Breakthrough Technologies for the Biorefining of Organic Solid and Liquid Wastes

Organic solid and liquid wastes contain large amounts of energy, nutrients, and water, and should not be perceived as merely waste. Recycling, composting, and combustion of non-recyclables have been practiced for decades to capture the energy and values from municipal solid wastes. Treatment and disposal have been the primary management strategy for wastewater. As new technologies are emerging, alternative options for the utilization of both solid wastes and wastewater have become available. Considering the complexity of the chemical, physical, and biological properties of these wastes, multiple technologies may be required to maximize the energy and value recovery from the wastes. For this purpose, biorefin- ing tends to be an appropriate approach to completely utilize the energy and value available in wastes. Research has demonstrated that non-recyclable waste materials and bio-solids can be converted into usable heat, electricity, fuel, and chemicals through a variety of processes, and the liquid waste streams have the potential to support crop and algae growth and provide other energy recovery and food production options. In this paper, we propose new biorefining schemes aimed at organic solid and liquid wastes from municipal sources, food and biological processing plants, and animal production facilities. Four new breakthrough technologies-namely, vacuum-assisted thermophilic anaerobic digestion, extended aquaponics, oily wastes to biodiesel via glycerolysis, and microwave-assisted thermochemical conversion-can be incorporated into the biorefining schemes, thereby enabling the complete utilization of those wastes for the production of chemicals, fertilizer, energy （biogas, syngas, biodiesel, and bio-oil）, foods, and feeds, and resulting in clean water and a significant reduction in pollutant emissions.

微波裂解海藻快速制取生物燃油的试验

为了探索低成本的海藻生物油快速制取工艺技术,研究组已成功开发出一套海藻的选育、培养、收获、干制技术。利用自行优选、培养、收获并干制的海藻粉,基于课题组在生物质的微波裂解技术已取得的突破,采用自行研制的玉米秸秆微波裂解的相关设备,对微波裂解海藻制取生物燃油的技术进行试验研究,获得大量在自然条件下可分层的海藻生物油。采用气相色谱-质谱(GC-MS)分析了所得到的生物油产品中两相油组分,得到了生物油产品中的物质组成及其相对含量,可为海藻生物油的精制及其副产品的开发利用提供了参考。研究表明,微波裂解海藻是一种低成本、快速、高效制取海藻生物燃油的方法,为海藻生物油的规模化生产提供参考。

玉米秸秆的催化微波裂解及生物油成分

近年来,生物质热化学裂解已引起了越来越广泛的兴趣。但常规的生物质热裂解技术(如流化床等)要求细小的生物质原材料,因此粉碎能耗大。而且裂解所得的生物油和合成气产物易受生物质粉末污染。微波裂解虽然能帮助解决这些问题,但目前的微波裂解所得的生物油成分和其他热裂解技术一样,仍然过于复杂,因此尽管生物质热解获取生物油的成本低于生物质发酵所获得的燃料,生物质热解技术也仍未在工业上得到推广应用。该研究旨在帮助解决这一难题。利用玉米秸秆颗粒为原料,采用了4%的硫酸或磷酸的预处理,或者采用氯化物等催化剂直接混入原料,然后利用微波进行催化裂解,并获得气态、固态和液态生物油3种产物。利用气质联用设备(GC-MS),对所得到的液态产物(生物油,Bio-oil)进行成分分析。在大量的试验基础上,该文筛选出的酸预处理,MgCl2、ZnCl2、及AlCl3直接催化是可以使所得的生物油成分简化的实用技术。

生物质微波裂解技术的研究进展

能源是人类生存与发展的物质基础,但是矿物能源资源的有限性、不可再生性及其利用所造成的环境污染,使人们越来越重视清洁可再生的生物质能源开发利用。生物质热化学裂解已引起了越来越广泛的兴趣,但微波裂解更具优势而备受关注。为梳理生物质微波裂解技术的现状和预测未来发展方向,综述了其研究进展。同时,着重介绍了微波加热的特点、机理、优势及应用,考察了微波裂解对不同原料的加工效果及其主要研究成果,综述了微波裂解气态产物和液态产物的特点、优势与应用前景。最后预测了生物质微波裂解未来的发展方向,主要包括寻求如海藻等高效低耗的生物质原料,开发更经济高效的转化技术和设备,探索有效的生物质催化裂解技术,开发高价值的生物油及其副产品等。

玉米棒芯的连续微波裂解制取生物油

生物质能的研究和利用当前备受关注,目前推出的生物质能主要集中在淀粉类发酵制取生物燃料乙醇方面,生物质热裂解的规模化利用大都还停留在试验探索阶段,但其利用都因成本效益低等因素而具一定的局限性。研究组在生物质批式微波裂解试验研究的基础上,研制出了一套每小时处理50～70kg生物质原料的连续微波裂解设备。利用自行研制的设备,以未处理和经稀硫酸预处理的玉米棒芯为原料进行微波裂解制取生物油的试验,得到含不同组分的生物油产物。通过GC-MS分析,发现用酸预处理过的原料所得的生物油成分较为简单。此研究为利用农林废弃物等生物质原料制取生物油提供理论支持和设备参考。

