物质材料增强聚合物的应用研究进展

综述了生物质,如纤维素晶须、稻壳灰、油棕灰等作为填料对聚合物的增强作用及其应用研究进展,提出了生物质材料作为聚合物填料的研究方向。

生物质锅炉的应用、发展和改善

介绍了生物质锅炉的应用和发展,对棕榈壳的特性做了简要分析,对公司在用的锅炉存在的问题和结构上的改善做了详细的分析说明。实践证明,重新选型设计的生物质锅炉很好的满足了工艺要求,新锅炉热效率高燃料成本降低,实现了良好的经济效益。

固体生物质燃料棕榈壳基本特性研究

棕榈壳作为棕榈油产业的废弃物,资源十分丰富。文章对固体生物质燃料棕榈壳的工业分析、燃烧特性和化学特性做了比较全面地分析研究。结果表明:棕榈壳有着高发热量、高挥发、低灰分、低全硫含量和低有害元素砷、磷、氟、氯和汞等含量等优异特性。是一种非常良好的环保固体生物质燃料。

热带木本生物质能源树种——油棕

油棕是一种重要的热带木本生物质能源树种,具有结果期长、产量和含油量高等特点。随着原油价格的不断上涨,生物柴油的发展日益受到关注。而棕榈油由于生产成本低廉,成为生产生物柴油最具竞争力的原料。本文分别综述了油棕的基本特性、全球及我国棕榈油生产贸易和消费状况、我国发展油棕产业的重要意义,在此基础上对我国发展油棕产业的可行性和前景进行了探讨。

棕榈废弃物直燃发电技术研究及经济性分析

针对马来西亚的棕榈废弃物生物质燃料,进行了元素分析、工业分析和灰熔融性分析和灰成分分析,并与国内生物质燃料对比。结果表明,棕榈壳的水分低、热值高、灰熔点高,适用于直燃发电。棕榈空果串和棕榈纤维水分高、热值低、灰熔点较低,且碱金属、氯含量较高,有较高的结渣倾向;根据燃料特性,提出了有关锅炉设计的建议措施和技术可行性分析;以棕榈空果串为例进行了直燃发电经济性分析,项目总投资静态回收期为7.65年,具有良好的经济收益。