微波快速催化热解生物质制备富烃燃油的研究进展

回顾了微波快速催化热解生物质制备富烃生物油的国内外研究现状,重点叙述了有效氢碳比(H/C_(eff))及催化剂对微波快速催化热解生物质制备富烃生物油的影响。指出可通过提高热解原料H/C_(eff)、选择合适催化剂来调节生物油烃类组分;着重介绍了不同H/C_(eff)生物质原料、HZSM-5催化剂等影响因素,并对微波快速催化热解生物质制备富烃生物油进行了展望。

Effects of Microwave Torrefaction with Mg（OH）2 on Characteristics of Bio-oil from Co-pyrolysis of Straw Stalk and Soapstock

This study investigated the effects of torrefaction with Mg(OH)2 on the properties of bio-oil formed from the microwave-assisted catalytic fast co-pyrolysis of straw stalk and soapstock.The effects of torrefaction temperature and residence time on the yield and composition of bio-oil were discussed.Results showed that the torrefaction temperature and residence time remarkably influenced the yield and composition of bio-oil.With the increase in temperature and time,the bio-oil yield and the proportion of oxygen-containing compounds decreased,while the proportion of aromatic compounds increased.When the feedstocks were subject to torrefaction reaction for 20 min at 260°C,the proportion of oxygen-containing compounds decreased from 29.89%to 16.49%.Meanwhile,Mg(OH)2 could render the deoxidization function of torrefaction process increasingly noticeable.The proportion of the oxygen-containing compounds reached a minimum(14.41%),when the biomass-to-Mg(OH)2 ratio was 1:1.

Conversion of Biomass to Hydrocarbon-rich Bio-oil via Microwave-assisted Catalytic Pyrolysis： A Review

The method for pyrolysis of biomass to manufacture hydrocarbon-rich fuel remains challenging in terms of conversion of multifunctional biomass with high oxygen content and low thermal stability into a high-quality compound, featuring high content of hydrocarbons, low oxygen content, few functional groups, and high thermal stability. This study offers a promising prospect to derive hydrocarbon-rich oil through microwave-assisted fast catalytic pyrolysis by improving the effective hydrogen to carbon ratio(H/Ceff) of the raw materials. The proposed technique can promote the production of high-quality bio-oil through the molecular sieve catalyzed reduction of oxygenated compounds and mutagenic polyaromatic hydrocarbons. This work aims to review and summarize the research progress on microwave copyrolysis and microwave catalytic copyrolysis to demonstrate their benefits on enhancement of bio-oils derived from the biomass. This review focuses on the potential of optimizing the H/Ceff ratio, the microwave absorbent, and the HZSM-5 catalyst during the microwave copyrolysis to produce the valuable liquid fuel. This paper also proposes future directions for the use of this technique to obtain high yields of bio-oils.

Size matters:small distributed biomass energy production systems for economic viability

Current large scale biomass energy production systems including cellulosic ethanol,gasification,and pyrolysis facilities face significant technical and economic hurdles.Compared with these large scale systems,small distributed biomass energy production systems(DBEPS)are believed to offer advantages including lower capital costs,lower feedstock costs,simplified transportation and logistics and higher returns for biomass producers.DBEPS compliant technologies are expected to make utilization of regional biomass supplies practical and economically viable in the near-term.This paper presents arguments on the need and importance of DBEPS,available DBEPS options,and an economic scenario of DBEPS implementation on an average size farm in the US.

Biorefinery process for production of bioactive compounds and bio-oil from Camellia oleifera shell

A biorefinery process was developed in this study to obtain bioactive compounds and bio-oil from Camellia oleifera shells.Four different extraction techniques(water,ethanol,ultrasound-assisted deionized water,and ultrasound-assisted ethanol)were utilized to extract tea saponin and tannin from C.oleifera shells.Results showed that ethanol had better extraction capacity than did deionized water,and ultrasound could promote the dissolution of tannin and tea saponin in solution.The thermogravimetric curves of the samples treated under the four conditions moved toward high temperatures.This phenomenon indicated the thermal stability of the residue was significantly improved.The pretreatment showed a slight effect on the chemical compositions of bio-oil.Specifically,the samples treated with ethanol and ultrasound-assisted deionized water contained higher phenol contents(81.07%and 81.52%,respectively)than the other samples.The content of organic acid decreased with an increase in the phenol content.

Two-step fast microwave-assisted pyrolysis of biomass for bio-oil production using microwave absorbent and HZSM-5 catalyst

A novel technology of two-step fast microwave-assisted pyrolysis（f MAP） of corn stover for bio-oil production was investigated in the presence of microwave absorbent（Si C） and HZSM-5catalyst. Effects of f MAP temperature and catalyst-to-biomass ratio on bio-oil yield and chemical components were examined. The results showed that this technology, employing microwave, microwave absorbent and HZSM-5 catalyst, was effective and promising for biomass fast pyrolysis. The f MAP temperature of 500°C was considered the optimum condition for maximum yield and best quality of bio-oil. Besides, the bio-oil yield decreased linearly and the chemical components in bio-oil were improved sequentially with the increase of catalyst-to-biomass ratio from 1：100 to 1：20. The elemental compositions of bio-char were also determined. Additionally, compared to one-step f MAP process, two-step f MAP could promote the bio-oil quality with a smaller catalyst-to-biomass ratio.

Synthesis and characterization of a starch-based cationic flocculant for microalgae harvesting

A process for making a starch-based cationic flocculant for microalgae harvest was studied and the performance of the flocculant was evaluated.The substituted cationic starch was prepared by reacting corn starch with glycidyltrimethylammonium chloride(GTAC),during which the hydroxyl groups of anhydroglucose units of the starch were partially substituted by the ammonium groups through etherification.The factors affecting degree of substitution(DS),such as reaction temperature and time,catalyst amount,and the water content were investigated and optimal reaction conditions were determined.The relationship between DS and microalgae harvest was determined.A batch of cationic starch with optimal DS was synthesized and used for flocculation experiments.The flocculation experiment results showed that,for the original microalgae concentration(dry weight)of 1 g/L,the cationic starch-based flocculants can harvest over 90%of the microalgae in pH from 5 to 10,with the aggregation and precipitation time of 10 min to 30 min,and the mass ratios of flocculants to microalgae of 1:8-1:18(dry mass ratio).Using starch-based flocculant to harvest microalgae in the effluent is not only efficient,but also nontoxic to the water system,which is very important to the effluent reuse and certain microalgae applications.

IJABE Guidelines for Authors

1 About IJABE Focus and Scope Int.J.Agric.&Biol.Eng(IJABE)is an international peer-reviewed open-access journal sponsored and published jointly by US-based Association of Overseas Chinese Agricultural,Biological and Food Engineers(AOCABFE)and Chinese Society of Agricultural Engineering(CSAE).The ISSN 1934-6344 and eISSN 1934-6352 numbers for the IJABE have been registered,which allow IJABE to publish in both online and hard copy.Open access IJABE provides easy sharing of knowledge,and is thus in the best interest of authors,readers,and increases the availability,accessibility,visibility and impact of the papers,and journal as a whole.

IJABE Guidelines for Authors

1 About IJABE Focus and Scope Int.J.Agric.&Biol.Eng(IJABE)is an international peer-reviewed open-access journal sponsored and published jointly by US-based Association of Overseas Chinese Agricultural,Biological and Food Engineers(AOCABFE)and Chinese Society of Agricultural Engineering(CSAE).The ISSN 1934-6344 and eISSN 1934-6352 numbers for the IJABE have been registered,which allow IJABE to publish in both online and hard copy.Open access IJABE provides easy sharing of knowledge,and is thus in the best interest of authors,readers,and increases the availability,accessibility,visibility and impact of the papers,and journal as a whole.

Design,application and verification of a novel system utilizing bacteria and microalgae to treat swine farm wastewater and produce value-added biomass

Swine farm wastewater is extremely harmful to the environment if not treated before it is discharged.In this study,a system was developed and optimized for testing the high levels of organic matter in swine farm wastewater utilizing a microalgae/bacteria co-culture combined with a novel closed-loop extraction and dilution process.Importantly,the system produces biomass that also could be harvested and used in value-added applications.The efficacy of biomass as a biofertilizer was demonstrated by using a model plant of Arabidopsis.In addition,the analysis of biomass indicates that it also has potential as a source for biofuel.After a 20-d cultivation period,a yield of biomass was achieved to 2.063 g/L of wastewater.The highest removal rates recorded in steady state conditions were:13.8 mg/L·d of Total Nitrogen(TN);11.5 mg/L·d of Ammonia Nitrogen(NH_(4)^(+)-N);24.8 mg/L·d of Chemical Oxygen Demand(COD);and 16.9 mg/L·d of Total Phosphorus(TP).After cultivation,the composition of the biomass was analyzed on a dry basis;the major components were protein(44.9%),lipids(24.6%),carbohydrates(19.9%),Chlorophyll-A(2.75%),Chlorophyll-B(1.66%),and carotenoids(0.57%).This biomass was diluted with water(5%by weight)and used as a biofertilizer to grow Arabidopsis.The results showed that the average root and stem lengths of Arabidopsis were 43.0%and 55.0%longer compared to those of the control group.Additionally,the number of leaves and the maximum leaf length increased by 30.2%and 39.7%;and the fresh and dry leaf weights increased by 44.0%and 33.7%,respectively.These results demonstrate the efficacy of this system for treating swine farm wastewater whilst simultaneously producing a value-added microalgae/bacteria biomass.This paper also demonstrated the use of biomass as a fertilizer for cultivating a value-added crop and,based on the compositional analyses,propose that the biomass could be used as a raw material for biofuel production due to its high lipid content of 24.6%.By constructing a microalgae/bacteria symbiosis system,Swine farm wastewater can be treated as resources utilizing producing value-added biomass with demonstrated efficacy as a biofertilizer.

Review of the biological and engineering aspects of algae to fuels approach

Current biofuel production relies on limited arable lands on the earth,and is impossible to meet the biofuel demands.Oil producing algae are alternative biofuel feedstock with potential to meet the world’s ambitious goal to replace fossil fuels.This review provides an overview of the biological and engineering aspects in the production and processing technologies and recent advances in research and development in the algae to fuels approach.The article covers biology,selection and genetic modification of algae species and strains,production systems design,culture media and light management,harvest and dewatering,downstream processing,and environment and economic assessment.Despite the many advances made over several decades,commercialization of algal fuels remains challenging chiefly because of the techno-economic constraints.Technological breakthroughs in all major aspects must take place before commercial production of algal fuels becomes economically viable.

Catalytic microwave assisted pyrolysis of aspen

The effect of catalysts on the microwave pyrolysis of aspen pellets was studied.A range of chlorides,nitrates and metal-oxides were added at 2%of the aspen mass(air dry aspen pellet weight basis).Chlorides in particular were found to favor liquid yield,especially the yield of water phase residue.Average liquid yield with added chlorides was 41%mass of the total biomass input,compared to 35%mass without catalyst.Metal-oxides were found to favor pyrolysis heavy oil,and thus total oil yield,since the yield of light oils seemed to be fairly constant.Nitrates were found to favor pyrolysis gas production.Pure light oils and light oils blended with diesel were found to be a potential diesel fuel substitute.

Fractionation and characterization of bio-oil from microwave-assisted pyrolysis of corn stover

Bio-oil from thermochemical conversion of biomass is a complex mixture of polar and non-polar compounds,and cannot be used directly as a combustion engine fuel due to its low heating value,high viscosity,chemical instability,and incomplete volatility.Mixed-solvent extraction was developed to fractionate bio-oils from microwave-assisted pyrolysis of corn stover to produce light oil(a mixture of light and inflammable fuel oil components from bio-oil)with low viscosity and low combustion residue,and high value chemicals.Different fractions from bio-oil were characterized using GC/MS and TG,and a major chemical(hydroxy-butanedioic acid diethyl ester)was separated.

Microwave-assisted pyrolysis of vegetable oil soapstock:Comparative study of rapeseed,sunflower,corn,soybean,rice,and peanut oil soapstock

In this study,the effects of catalytic temperature and the type of soapstock on products from microwave-assisted pyrolysis were investigated.HZSM-5 was used as the catalyst to study the pyrolysis of six different soapstocks at 200℃,300℃,and 400℃ catalytic temperature.Results showed that the bio-oil yields initially increased and then decreased with the increase in catalytic temperature.When the catalytic temperature was 300℃,the bio-oil reached up to the maximum value(65.8 wt.%).Findings indicated that the composition of bio-oil was related to the degree of unsaturation of fatty acids sodium in the soapstocks.In the case of saturated fatty acid sodium,a series of alkanes was formed,whereas the pyrolysis of monounsaturated fatty acid sodium resulted mainly in cycloalkanes,the cycloalkenes obtained from bio-oil was produced by polyunsaturated fatty acid sodium.

氢氧化钠溶液吸收硫酰氟的传质反应动力学（英文）

研究目的:确定氢氧化钠溶液化学吸收硫酰氟的传质反应动力学区域,建立增强因子模型。研究方法:研究气液传质测定设备双搅拌釜中氢氧化钠溶液化学吸收硫酰氟的过程,并结合实验研究与理论分析建立了增强因子模型。重要结论:基于氢氧化钠溶液化学吸收硫酰氟过程的实验研究,确定了氢氧化钠溶液化学吸收硫酰氟的传质反应动力学区域为快速拟一级反应。得到了298 K下其二级反应速率常数为1.44 m3/(mol·s),并建立了增强因子模型E=68.08CBL1/2,为脱除熏蒸后残留硫酰氟的工业化应用提供了理论依据。